Intravenous Nicotine and Caffeine: Subjective and Physiological Effects in Cocaine Abusers
- Departments of 1Psychiatry and Behavioral Sciences (B.E.G., R.R.G.), and 2Neuroscience (R.R.G.), Johns Hopkins University School of Medicine, Baltimore, Maryland
Abstract
The subjective and physiological effects of intravenously administered caffeine and nicotine were compared in nine subjects with histories of using caffeine, tobacco, and cocaine. Subjects abstained from tobacco cigarette smoking for at least 8 h before each session. Dietary caffeine was eliminated throughout the study; however, to maintain consistency with the nicotine intake, subjects were administered caffeine (150 mg/70 kg b.i.d.) in capsules, with the last dose administered 15 to 18 h before each session. Under double-blind conditions, subjects received placebo, caffeine (100, 200, and 400 mg/70 kg), and nicotine (0.75, 1.5, and 3.0 mg/70 kg) in mixed order. Physiological and subjective data were collected before and repeatedly after drug or placebo administration. Compared with the highest dose of caffeine, the highest dose of nicotine produced greater subjective ratings on a number of scales. At doses that produced comparable ratings of drug effect (1.5 mg/70 kg of nicotine and 400 mg/70 kg of caffeine), both drugs produced similar increases in ratings of good effect, liking, high, stimulated, and bad effect. Nicotine showed a somewhat faster time to peak subjective effects than caffeine (2 versus 4 min). Subjective ratings that differentiated caffeine and nicotine were ratings of rush, blurry vision, and stimulant identification (elevated by nicotine) and ratings of unusual smell and/or taste (elevated by caffeine). Both caffeine and nicotine decreased skin temperature and increased diastolic blood pressure; however, caffeine decreased whereas nicotine increased heart rate. The study documents both striking similarities and some notable differences between caffeine and nicotine, which are among the most widely used mood-altering drugs.
Footnotes
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Send reprint requests to: Dr. Roland R. Griffiths, Johns Hopkins University School of Medicine, 5510 Nathan Shock Dr., Suite 3000, Baltimore, MD 21224-6823. E-mail:rgriff{at}jhmi.edu
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↵1 Present address: Office on Smoking and Health, National Center for Chronic Disease Prevention and Health Promotion, Centers for Disease Control and Prevention, Atlanta, GA 30341.
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This research was supported by United States Public Health Services Research Grant R01 DA03890 from the National Institute on Drug Abuse. Portions of these data were presented as a poster at the 59th Annual Scientific Meeting of the College on Problems of Drug Dependence, Inc., in June 1997.
- Abbreviations:
- ARCI
- Addiction Research Center Inventory
- PCAG
- pentobarbital-chlorpromazine alcohol group
- MBG
- morphine-benzedrine group
- LSD
- lysergic acid diethylamide
- BG
- benzedrine group
- A
- amphetamine
- ECG
- electrocardiogram
- PCP
- phencyclidine
- bpm
- beats per minute
- MDMA
- 3,4-methylenedioxymethamphetamine
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- Received June 27, 2000.
- Accepted October 16, 2000.
- U.S. Government
