Heroin

Journal of Analytical Toxicology, Vol, 20, October ] 996

Forensic Drug Testing for Opiates. VII. Urinary Excretion Profile of Intranasal (Snorted) Heroin Edward J. Cone*, Rebecca Jufer, and William D. Darwin

Addiction Research Center, National Institute on Drug Abuse, National Institutes of Health, Baltimore, Maryland 21224 Saul B. Needleman

Navy Drug Screening Laboratory, Great Lakes, Illinois 60088

Abstract The urinary excretion profile of free and conjugated morphine and 6-acetylmorphine was determined by gas chromatography-mass spectrometry (GC-MS) and immunoassayfor six healthy male subjectsafter intranasal administration of 6 and 12 mg of heroin HCI. Resultswere compared with heroin administration (6 ms) by the intramuscularroute. Heroin metabolites were rapidly excreted with peak concentrationsappearing in the first or second specimen collection after drug administration. Concentrationsof total morphine and 6-acetylmorphine after intranasal heroin were similar to thoseafter intramuscularadministration, but free morphine concentrationsafter the lower intranasal dose were significantly lower than the same dose given intramuscularly. Detection timesfor total morphine by GC-MS and immunoassay (300-ng/mL cutoff concentration) were generally 24-36 h, but were reduced to less than 12 h at the higher cutoff concentration of 2000 ng/mL. 6-Acetylmorphine concentrationswere highly variable and short-lived;detection times (10 ng/mL) were approximately 2-3 h for most subjects, but some failed to produce positive specime,ps. Of 14 specimens with 6-acetylmorphine concentrationsof 10 ng/mL or more, ten were associatedwith total morphine concentrations greater than 2000 ng/mL, and four specimenshad total morphine concentrationslessthan 2000 ng/mt. Overall, intranasal administration of heroin produced a similar profile of excretion of heroin metabolites to intramuscularadministration.

Introduction

In a recent study of current heroin users in New York, Chicago, and San Diego, it was reported that the average user purchased approximatelytwo "bags" of heroin (each containing approximately25 mg of pure heroin) twice daily for an average weekly cost of $267.40 (standard deviation, $245.90) (1). The majority of users (79%) preferred the intravenous route, but 15% relied on the intranasal (snorting) route. Although this study was limited to data collected from only 150 heroin users 9Authorto whom correspondenceshould be addressed.

in three cities, it exemplifiesthe growing importance that the intranasal route of administration has assumed in the lives of heroin users. Traditionally, heroin has been administered by the intravenous route; however,the intranasal route was once popular and was commonly used prior to 1930. Over the last five years, use of the intranasal route has increased. The route of drug administration directly influences pharmacologicoutcome by determining the rate of onset, duration, and intensity of effects. The selection of the route of drug administration is generally based on the subject's personal experience with the route, desire for rapid or delayed effects, convenience, purity, physicochemical characteristics of the drug, fear of overdose, disease, and various other factors. Availability and drug cost are also major determinants in selection of route of administration. The steady increase in purity of heroin and decrease in price over the last decade (2,3) coincides with reported shifts in heroin administration from the intravenous route to the intranasal route (1,4). The intranasal route of administration allows the heroin user to achieve pharmacologic effects similar to the intravenous route without the trauma of needles and the associated fear of disease. Penetration of the mucous membranes occurs rapidly and peak blood concentrations are attained within 5 min of intranasal administration (5). However, when compared with the intramuscular route, the relative potency of intranasal heroin is approximately 50%. The reduced potency of intranasal heroin is likely a result of loss of drug to the oral route by swallowing and possible extrahepatic metabolism during absorption. Despite these limitations on the bioavailability of intranasal heroin, a substantial portion of the dose appears in blood as either heroin or 6-acetylmorphine, morphine, and conjugated morphine (5). Although the pharmacokinetic profile of intranasal heroin in blood has been described, there is a lack of information on the urinary excretion of heroin by this route of administration. It is important that this route be evaluated critically to determine if current drug testing practices apply equally to this mode of heroin use. Of particular interest is the relationship of detection times for 6-acetylmorphine and "total" morphine to designated cutoff concentrations. The present report describes

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379

Journal of Analytical Toxicology,VoL 20, October 1996

the urinary excretion profile of intranasal heroin administered to six human subjects. Specimens were analyzed by immunoassay and by gas chromatography-mass spectrometry (GC-MS) for free and total morphine and 6-acetylmorphine. Detection times following intranasal heroin administration were compared with detection times following intramuscular administration in the same group of subjects.

Materials and Methods Subjects, dosing, and urine collection Six healthy, male volunteer subjects with a recent history of heroin abuse participated in the study. The characteristics of the subjects and details of the clinical study have been published (5). The study was conducted under the guidelines for the protection of human subjects, and each volunteer gave informed consent. Subjects resided for 4-6 weeks on the closed research ward of the Addiction Research Center, National Institute on Drug Abuse (Baltimore, MD). At weekly intervals, single doses of heroin or placebo were administered by the intranasal and intramuscular routes under double-blind, double-dummy conditions. Each subject experienced the following four drug conditions: 6 mg heroin hydrochloride (intranasal), saline placebo (intramuscular); 12 mg heroin hydrochloride (intranasal), saline placebo (intramuscular); 6 mg heroin hydrochloride (intramuscular), lactose placebo (intranasal); and lactose placebo (intranasal), saline placebo (intramuscular). Intranasal heroin doses were mixed with lactose to provide a total weight of 100 mg and divided into equal portions. Subjects inhaled equal amounts in each nostril through a short soda straw. Subjects were provided with polypropylene collection bottles in which they collected all urine specimens throughout the study. Specimens were stored at 2--4~ for periods up to 48 h before processing. Aliquots (2.5 mL) were placed in coded polypropylene cryotubes and stored frozen at -30~

GC-MS assaysfor total morphine, morphine, and 6-acetylmorphine Urine specimens were analyzed in random order under blind conditions for total morphine and 6-acetylmorphine. The assays were performed by liquid-liquid extraction followed by GC-MS analysis according to published procedures (6-9). Free morphine was analyzed by the same procedure as total morphine, but without the hydrolysis step. Specimens were analyzed in batches of 20 plus accompanying control samples. Calibrator samples contained target concentrations of 300 ng/mL of free and total morphine and 10 ng/mL of 6-acetylmorphine. Each batch of specimens was accompanied by control samples targeted to contain free and total concentrations of morphine at 150, 300, 600, and 1200 ng/mL and 6-acetylmorphine at 2.5, 5, 10, and 20 ng/mL. Mean concentrations and coefficents of variation (%CV) at each concentration were as follows:free morphine (N = 26), 158 ng/mL, 2.6%; 302 ng/mL, 2.1%; 597 ng/mL, 3.0%; 1,141 ng/mL, 4.1%; total morphine (N = 27), 150 ng/mL, 6.9%; 301 ng/mL, 2.1%; 591 ng/mL, 4.3%; 1111 ng/mL, 5.4%; 6-acetylmorphine (N = 25), 2.6 ng/rnL, 4.6%; 4.8 ng/mL, 4.1%; 10.3 ng/mL, 3.5%; 19.5 ng/mL, 3.3%, respectively.Prior to initiation of the study, the limit of quantitation (LOQ) of each assay was determined by analysis of serially diluted specimens. The LOQ was determined as the lowest concentration for which all five replicates satisfied acceptance criteria (• 20% of target concentration, • 20% ion ratios). The LOQ determinations were as follows: free morphine, 37.5 ng/mL; total morphine, 37.5 ng/mL; and 6-acetylmorphine, 5 ng/mL. GC-MS concentrations below the LOQ were recorded and appear in Table I, but should be interpreted with caution regarding their accuracy.

