How long after receiving cefalosporin can one drink alcohol?

After receiving cephalosporin antibiotics, you should wait at least seven days before consuming alcohol.

This is because some cephalosporin antibiotics contain a "methyltetrazole thiol group" that can inhibit the activity of aldehyde dehydrogenase, an enzyme in the liver. When alcohol is consumed, acetaldehyde produced from alcohol metabolism cannot be properly processed and accumulates in the body, triggering a disulfiram-like reaction.

Mild disulfiram-like reactions may present as facial flushing, headache, nausea, and similar symptoms, while severe reactions can cause sudden drops in blood pressure, difficulty breathing, and even life-threatening shock. The risks are higher for elderly individuals and those with impaired liver or kidney function. Different cephalosporin drugs are metabolized at varying rates in the body. Although short-acting cephalosporins theoretically have shorter metabolic times, a seven-day interval is still required to avoid residual effects. Medium- to long-acting cephalosporins have longer half-lives and similarly require more than seven days between the last dose and alcohol consumption.

In addition, food or topical products containing alcohol may also trigger reactions. After discontinuation of the medication, if cephalosporins have been used, it is important to confirm that drug concentrations have dropped to a safe level. For safety reasons, it is essential to strictly observe a seven-day alcohol abstinence period after completing cephalosporin treatment and not to rely on luck.

If, after stopping the medication for more than a week, any discomfort or unusual reactions occur, alcohol consumption should be stopped immediately and medical attention sought promptly.