How Long Does Metronidazole Take to Work?

Metronidazole begins to treat an infection immediately, though symptoms will likely persist through the first few days of treatment, according to WebMD. Also known by the brand name Flagyl, metronidazole is a type of antibiotic that stops the growth of bacteria and some protozoa. It doesn’t treat viral infections.

Users should avoid alcohol during treatment with metronidazole and for several days afterward, as nausea, vomiting, cramps, headache and flushing can occur, according to PDRhealth. For best results, the drug should be taken throughout the day in evenly spaced intervals to keep a constant level in the bloodstream. Missing doses should be avoided, and all of the antibiotic should be taken.

An unpleasant taste in the mouth, abdominal cramping, nausea, vomiting and loss of appetite are some of the side effects of metronidazole, states PDRhealth. Other common side effects include headache, dizziness, constipation, dry mouth and rash. Serious side effects include seizures, numbness and tingling of the hands and feet, states If these symptoms occur, users are advised to discontinue the drug and contact a doctor immediately.

Metronidazole should not be taken by those with some central nervous system disorders, seizure disorders or epilepsy, according to PDRhealth. Additionally, it should not be taken by those with liver disease, fungal infections, or certain blood disorders.