THE MAJOR HAZARDS OF MORPHINE, AS OF OTHER NARCOTIC ANALGESICS, ARE RESPIRA-TORY
DEPRESSION AND, TO A LESSER DEGREE, CIRCULATORY DEPRESSION, RESPIRATORY ARREST, SHOCK, AND CARDIAC ARREST HAVE OCCURRED.
The most frequently observed adverse reactions include lightheadedness, dizziness,
sedation, nausea, vomiting, and sweating. These effects seem to be more prominent
in ambulatory patients and in those who are suffering severe pain. In such individuals,
lower doses are available. Some adverse reactions may be alleviated in the ambulatory
patient if he lies down.
Other adverse reactions include the following
Central Nervous System: Euphoria, dysphoria, weakness, headache, insomnia,
agitation, disorientation, and visual disturbances.
Gastrointestinal: Dry mouth, anorexia, constipation, and biliary tract
Cardiovascular: Flushing of the face, bradycardia, palpitation, faintness
Allergic: Pruritus, urticaria, other skin rashes, edema, and, rarely
Treatment of the most frequent adverse reactions
Ample intake of water or other liquids should be encouraged. Concomitant administration
of a stool softener and a peristaltic stimulant with the narcotic analgesic
can be an effective preventive measure for those patients in need of therapeutics.
If elimination does not occur for two days, an enema should be administered
to prevent impaction.
In the event diarrhea occurs, seepage around fecal impaction is a possible
cause to consider before antidiarrheal measures are employed.
Nausea and Vomiting
Phenothiazines and antihistamines can be effective treatments of nausea of
the medullary and vestibular sources respectively. However, these drugs may
potentiate the side effects of the narcotic or the antinauseant.
Once pain control is achieved, undesirable sedation can be minimized by titrating
the dosage to a level that just maintains a tolerable pain or pain free state.
Drug Abuse And Dependence
Morphine Sulfate, a narcotic, is a Schedule II controlled substance under the
Federal Controlled Substance Act. As with other narcotics, some patients may
develop a physical and psychological dependence on morphine. They may increase
dosage without consulting a physician and subsequently may develop a physical
dependence on the drug. In such cases, abrupt discontinuance may precipitate
typical withdrawal symptoms, including convulsions. Therefore the drug should
be withdrawn gradually from any patient known to be taking excessive dosages
over a long period of time.
In treating the terminally ill patient the benefit of pain relief may outweigh
the possibility of drug dependence. The chance of drug dependence is substantially
reduced when the patient is placed on scheduled narcotic programs instead of
a “pain to relief-of-pain” cycle typical of a PRN regimen.
Generally, effects of morphine may be potentiated by alkalizing agents and
antagonized by acidifying agents. Analgesic effect of morphine is potentiated
by chlorpromazine and methocarbamol. CNS depressants such as anaesthetics, hypnotics,
barbiturates, phenothiazines, chloral hydrate, glutethimide, sedatives, MAO
inhibitors (including procarbazine hydro-chloride), antihistamines, β-blockers
(propranolol), alcohol, furazolidone and other narcotics may enhance the depressant
effects of morphine.
Morphine may increase anticoagulant