It is best not to take painkillers immediately after drinking coffee. 1. Painkillers belong to non-steroidal anti-inflammatory drugs, which can stimulate the gastrointestinal tract, damage the gastric mucosa, leading to the occurrence of peptic ulcer; coffee also has a stimulating effect on the gastrointestinal tract, which may increase the probability of the occurrence of adverse reactions to painkillers. 2. Coffee has the function of promoting excretion, which will shorten the time that painkillers stay in the body, leading to a decrease in the efficacy of the drug. 3. Painkillers are compound antipyretic and analgesic drugs, one of the active ingredients of which is caffeine, and the main ingredient in coffee is also caffeine, which has an excitatory effect on the nervous system, and will cause the nerves to be in a state of excitement, leading to poor sleep or difficulty in falling asleep. You need to eat a light diet and have a regular routine while taking painkillers. The medication needs to be used under the supervision of a doctor.