Pharmacokinetic and statistical analyses Terminal elimination half-liveswere estimated by the sigmaminus method (10). Detection times were defined as time to last positive specimen at selected cutoff concentrations. Statistical data were analyzed by a single factor (dose/route) analysis of variance. Significance differences were reported for p < .05.

Immunoassay,creatinine, specific gravity, and pH All assays were performed on freshly thawed specimens. The specimens were assayed in random order under blind conditions. Results were decoded only after completion of the assay. Specimens were tested by EMIT| II Opiate Assay (EMIT) (Behring Diagnostics, San Jose, CA) with a Hitachi 717 instrument (Boehringer Mannheim, Indianapolis, IN). The calibrator (300 ng/mL) response was automatically set to zero. Specimens with absorbance rates greater than or equal to zero were identified as positive. A drug-free control sample and a control sample containing morphine (375 ng/mL) were included with each batch of 20 specimens. Creatinine measurements were performed by the Jaffe method with Boehringer Mannheim Diagnostic reagents on a Hitachi 704 analyzer. Specific gravity measurements were made with an Atago Clinical Refractometer T2 (Atago, Tokyo, Japan). Urine pH measurements were performed with colorfixed indicator sticks (pH 4.5-10.0, Gallard-Schlesinger, Carle Place, NY).

380

Results Prior to heroin dosing, all subjects were required to test negative for three consecutive days by immunoassay (EMITII, 300-ng/mL cutoff concentration). Each subject was dosed with a low (6 rag) and high dose (12 rag) of heroin HCI by the intranasal route and an intramuscular dose (6 rag). Dosing sessions occurred at 1-week intervals. Urine specimens were collected before dosing and throughout the week following dosing. All specimens were tested by immunoassay (EMIT II assay for opiates) and by GC-MS for heroin metabolites (free and total morphine and 6-acetylmorphine). In addition, pH, specific gravity, and creatinine concentrations were measured. Results for the six subjects are reported in Table I. Prior to dosing, one subject's (Subject UU) specimen contained 197 ng/mL of total morphine, 12 ng/mL of free morphine, and 2 ng/mL of 6-acetylmorphine (Table I). These results were

Journalof Analytical Toxicology,Vol. 20, October 1996

Table I. Urinary Excretion of Total Morphine, Free Morphine, and 6-AM* following Heroin Administration by the Intranasal and Intramuscular Routes to Six Human Subjects* Dose/ route

~Time~ (h)

Vol (mL)

RR

6 rag/ IN

RR

12 mg/ IN

RR

6 mg/ IM

-0.42 5.25 7.83 10.92 16.50 20.83 25.92 28.17 30.25 31.83 33.58 35.75 43.83 45.00 48.00 49.75 51.92 53.83 56.17 57.75 61.50 67.58 -5.00 4.67 10.17 15.50 20.92 23.92 26.33 30.17 31.83 35.58 38.50 42.50 44.17 50.50 53.75 56.33 57.92 67.92 71.58 -0.08 8.33 12.25 20.08 26.96 31.50 34.00 34.83 38.17 39.67 41.67

90 118 146 129 148 240 130 142 150 135 145 140 155 148 136 148 150 242 140 116 90 156 230 250 199 240 186 120 200 125 80 170 155 165 170 165 160 150 90 244 136 120 190 185 235 150 175 170 170 155 225 245

Subject

pH

Specific gravity

EMIT (~abs)

Total morphine* (ng/mL)

Free morphine* (ng/mL)

6-AM* (ng/mL)

Creatinine (mg/dL)

8.5 9.0 7.0 6.0 6.0 6.0 8.5 7.0 6.0 6.0 6.5 7.0 6.5 6.5 6.5 6.5 7.0 9.0 7.5 7.0 5.5 7.0 7.5 8.5 8.0 7.0 6.5 6.0 7.0 6.0 6.0 6.0 6.0 8.0 8.0 6.0 7.0 7.5 6.5 8.0 7.0 6.0 6.5 8.0 8.5 6.0 6.5 7.0 8.0 6.5 7.5 8.5

1.0205 1.0255 1.0185 1.0230 1.0250 1.0140 1.0200 1.0212 1.0240 1.0210 1.0170 1.0200 1.0102 1.0180 1.0180 1.0145 1.0202 1.0100 1.0220 1.0200 1.0240 1.0150 1.0160 1.0260 1.0285 1.0285 1.0235 1.0250 1.0250 1.0300 1.0250 1.0280 1.0280 1.0140 1.0150 1.0245 1.0250 1.0225 1.0200 1.0230 1.0275 1.0198 1.0225 1.0230 1.0215 1.0320 1.0285 1.0210 1.0170 1.0215 1.0150 1.0102

-51 61 57 37 28 10 7 -9 -12 -20 -36 -34 -45 -44 -45 -46 -47 -48 -47 -48 -48 -49 -50 76 61 25 21 34 23 10 -8 -16 -25 -43 -43 -38 -43 -46 -47 -48 -47 -50 25 26 56 37 4 -20 -34 -27 -41 -43

0 3455 2284 1350 867 520 430 281 304 215 161 155 25 65 55 41 40 14 0 16 29 10 0 6670 2839 857 751 873 765 441 328 162 190 77 83 115 59 40 32 28 27 0 2169 957 855 1309 494 158 153 199 63 45

0 148 76 28 0 27 18 12 0 0 7 9 3 0 0 0 0 0 0 0 0 0 0 1113 190 37 39 68 34 0 0 10 13 6 8 4 2 0 0 0 0 0 116 0 49 39 19 0 0 0 5 0

0 0 1 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 97 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

160 206 157 206 239 143 178 165 186 156 104 133 67 142 140 118 159 65 188 153 197 135 86 243 261 225 151 227 200 243 215 238 205 78 86 190 202 176 152 189 246 155 239 179 188 431 279 161 105 160 89 60

'Abbreviations: 6-AM = 6-acetylmorphine; IN = intranasal; IM = intramuscular; Aabs = milliabsorbance change; M = missing. t Elapsed time {h) before or after dosing. * Concentrations of total and free morphine and 6-acetylmorphine are reported below the experimentally determined LOQ, but should be interpreted with caution regarding their accuracy.

