Effects of nicotine on methadone self-administration in humans.
The effects of nicotine abstinence, ad libitum smoking, and 0, 2, and 4 mg nicotine gum on methadone self-administration were investigated. Five methadone-maintained patients with a history of smoking (18-30 cigarettes/day) were recruited as subjects. Upon arrival expired carbon monoxide levels were measured to confirm self-reported abstinence of 10-12 h. At 30 min prior to the methadone self-administration session, two response options were concurrently available. When a 64-button press requirement (FR64) was completed, 10 ml of 0.054 mg/ml methadone solution, or vehicle, was delivered. Immediately following, and 30, 60, 90, and 120 min after the self-administration session, expired carbon monoxide levels and typical symptoms of nicotine withdrawal were assessed. Relative to abstinence, subjects consumed more methadone following the 4-mg nicotine gum and ad libitum smoking conditions. Ratings of cigarette craving were significantly less following ad libitum smoking or administration of 4-mg nicotine gum, than following abstinence. Implications for understanding opioid and nicotine interactions are discussed.
Spiga
R
R
Department of Psychiatry and Behavioral Sciences, Houston, TX 77030, USA. rspiga@msi66.msi.uth.tmc.edu
Schmitz
J
J
Day
J
J
D000328:Adult; D000704:Analysis of Variance; D016739:Behavior, Addictive / Q000139:chemically induced*; D002248:Carbon Monoxide / Q000032:analysis; D004347:Drug Interactions; D005260:Female; D006556:Heroin Dependence / Q000150:complications / Q000534:rehabilitation*; D006801:Humans; D008297:Male; D008691:Methadone / Q000008:administration & dosage / Q000494:pharmacology*; D009294:Narcotics / Q000008:administration & dosage / Q000494:pharmacology*; D009538:Nicotine / Q000494:pharmacology*; D018722:Nicotinic Agonists / Q000494:pharmacology*; D012646:Self Administration / Q000706:statistics & numerical data; D012907:Smoking / Q000009:adverse effects / Q000503:physiopathology / Q000523:psychology; D016540:Smoking Cessation / Q000523:psychology; D013375:Substance Withdrawal Syndrome / Q000503:physiopathology; D014029:Tobacco Use Disorder / Q000150:complications* / Q000503:physiopathology / Q000523:psychology
D009294:Narcotics; D018722:Nicotinic Agonists; D009538:Nicotine; D002248:Carbon Monoxide; D008691:Methadone