Metronidazole alternatives: what to use for different infections

Metronidazole has been a go-to antibiotic for anaerobic bacteria and some parasites. Lately, doctors are choosing other options more often because of resistance, side effects (hello, metallic taste and alcohol reactions), and new drugs that work better for certain bugs. If you’re wondering what can replace metronidazole, this page lays out common swaps by infection and what to watch for.

Common drug swaps

For bacterial vaginosis (BV): clindamycin and tinidazole are the main alternatives. Clindamycin comes as a 2% vaginal cream or oral pills; the topical form avoids systemic side effects for many people. Tinidazole is an oral option and can be effective when metronidazole fails.

For trichomoniasis: tinidazole is typically more convenient because a single 2 g oral dose often clears the infection. If tinidazole isn’t suitable, multi-day regimens of metronidazole or clinician-guided alternatives can be used.

For giardiasis and some protozoal infections: tinidazole or nitazoxanide are common choices. Nitazoxanide is usually given as a short course and is an alternative when standard treatments aren’t tolerated.

For anaerobic bacterial infections (like dental infections, abscesses): clindamycin is a frequent substitute. For more severe infections, doctors may use beta-lactam/beta-lactamase inhibitor combos (for example, amoxicillin-clavulanate) or advanced drugs like carbapenems in hospital settings.

For C. difficile infections: metronidazole used to be common, but current practice favors oral vancomycin or fidaxomicin. Vancomycin (oral) and fidaxomicin have better cure rates and lower recurrence for many patients.

How to pick the right alternative

Match the drug to the bug and your situation. Are you pregnant? Pregnant people need specific safe options. Do you drink alcohol regularly? If so, metronidazole and tinidazole can cause unpleasant reactions with alcohol. Do you have liver disease or are you taking other meds that interact? All of these matter.

If you’re seeing recurring infections or severe symptoms, ask your provider about culture or testing. That helps pick a targeted antibiotic instead of guessing. Also mention allergies — penicillin allergy might push your clinician toward clindamycin or other non-beta-lactam options.

No single replacement fits every case. Talk to a clinician, bring a list of your medicines, and ask about side effects and follow-up testing. If you have worsening symptoms, fever, or signs of spreading infection, get medical care quickly.

Want quick help figuring this out? Use this guide when you talk to your healthcare provider so you can ask the right questions and get a treatment that fits your health and lifestyle.