381

Journal of Analytical Toxicology,Vol. 20, October 1996

Table I continued. Urinary Excretion of Total Morphine, Free Morphine, and 6-AM* following Heroin Administration by the Intranasal and Intramuscular Routes to Six Human Subjects* Dose/ route

~Timet (h)

Vol (mL)

RR

6 rag/ IM

47.50 50.33 52.42 55.33 58.17 60.00 62.42 64.00 66.00 71.83

240 140 110 165 160 160 155 135 210 135

TT

6 mg/

-3.82

275

IN

3.30 8.18 12,23 14.53 15.60 22.33 24.28 27.25 30.05 34.18 36.20 39.45 44.83 51.68 58.23 60.10 63.07 68.75 72.85 -1.92 2,60 7.05 10.18 12.67 16.93 21.40 30.10 32.27 34.13 35.72 39.75 44.43 48.40 51.90 54.07 56.52 60.72 64.53 70.33 -1.47 1.72

270 250 250 200 250 250 250 250 250 170 200 175 120 M 245 265 210 255 260 257 201 280 255 260 285 285 210 170 190 265 265 270 235 245 270 275 260 85 270 205 245

Subject

TT

12 rag/ IN

TT

6 mg/ IM

pH

Specific gravity

EMIT (Aabs)


7.0 7.5 6.0 6.5 6.0 7.0 6.5 6.5 8.0 6.0

1.0135 1.0210 1.0210 1.0210 1.0210 1.0180 1.0215 1.0125 1.0110 1.0205

-39 -31 -34 -40 -41 -44 -44 -47 -47 -46

79 155 110 92 79 47 50 18 9 28

7.5

1.0250

-53

0

0

0

167

7.0 6.5 7.0 6.0 6.5 6.0 6.0 6.0 6.5 5.5 6.0 5.5 5.5 5.5 6.0 6.0 6.0 6.0 6.0 5.5 5.5 5.5 6.0 6.0 6.5 7.0 7.5 8.0 7.5 8.5 6.5 7.5 6.5 7.5 6.0 7.0 6.0 5.5 6.0 6.0 5.5

1.0230 1.0240 1.0230 1.0240 1.0088 1.0201 1.0110 1.0155 1.0135 1.0162 1.0160 1.0205 1.0252 1.0250 1.0150 1.0100 1.0175 1.0215 1.0080 1.0215 1.0230 1.0252 1.0255 1.0218 1.0200 1.0210 1.0245 1.0230 1.0155 1.0140 1.0240 1.0230 1.0150 1.0200 1.0155 1.0235 1.0240 1.0275 1.0275 1.0250 1.0200

56 44 23 13 -34 -10 -36 -31 -37 -39 -43 -42 -42 -47 -49 -50 -50 -50 -50 -51 74 68 57 41 31 32 -25 -27 -44 -46 -46 -47 -49 -49 -49 -50 -50 -49 -50 -52 62

1348 1628 730 425 41 229 116 110 88 91 60 89 83 35 5 3 3 5 3 0 4346 4997 2182 1312 678 909 222 166 68 29 42 29 16 0 9 15 8 0 9 0 1869

326 111 37 25 0 0 9 0 0 0 0 0 0 0 0 0 0 0 0 0 1195 396 156 62 46 52 0 14 2 0 0 0 0 0 2 0 0 0 1 0 627

42 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 183 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 121

130 145 139 139 35 123 60 85 75 109 106 157 254 221 100 66 105 179 46 130 152 185 188 143 121 146 173 153 79 67 151 157 90 104 89 156 141 217 200 150 ]13

*Abbreviations:6-AM= 6-acetylmorphine;IN = intranasakIM = intramuscular;Aabs= milliabsorbancechange;M = missing. Elapsedtime(h) beforeor afterdosing. * Concentrationsof totaland freemorphineand 6-acetylmorphineare reportedbelowthe experimentallydeterminedLOQ, but shouldbe interpretedwith cautionregardingtheiraccuracy.

382

Free morphine* (ng/mL) 6 0 6 0 0 0 0 0 0 4

6-AM* (ng/mL)

Creatinine (mg/dL)

0 0 0 0 0 0 0 0 0 0

121 197 193 163 171 106 146 63 55 193

Journalof AnalyticalToxicology,Vol. 20, October 1996


~Time* (h)

Vol (mE)

IT

6 mg/ IM

UU

6 mg/ IN

UU

12 mgl IN

UU

6 mg/ IM

8.47 14.32 17.12 22.22 26.88 31.88 38.00 39.57 44.52 46.60 51.28 55.68 57.62 62.43 64.28 70.30 -3.92 1.42 4.25 9.25 14.25 20.75 27.33 30.67 34.00 38.83 46.83 48.33 51.00 58.08 68.50 -3.33 8.00 12.00 14.53 20.50 23.58 27.00 30.00 32.00 35.02 44.50 47.25 53.75 56.52 59.10 62.00 68.50 -3.50 2.75 5.08

250 250 125 250 250 270 270 205 280 210 270 253 256 201 150 254 280 200 110 195 285 265 155 203 153 254 201 253 200 230 245 198 280 270 235 285 95 150 285 135 185 275 80 270 110 200 245 195 235 120 140

Subject

pH

Specific gravity

EMIT (Aabs)



6-AM* (ng/mL)

Creatinine (mg/dL)

5.5 6.0 6.0 6.0 7.0 6.5 6.0 6,0 8.0 6.0 6.5 6.0 6.0 5.5 5.5 5.5 6.5 6.5 6.0 5.5 6.0 6.0 8.0 7.5 6.0 7.0 6.5 8.0 8.5 7.0 7.0 6.0 6.0 5.5 6.0 6.0 6.0 6.5 7.5 6.5 6.5 6.0 6.0 8.0 8.0 6.0 7.5 6.5 6.0 5.5 6.5

1.0285 1.0265 1.0218 1.0250 1.0135 1.0200 1.0160 1.0162 1.0218 1.0250 1.0248 1.0252 1.0100 1.0225 1.0210 1.0252 1.0215 1.0240 1.0250 1.0260 1.0210 1.0210 1.0205 1.0240 1.0240 1.0240 1.0070 1.0050 1.0155 1.0220 1.0205 1.0200 1.0251 1.0260 1.0230 1.0238 1.0290 1.0245 1.0100 1.0175 1.0201 1.0123 1.0205 1.0165 1.0235 1.0230 1.0208 1.0220 1.0080 1.0248 1.0240

53 18 -26 -32 -46 -45 -49 -49 -49 -50 -50 -51 -50 -50 -50 -50 -48 60 80 57 21 12 9 6 -2 -13 -43 -43 -38 -44 -45 -48 81 47 35 49 56 48 8 14 5 -16 6 -24 -30 -40 -40 -40 -47 82 71

1869 533 165 150 42 34 7 6 8 11 8 0 0 0 0 4 197 1174 3263 1834 698 470 482 373 370 124 11 16 52 34 28 3 8511 1575 710 1585 2445 1478 446 546 472 238 425 157 134 65 72 72 0 5347 3891

194 30 0 0 4 0 0 0 0 0 0 0 0 0 0 0 12 309 342 95 32 25 24 58 19 0 0 0 45 0 2 0 449 83 62 85 187 122 0 15 0 10 0 0 0 0 0 0 0 1136 334

3 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 2 41 4 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 125

183 164 101 133 66 113 90 85 148 169 146 146 46 118 123 192 181 181 230 242 177 158 143 156 179 166 49 36 135 166 151 244 295 237 176 215 311 208 74 141 147 132 276 169 245 169 168 202 64 237 226

*Abbreviations: 6-AM = 6-acetylmorphine; IN = intranasal; IM = intramuscular; Aabs = milliabsorbance change; M = missing. t Elapsed time (h) before or after dosing. * Concentrations of total and free morphine and 6-acetylmorphine are reported below the experimentally determined LOQ, but should be interpreted with caution regarding their accuracy.

