The modes of administration for morphine include, oral, intravenous, intrathecal, epidura

The modes of administration for morphine include, oral, intravenous, intrathecal, epidural, subQ, and rectal. It is also abused through inhalation. However, the most convenient route is IV. The drug is distributed in blood with a peak plasma half-life of 20 minutes. Its metabolism occurs in the liver through the Cytochrome P450 enzymes of phase I and glucuronidation to form morphine-3-glucuronide (M3G) and morphine-6-glucuronide (M3G) during phase II reactions (Ebadi 20). The phase II reactions are catalyzed by the enzyme, UDP-glucuronosyl transferase-2B7 located in the mitochondria of the hepatocytes. Consequently, a single dose of morphine yields about 60% of M3G and 10% M6G. The process of morphine metabolism can also be facilitated in the brain and kidneys. About 87% of the metabolized morphine is excreted through urine. Therefore, the elimination half-life of morphine is about 120 minutes (Ebadi 22).