[Clinical pharmacology of analgesics].

The orthopedist can choose from three classes of drugs to relieve pain. Nonsteroidal anti-inflammatory drugs (NSAID) possess sufficient analgetic efficacy, but they are hampered by often causing gastrointestinal pain and bleeding. Opioids are strong analgetics that can be successfully used against strong pain. Their use is limited by spasms in both the gastrointestinal and the urinary tract causing constipation and retention of urine, respectively. A particular problem is respiratory depression that may be the ultimate cause of death in severely ill patients.Among nonacidic analgetics derivatives of pyrazole (e.g. dipyrone = metamizole) may also be used in situations associated with strong pain. Because of the risk of damage to white blood cells leading to agranulocytosis with foudroyant infections their use should be strictly limited to conditions that justify such a risk like tumor or colic pain. The aniline derivative acetaminophen (= paracetamol) is well tolerated and is the drug of choice in usual common pain. Large doses are to be avoided because of liver damage, especially in children.