Metronidazole does not treat bad breath, but it can treat oral infections, and is usually administered for 7~10 days. Halitosis if caused by oral anaerobic bacterial infections, you can use this product as appropriate under the guidance of the doctor anti-infective treatment, according to the instructions, usually metronidazole course of 7 ~ 10 days, more than this time may cause the body flora imbalance, aggravate the adverse effects of the drug. The adverse reactions of this product include inhibition of platelet and leukocyte production, causing nausea, vomiting, dizziness and other symptoms, and a few patients may also have allergic reactions. The appearance of bad breath should go to the hospital in a timely manner, to clarify the cause of the disease, symptomatic treatment. The use of metronidazole must be taken in accordance with medical advice, and pregnant women, lactating women and patients with hematologic disorders need to be prohibited.