reserpine inhibits the analgesic action of morphine. veratrum alkaloids may have additive effects, particularly on respiratory depression, when administered concurrently withmorphine. atropineantagonizes morphine respiratory depression. levallorphan and nalorphine antagonize morphine actions,principally the respiratory depression.

algesic effects and increasingly higher doses of morphine are required to produce analgesia. the higher morphine doses produce significant and often life-threatening side effects (see “ adverse reactions ”). the peak and trough effects produced by intermittent administration cause fluctuations in pain control. repeated i.m. injections are frequently unacceptable due to the lack of muscle mass in the debilitated patient, the tendency for bruising and bleeding at the injection site, and the anxiety and pain associated with the injection. continuous i.v. infusion of morphine (see “ dosage and administration ”) has been employed as an alternative to the traditional modes of administration. lower doses of morphine produce uniform pain control because a steady morphine concentration is maintained. titration of the dosage to the patient’s needs is easily achieved by adjusting the infusion rate. the lag time between the patient’s request for pain medication and administration of the dose and the amount of nursing time necessary for preparation and administration of frequent doses are reduced. the degree of respiratory depression and sedation may be decreased, and the anxiety experienced by the patient in anticipation of i.m. administration is avoided. some investigators feel that tolerance to the analgesic effects may develop more slowly with continuous i.v. infusion. in addition to analgesia, the drug may relieve anxiety and reduce left ventricular work by reducing preload pressure. morphine is also used in the therapy of dyspnea associated with acute left ventricular failure and pulmonary edema. care must be taken to avoid inducing respiratory depression in such patients. for open-heart surgery, especially in high risk patients with cardiac disease, some anesthesiologists use morphine to produce anesthesia.

s do not develop drug seeking behavior or compulsive drug use. personality characteristics play a major role in determining which patients are likely to abuse drugs. morphine should be used only if other drugs with fewer hazards are inadequate, and with the recognition of the possibility that it may mask significant manifestations of disease which should be identified for proper diagnosis and treatment.

morphine and its capacity to elevate cerebrospinal fluid pressure may be markedly exaggerated in the presence of head injury, brain tumor, other intracranial lesions, or a preexisting increase in intracranial pressure. furthermore, narcotics produce adverse reactions which may obscure the clinical course of patients with head injuries. asthma and other respiratory conditions – the use of bisulfites is contraindicated in asthmatics. bisulfites and morphine may potentiate each other, preventing use by causing severe adverse reactions. use with extreme caution in patients having an acute asthmatic attack, patients with chronic obstructive pulmonary disease or cor pulmonale, patients with a substantially decreased respiratory reserve, and patients with preexisting respiratory depression, hypoxia or hypercapnia. in such patients, even usual therapeutic doses of narcotics may decrease respiratory drive while simultaneously increasing airway resistance to the point of apnea. hypotensive effect – administration may result in severe hypotension in the postoperative patient or in any individual whose ability to maintain blood pressure has already been compromised by a depleted blood volume or concurrent administration of drugs such as phenothiazines or general anesthetics. narcotics may produce orthostatic hypotension in ambulatory patients. supraventricular tachycardias – caution should be used in patients with atrial flutter and other supraventricular tachycardias due to a possible vagolytic action which may produce a significant increase in the ventricular response rate. acute abdominal conditions – the administration of morphine or other narcotics may obscure the diagnosis or clinical course in patients with acute abdominal conditions. use also with caution in patients with gastrointestinal hemorrhage, ulcerative colitis, or recent gi or urinary tract surgery. special-risk patients – caution must be exercised in elderly and debilitated patients and in patients who are known to be sensitive to cns depressants, including those with cardiovascular or pulmonary disease, myxedema, acute alcoholism, delirium tremens, cerebral arteriosclerosis, emphysema, fever, bronchial asthma, kyphoscoliosis, addison’s disease, prostatic hypertrophy or urethral stricture, toxic psychosis. renal and hepatic dysfunction – morphine may have a prolonged duration and cumulative effect in patients with renal or hepatic dysfunction. convulsions – morphine may aggravate preexisting convulsive disorders. convulsions may occur in individuals without a history of convulsive disorders if dosage is substantially escalated above recommended levels because of tolerance development.

administeredby i.v. push to alleviate pain. the infusion dosage range is 0.8 mg/hr to 80 mg/hr, though doses of up to 144 mg/hr have been used. thus, for the 1 mg/ml solution, the infusion may be run from 0.8 ml/hr to 80 ml/hr, and for the 0.5 mg/ml solution, the infusion may be run from 1.6 ml/hr to 160 ml/hr. a constant infusion rate must be maintained with an infusion pump in order to assure proper dosage control. care must be taken to avoid overdosage (respiratory depression) or abrupt cessation of therapy, which may give rise to withdrawal symptoms. note: parenteral drug products should be inspected visually for particulate matter and discoloration prior to administration, whenever solution and container permit.

patients with chronic ulcerative colitis may experience increased colonic motility; toxic dilatation has been reported in patients with acute ulcerative colitis. cardiovascular: flushing of the face, peripheral circulatory collapse, tachycardia, bradycardia, palpitation, faintness, hypotension, syncope, and phlebitis following i.v. injection. genito-urinary: ureteral spasm and spasm of vesical sphincters, urinary retention or hesitancy, oliguria, antidiuretic effect, reduced libido and/or potency. allergic: pruritus, urticaria, other skin rashes, edema, and (rarely) hemorrhagic urticaria. wheal and flare over the vein with i.v. injection may occur. anaphylactoid reactions have been reported following i.v. administration. an isolated case of thrombocytopenia has been reported to be induced by morphine.

reserpine inhibits the analgesic action of morphine. veratrum alkaloids may have additive effects, particularly on respiratory depression, when administered concurrently withmorphine. atropineantagonizes morphine respiratory depression. levallorphan and nalorphine antagonize morphine actions,principally the respiratory depression.

binding sites or receptors in the brain and other tissues. morphine is about two-thirds absorbed from the gastrointestinal tract with the maximum analgesic effect occurring 60 minutes post administration. onset of analgesia following intramuscular or subcutaneous administration occurs within 10 to 30 minutes. the effect persists for 4 to 5 hours. approximately 90% of a parenteral dose of morphine appears in the urine within 24 hours as the product of glucuronide conjugation. most of the remainder is excreted in the bile and eliminated in the feces.