Tinidazole

Key facts

• Tinidazole is a nitroimidazole antibiotic and antiparasitic that kills susceptible bacteria and parasites by damaging their DNA.
• Usually taken as a single dose or a short course, with food to reduce stomach upset.
• Do not drink alcohol during treatment or for 72 hours after your last dose. Combining tinidazole with alcohol can cause severe flushing, nausea, vomiting, and a fast heartbeat.
• Seek urgent care for a severe allergic reaction, persistent vomiting, or signs of liver trouble such as yellowing of the skin or eyes.

What tinidazole treats

Tinidazole treats bacterial vaginosis, trichomoniasis (a sexually transmitted parasite infection), and giardiasis, a parasite infection often picked up from contaminated water. It also treats amoebic infections of the intestine or liver, and some anaerobic bacterial infections, including certain dental and abdominal infections.

How tinidazole works

Tinidazole enters the cells of susceptible bacteria and parasites, where it is converted into a reactive form that damages their DNA. This stops the organisms from multiplying and eventually kills them. Human cells are unaffected because they lack the enzymes that activate the drug.

Before you take it

• Do not drink alcohol during treatment or for 72 hours afterward; the combination can cause a severe reaction with flushing, vomiting, and a fast heartbeat.
• Tell your prescriber about liver disease, a history of blood disorders, or a known allergy to nitroimidazole drugs.
• If you are being treated for trichomoniasis or bacterial vaginosis, your sexual partner may also need treatment, and you should avoid sex until treatment is complete.
• Tinidazole is generally avoided in the first trimester of pregnancy; tell your prescriber if you are pregnant, planning pregnancy, or breastfeeding.

Side effects

Common effects include a metallic or bitter taste, nausea, headache, dizziness, and mild abdominal cramps. Urine may turn dark; this is harmless and clears after stopping the drug.

Stop and seek urgent medical care for any of these:

• A severe allergic reaction, such as rash, swelling, or difficulty breathing.
• Persistent vomiting or inability to keep fluids down.
• Sudden, intense abdominal pain.
• Yellowing of the skin or eyes.

Safety essentials

• Avoid alcohol completely from the start of treatment until 72 hours after the last dose. Even small amounts can trigger a severe reaction with flushing, vomiting, and a racing heart.
• Complete the full course exactly as prescribed, even for a single-dose treatment, and avoid sex until you and any partner have finished treatment for trichomoniasis or bacterial vaginosis.
• Tell your prescriber if you develop numbness, tingling, or weakness, since prolonged or repeated courses have rarely been linked to nerve damage.

This page is educational and does not replace advice from a doctor or pharmacist who knows your health history.