The difference between metronidazole suppositories and metronidazole tablets is that one is for vaginal use and the other is for oral use. Metronidazole suppositories can only be placed vaginally and should never be taken orally. Metronidazole tablets are for oral use and are mainly used to treat systemic trichomoniasis or anaerobic infections. In exceptional cases, metronidazole tablets can be placed vaginally if suppositories are not available locally, but vaginal placement is not as effective as metronidazole suppositories. Also patients who are not sexually active, in which case only metronidazole tablets can be used and not metronidazole suppositories etc., are used in clinical practice for the treatment of trichomoniasis and bacterial vaginosis.