- Full explanation of diagnosis with written information.
- Screening for other STIs
Recommended regimes (Ia, A)
- Metronidazole 2g orally in a single dose or
- Metronidazole 400-500mg twice daily for 5-7 days
- Tinidazole 2g orally in a single dose
Pregnancy and breast feeding
- It is not known if metronidazole has any effect on pregnancy outcomes. Meta-analyses have concluded that there is no evidence of teratogenicity during the first trimester of pregnancy (Ia).
- Metronidazole can be used in all stage of pregnancy and during breast feeding. Symptomatic women should be treated at diagnosis, although some clinicians have preferred to defer treatment until the second trimester.
- The BNF advises against high dose regimens in pregnancy.
- Metronidazole enters breast milk and may affect its taste. Avoid high doses if breastfeeding or if using a single dose of metronidazole, breastfeeding should be discontinued for 12-24 hours to reduce infant exposure.
- Tinidazole’s safety in pregnant women has not been well-evaluated. The manufacturer states that the use of tinidazole in the first trimester is contraindicated.
HIV positive individuals
- Few data available, but a recent randomized clinical trial demonstrated that a 2g single oral dose of metronidazole was not as effective as 500mg of metronidazole twice daily for 7 days among HIV-infected women
Reactions to treatment
- Patients should be advised not to take alcohol for the duration of treatment and for at least 48 hours, (72 hours for tinidazole) afterwards because of the possibility of a disulfiram-like reaction.
- It is unknown whether there is cross reactivity between the two agents.
In cases of true allergy, desensitization to metronidazole could be considered.
- Sexual contact(s) should be treated simultaneously and patients should be advised to abstain for at least one week until they and their partner(s) have completed treatment and follow-up.
- Any partners within the four weeks prior to presentation should be screened for the full range of STIs and treated for TV (Ib A).
- Male TV contacts with urethritis may be treated initially for TV and repeat urethral smear before treating additionally for NGU (III)
- Male partners of women with treatment failure should be evaluated and treated with either metronidazole 400-500mg twice daily for 7 days or tinidazole 2g single dose (expert opinion).
- Persistent or recurrent TV is due to inadequate therapy, re-infection, or resistance. Therefore check compliance, vomiting post metronidazole and assess for risk of reinfection.
- Resistance tests can be of clinical benefit. Resistance data from the UK are lacking due to the absence of a metronidazole resistance testing service.
- Treatment protocol for non-response to standard TV therapy
Repeat course of 7-day standard therapy
Metronidazole 400-500mg twice daily for 7 days (III)
For patients failing this second regimen:
- Higher dose course of nitroimidazole
Metronidazole or tinidazole 2g daily for 5-7 days or
Metronidazole 800mg three times daily for 7 days (III)
For those failing this third regimen, resistance testing should be performed if available. If resistance testing is not available high dose tinidazole regimens may be considered:
- Very high dose course of tinidazole
Tinidazole 1g twice or three times daily, or 2g twice daily for 14 days +/- intravaginal tinidazole 500mg twice daily for 14 days (III)
- Other treatments with some reported success (IV/anecdotal)
Paromomycin* intravaginally 250mg once or twice daily for 14 days
Furazolidone* intravaginally 100mg twice daily for 12-14 days
Acetarsol* pessaries 500mg nocte for 2 weeks
6% Nonoxynol–9* pessaries nightly for 2 weeks
*The medicines suggested for use in treatment failure are unlicensed products and may not be readily available for purchase in the UK.
- Test of cure only recommended if the patient remains symptomatic following treatment, or if symptoms recur. (IV, C)