Alcohol Interactions

Combining alcohol with acetaminophen significantly increases risk of severe liver damage.

Alcohol affects warfarin in two opposing ways: acute heavy drinking inhibits hepatic CYP2C9 metabolism of warfarin, raising INR and bleeding risk, while chronic heavy drinking induces enzymes that lower INR and increase clot risk. Alcohol also damages the liver and platelets, compounding bleeding hazards.

Alcohol and alprazolam (Xanax) both depress the central nervous system through GABA-A receptor potentiation, producing additive sedation, profound respiratory depression, and impaired psychomotor function. The combination significantly increases risk of overdose death, even at moderate doses of each substance.

Diazepam (Valium) and alcohol are both GABA-A receptor positive allosteric modulators, producing additive and supra-additive CNS depression with profound risk of respiratory depression, coma, and death. Diazepam's long half-life and active metabolites extend the window of dangerous interaction far beyond the dosing interval.

Zolpidem (Ambien) and alcohol both potentiate GABA-A receptor activity at the alpha-1 subunit, producing additive sedation, profound impairment of psychomotor performance, and significantly elevated risk of complex sleep behaviors, falls, respiratory depression, and motor vehicle crashes. Alcohol also increases zolpidem absorption and peak concentrations.

Tramadol combined with alcohol produces additive CNS and respiratory depression, and the combination significantly lowers the seizure threshold, increasing the risk of convulsions, serotonin syndrome, and overdose death. Tramadol has unique serotonergic and noradrenergic activity that compounds alcohol's effects beyond what occurs with pure opioids.

Codeine combined with alcohol produces additive CNS and respiratory depression, with risk of fatal overdose particularly elevated in CYP2D6 ultra-rapid metabolizers who convert codeine to morphine rapidly. The combination also increases sedation, impaired judgment, and the risk of accidents.

Hydrocodone combined with alcohol produces dangerous additive CNS and respiratory depression with high risk of fatal overdose. Extended-release hydrocodone formulations can experience dose dumping when combined with alcohol, releasing the entire dose at once and causing potentially lethal blood concentrations.

Alcohol blocks thiamine (vitamin B1) at every level — reducing intestinal absorption, impairing hepatic phosphorylation to its active form, and accelerating urinary loss. Thiamine deficiency in drinkers causes Wernicke encephalopathy (acute) and Korsakoff syndrome (chronic, often irreversible).

Alcohol suppresses hepatic gluconeogenesis, removing a key safety net against low blood sugar; insulin lowers glucose directly. Combined, they can cause severe, prolonged, and delayed hypoglycemia, especially when drinking on an empty stomach or overnight.

Combining alcohol with oxycodone causes additive central nervous system and respiratory depression, dramatically increasing the risk of fatal overdose, sedation, and impaired breathing. Alcohol can also accelerate the release of oxycodone from extended-release formulations, causing dangerous spikes in blood levels.

Alcohol increases risk of lactic acidosis with metformin and can cause dangerous drops in blood sugar.

Lithium has a narrow therapeutic window and is excreted by the kidneys. Alcohol causes diuresis and dehydration, which reduces renal lithium clearance and raises serum lithium levels — pushing patients toward lithium toxicity (tremor, confusion, ataxia, arrhythmia). Alcohol also worsens mood instability in bipolar disorder.

Kava and alcohol both depress the central nervous system through GABAergic and other mechanisms, producing additive sedation and motor impairment. More importantly, both substances are hepatotoxic, and concurrent use significantly increases the risk of severe liver injury, including cases of fulminant liver failure requiring transplantation.

Metronidazole can produce a disulfiram-like reaction when combined with alcohol, causing flushing, nausea, vomiting, abdominal cramps, headache, and tachycardia. The FDA label warns against alcohol use during therapy and for at least 3 days afterward.

Duloxetine (Cymbalta) and heavy alcohol use both can damage the liver. The FDA-approved label explicitly states that Cymbalta should not be prescribed to patients with substantial alcohol use because the combination has been linked to severe, sometimes fatal, hepatotoxicity in clinical trial data.

Amitriptyline is a tricyclic antidepressant with strong sedating, anticholinergic, and antihistaminic effects. Combining it with alcohol — also a CNS depressant — produces marked additive sedation, impaired psychomotor performance, and increased risk of falls, accidents, and respiratory depression in overdose.

Pregabalin (Lyrica) and alcohol are both central nervous system depressants with additive effects on sedation, coordination, and respiratory drive. The FDA's 2019 Drug Safety Communication warned that pregabalin can cause life-threatening respiratory depression when combined with CNS depressants such as alcohol, particularly with opioids or in patients with lung disease.

Trazodone and alcohol both depress the central nervous system, producing additive sedation, dizziness, orthostatic hypotension, and impaired psychomotor performance. The combination also increases risk of falls, accidents, and rarely, dangerous arrhythmias related to QT prolongation.

Naproxen and alcohol combine to substantially increase the risk of stomach bleeding, ulcers, and kidney injury through additive effects on gastric mucosal damage, platelet inhibition, and reduced renal perfusion. Naproxen's longer half-life means the interaction window is more prolonged than with shorter-acting NSAIDs.

Mirtazapine and alcohol both depress the central nervous system, producing additive sedation, profound drowsiness, impaired psychomotor performance, and increased risk of accidents and falls. Mirtazapine's strong H1-antihistamine activity makes the sedative interaction with alcohol particularly pronounced, especially at lower doses.

Alcohol potentiates the hypoglycemic effect of glipizide by suppressing hepatic gluconeogenesis, and in rare cases can trigger a disulfiram-like reaction with flushing, headache, nausea, and palpitations. Sulfonylurea-induced hypoglycemia tends to be prolonged and recurrent.

