A number of drugs can make you sick when you drink alcohol. Some are due to adverse drug reactions or a deliberate pharmacologic effect of a drug that produces high concentrations of a noxious chemical, acetaldehyde, to help alcoholics stop drinking.
According to Mentalhealth.com, disulfiram--brand name Antabuse--produces sensitivity to alcohol that causes a very unpleasant reaction when an alcoholic patient ingests small amounts of alcohol. Disulfiram blocks alcohol metabolism at the acetaldehyde stage, which results in flushing, headache, difficulty breathing, nausea, vomiting, sweating, thirst, palpitation, tachycardia, hypotension, syncope, weakness, vertigo, blurred vision and confusion.
According to the National Institute on Alcohol Abuse and Alcoholism, in combination with alcohol consumption, some antibiotics may cause nausea, vomiting, headache and possibly convulsions. These antibiotics include furazolidone, griseofulvin, metronidazole, and the antimalarial quinacrine.
According to Mentalhealth.com, diphenhydramine or Benadryl--an antihistamine available over the counter to treat allergic symptoms and insomnia in the presence of alcohol--may intensify the sedation caused by Benadryl. The combination may cause excessive dizziness and sedation in older people.
The National Institute on Alcohol Abuse and Alcoholism says oral hypoglycemic drugs such as tolbutamide or Orinase lower blood sugar levels in some diabetic patients. Acute alcohol consumption prolongs, and chronic alcohol consumption decreases, the availability of tolbutamide. Alcohol also interacts with some drugs of this class to produce symptoms of nausea and headache.
Warfarin--brand name Coumadin--prevents blood from clotting. According to the National Institute on Alcohol Abuse and Alcoholism, acute alcohol consumption enhances warfarin's availability, increasing the risk for life-threatening hemorrhages. Chronic alcohol consumption reduces warfarin's availability, decreasing the patient's protection from blood-clotting disorders.
Davidson's Principles and Practice of Medicine says people taking antidepressants belonging to the monoamine oxidase inhibitor class should avoid foods rich in tyramine--a chemical found in cheese, some beers and chianti--because this combination may result in a hypertensive crisis. One drink may cause this interaction.
According to the National Institute on Alcohol Abuse and Alcoholism, antipsychotic drugs such as chlorpromazine--brand name Thorazine--decrease symptoms such as delusions and hallucinations. Acute alcohol consumption increases the sedative effect of these drugs, resulting in impaired coordination and potentially fatal breathing difficulties.