[Drugs for relief of pain]

Currently, the pharmacology of analgesics can be sum up to three main compounds: morphine, paracetamol and aspirin. The use of antidepressants and anticonvulsants will also be mentioned. Morphine remains the reference compound among centrally acting analgesics both for acute and chronic pain. Its mechanism of action is relatively well known as well as the role of opiate receptors. Paracetamol is largely used as analgesic for relief of slight to moderate pain. Its mechanism of action still remains unclear. Usually the tolerability of this compound is considered as being excellent. However overdosage can induce severe and possible lethal liver necrosis. Aspirin is also a very old and a largely used compound. Its inhibiting effect on cyclooxygenase acts mainly peripherally but it could also act centrally. According to the current knowledge of its mechanism of action, it seems that the main pharmacological properties as well as adverse events of aspirin are all related to its enzyme inhibiting effect. Slight to moderate pain, related or not to inflammatory disease responds well to aspirin and other NSAIDs.