Statins and alcohol are both metabolized by the liver and can independently raise transaminases; combined heavy use increases the risk of hepatotoxicity and, in some cases, myopathy or rhabdomyolysis. Atorvastatin plasma levels rise sharply in patients with alcoholic liver disease.

Chronic alcohol use causes folate deficiency through multiple mechanisms: it inhibits the reduced folate carrier in the intestine (blocking absorption), reduces hepatic uptake and storage, and increases urinary folate excretion. Folate depletion accelerates alcohol-induced liver injury and disrupts one-carbon metabolism and DNA methylation.

Co-administration of alcohol with THC significantly increases peak blood THC and 11-OH-THC concentrations versus cannabis alone, and produces additive impairment of psychomotor performance, judgment, and reaction time.

Alcohol and aspirin together significantly increase the risk of gastrointestinal bleeding because aspirin irreversibly inhibits platelets for their entire 7-10 day lifespan while alcohol damages the gastric lining and impairs clot formation. The risk is particularly elevated for daily low-dose aspirin users who drink regularly.

Gabapentin and alcohol are both central nervous system depressants. The FDA issued a 2019 Drug Safety Communication warning that gabapentin can cause serious, potentially fatal respiratory depression when combined with CNS depressants including alcohol, particularly in older adults and patients with respiratory disease.

Alcohol depletes hepatic vitamin A by inducing cytochrome P450 enzymes (especially CYP2E1, CYP26A1, CYP26B1) that catabolize retinol. Paradoxically, vitamin A supplementation in heavy drinkers is hepatotoxic — alcohol potentiates retinol's toxicity to liver cells, and high-dose beta-carotene combined with alcohol increases liver injury.

Alcohol and ibuprofen each independently irritate the gastric lining and impair platelet function, and together they significantly increase the risk of gastrointestinal bleeding, ulcers, and acute kidney injury. Chronic combined use also accelerates kidney damage through dehydration and reduced renal perfusion.

Both nitroglycerin and alcohol are vasodilators; combined, they cause additive hypotension that can produce severe dizziness, fainting, or cardiovascular collapse, particularly with sublingual or fast-acting nitrate formulations. The classic interaction was first described in the New England Journal of Medicine in 1965.

Alcohol can increase drowsiness from melatonin and reduce sleep quality.

Alcohol can increase iron absorption to potentially harmful levels and damage the liver.

Regular alcohol use impairs B12 absorption and can lead to deficiency.

Venlafaxine (Effexor) is an SNRI that, like other antidepressants, has additive CNS-depressant effects with alcohol. The FDA-approved label warns patients to avoid alcohol because of worsening drowsiness, dizziness, impaired judgment, and the potential to aggravate the underlying mood or anxiety disorder.

Alcohol and propranolol can produce additive hypotension, dizziness, and sedation through combined vasodilation and central nervous system depression; propranolol also masks the warning symptoms of low blood sugar and rapid heart rate. Chronic heavy drinking induces hepatic enzymes and can reduce propranolol effectiveness.

Hydrochlorothiazide and alcohol both lower blood pressure and promote dehydration; combined use causes additive hypotension, dizziness, and orthostatic syncope, especially on standing or in hot weather. The combination also worsens electrolyte loss, particularly potassium and magnesium.

Alcohol can precipitate atrial fibrillation and other arrhythmias that overlap with digoxin's narrow therapeutic window; concurrent diuretic-induced hypokalemia and hypomagnesemia, common in this population, sharply increase the risk of digoxin toxicity. Alcohol may also alter digoxin absorption and worsen heart failure that the drug is meant to treat.

Chronic alcohol use causes zinc deficiency through reduced intake, impaired absorption, increased urinary excretion, and altered zinc transporters (especially ZIP14). Zinc deficiency in turn worsens alcoholic liver disease by disrupting intestinal barrier function, increasing endotoxin leak, and amplifying hepatic oxidative stress.

Valerian root acts on GABA-A receptors and may inhibit GABA breakdown, producing sedative effects that are additive with alcohol's CNS depressant effects. The combination produces increased drowsiness, impaired psychomotor performance, and risk of falls, particularly in older adults.

Celecoxib combined with alcohol increases the risk of gastrointestinal bleeding and ulcers, though somewhat less than non-selective NSAIDs because celecoxib spares COX-1 and has minimal platelet effects. The combination also increases liver enzyme elevations and kidney injury risk through additive effects on hepatic metabolism and renal perfusion.

Sertraline (Zoloft) and alcohol are both central nervous system depressants. Although controlled studies in healthy subjects showed sertraline did not potentiate alcohol's psychomotor impairment, the FDA label still advises against concurrent use because alcohol can worsen depression, anxiety, drowsiness, and judgment in patients being treated for mood disorders.

Fluoxetine (Prozac) and alcohol both depress the central nervous system, increasing drowsiness, dizziness, and impaired judgment. Fluoxetine and its active metabolite norfluoxetine have unusually long half-lives (1 to 4 days and 4 to 16 days), so alcohol effects can be amplified even when the drink and dose are taken hours apart.

Alcohol acts as an acute magnesium diuretic, dramatically increasing urinary magnesium excretion within hours of intake. Chronic drinking depletes body magnesium stores through this renal wasting combined with reduced intestinal absorption, leading to hypomagnesemia in up to 60 percent of heavy drinkers.

Alcohol may increase triglyceride levels, counteracting omega-3 benefits.

N-acetylcysteine (NAC) is a glutathione precursor that supports the liver's primary antioxidant defense against acetaldehyde — the toxic intermediate of alcohol metabolism. Animal studies and small human trials show NAC reduces alcohol-induced oxidative stress and may modestly reduce hangover symptoms, though it does not prevent liver damage from heavy drinking.