It is usually necessary to take oral painkillers at least 24 hours after drinking alcohol. Painkiller is a compound preparation, the main ingredients are aminopyrine, finasteride, caffeine, phenobarbital, of which aminopyrine is more stimulating to the gastric mucosa, which can cause vomiting, rash and other side effects, finasteride is detrimental to the liver function and has a certain degree of toxicity to the retina, the side effects of these two ingredients are similar to those of the alcohol ingredients, and the joint action with alcohol will aggravate these adverse reactions. The human liver normally metabolizes alcohol at a rate of 15-20 ml/hour, and both painkillers and alcohol need to be metabolized by the liver. Taking painkillers orally when alcohol is not fully metabolized is likely to cause liver damage. Therefore, it is usually necessary to take painkillers at least 24 hours after drinking alcohol. Painkillers should be used under the guidance of a medical professional and should not be taken blindly.