Morphine ADME

A – IV – rapid increase in drug concentration within the blood leading to the brain – faster route as no absorption phase – long lasting Oral – 40-50% of dose reaches CNS (30 mins for immediate release morphine, 90 mins extended release form) - Absorbed in the small intestine D – Liver, kidney, lungs or spleen, crosses BBB M – Metabolised in liver by demethylation and glucuronidation Metabolites = M6G, M3G, codeine, hydromorphone and normorphine Phase 1 and phase 2 by enzymes E – Metabolites eliminated via renal filtration - Elimination ½ life = 120 mins