chapter
Alcohol
Pages 7

Be aware. The FDA has considered the probability of inactivation of stomach alcohol dehydrogenase as ‘not dangerous’

ALCOHOL OPIOIDS ≠ sedation. Report of hypotension with codeine

Additive effect Warn patients

ALCOHOL ANTIBIOTICS

ALCOHOL CEPHALOSPORINS Disulfiram-like reaction, with flushing, wheezing, breathing difficulties, nausea and vomiting with some cephalosporins. This potentially dangerous interaction can come on right away, or it may be delayed by as much as a few days

It is considered that a reactive metabolite probably inactivates alcohol dehyrogenase

Do not consume alcohol for 3 days following stopping the antibiotic

ALCOHOL CYCLOSERINE Risk of fits Additive effect; cycloserine can cause fits

Warn patients to drink alcohol only minimally while taking cycloserine

caused by metronidazole may be aggravated by alcohol

Metronidazole inhibits aldehyde dehydrogenase. Additive side-effects

Avoid co-ingestion

ALCOHOL TETRACYCLINE Likely ↓ efficacy of antibiotic Uncertain Be aware ALCOHOL ANTICANCER AND IMMUNOMODULATING DRUGS

ALCOHOL METHOTREXATE ≠ risk of liver damage/toxicity Additive liver toxicity Be aware; advocate abstinence. Monitor liver function

ALCOHOL PROCARBAZINE May cause a disulfiram-like reaction, additive depression of the CNS and postural hypotension

Some alcoholic beverages (beer, wine, ale) contain tyramine, which may induce hypertensive reactions

Avoid co-administration

ALCOHOL ANTICOAGULANTS – ORAL Fluctuations in anticoagulant effect in heavy drinkers or patients with liver disease who drink alcohol

Alcohol may reduce the half-life of oral anticoagulants by inducing hepatic enzymes. Also they may alter the hepatic synthesis of clotting factors

Caution should be taken when prescribing oral anticoagulants to alcoholics, particularly those who binge drink or have liver damage

ALCOHOL ANTIDEPRESSANTS

ALCOHOL MAOIs Additive depression of CNS ranging from drowsiness to coma and respiratory depression

Synergistic depressant effects on CNS function

Necessary to warn patients, particularly regards activities that require attention, e.g. driving or using machinery and equipment that could cause self-harm

ALCOHOL SSRIs ≠ risk of sedation Additive CNS depressant effects. Acute ingestion of alcohol inhibits CYP2D6 and CYP2C19, whereas chronic use induces CYP2E1 and CYP3A4

Be aware and caution against excessive alcohol intake

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MISCELLANEOUS ALCOHOL

Additive effect Warn patients about this effect

ALCOHOL BARBITURATES ≠ sedation Additive sedative effect Warn patients about this effect ALCOHOL TOPIRAMATE ≠ sedation Additive sedative effect Warn patients about this effect ALCOHOL ANTIDIABETIC DRUGS

ALCOHOL ANTIDIABETIC DRUGS Tends to mask signs of hypoglycaemia and ≠ risk of hypoglycaemic episodes

Inhibits glucose production and release from many sources including the liver

ALCOHOL METFORMIN Enhanced effect of metformin and ≠ risk of lactic acidosis. May cause a disulfiram-like interaction

Alcohol is known to potentiate the effect of metformin on lactate metabolism. It inhibits glucose production and release from many sources including the liver

The onset of lactic acidosis is often subtle with symptoms of malaise, myalgia, respiratory distress and ≠ non-specific abdominal distress. There may be hypothermia and resistant bradyarrhythmias

ALCOHOL ANTIFUNGALS

ALCOHOL GRISEOFULVIN A disulfiram-like reaction can occur Uncertain Warn patients not to drink alcohol while taking griseofulvin

ALCOHOL KETOCONAZOLE May ≠ risk of liver damage. Symptoms of nausea, headache, flushing and discomfort (similar to a disulfiram-type reaction) may occur

Additive liver toxicity Be aware

antihistamines

Additive effect Warn patients about this effect. Remember that cold medicines as well as allergy pills may well contain antihistamines

ALCOHOL CIMETIDINE, RANITIDINE Alleged ≠ effects of alcohol after relatively innocuous amounts of wine, beer, etc., which made it popular among users; the effect is, however, unproven

A study suggested the presence of alcohol dehydrogenase in the stomach of some men, which was inactivated by cimetidine and ranitidine

Be aware. The FDA has considered the probability of inactivation of stomach alcohol dehydrogenase as ‘not dangerous’

ALCOHOL ANTIHYPERTENSIVES AND HEART FAILURE DRUGS

ALCOHOL ANTIHYPERTENSIVES AND HEART FAILURE DRUGS, e.g. PRAZOSIN

1. Acute alcohol ingestion may ≠ hypotensive effects 2. Chronic moderate or heavy drinking ↓ hypotensive effects

1. Additive hypotensive effect 2. Chronic alcohol excess is associated with hypertension

Monitor BP closely as unpredictable responses can occur. Advise patients to drink alcohol only in moderation and to avoid large variations in the amount of alcohol drunk

ALCOHOL ALPHA-BLOCKERS ≠ levels of both alcohol and indoramin occur with concurrent use

Uncertain Warn patients about the risk of ≠ sedation

ALCOHOL CENTRALLY ACTING ANTIHYPERTENSIVES

Clonidine and moxonidine may exacerbate the sedative effects of alcohol, particularly during initiation of therapy

Uncertain Warn patients of this effect, and advise them to avoid driving or operating machinery if they suffer from sedation

