Bitter mouth in the middle of the night after taking Quadruple may be caused by an adverse reaction to taking anti-Helicobacter pylori medication. Quadruplex mainly includes omeprazole enteric-coated capsules, colloidal bismuth particles, clarithromycin tablets, amoxicillin loose tablets and other drugs. Taking Quadruplex after half the night mouth bitter may be the adverse reaction of the drug related, due to the Quadruplex contains clarithromycin tablets, is a kind of macrolide antibiotic drugs, has a better antibacterial and anti-inflammatory effect, due to the drug itself is more heavy bitter taste, so it is easy to take this kind of drug when the symptoms of mouth bitter, although this is the adverse reaction of the drug, but is a normal phenomenon. Due to the second half of the night the drug stays in the mouth for a long time, the drug melts, the drug itself bitter taste is heavy. It is recommended that patients can rinse their mouths with water when the phenomenon of bitter mouth occurs, and take the medicine quickly with warm water. When taking this kind of medicine should avoid eating some spicy stimulating food, avoid eating some cold food, keep a good mood, drink more water as appropriate, eat more fresh vegetables and fruits, can improve this abnormal symptom. During the period of taking this medicine, the symptoms of bitter mouth are more serious, it is recommended to consult the doctor in time and follow the doctor’s instructions strictly.