Chapter 38 Drug Abuse II: Alcohol 1

Alcohol Most commonly used and abused psychoactive agent in the United States Some therapeutic use Primarily used for nonmedical purposes Moderate consumption (less than 2 drinks/day): prolongs life, reduces risk of dementia and cardiovascular disorders Excessive consumption: diminishes quality and quantity of life 1 drink= one shot of hard alcohol, one glass of wine, or 1 beer 2

Basic Pharmacology of Alcohol Acute overdose: CNS depression, cardiovascular collapse, respiratory depression Treatment of acute overdose: gastric lavage and dialysis Central nervous system effects Acute effects General depression of CNS function Enhances GABA-mediated inhibition Dose-dependent Activation of the reward circuit Binds with 5-HT3 receptors 3

Basic Pharmacology of Alcohol Chronic effects Two neuropsychiatric syndromes Wernicke’s encephalopathy- abnormal eye movements, nystagmus- REVERSIBLE WITH THIAMINE Korsakoff’s psychosis- memory loss, polyneuropathy- IRREVERSIBLE Impact on cognitive function Effect on sleep 4

Basic Pharmacology of Alcohol Other pharmacologic effects Cardiovascular system- acute overdose- vasodilation, chronic use- heart failure, hypertension Respiration Liver- fatty liver, hepatits, then cirrhosis Stomach- gastritis Pancreas Cancer: breast and colorectal cancer rates increased Pregnancy and lactation Impact on longevity 5

Basic Pharmacology of Alcohol Pharmacokinetics Absorption Distribution Metabolism Blood levels Tolerance Physical dependence- abstinence syndrome is potentially lethal 6

Basic Pharmacology of Alcohol Drug interactions CNS depressants Nonsteroidal anti-inflammatory drugs Acetaminophen- increased risk of liver toxicity Disulfiram Antihypertensive drugs 7

Basic Pharmacology of Alcohol Acute overdose Vomiting, coma, pronounced hypotension and respiratory depression 8

Alcohol Use Disorder Relapsing disorder Impaired control over drinking Preoccupation with alcohol consumption Use of alcohol despite awareness of adverse consequences Distortions in thinking Influenced by genetics and psychosocial and environmental factors 9

Drugs for Alcohol Use Disorder Drugs used to facilitate withdrawal (benzodiazepines) Drugs used to maintain abstinence (naltrexone, disulfuram, acamprosate) Other drugs used in the treatment of alcohol abuse 10

Drugs Used to Facilitate Withdrawal Benzodiazepines- these are life-saving for acute severe withdrawal Chlordiazepoxide (Librium, others) Diazepam (Valium) Oxazepam (Serax) Lorazepam (Ativan) Adjuncts to benzodiazepines Carbamazepine (antiepileptic drug) Clonidine (alpha-adrenergic blocker) Atenolol and propranolol (beta-adrenergic blockers) 11

Drugs Used to Maintain Abstinence Disulfiram aversion therapy Refrain from drinking Causes irreversible inhibition of aldehyde dehydrogenase Effects caused by alcohol plus disulfiram are referred to as acetaldehyde syndrome Patients must be CAREFULLY CHOSEN Patients must be thoroughly informed to avoid all forms of alcohol Sauces, cough syrups Alcohol applied to the skin (lotions, colognes, liniments) 12

Fig. 38–1. Ethanol metabolism and the effect of disulfiram. 13

Drugs Used to Maintain Abstinence Naltrexone (Revia) Pure opioid antagonist Decreases craving for alcohol Blocks reinforcing effects of alcohol Mechanism unclear Adverse effects Nausea Headache 14

Drugs Used to Maintain Abstinence Acamprosate (Campral) Reduces unpleasant feelings brought on by abstinence Devoid of direct anxiolytic, anticonvulsant, and antidepressant activity Does not cause alcohol aversion Administered orally Excreted unchanged in the urine Adverse effects and drug interactions Diarrhea Avoid during pregnancy 15

Nutritional Support, Fluid Replacement, and Antibiotics B vitamins Thiamine Folic acid Cyanocobalamin Vitamin supplements Fluid replacement therapy Antibiotics 16