Page 603 - Basic _ Clinical Pharmacology ( PDFDrive )

CHAPTER 32 Drugs of Abuse 589

Pharmacokinetics, Toxicities,
Subclass, Drug Mechanism of Action Effects Clinical Application Interactions
BENZODIAZEPINES
• Oxazepam, Positive modulators of the Enhances GABAergic Delirium tremens Half-life 4–15 h • pharmacokinetics not
others GABA A receptors, increase synaptic transmission; affected by decreased liver function
frequency of channel attenuates withdrawal
opening symptoms (tremor,
hallucinations, anxiety) in
alcoholics • prevents
withdrawal seizures
• Lorazepam: Alternate to oxazepam with similar properties
N-METHYL-d-ASPARTATE (NMDA) ANTAGONIST
• Acamprosate Antagonist of NMDA May interfere with forms of Treatment of alcoholism • Allergic reactions, arrhythmia, and low
glutamate receptors synaptic plasticity that effective only in combination or high blood pressure, headaches,
depend on NMDA receptors with counseling insomnia, and impotence •
hallucinations, particularly in elderly
patients
CANNABINOID RECEPTOR INVERSE AGONIST
• Rimonabant CB 1 receptor inverse agonist Decreases neurotransmitter Approved in Europe from Major depression, including increased
release at GABAergic and 2006 to 2008 to treat risk of suicide
glutamatergic synapses obesity, then withdrawn
because of major side effects
• smoking cessation has
never been approved, but
remains an off-label
indication

REFERENCES Pharmacology of Drugs of Abuse
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tion to emulate optogenetic treatment of synaptic pathology. Science 2015;
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Everitt BJ, Robbins TW: Drug addiction: Updating actions to habits to compul- 2005;5:79.
sions ten years on. Annu Rev Psychol 2016;67:23. Nichols DE: Hallucinogens. Pharmacol Ther 2004;101:131.
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Nat Rev Genet 2005;6:521. neuron stimulation for the progression to addiction. Neuron 2015;88:1054.
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C ASE STUD Y ANSWER

When found by his parents, the patient was having visual exogenous cannabis with endocannabinoids that fine-tune
hallucinations of colorful insects. Hallucinations are often synaptic transmission and plasticity. While probably not
caused by a cannabis overdose, especially when hashish is fulfilling the criteria for addiction at present, the patient is at
ingested. The slower kinetics of oral cannabis are more dif- risk as epidemiologic studies show that drug abuse typically
ficult to control compared to smoking marijuana. The poor begins in late adolescence. The fact that he is not yet using
learning performance may be due to the interference of other drugs is a positive sign.