383



ATimet (h)

Vol (mL)

UU

6 rag/ IM

VV

6 rag/ IN

VV

12 mg/ IN

VV

6 mg/ IM

8.42 15.77 20.50 23.00 27.00 35.00 44.75 47.83 51.00 53.05 58.00 62.08 68.75 71.30 -1.33 4.83 9.33 12.75 16.50 23.17 29.08 32.17 33.97 38.00 47.25 51.75 55.75 58.67 63.00 68.80 -7.00 6.50 15.50 20.83 24.25 28.00 34.50 40.00 47.75 55.75 61.92 72,25 -6.50 4.17 10,50 17.00 23.75 25.50 34.00 40.50 47.50

200 230 270 70 140 253 263 96 128 173 260 230 148 80 312 M 370 370 500 490 430 495 505 710 460 345 575 475 480 660 370 565 315 550 490 465 500 550 465 355 505 485 410 510 495 490 360 110 475 385 490

Subject

pH

Specific gravity

EMIT (~abs)



6-AM* (ng/mL)

Creatinine (mg/dL)

6.5 5.5 6,0 6.0 6.0 6.0 6.5 5.5 7.0 7.0 6.5 6.5 6.5 5.5 6.0 7.0 7.0 6.5 7.5 6.0 7.0 7.0 8.5 7.0 5.5 8.5 8.0 8.0 6.5 5,5 7.0 7.0 6.5 8.0 6.0 7.0 8.5 7.0 5.5 7.0 7.0 5.5 5.5 6.0 5.5 5.5 6.0 5.5 6.5 7.0 6.0

1.0152 1.0280 1.0150 1.0225 1.0260 1.0270 1.0260 1.0300 1.0170 1.0180 1.0235 1.0252 1.0270 1.0302 1.0230 1.0220 1.0208 1.0201 1.0151 1.0200 1.0225 1.0175 1.0098 1.0105 1.0192 1.0200 1.0155 1.0145 1.0192 1.0155 1.0188 1.0180 1.0248 1.0195 1.0140 1.0162 1.0200 1.0140 1.0165 1.0202 1.0210 1.0240 1.0252 1.0252 1.0245 1.0230 1.0249 1.0245 1.0248 1.0235 1.0248

32 18 -3 18 32 -12 -15 -9 -34 -38 -40 -42 -43 -42 -50 62 38 15 1 -3 -14 -42 -45 -45 -46 -46 -48 -48 -48 -48 -50 76 52 21 -1 -10 -13 -36 -36 -44 -46 -45 -49 58 43 21 15 8 -10 -36 -44

809 603 356 331 818 236 226 226 121 59 88 62 58 47 0 2281 1248 530 363 250 243 78 30 17 31 18 9 0 7 0 0 4535 1790 586 181 262 193 92 86 38 26 25 0 2422 1375 558 371 384 222 104 31

44 37 0 44 37 33 0 16 5 0 3 0 0 0 0 196 32 0 0 6 16 0 1 0 3 0 0 0 0 0 0 358 171 14 0 0 7 18 0 0 0 0 0 267 53 32 16 16 0 0 0

0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 14 0 0 0 0 0 0 0 0 0 0 0 37 0 0 0 0 0 0 0

116 226 118 231 271 217 215 274 118 106 144 169 198 275 159 158 148 107 88 135 128 47 45 120 118 130 85 72 99 91 102 156 186 133 85 92 159 113 190 167 183 281 194 185 162 182 238 240 220 211 201

"Abbreviations: 6-AM = 6-acetylmorphine; IN = intranasal; IM = intramuscular; gabs = milliabsorbance change; M = missing. Elapsed time (h) before or after dosing. * Concentrations of total and free morphine and 6-acetylmorphine are reported below the experimentally determined LOQ, but should be interpreted with caution regarding their accuracy.

384

Journalof AnalyticalToxicology,Vol. 20, October 1996


ATime* (h)

Vol (mL)

WW

6 mg/ IM

WW

6mg/ IN

WW

12rag/ IN

53.75 62.83 71.67 -0.83 3.00 4.08 6.42 8.17 9.92 12.00 16,00 17.50 20.75 23.17 29.42 32.08 34.00 36.58 38.75 44.58 55.25 49.50 50.58 52.00 54.08 55.50 57.25 60.08 62.82 64.42 68.50 71.50 -0.82 2.50 4.25 7.75 8.17 10.00 10.17 12.25 14.92 23.83 20.50 23.92 27.00 29.75 31.83 33.50 35.92 37.00 38.83 40.00

405 500 500 70 250 255 134 115 130 75 250 40 160 88 M 80 40 40 80 260 100 205 150 50 70 102 60 94 186 96 174 132 45 160 220 182 240 270 69 155 123 40 276 188 84 215 130 50 130 35 100 70

Subject

pH

Specific gravity

EMIT (Aabs)

6.5 5.5 5.5 6.0 6.0 6.0 6.0 6.0 6.0 6.5 6.0 6.0 6.0 6.0 6.5 6.0 6.0 6.0 6.0 7.0 7.0 7.0 9.0 8.0 8.5 9.0 6.5 6.5 7.5 8.5 6.5 6.5 5.5 6.0 5.5 6.0 6.0 6.0 6.0 6.0 5.5 6.0 6.0 6.0 6.5 7.0 6.0 6.5 8.0 7.0 7.0 6.5

1.0245 1.0220 1.0240 1.0245 1.0151 1.0065 1.0170 1.0155 1.0101 1.0210 1.0230 1.0210 1.0201 1.0210 1.0201 1.0250 1.0299 1.0340 1.0290 1.0251 1.0265 1.0102 1.0100 1.0240 1.0268 1.0201 1.0251 1.0330 1.0250 1.0220 1.0265 1.0249 1.0270 1.0213 1.0110 1.0198 1.0025 1.0070 1.0060 1.0199 1.0215 1.0230 1.0199 1.0200 1,0255 1.0155 1.0208 1.0265 1.0251 1.0310 1.0270 1.0255

-47 -48 -48 -51 76 43 60 44 21 45 21 7 -9 -24 -35 -42 -39 -43 -49 -50 -49 -49 -49 -49 -50 -49 -51 -51 -50 -50 -50 -51 -50 85 72 67 -7 18 17 37 31 27 20 17 27 2 -1 5 -14 -12 -33 -39

Total morphine* (ng/mL) 21 0 0 2 2847 1194 1431 1311 278 1131 619 520 207 170 123 79 98 70 0 0 15 6 0 13 0 8 0 0 0 0 6 0 0 10,425 5456 3204 201 650 581 1242 1100 1010 633 669 693 453 358 420 206 256 116 72

Free morphine* (ng/mL) 0 0 0 0 557 70 101 0 22 67 31 23 0 9 6 5 0 4 0 0 0 0 0 0 0 0 1 0 0 4 0 0 0 1781 300 157 9 20 22 61 58 45 18 14 48 10 44 18 6 12 7 0

6-AM* (ng/mL) 0 9 0 0 39 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 133 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Creatinine (mg/dL) 193 165 199 234 139 50 170 142 94 269 212 207 204 259 279 305 434 532 328 248 271 113 86 276 296 180 270 315 192 173 238 216 293 187 104 190 22 62 58 171 168 184 158 194 289 147 179 284 255 379 231 200

'Abbreviations: 6-AM = 6-acetytmorphine; IN = intranasal; IM = intramuscular; gabs = milliabsorbance change; M = missing. Elapsed time (h) before or after dosing. Concentrations of total and free morphine and 6-acetylmorphine are reported below the experimentally determined LOQ, but should be interpreted with caution regarding their accuracy.

