You have on hand morphine 500 mg in 500 ml normal saline. You need to administer morphine 80 mg/hour in a continuous iv infusion to a patient with terminal cancer pain. How many ml per hour will you set on the infusion pump?
Answers
Hypersensitivity to the active substance or to any of the excipients listed in section 6.1
Respiratory depression or insufficiency
Obstructive airways disease
Cerebral trauma
Increased intracranial pressure
Coma
Convulsive disorders
Acute alcoholism
Renal failure
Ureteral stenosis
Pancreatitis
Liver failure
Gall-bladder dysfunction
Ileus
Inflammatory bowel disease
Hypotension with hypovolaemia
Prostatic hypertrophy
Myxoedema
Phaeochromocytoma
Concurrent administration of MAO inhibitors or within two weeks of discontinuation of their use.
4.4 Special warnings and precautions for use
Risk from concomitant use of sedative medicines such as benzodiazepines or related drugs
Concomitant use of morphine and sedative medicines such as benzodiazepines or related drugs may result in sedation, respiratory depression, coma and death. Because of these risks, concomitant prescribing with these sedative medicines should be reserved for patients for whom alternative treatment options are not possible. If a decision is made to prescribe morphine concomitantly with sedative medicines, the lowest effective dose should be used, and the duration of treatment should be as short as possible.
The patients should be followed closely for signs and symptoms of respiratory depression and sedation. In this respect, it is strongly recommended to inform patients and their caregivers to be aware of these symptoms (see section 4.5).
Dependence and withdrawal (abstinence) syndrome
Use of opioid analgesics may be associated with the development of physical and/or psychological dependence or tolerance. The risk increases with the time the drug is used, and with higher doses. Symptoms can be minimised with adjustments of dose or dosage form, and gradual withdrawal of morphine. For individual symptoms, see section 4.8. However, when doses of morphine are carefully titrated against pain, clinically significant respiratory depression, dependence, rapid tolerance and euphoria rarely develop. If patients no longer require morphine for relief of pain, doses should be gradually reduced in order to prevent withdrawal symptoms. Clinically significant tolerance to morphine is unusual in cancer patients with severe pain.
Hypotension, hypothyroidism, asthma (avoid during attack), and decreased respiratory reserve; pregnancy and breast-feeding; may precipitate coma in hepatic impairment (reduce dose but many such patients tolerate morphine well); reduce dose in renal impairment, elderly and debilitated (reduce dose); dependence (severe withdrawal symptoms if withdrawn abruptly).
Acute chest syndrome (ACS) in patients with sickle cell disease (SCD)
Due to a possible association between ACS and morphine use in SCD patients treated with morphine during a vaso-occlusive crisis, close monitoring for ACS symptoms is warranted.
Adrenal insufficiency
Opioid analgesics may cause reversible adrenal insufficiency requiring monitoring and glucocorticoid replacement therapy. Symptoms of adrenal insufficiency may include e.g. nausea, vomiting, loss of appetite, fatigue, weakness, dizziness, or low blood pressure.
Decreased Sex Hormones and increased prolactin
Long-term use of opioid analgesics may be associated with decreased sex hormone levels and increased prolactin. Symptoms include decreased libido, impotence or amenorrhea.
Hyperalgesia
Hyperalgesia that does not respond to a further dose increase of morphine may occur in particular in high doses. A morphine dose reduction or change in opioid may be required.
Abuse potential
Morphine has an abuse potential similar to other strong agonist opioids, and should be used with particular caution in patients with a history of alcohol or drug abuse.
Rifampicin
Plasma concentrations of morphine may be reduced by rifampicin. The analgesic effect of morphine should be monitored and doses of morphine adjusted during and after treatment with rifampicin (see section 4.5).
Sodium content
This medicine contains less than 1 mmol sodium (23 mg) per each 1 ml ampoule, that is to say essentially 'sodium-free'.