How long does it take for metronidazole to work?
Metronidazole starts to work 1 to 2 hours after you take it, because it is quickly absorbed, and it reaches its maximum concentration after 20 minutes to 3 hours. But it may take a couple of days before you start to feel better or notice an improvement in your symptoms. It is important that you still finish the course of metronidazole that your doctor has prescribed, even if you feel better, because the infection may still be present, and it could flare up or recur if you haven’t finished the course.
References
- Metronidazole Tablets 500 mg Medicines.org.UK. https://www.medicines.org.uk/emc/product/5882/smpc#gref
- Metronidazole Northern Devon Healthcare. https://www.northdevonhealth.nhs.uk/wp-content/uploads/2017/11/Metronidazole-sexual-health-clinics.pdf
Read next
What happens if you drink alcohol with metronidazole?
Drinking alcohol while taking metronidazole is not recommended because the combination of metronidazole and alcohol can cause a reaction (often referred to as a disulfiram-like reaction) in some people. Symptoms may include flushing, headaches, nausea, vomiting, and stomach cramps. There has been one reported death associated with this reaction. The product information and health professionals recommend not to drink alcohol during metronidazole treatment and for 3 days after finishing the course. Continue reading
Can metronidazole cause a yeast infection?
About 10% of women report a vaginal yeast infection (vaginal candidiasis) as a side effect of metronidazole treatment. Although metronidazole spares vaginal lactobacilli, which are naturally resistant to nitroimidazoles such as metronidazole, it does not restore a Lactobacillus-dominated microbiome and disruption in the normal vaginal microbiota can persist. Continue reading
What can I do about the metallic taste of Flagyl?
Metronidazole (brand: Flagyl) can leave a bitter, metallic taste in your mouth. This is a well-known side effect. For many, the bad taste lasts throughout treatment, too, not just when you're swallowing the medicine. There are ways to help mask this taste with certain foods. Continue reading
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Drug information
- Metronidazole Information for Consumers
- Metronidazole prescribing info & package insert (for Health Professionals)
- Side Effects of Metronidazole (detailed)
Related support groups
- Metronidazole (129 questions, 350 members)