Drug Guide

Generic Name

Morphine Sulfate

Brand Names Duramorph Pf, Infumorph, Ms Contin, Oramorph Sr, Morphine Sulfate (autoinjector), Kadian, Avinza, Depodur, Astramorph Pf, Mitigo, Morphabond Er, Arymo Er

Classification

Therapeutic: Analgesic, Opioid

Pharmacological: Mu-opioid receptor agonist

FDA Approved Indications

Moderate to severe pain management

Mechanism of Action

Binds to mu-opioid receptors in the central nervous system, altering the perception of and response to pain.

Dosage and Administration

Adult: Dose varies based on severity; typically 10-30 mg every 4 hours as needed, titrated to response.

Pediatric: Dosing based on weight and severity; consult specific pediatric guidelines.

Geriatric: Start with lower doses due to increased sensitivity; titrate carefully.

Renal Impairment: Use cautiously; adjust doses as needed.

Hepatic Impairment: Use cautiously; start with lower doses; monitor closely.

Pharmacokinetics

Absorption: Well absorbed IM, subcutaneously, and orally.

Distribution: Widely distributed; crosses the blood-brain barrier.

Metabolism: Primarily hepatic via conjugation.

Excretion: Renal excretion of metabolites.

Half Life: 2-4 hours in typical adult dosing, variable with formulation.

Contraindications

Significant respiratory depression
Acute or severe bronchial asthma

Precautions

Use with caution in patients with head injury, dehydration, or CNS depression; addiction history; monitor respiratory and sedation levels closely.

Adverse Reactions - Common

Respiratory depression (Serious)
Sedation (Common)
Nausea (Common)
Vomiting (Common)

Adverse Reactions - Serious

Hypotension (Less common)
Circulatory depression (Less common)
Confusion (Common)
Addiction, abuse, and misuse (Serious)

Drug-Drug Interactions

CNS depressants (e.g., benzodiazepines, alcohol) increase risk of respiratory depression
MAO inhibitors can cause excitation, seizures, or severe hypotension

Drug-Food Interactions

Alcohol may potentiate CNS depression

Drug-Herb Interactions

N/A

Nursing Implications

Assessment: Monitor pain relief, respiratory rate, level of consciousness, sedation, blood pressure.

Diagnoses:

Risk for respiratory depression
Impaired comfort

Implementation: Administer cautiously, observe for signs of overdose, titrate dose to pain relief.

Evaluation: Assess pain relief effectiveness and monitor for adverse effects.

Patient/Family Teaching

Do not operate heavy machinery or perform hazardous tasks while on medication.
Avoid alcohol and CNS depressants.
Report signs of respiratory depression, excessive sedation, or allergic reactions.

Special Considerations

Black Box Warnings:

Addiction, abuse, and misuse can lead to overdose and death.
Life-threatening respiratory depression.

Genetic Factors: Genetic variations may influence metabolism (e.g., CYP2D6 activity).

Lab Test Interference: May interfere with certain drug screening tests, causing false positives or negatives.

Overdose Management

Signs/Symptoms: Respiratory depression, sedation, pinpoint pupils, unconsciousness.

Treatment: Administer naloxone promptly; supportive measures include maintaining airway, ventilation, and cardiovascular support.

Storage and Handling

Storage: Store at room temperature away from light and moisture.

Stability: Stable when stored properly; check specific product labeling for expiry details.