Metronidazole Tablets Side Effects You Should Be Aware Of

Metronidazole is a derivative of nitroimidazole that is rapidly and completely absorbed after oral administration. According to clinical reports, between 15% to 30% of patients experience some type of adverse reaction after taking metronidazole tablets. The most commonly reported side effects are gastrointestinal issues such as nausea, vomiting, loss of appetite, and abdominal cramps. These symptoms are usually mild and do not interfere with the continuation of treatment.

Common Neurological and Allergic Reactions

In addition to digestive problems, some patients may experience neurological symptoms like headaches, dizziness, and occasionally abnormal sensations, numbness in the limbs, ataxia, or symptoms of polyneuropathy. High doses of metronidazole may even lead to seizures. Allergic-type reactions can also occur, including hives, flushing, itching, and in some cases, cystitis or difficulty urinating. Additional side effects may include a metallic taste in the mouth and a decrease in white blood cell count. Fortunately, these effects are generally reversible and tend to resolve on their own once the medication is discontinued.

Serious Side Effects and Health Risks

Potentially Severe Reactions

While rare, metronidazole use has been associated with more serious adverse events. These include toxic epidermal necrolysis, a severe skin reaction, as well as significant decreases in white blood cell count, aseptic meningitis, peripheral neuropathy, convulsions, optic nerve damage, ototoxicity, hemolytic uremic syndrome, and even encephalopathy. These conditions require immediate medical attention and discontinuation of the medication.

Important Precautions and Contraindications

Metronidazole is contraindicated in individuals with active central nervous system disorders or blood-related diseases. It is categorized as Pregnancy Category B, meaning it may be used during pregnancy only if clearly needed, but should be avoided during breastfeeding. Animal studies in mice and rats have shown evidence of carcinogenic potential, so unnecessary use should be avoided.

Patients undergoing treatment with metronidazole should strictly avoid alcohol consumption during the treatment period and for at least three days after completing the course. Combining metronidazole with alcohol can lead to a disulfiram-like reaction, causing symptoms such as flushing, rapid heartbeat, nausea, and headache.