385

Journal of Analytical Toxicology, Vol. 20, October 1996


~Timet (h)

Vol (mL)

WW

12mg/ IN

WW

6 mg/ IM

XX

6 mg/ IN

44.75 47.17 50.08 57.00 53,88 56.25 58.42 60.42 62.58 65.50 68.75 70.92 -1.50 4.25 6.17 8.17 10.00 11.83 13.42 18.42 20.50 23.17 24.92 26.92 30.00 32.25 33.75 35.50 37.25 40.87 44.50 46.92 49.75 51.00 53.92 56.00 58.17 60.00 62.50 64.25 68.52 71.25 -3.00 3.00 5.75 10.00 12.50 14.75 21.00 30.00 34.00 36.25

170 80 80 28 98 90 52 110 102 174 112 70 45 150 80 80 70 120 55 225 255 175 195 100 195 84 64 147 100 210 154 120 76 28 130 125 115 110 130 115 135 120 140 130 125 175 110 145 130 175 88 70

Subject

pH

Specific gravity

EMIT (L~abs)



6.0 6.0 7.0 9.0 6.5 6.0 5.5 8.5 8.5 7.0 6.5 6.0 6.0 5.5 5.5 5.5 6.0 6.5 5.5 6.0 6.0 5.5 6.0 6.0 7.0 6.0 6.0 7.0 6.5 5.5 6.0 6.0 6.5 7.0 6.5 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.0 6.5 6.0 6.0 6.0 6.5 6.0 7.0

1.0285 1.0290 1.0301 1.0298 1.0288 1.0310 1.0295 1.0270 1.0285 1.0252 1.0290 1.0290 1.0275 1.0298 1.0270 1.0252 1.0270 1.0188 1.0262 1.0199 1.0195 1.0182 1.0100 1.0181 1.0190 1.0251 1.0249 1.0218 1.0249 1.0295 1.0251 1.0245 1.0301 1.0340 1.0245 1.0260 1.0300 1.0310 1.0270 1.0295 1.0325 1.0282 1.0150 1.0200 1.0200 1.0055 1.0200 1.0201 1.0165 1.0200 1.0200 1.0135

-38 --40 -39 -44 -45 -46 -47 -48 -49 -50 -48 -48 -49 78 62 55 49 33 37 -2 -3 -28 -38 -26 -40 -41 -45 -46 -46 -47 -48 -48 -46 -47 -48 -49 -51 -49 -50 -50 -50 -50 -48 66 54 -22 11 17 10 4 -19 -34

88 83 83 0 37 37 0 14 0 100 14 11 7 6117 3403 2827 1737 1082 1467 435 377 140 93 161 47 78 52 20 33 32 0 16 30 28 12 10 10 0 7 9 11 8 2 3450 2664 208 537 573 542 356 162 136

3 0 0 0 0 0 0 0 0 0 0 2 0 1477 276 182 65 42 0 0 16 7 5 6 0 4 0 0 5 0 0 0 2 0 0 0 0 0 0 0 0 I 0 614 114 t2 29 32 0 25 11 5

*Abbreviations: 6-AM = 6-acetylmorphine; IN = intranasal; IM = intramuscular; gabs = milliabsorbance change; M = missing, t Elapsed time (h) before or after dosing, * Concentrations of total and flee morphine and 6-acetylmorphine are reported below the experimentally determined LOQ, but should be interpreted with caution regarding their accuracy.

386

6-AM* (ng/mL) 0 0 0 0 0 0 0 0 0 0 0 0 0 206 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 81 0 0 0 0 0 0 0 0

Creatinine (mg/dL) 278 318 367 289 245 332 289 213 234 191 274 290 337 333 258 264 298 173 290 160 156 145 95 203 162 287 237 161 205 236 213 198 382 374 195 208 247 332 217 274 307 247 96 113 127 44 151 146 120 148 133 87


attributed to previous illicit use of heroin that occurred just prior to admission to the clinical ward. During dosing there was evidenceof minor carryover of metabolites from session to session. Subjects UU, WW, and XX had less than 10 ng/mL of total morphine in their specimens prior to the second and/or third dosing.

Heroin metabolites (morphine and 6-acetylmorphine) appeared in urine shortly after dosing with heroin by either route of administration. The first specimen collected after dosing (1--8 h) frequently contained the highest concentration of total morphine. Peak concentrations of total morphine by GC-MS ranged from 1628 to 3455 ng/mL, from 3085 to 10,425 ng/mL,


~Timet (h)

Vol (mt)

XX

6mgl IN

XX

12 mg/ IN

XX

6 mg/ IM

45.00 53.75 58.00 62.00 69.00 -3.83 1.33 4.17 6.08 8.00 11.75 15.00' 20.58 22.92 26.25 28.67 31.25 33.58 35.33 37.42 40.75 44.75 50.92 52.75 54.00 58.25 61.42 72.00 -6.00 2.00 8.17 12.00 15.00 21.00 29.33 33.58 40.08 45.00 50.33 52.50 54.00 55.92 60.33 62.25 69.00

134 124 123 121 150 50 150 125 175 130 185 85 45 125 125 115 125 150 130 145 118 136 118 148 214 138 126 134 145 145 115 135 145 155 160 150 140 170 140 165 155 125 155 125 150

Subject

pH

Specific gravity

EMIT (~abs)

Total morphine* (ng/mt)


6.0 6.0 6.5 6.5 6.5 6.0 8.5 6.0 6.0 5.5 5.5 6.0 6.5 5.5 6.0 6.0 6.5 7.0 7.0 6.0 6.5 7.0 9.5 8.5 9.0 8.5 7.5 7.0 5.5 6.0 5.5 6.0 6.0 6.5 6.5 6.5 6.0 6.0 7.5 6.5 6.0 6.0 6.0 6.0 6.0

1.0155 1.0130 1.0210 1.0215 1.0240 1.0200 1.0201 1.0230 1.0135 1.0068 1.0150 1.0225 1.0160 1.0125 1.0180 1.0055 1.0165 1.0160 1.0145 1.0230 1.0199 1.0151 1.0220 1.0118 1.0100 1.0200 1.0150 1.0082 1.0190 1.0275 1.0251 1.0235 1.0245 1.0170 1.0225 1.0170 1.0251 1.0220 1.0210 1.0092 1.0095 1.0201 1.0190 1.0210 1.0215

-33 -45 -44 -45 -45 -45 58 83 61 48 52 37 24 11 31 -16 10 6 -17 15 1 -13 4 -29 -37 -29 -39 -44 -48 75 67 27 18 13 9 -26 -23 -31 -41 -46 -45 -44 -44 -44 -45

