White plus black cold medicine is divided into white and black tablets, with white tablets taken during the day and black tablets taken at night. Because the ingredients in white tablets and black tablets are different, white tablets usually contain several ingredients such as acetaminophen, pseudoephedrine hydrochloride and dextromethorphan hydrobromide, which have the effect of reducing fever and pain and relieving cough and phlegm. The black tablets taken at night are mainly composed of acetaminophen, pseudoephedrine hydrochloride and dextromethorphan hydrobromide, with the addition of diphenhydramine, so the black tablets taken at night can improve the symptoms of fever, headache, aching limbs, sneezing, runny nose, nasal congestion and coughing, and also have a certain sedative-hypnotic effect, so that the quality of sleep at night is better. But usually this drug is not recommended for long-term use, the symptoms do not improve after three days of medication should promptly go to the hospital.