MORPHINE

Pharmacokinetics

  • 90% a given dose is excreted in the urine; the remaining 10% is excreted in the feces.

Pharmacologic effects

CNS effects:

  • Dose-related analgesia.
  • patients taking morphine become euphoric (feel freedom for anxiety).
  • Morphine can treat all types of pain except itching.
  • Morphine produces meiosis by stimulating the Edinger-Westphal nucleus and pinpoint pupils are indicative of toxic dosage prior to asphyxia.
  • Morphine is a powerful respiratory depressant.

Autonomic effects: Cardiovascular effects: Histamine release: Spasmogenic effects:   Uses: 3As

Adverse effects

CNS:Z

  • Dysphoria, restlessness, hyperactivity and mental cloudiness can occur
  • Long-term chronic administration can result in physical dependence.
  • Increased intracranial tension.
  • Tolerance and dependence:
  • Physical dependence occurs within 24 hours if given /4 hours.

Respiratory: Depression is the most important effect and is dose dependent. Bronchoconstrictive action   Gastrointestinal: Nausea and constipation.   Genitourinary: Urine retention.   Allergic reactions: can occur and skin rashes are a common manifestation (due to histamine release).

Eye: Pinpoint pupils are a consistent finding in addiction.

CVS: Postural hypotension