115 28 31 37 26 0 1362 M 2505 3085 1598 951 826 286 921 399 479 399 197 512 300 QNS 349 108 77 147 94 33 9 5430 3484 910 502 449 522 133 199 123 64 25 28 48 34 39 0

8 0 0 2 0 0 465 2145 133 62 77 55 0 31 100 0 20 16 15 33 11 18 15 6 4 8 4 3 0 1111 314 43 35 23 51 8 0 0 0 0 0 0 0 0 0

6-AM* (ng/mt) 0 0 0 0 0 0 13 9 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 216 6 0 0 0 0 0 0 0 0 0 0 0 0 0 0

Creatinine (mg/dL) 112 85 155 148 197 141 185 196 111 50 140 178 120 83 134 35 96 65 81 162 128 89 178 80 69 150 102 48 131 243 214 169 156 113 169 113 166 142 119 45 55 124 136 148 154

'Abbreviations: 6-AM = 6-acelylmorphine; IN = intranasal; IM = intramuscular; Aabs = miliiabsorbance change; M = missing. t Elapsed time (h) before or after dosing. Concentrations of total and free morphine and 6-acetylmorphine are reported below the experimentally determined LOQ, but should be interpreted with caution regarding their accuracy.

387


and from 1869 to 6117 ng/mL following 6 mg and 12 mg intranasal and 6 mg intramuscular administration of heroin HCI, respectively (Table It). Concentrations of total morphine declined rapidlyafter dosing and dropped below the 300 ng/mL cutoff concentration in a mean time of 23.8 h (range 14.534.0 h) after administration of 6 mg and 34.3 h (range 20.8-50.9 h) after 12 mg of heroin HC1 by the intranasal route (Table II). Following intramuscular administration of 6 mg of heroin, the average detection time for total morphine was

24.7 h (range 14.3-31.5 h). For comparison, data obtained from a similarly conducted previous study (11) in which heroin was administered by the intramuscular route are included in Table II (bottom). Individual detection times (time to last positive) at cutoff concentrations of 300 ng/mL and 2000 ng/mL of total morphine following each dose and route of heroin administration are listed in TableIII. Therewere no significant differences in detection times between doses or routes of administration. As shown in Tables II and III, elevation of the cutoff concentration for total morphine from 300 Table II. Comparison of Detection Times, Maximum Concentrations, and First to 2000 ng/mL substantially reduced the Specimen Concentration of Heroin Metabolites After Intramuscular and detection times to averages of 4.3 h (6 mg Intranasal Administration of Heroin intranasal), 11.1 h (12 mg intranasal) and I-leroin dose 5.3 h (6 mg intramuscular). At a 300-ng/mL Free Cutoff Total morphine morphine 6-AM* route N, cutoff concentration, detection times for (Reference) opiate metabolites by EMIT II assay were concentrations 2000 ng/mt 300 ng/mL 25 ng/mt 10 ng/mL similar to those observedfor total morphine Detection time, h 4.3 23.8 20.2 1.8 6 rag,IN,6 by GC-MS (Table III). (range) (0-7.8) (14.5-34.0) (9.3-30.7) (0-3.3) Free morphine was also detected in each of the firstspecimens collected immediately Maximum after heroin dosing by the intranasal and concentration 2821 364 34 (range) (1628-3455) (148-614) (0-81) intramuscular routes. Concentrations of time,h 4.8 4.0 3.9 free morphine determined by GC-MS in (range) (3.0-8.2) (3.0-53) (1.4-7.8) these first specimens ranged from 148 to 614 ng/mL, from 358 to 2145 ng/mL, and First specimen from 116 to 1477 ng/mL following 6 mg concentration 2426 358 34 and 12 mg intranasal and 6 mg intramus(range) (1174-3455) (148-614) (0-81) cular administration of heroin HCI, respectime, h 3.5 3.5 3.5 tively (TableII). It was noteworthy that con(range) (1.4-5.3) (1.4-5.3) (1.4-5.3) centrations of free morphine declined Detection time, h 11.1 34.3 26.6 2.9 12 mg, IN, 6 rapidly thereafter and dropped below the (range) (6.5-23.6) (20.8-50.9) (15.5-37.4) (0-6.5) 25-ng/mL cutoff concentration in a mean time of 20.2 h (range 9.3-30.7 h) after adMaximum ministration of 6 mg and 26.6 h (range concentration 6371 1174 73 15.5-37.4 h) after 12 mg of heroin HCI by (range) (3085-10425) (358-2145) (0-183) the intranasal route (Table IlL Intramustime, h 6.1 4.8 5.4 cular administration of 6 mg was detectable (range) (2.5-8.0) (2.5-8.0) (2.5-8.0) for a mean time of 22.4 h (range 11.8First specimen 35.0 h). No significant differenceswere preconcentration 5975 894 73 sent in detection times between doses or (range) (1362-10425) (113-1781) (0-183) routes of administration. The ratio of free time, h 4.3 4.3 4.3 morphine to total morphine generally was (range) (1.3-8.0) (1.3-8.0) (1.3-8.0) highest immediately after dosing and 6 rag,IM,6 ranged from 5% to 34%; thereafter, free Detection time, h 5.3 24.7 22.4 2.9 morphine content generally was less than (range) (0-8.3) (14.3-31.5) (11.8-35.0) (0-5.1) 10% of total morphine. Maximum 6-Acetylmorphinewas detected only for a concentration 3892 789 118 short period after heroin dosing by the in(range) (1869-6117) (116-1477) (0-216) tranasal and intramuscular routes. Peak time, h 3.9 3.9 4.3 concentrations by GC-MS ranged from 0 (range) (1.7-8.3) (1.7-8.3) (1.7-8.3) to 81 ng/mL, from 0 to 183 ng/mL, and First specimen from 0 to 216 ng/mL following 6 and concentration 3892 789 97 12 mg intranasal and 6 mg intramuscular (range) (1869-6117) (116-1477) (0-216) administration of heroin HCI, respectively. time, h 3.9 3.9 3.9 6-Acetylmorphine concentrations dropped (range) (1.7-8.3) 1.7-8.3) (1.75-8.3) below the 10-ng/mL cutoff concentration in a mean time of 1.8 h (range 0-3.3 h) after *Abbreviations:6-AM = 6-acetylmorphine;IN = intranasal;tM = intramuscular. administration of 6 mg and 2.9 h (range

