Sign Out
Pharmacotherapeutic Group: Analgesics, opioids, natural opium alkaloids, morphine. ATC Code: N02AA01.
Pharmacology: Pharmacodynamics: Morphine binds to specific receptors located in the CNS and in various peripheral organs. Pain sensation and affective reaction to the pain is reduced by interaction with CNS receptors.
Pharmacokinetics: Absorption: Following oral application morphine sulfate pentahydrate is absorbed rapidly from the gastrointestinal tract.
Two thirds of an oral dose is absorbed with the maximum analgesic effect occurring after 60 minutes. However, the effect of a given dose is variable. The time curve is often long by the oral route and peak plasma levels are reached after approximately 2-3 hour following application of morphine solution with large inter-subject variability.
Distribution and biotransformation: Morphine crosses the blood brain barrier but distributes into all tissues.
Metabolism occurs in the bowel and in the liver leading to the formation of morphine glucuronides with morphine-6-glucuronide probably being pharmacologically active.
Elimination: About 10% of a dose of morphine is excreted through the bile in to the faeces. The remainder as conjugates or free morphine is excreted via glomerular filtration in the urine. Small quantities are excreted in breast milk and sweat.
About 90% of a single dose of morphine is excreted in 24 hours with traces up to 48 hours.
Toxicology: Preclinical safety data: In male rats, reduced fertility and chromosomal damage in gametes have been reported.
