Class: Opioid Analgesic. C-II
Dosage Forms. Tablet, Extended Release: 15 mg, 30 mg, 60 mg, 100 mg, 200 mg; Capsule, Extended Release: 10 mg, 20 mg, 30 mg, 40 mg, 50 mg, 70 mg, 80 mg, 100 mg, 130 mg, 150 mg, 200 mg; Capsule, Extended Release, 24-h Dosing: 30 mg, 45 mg, 60 mg, 75 mg, 90 mg, 120 mg
Common FDA Label Indication and Dosing.
1. Pain, chronic, moderate to severe: 10-20 mg po q12h, titrate to response
Off-Label Uses. None
MOA. Morphine is pure mu agonist. Mu receptors are responsible for analgesia, respiratory depression, miosis, decreased GI motility, and euphoria. In the CNS, it promotes analgesia and respiratory depression by decreasing brain stem respiratory centers’ response to carbon dioxide tension and electrical stimulation. It also decreases gastric, biliary, and pancreatic secretion, induces peripheral vasodilation, and promotes opioid-induced hypotension due to histamine release.
Drug Characteristics: Morphine ER
Medication Safety Issues: Morphine ER
Drug Interactions: Morphine ER
Adverse Reactions: Morphine ER
Efficacy Monitoring Parameters. Relief of pain.
Toxicity Monitoring Parameters. Excessive drowsiness, decreased breathing, severe constipation, chest pain, dizziness, vital signs.
Key Patient Counseling Points. Use a stool softener and stimulant or laxative for preventing constipation. May cause drowsiness; avoid driving or other tasks requiring motor coordination. Avoid alcohol and other CNS depressants.
Clinical Pearls. Tolerance and physical dependence may occur with chronic use; avoid abrupt discontinuation. Extended-release products must not be crushed or chewed. Crushing or chewing will release the total dose of morphine at once and increase risk of respiratory depression. Extended-release products are not for use in children. Fatal respiratory depression has occurred; highest risk at initiation and with dosage increases. Avinza capsules are a modified-release formulation of morphine sulfate indicated for once daily administration; other extended-release products are for q12h administration Do not administer Avinza with alcoholic beverages or ethanol-containing products, which may disrupt extended-release characteristic of product. Highly concentrated oral solutions are available. Check doses carefully when using highly concentrated oral solutions. The 100 mg/5 mL (20 mg/mL) concentration is indicated for use in opioid-tolerant patients only.