ALCOHOL RESERPINE ≠ effects of both reserpine and alcohol

Reserpine has CNS effects, while alcohol may act as a vasodilatorhypotensive

Avoid concomitant use

ALCOHOL ANTIMUSCARINICS – ATROPINE, GLYCOPYRRONIUM

≠ sedation Additive effect Warn patients about this effect, and advise them not to drink while taking these antimuscarinics

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MISCELLANEOUS ALCOHOL

Uncertain Warn patients not to drink alcohol while taking levamisole

ALCOHOL TINIDAZOLE Risk of a disulfiram-like reaction Uncertain Warn patients not to drink alcohol while taking tinidazole

ALCOHOL ANTIPSYCHOTICS Risk of excessive sedation Additive effect Warn patients of this effect, and advise them to drink alcohol only in moderation

CNS DEPRESSANTS – INCLUDING ALCOHOL

ANXIOLYTICS AND HYPNOTICS

≠ sedation Additive effect Warn patients to be aware of this added effect

ALCOHOL BETA-BLOCKERS Acute alcohol ingestion may ≠ hypotensive effects. Chronic moderate or heavy drinking ↓ hypotensive effects. Might cause higher blood alcohol levels from modest amounts of alcohol

Additive hypotensive effect. Mechanism underlying the opposite effect with chronic intake is uncertain. A study suggested the presence of alcohol dehydrogenase in the stomach of some men, which was inactivated by propranolol

Monitor BP closely as unpredictable responses can occur. Advise patients to drink alcohol only in moderation and to avoid large variations in the amount of alcohol drunk. The FDA has considered the probability of inactivation of stomach alcohol dehydrogenase as ‘not dangerous’

ALCOHOL BETA-CAROTENE (a precursor to vitamin A and a popular antioxidant supplement)

≠ risk of liver damage Alcohol combined with betacarotene led to more liver damage than was produced by alcohol exposure alone

Be aware

ALCOHOL BROMOCRIPTINE ≠ risk of severe side-effects if alcohol is taken at the same time. (e.g. nausea, stomach pain, dizziness)

Uncertain Be aware

moderate or heavy drinking ↓ hypotensive effects 2. Verapamil may ≠ peaked serum concentration and prolong the effects of alcohol

1. Additive hypotensive effect with acute alcohol excess. Chronic alcohol excess is associated with hypertension 2. Uncertain at present, but presumed to be due to inhibition of the hepatic metabolism of alcohol, a mechanism similar to that with cimetidine, ranitidine and aspirin

1. Monitor BP closely as unpredictable responses can occur. Advise patients to drink alcohol only in moderation and to avoid large variations in the amount of alcohol drunk 2. Warn patients about potentiation of the effects of alcohol, particularly the risks to driving

ALCOHOL DRUG DEPENDENCE THERAPIES

ALCOHOL BUPROPION Rare reports of adverse neuropsychiatric events, including report of seizures. ↓ alcohol tolerance

Uncertain Warn patients to avoid or minimize alcohol intake during bupropion treatment

ALCOHOL DISULFIRAM Disulfiram reaction See Drugs Acting on the Nervous System

Do not co-administer. Disulfiram must not be given within 12 hours of ingestion of alcohol. This reaction could occur even with the small amounts of alcohol found in cough syrup or cold remedies

ALCOHOL, BZDs, BARBITURATES

LOFEXIDINE ≠ sedation Additive effect Warn patients of risk of excessive sedation

ALCOHOL MINERALS Regular intake of alcohol could cause depletion of iron, zinc, magnesium and selenium. Alcoholic drinks such as wine and whisky may have high or potentially toxic contents of the toxic element cadmium

Attributed to ↓ absorption or ↓ intake of nutrients

Be a ware. Monitor cadmium levels as well as plasma levels of other minerals

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MISCELLANEOUS ALCOHOL

TIZANIDINE

Additive effect Warn patients; advise them to drink alcohol only in moderation and not to drive if they have drunk any alcohol while taking these muscle relaxants

ALCOHOL NITRATES, NITROGLYCERIN ≠ risk of postural ↓ BP when GTN is taken with alcohol

Additive effect; both are vasodilators

Warn patients about the risk of feeling faint. Advise them to drink alcohol only in moderation and to avoid binge drinking

ALCOHOL PARACETAMOL ≠ risk of liver damage. Might cause higher blood alcohol levels from modest amounts of alcohol, as with aspirin, cimetidine, ranitidine, propranolol and verapamil

Paracetamol tends to cause greater toxicity in chronic alcoholics with malnutrition or diseased livers. A study suggested the presence of alcohol dehydrogenase in the stomach of some men, which could be inactivated by paracetamol

Be aware, particularly when toxic doses of paracetamol have been taken. The FDA has considered the probability of inactivation of stomach alcohol dehydrogenase as ‘not dangerous’

ALCOHOL POTASSIUM CHANNEL ACTIVATORS

Acute alcohol ingestion may ≠ hypotensive effects. Chronic moderate or heavy drinking ↓ hypotensive effects

Additive hypotensive effect. Mechanism underlying the opposite effect with chronic intake is uncertain

Monitor BP closely as unpredictable responses can occur. Advise patients to drink alcohol only in moderation and to avoid large variations in the amount of alcohol drunk

ALCOHOL VITAMIN C (large doses, e.g. 1000 mg)

May ≠ elimination of alcohol, but this is unproven

Uncertain Unlikely to be of clinical significance

NOTE: Alcohol is an ingredient in many OTC and even some prescription medicines. The amounts are modest in most cases, but a few reach concentrations of 40% or 50% proof. Cough and cold elixirs are the most likely sources, but some vitamin ‘tonics’ and laxatives also contain alcohol.