Mst Continus (Morphine Sulfate)

Morphine sulfate is an opioid analgesic used to manage pain through central nervous system pathways.

• Moderate to severe acute pain: provides rapid analgesia for short‑term painful episodes.
• Chronic cancer pain: offers sustained relief for ongoing malignant pain.
• Post‑operative pain: reduces pain after surgical procedures.
• Severe chronic non‑cancer pain: used when other analgesics are insufficient.
• Palliative care pain: helps improve comfort in end‑of‑life patients.

• Morphine sulfate acts as a full agonist at mu‑opioid receptors in the central nervous system. Binding to these G‑protein‑coupled receptors inhibits adenylate cyclase activity, reduces calcium influx, and increases potassium efflux, which diminishes neuronal excitability and blocks transmission of nociceptive signals, resulting in analgesia.

Morphine sulfate may cause a range of adverse reactions, varying from mild to life‑threatening.

Common Side Effects

• Nausea: feeling of sickness often accompanied by an urge to vomit.
• Constipation: reduced bowel movements due to decreased gastrointestinal motility.
• Drowsiness: increased sleepiness or reduced alertness.
• Dry mouth: reduced salivation leading to a parched sensation.

Serious or Rare Side Effects

• Respiratory depression: slowed or shallow breathing that can be fatal.
• Severe hypotension: marked drop in blood pressure causing dizziness or fainting.
• Dependence or addiction: development of physical or psychological reliance on the drug.

When prescribing morphine sulfate, clinicians should consider several safety measures.

• Assess pain severity: confirm that opioid therapy is appropriate for the level of pain.
• Evaluate respiratory function: monitor for signs of respiratory compromise before and during treatment.
• Monitor for dependence: watch for signs of tolerance, misuse, or addiction.
• Adjust dose in organ impairment: reduce dosage in patients with hepatic or renal dysfunction.
• Avoid in known hypersensitivity: do not use if the patient has a documented allergy to morphine or other opioids.
• Store at ambient temperature: keep in the original pack, protect from moisture.

Morphine sulfate can interact with other medicines, altering its efficacy or safety.

Major Interactions (Avoid)

• Monoamine oxidase inhibitors (MAOIs): risk of severe serotonin syndrome.
• Central nervous system depressants (e.g., benzodiazepines): additive respiratory depression.
• Other opioids: increased risk of overdose and profound sedation.

Moderate Interactions (Monitor Closely)

• CYP3A4 inhibitors (e.g., ketoconazole): may raise morphine plasma levels.
• Diuretics: can enhance hypotensive effects when combined with morphine.