The duration of pain medication maintenance is highly dependent on an individual’s constitution and sensitivity to the medication. It usually ranges from a few hours to tens of hours. Different painkillers, maintenance time is not the same, the general maintenance time of painkillers in about 6 to 12 hours. Such as clinically used ibuprofen, celecoxib, flurbiprofen ester and so on. Such drugs have a weak pain-relieving effect, short duration, and are generally less likely to become addictive. If the pain is more intense, you can use morphine, oxycodone, pethidine, etc., such drugs belong to the opioid class, long-term use is prone to addiction. Fentanyl transdermal patch belongs to the strong opioid drug preparation, suitable for moderate and severe cancer pain, the duration of action up to 72 hours. Painkillers, especially opioid painkillers, are strictly controlled by the state, and need to be prescribed by professional physicians and used in strict compliance with medical advice. It should not be used blindly on its own to avoid serious adverse consequences.