Stinging symptoms after the use of metronidazole effervescent tablets may be due to drug irritation after the first use, or may be caused by drug allergy. When discomfort occurs, patients should promptly consult a doctor for proper medication treatment under medical supervision. The main reason 1, bacterial infection: the tingling in the vagina after the first use of metronidazole effervescent tablets may be due to more bacterial infections in the mucous membrane of the vaginal wall and the stimulation of the mucous membrane by the drug, resulting in the tingling sensation, which usually disappears slowly after half an hour. 2, drug allergy: if the tingling, redness or itching in the vagina persists after the use of metronidazole effervescent tablets, it is considered to be due to allergy to the effervescent tablets. Allergy to the raw material. Treatment 1. After the stinging of metronidazole effervescent tablets, it is best to remove the effervescent tablets from the vagina in time and use professional gynecological lotion to wash the vagina under the guidance of a doctor to reduce inflammation and pain, and then replace the treatment with other drugs, such as nifurtimox, tinidazole or suppositories of metronidazole. 2. If you have allergic symptoms, you should also use anti-allergic drugs, such as loratadine, under the guidance of your doctor. Caution 1: When using metronidazole effervescent tablets, the stinging sensation once in a while is not very serious, so you can continue to use the medicine. If the stinging is still painful after using the medication again, and the stinging sensation is aggravated and accompanied by vaginal redness and swelling, you should stop using the medication. 2. During the treatment period, sexual intercourse should be prohibited and spicy and acidic food should be avoided.