388


0-6.5 h) after 12 mg of heroin HCI by the intranasal route (Table II). Intramuscular administration of 6 mg was detectable for a mean time of 2.9 h (range 0-5.1 h). Detection times for 6-acetylmorphine were not significantly different between doses or routes of administration. The concordance of 6-acetylmorphine concentrations with total morphine concentrations by GC-MS is shown in Table IV. There were a total of 14 specimens that contained greater than or equal to 10 ng/mL 6-acetylmorphine. Of these, four specimens were associated with total morphine concentrations in the range of 1000-1999 ng/mL, and the remainder contained 2000 ng/mL or more of total morphine. The first specimen collected after heroin administration consistently contained high concentrations of heroin metabolites and frequently contained the highest concentrations of total morphine, free morphine, and 6-acetylmorphine (Table II). The time of first specimen collection varied over the three dose conditions from 1.3 to 8.3 h. The time to maximum concentration varied from 1.7 to 8.3 h, from 1.7 to 8.3 h, and from 1.4 to 8.3 h for total morphine, free morphine, and 6-acetylmorphine, respectively. Conjugated morphine concentrations were determined by

subtraction of free morphine concentrations from respective total morphine concentrations. Half-lives for conjugated morphine, free morphine, and 6-acetylmorphine were estimated by means of sigma-minus plots. Estimates of half-lives and percent dose of metabolite excreted in urine are shown in Table V. Half-lives for both conjugated morphine and free morphine were similar and generally ranged from 6 to 8 h with no significant differences between doses or between the intranasal and intramuscular routes. Mean percent dose excretion of conjugated morphine was 27.4% (range 22.4-33.0%) and 31.4% (range 12.6-42.2%) following administration of 6 mg and 12 mg of heroin HCI, respectively, and 33.9% (range 20.250.6%) following administration of 6 mg by the intramuscular route. The amount of conjugated morphine excreted by the different routes of administration were not significantly different. Mean percent dose excretion of free morphine was 2.4% (range 0.5-4.0%) and 7.7% (range 4.9-9.5%) following administration of 6 and 12 mg of heroin HC1, respectively, and 4.2% (range 1.0-6.0%) following administration of 6 mg by the intramuscular route. The amount of free morphine excreted following 6 mg of heroin by the intranasal route was significantly lower (p < 0.05) than the amount excreted following administration of 6 mg by the intramuscular route. Halflives for 6-acetylmorphine were extremely Table II continued. Comparison of Detection Times, Maximum short and could not be accurately estimated. Concentrations, and First Specimen Concentration of Heroin Metabolites After Intramuscular and Intranasal Administration of Heroin Mean percent dose excretion of 6-acetylI'leroindose morphine was 0.1% (range 0-0.2%) and Free 0.3% (range 0-0.7%) following intranasal Cutoff Total morphine morphine 6-AM* route N, (Reference) administration of 6 and 12 mg of heroin concentrations 2000 ng/mt 300 ng/mt 25 ng/ml. 10 ng/mt HC], respectively, and 0.4% (range 0-0.6%) Detectiontime,h 3.6 17.2 11.8 2.4 3 rag,IM, 6 following administration of 6 mg by the (range) (0-8.0) (9.3-36.0) (6.2-24.0) (1.1-3,6) (I I) intramuscular route. Measurements of urinary pH for the six Maximum subjects following heroin ranged from 5.5 concentration 2944 341 73 to 9.5 (Table I). Specific gravity measure(range) (I 852-4953) (I 44-724) (42-I 48) ments ranged from 1.0025 to 1.0340; howtime, h 4.3 2.9 2.4 ever, only one specimen measured less than (range) (I .2-8.0) (I .2-4.0) (I .I-3.6) 1.0030 (Subject WW, 12 mg intranasal, First specimen 8.17 h, specific gravity = 1.0025). Creaticoncentration 2563 333 73 nine concentrations ranged from 22 to 532 (range) (850-4953) (109-724) (42-148) mg/dL with none testing below 20 mgldL.

time, h (range)

Detectiontime,h (range)

2.4 (1.1-3.6)

5.7 (2.8-7.4)

2.4 (1.1-3.6)

26.0 21.8 (24.0-36.0) (I 0.9-24.0)

2.4 (I .I-3.6)

4.2 (3.3-5.3)

Maximum concentration (range) time, h (range)

7535 (3316-I 2022) 3.8 (2.8-4.5)

916 (296-I 280) 3.8 (2.8-4.5)

138 (50-235) 2.9 (1.1-4.3)

First specimen concentration (range) time, h (range)

6022 (I 342-I 2022) 2.9 (I .I-4.3)

810 (244-I 280) 2.9 (I .I-4.3)

138 (50-236) 2.9 (I .I-4.3)

*Abbreviations:6-AM = 6-acetylmorphine;IN = intranasal; I M = intramuscular.

6 mg, IM, 6 (I I)

Discussion The physiologic, behavioral, and performance effects produced by intranasal heroin administration have been shown to be similar to the effects observed following intramuscular administration, but the potency of the intranasal route was reduced by approximately 50% relative to the intramuscular route (5). Despite reduction in potency, the convenience of use of the intranasal route combined with the fear of the spread of disease from the use of needles and the recent availability of 389


inexpensive and highly pure drug makes this route of administration attractive to heroin users. This gradual shift in the pattern of heroin administration to the intranasal route is recent, and no previously published information is available on the excretion pattern of heroin administered by this route. In the present study, the urinary excretion profile of intranasal heroin was compared with intramuscular heroin administration in six male volunteer subjects. Peak urine concentrations of total morphine after administration of 6 mg of intranasal heroin were equivalent to those observed following administration of the same dose by the intramuscular route. A dose of 12 mg of heroin by the intranasal route produced an approximate doubling of peak urinary concentrations. The similarities in peak concentrations and in recoveries of total morphine following administration of 6 mg of heroin by the intranasal and intramuscular routes indicate that absorption was complete despite the reduced pharmacologic potency by the intranasal route. The significantly lower amounts of free morphine measured in urine following the lower dose by the intranasal route are important in explaining the observed differences in potency. Absorption of heroin by the intramuscular route releases the majority of drug into the bloodstream as heroin, 6-acetylmorphine, and morphine. Intranasal administration produced lower blood concentrations of each of the three analytes (5). It is likely that when heroin is snorted, some of the drug is swallowed and subjected to metabolism by enzymes in the gut wall and liver prior to its appearance in cir-

culation as inactive conjugates. As a result, the total amount of morphine absorbed by the intranasal route would be similar to the intramuscular route, but less of the active drug species (i.e., 6-acetylmorphine and free morphine) would be delivered directly to the bloodstream by intranasal administration. The excretion half-life estimates for conjugated and free morphine generally ranged from 6--8h following intranasal and intramuscular administration of heroin. The data for the excretion half-life of conjugated morphine compare favorably with a previous estimate of 7.9 h obtained from six subjects following intramuscular administration of 6 mg of heroin (11). However, a lower estimate of 4.4 h was obtained in the same study for the half-life of free morphine. This difference in estimates for the half-life of free morphine may be related to differences in the methods used for pharmacokinetic analysis. The previous method used excretion rate analysis for estimation of pharmacokinetic parameters. This approach involved plotting metabolite excretion rate versus the midpoint of the specimen collection period. The sigma-minus method used in the current study required collection of all drug-containing specimens for accurate estimates of the total amount of metabolite excreted and for calculation of valid pharmacokinetic parameters. The logarithm of the amount of metabolite remaining to be excreted was plotted versus the time of the collection. This latter approach is more precise, primarily because the midpoint used in rate analysis is only an average or estimated value. Consequently, the sigma-minus method generally produces

Table III. Detection Times by GC-MS and EMIT for Opiates Following Administration of Heroin to Six Human Subjects* GC-MS

Total morphine

Total morphine

Free morphine

Route

(2000 ng/mL)

(300 ng/mL)

(25 ng/mL)

6-AMt (10 ng/mL)

EMIT II (300 ng/mL)

