The vast majority of people who use metronidazole vaginal effervescent tablets do not have any reaction, but some people may experience a localized burning sensation, which often disappears with continued use of the medicine. Others may experience allergic reactions, such as localized redness and swelling of the vaginal opening accompanied by itching, once this occurs, it is recommended to stop the drug immediately and use other drugs for treatment. If the allergic reaction symptoms are relatively serious, you need to go to the hospital for anti-allergy treatment. In addition, metronidazole vaginal effervescent tablets, mainly for the treatment of anaerobic infections or trichomonas infections caused by vaginal inflammation, must be under the guidance of the doctor before using the drug. It is recommended that you don’t have sex during the medication, so as not to reduce the efficacy of the medication.