Tinidazole: what it treats, how to take it, side effects
Last updated September 3, 2026.
Tinidazole is a nitroimidazole antimicrobial - it kills the organisms behind several specific infections. You may know it as Tindamax. One absolute rule rides with it: no alcohol during treatment and for 3 days after.
What does it treat?
Four infections: trichomoniasis (a sexually transmitted infection), bacterial vaginosis, giardiasis, and amebiasis - the intestinal infections that bring diarrhea, gas, and cramps, with amebiasis able to spread to the liver.
How do you take it?
Exactly as directed - with food to blunt the stomach upset, on the schedule written for you: some infections are a single dose, others run days. The alcohol rule is absolute: no alcoholic drinks or alcohol- or propylene-glycol-containing products during treatment and for 3 days after - the combination brings vomiting, cramps, headache, sweating, and flushing. For trichomoniasis, the partner gets treated too, or the infection comes back. Missed dose: take it when you remember unless the next one is close; never double up.
Side effects to know
- Common: a sharp, unpleasant metallic taste; nausea, vomiting, loss of appetite; constipation, stomach pain, or cramps; headache; tiredness or weakness; dizziness; and thick, white, odorless vaginal discharge.
- Serious - call your doctor immediately: the uncommon set includes allergic reactions - rash, swelling, trouble breathing - and any numbness or tingling. Report anything unusual promptly.
Who should not take it?
Anyone who reacted to metronidazole or another nitroimidazole. Flag liver disease and blood disorders. Pregnancy - especially the first trimester - is a doctor-level decision: say it before the dose. Breastfeeding needs a pause plan - ask for the timing. If you become pregnant, call your doctor.
When is it an emergency?
Face or throat swelling or trouble breathing is a 911 call. For an overdose, call Poison Control at 1-800-222-1222. Pymander's escalation routing is built and tested specifically for this class of decision; see the safety architecture working paper.
What a Pymander AI doctor consult looks like
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Common questions
Why no alcohol - and why for 3 days after?
Tinidazole blocks alcohol breakdown - drink during or within 3 days after the last dose and the reaction is real: upset stomach, vomiting, stomach cramps, headaches, sweating, flushing. The 3-day tail exists because the drug lingers that long. Products count too: some mouthwashes, cough syrups, and flavorings carry alcohol or propylene glycol - check labels until the window closes.
Why does my partner need treatment for trichomoniasis?
Trichomoniasis passes between partners - treating one half of the pair is a revolving door: cured, then reinfected at the next encounter. The standard is simultaneous treatment for the partner, with sex paused until both are done. Nobody needs symptoms to carry it. That is the whole answer to "but they feel fine."
What is the metallic taste - and does it go away?
The drug reaches saliva and distorts taste - sharp and metallic, very common, and completely temporary: it clears as the drug clears. Water, mints, and citrus take the edge off. It is the most-remembered feature of this medication and the least harmful.
How fast does it work on giardia or BV?
Fast when it works: many infections are a single dose, and symptoms often turn within a day or two - cramps easing, discharge normalizing. Symptoms persisting past several days, or returning within weeks, is the call-your-doctor pattern: the organism may need a different drug or a retest. Diarrhea coming back after giardia treatment specifically earns a second look.
Can I take it while breastfeeding?
The drug passes into milk - the standard plan is pausing breastfeeding for a defined interval around the dose, with pumping to keep supply. The exact interval comes from your doctor or pharmacist for your dose - ask before the dose, not after. It is a planning question with a clean answer, not a barrier.
What happens if I miss a dose of tinidazole?
Take it as soon as you remember, unless it is almost time for the next one - then skip it and never double up. For the multi-day courses, the with-food anchor at the same meal keeps the rhythm. For the single-dose version, the question is only whether the dose stayed down - vomiting soon after means call about repeating it.