6

Intranasal

7.8 0 4.3 4.8 3.0 5.8 4,3_+1,1

30.3 14.5 34.0 16.5 17.5 30.0 23.8_+3.5

20.8 14.5 30.7 9.3 16.0 30.0 20.2_+3.5

0 3.3 1.4 0 3.0 3.0 1.8+0,6

25.9 14.5 30.7 16.5 17.5 30,0 22.54-2.9

RR TT UU VV WW XX Mean _+SE

12

Intranasal

10.2 10,2 23,b 6,5 7.8 8.0 11.1_+2.6

31.8 21.4 47.3 20.8 33.5 50.9 34.3+5.2

26.3 21.4 27.0 15.5 31.8 37.4 26.6_+3.1

4.7 2,6 0 6.5 2.5 1.3 2.9_+1.0

30.2 21.4 47.1:; 20.8 33.5 50.9 34.0_+5.2


6

Intramuscular

8.3 0 5.1 4.2 6.2 8.2 5.3+_1.3

31.5 14.3 27.0 25.5 20.5 29.3 24.7+2.6

27.0 14.3 35.0 17,0 11.8 29.3 22.4_+3.8

0 1.7 5.1 4,2 4.3 2.0 2.9_+0.8

31.5 14,3 27.0 25.5 13.4 29.3 23.5_+3.2

Dose (mg)


Subject

* Hours to detectionof lastpositiveat specifiedcutoff concentration. * 6-acetylmorphine.

390


more precise pharmacokinetic data. Lowerestimates of percent dose recovered of total morphine also were obtained in the present study (27-34%) compared with the earlier study (42-67%). These differences are likely a result of the wide intersubject variability that is frequently observed in excretion studies with opiate compounds. Heroin metabolites were detected in urine by immunoassay and GC-MS following intranasal administration of 6 mg of heroin for approximately 24 h (300-ng/mL cutoff concentration). A similar detection time was obtained by intramuscular administration of 6 mg of heroin. Theoretically,when the dose is doubled the detection time should increase by one excretion half-life. In the present study, the effect of doubling the intranasal dose to 12 mg produced a mean detection time of Table IV. Concordance of 6-Acetylmorphine Concentrations in Urine with Total Morphine Concentrations by GC-MS Assay after Single-Dose Heroin Administration* Total morphine,ng/mt

6-Acetylmorphine (ng/mL)

1000-1999

2000-4000

> 4000

10

4

4

6

* No specimens were collected that contained greater than 1 ng/mL of 6-acetylmorphine and less than 1000 ng/mL of total morphine.

34.3 h by GC-MS and 34.0 h by immunoassay.These estimates were in reasonable agreement with predicted values of 31.4 h and 30.0 h based on an estimated half-life of approximately 7.5 h. An increase of similar magnitude occurred in the detection time of free morphine by GC-MS. Recent proposed changes to the Department of Health and Human Services(DHHS) Guidelines (12) would raise the cutoff concentration for screening and confirmation from 300 to 2000 ng/mL and establish a new requirement to test for 6-acetylmorphine (10-ng/mL cutoff concentration). The changes are designed to eliminate the identification of most persons legitimately using opiate-containing phamaceuticals available by medical prescription and over-the-counter preparations and those who have ingested poppy seeds. Raising the cutoff concentration should decrease the detection time of codeine, morphine, and heroin. In the present study, the effect of increasing the cutoff concentration to 2000 ng/mL for total morphine resulted in greatly decreased detection times. When heroin was administered by the intranasal or intramuscular routes, the detection times for a 6 mg dose at the 2000-ng/mL cutoff concentration was approximately 4-5 h compared with approximately 24 h at the lower cutoff concentration. For a dose of 12 mg of intranasal heroin, the detection time at the 2000 ng/mL cutoff concentration was approximately 11 h. Similar reductions in detection times were observed as a result of changes in cutoff concentrations in a previous study by Cone et al. (11) for heroin administration by the intramuscular route (Table II) and for codeine (13). The increased cutoff

Table V. Half-Lives and Percent Dose of Heroin Metabolites Excreted in Urine after Heroin Administration Half-life (h) Dose (mg)

Route

RR TT UU VV WW XX Mean•

6

Intranasal

6,8 6.8 7.5 6.4 6.0 8.5 7.0•

6.7 4.3 8.8 6.9 8.2 7,0 7.0•

29.8 24.0 30,9 24.6 33.0 22.4 27.4•

1.0 2.8 3.5 0.5 4.0 2.5 2.4•

0 0.2 0.2 0 0.2 0.2 0.1•


12

Intranasal

7.5 6.1 8.3 7.9 7,2 8.6 7.6•

6.0 6.2 5.0 7.3 5.6 8.0 6.4•

25.2 31.1 42.2 36.0 41.6 12.6 31.4•

7.6 9.5 4.9 6.0 9.3 9.2 7.7•

0.4 0.7 0 0.1 0.4 0.1 0.3•


6

Intramuscular

8.3 6.5 9.7 6.2 7.0 8.8 7.8•

9,3 2.7 8.0 3.8 6.7 4.6 5.9•

26.7 20.2 37.0 50.6 38,2 30.7 33.9•

1.0 4.5 4.8 4.0 6.0 4.8 4.2•

0 0.6 0.3 0.4 0,6 0.6 0.4•

Subject

Conjugated morphine

Percenldose Free morphine

Conjugated morphine

Free morphine

6-AM*

' 6-acetylmorphine.

391


concentration requirement and the requirement for measurement of 6-acetylmorphine should also help eliminate most positives that result from poppy seed ingestion. Although urinary concentrations exceeding 2000 ng/mL of morphine have been reported from poppy seed studies (14-19), the majority of specimens contained much lower concentrations. In addition, the presence of 6-acetylmorphine is linked uniquely to heroin administration and is not formed metabolically from morphine, codeine, or from poppy seed ingestion. Unfortunately, 6-acetylmorphine has a very short half-life and appears in urine for only a short time after heroin administration.Following intranasalingestion, 6-acetylmorphine was detected for 2-3 h by GC-MS (10-ng/mL cutoff concentration), and variability was extremely high. Also, there were four occasions in which subjects failed to excrete sufficient 6-acetylmorphineto be detected. Consequently, some subjects who snort or inject heroin may not be positive for this metabolite. The presence of 6-acetylmorphine in urine, however, is a clear indication of recent heroin exposure.

Conclusion In conclusion, intranasal administration of heroin results in metabolism and excretion of heroin metabolites in urine in a manner similar to the excretionprofile reported for the parental administration of heroin. The only significant difference occurred in the excretion of lower amounts of free morphine following intranasal administration. Peak concentrations and detection times for total morphine in urine were equivalent following the administration of 6 mg of heroin by the intranasal and intramuscular routes. Increasing the cutoff concentration from 300 to 2000 ng/mL as proposed for total morphine reduced detection times followingsingle doses of heroin to less than 10 h. 6-Acetylmorphine concentrations in urine were short-lived (< 7 h) and highly variable, but were clearly associated with recent heroin exposure when present.

Acknowledgment The authors would like to thank Barbara A. Holicky for her assistance in conducting the clinical study.

References 1. A.M. Rocheleau and D. Boyum. Measuring Heroin Availability in Three Cities. Office of National Drug Control Policy, Washington, DC, 1994, pp 1-84.

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