1. Alcohol adds on with medicines like benzodiazepines, antidepressants, anti-allergics, sleep medicines and morphine and related pain killers, to cause marked depression of brain activities. Chances of accidents increase when alcohol is combined with them.
2. Some individuals taking a sulfonylurea, cefoperazone, or metronidazole have experienced disulfiram-like reactions when they consume alcohol. The symptoms include skin redness, palpitations, nausea, vomiting, headache and in severe cases circulatory collapse. This reaction occurs only in few individuals. Its symptoms decrease with time as alcohol is metabolized. Only reassurance and supportive treatment is needed.
3. Short-term alcohol ingestion inhibits, while long-term intake induces liver cytochrome P-450 enzymes (especially CYP2E1). Formation of toxic metabolite of paracetamol, that is NABQI, is increased in alcoholics. Safe dose limit of paracetamol is lower in them. Metabolism of tolbutamide, phenytoin and some other drugs is similarly affected by acute and chronic alcohol intake. These drugs increase chances of liver damage when taken with alcohol.
4. Hypoglycaemic action of insulin and sulfonylureas is increased by alcohol ingestion.
5. Aspirin and other NSAID pain killers cause more gastric bleeding when taken with alcohol.