Morphine

A. Acute opioid (or morphine) toxicity:

Symptoms and signs: The patient is comatosed with depressed respiration, pin point pupils, hypotension, pulmonary oedema ((with no relation of heart)) and shock may occur.

When death occurs, it is always due to respiratory failure.   Treatment: If large amounts are taken orally, gastric lavage is done with potassium permnganate solution.

Establish a patent airway and ventilate the patient by positive pressure ventilation if pulmonary oedema is present.

Opioid antagonists as: Naloxone:

  • Naloxone is a pure antagonist to opiates.
  • Can produce dramatic reversal of the respiratory depression.
  • It is given in a dose of 0.4 - 0.8 mg and repeated every 2 - 3 minutes for 2 - 3 doses.
  • Care should be taken as the antagonist may precipitate a severe withdrawal syndrome if a current addict of morphine.

Nalorphine: Agonist-antagonist like nalorphine can be used only when the diagnosis of morphine poisoning is certain (its agonist effect aggravates respiratory depression).  

B. Chronic opioid (or morphine) toxicity (addiction)

It results from addiction. The patient is emaciated, constipated with frequent flushes and itching. The intellectual functions are also depressed.

Withdrawal: severe sympathetic overactivity It results in what is called the abstinence syndrome where the patient becomes irritable, nervous, having tremors, hypertension, sweating, vomiting and with abdominal cramps.

These manifestations usually start 6-10 hours from last dose and peak effect are seen at 36-48 hours, after which manifestations gradually subside over 5-10 days.

  • In severe cases cardiovascular collapse and death may occur.

Tre atment of morphine addiction:

  • Hospitalization.
  • Gradual withdrawal is essential otherwise acute abstinence syndrome may occur. This is with replacement by the synthetic morphine substitute methadone then when stabilized on methadone, its dose should be gradually decreased to an end.
  • Clonidine; due sympathetic overactivity
  • Sedative can be used
  • Naltrexone (pure antagonist); ((may advertise otherwise - central multivitamin, just to deter patient from usage of morphine))