If you are taking oral metronidazole or using metronidazole gel for an infection that is linked with sexual activity, such as trichomoniasis, pelvic inflammatory disease, or bacterial vaginosis you should not have sex for 7 days after single-dose therapy (or until you have completed the 7-day treatment regimen) and your symptoms have resolved. This will help reduce the risk of reinfection. If your sexual partners are also being treated, then abstain from sexual intercourse until they have finished treatment.