Morphine
 NAME OF DRUG: Morphine h/PF, Duramorph, nfumorph, Morphine Sulfate, MS Contin, MSIR, Oramorph, Rescudose, Roxanol) |
| PHYSICAL CHARACTERISTICS: Morphine is a white crystalline powder. It is available by prescription in liquid or tablet form. |
| DOSAGE/OCCURRENCE/USAGE: Morphine is the primary constituent of opium. It was isolated as a pure alkaloid in 1803. It is typically administered by subcutaneous or intramuscular injection for the treatment of moderate to severe pain at an initial dose of 10 mg/70 kg. Although morphine is available for oral administration, its effects are diminished and unpredictable and therefore it is not commonly used. |
| BLOOD CONCENTRATIONS VS. DOSAGE: A single 10 mg dose administered intravenously produces an average initial serum concentration of 60 ng/mL which declines rapidly then levels off to a concentration of 3 ng/mL for up to 36 hours. An equivalent dose administered intramuscularly produces similar results, 70 ng/mL at 10 to 20 minutes and 20 ng/mL in 4 hours. The metabolite morphine -3-glucuronide appeared in serum within 20 minutes of administration and exceeded morphine concentrations after 2 hours. The plasma half-life of morphine in surgical patients averaged 1.08 hours in women and 2.9 hours in men. |
| URINE EXCRETION RATE: Up to 87% of a dose of morphine is eliminated in the 72 hour urine. Morphine glucuronide makes up 75% of the eliminated dose. Free morphine accounts for approximately 10% of the dose. Codeine that shows up in the urine following morphine administration is a result of the impurity of commercial morphine (0.04%). |
| METABOLITES: Morphine-3-glucuronide |
| TOXICITY: Symptoms or toxic effects of morphine usage include constriction of the pupils, constipation, urinary retention, nausea, vomiting, hypothermia, drowsiness, dizziness, apathy, confusion, respiratory depression, hypotension, cold clammy skin, coma, and pulmonary edema. In nontolerant adults, doses greater than 30 mg by subcutaneous or intramuscular injection, or 100 mg administered orally are toxic. A dose of 120 mg or more can be fatal. Morphine itself is not usually used by addicts in the U.S. |
| REFERENCES: Baselt RC. Disposition of Toxic
Drugs and Chemicals in Man, Second Edition. Davis, Calif.: Biomedical Publications, 1982. Clarke EGC. Isolation and Identification of Drugs. London: The Pharmaceutical Press, 1969. Goldberger, Bruce A. Opiates Abused Drugs Monograph Series. Ed. Caplan, Yale H. Irving: Abbott Laboratories, 1994. |