Table 21

Morphine rectal

Morphine rectal
What is it?Opioid analgesic
Mechanism of actionMu opioid receptor antagonist
Starting doseIR suppository 10 mg PR as required, maximum 2 hourly; conversion oral 1:rectal 1
Time to effect45–60 min17
FormulationImmediate release—suppositories are available as a specials order; when prescribing ‘Both the strength of the suppositories and the morphine salt contained in them must be specified by the prescriber.’16
Modified release—Morphine MST Continus tablets given rectally
IndicationModerate to severe pain, breathlessness
Common adverse effects‘Appetite decreased; asthenic conditions; gastrointestinal discomfort; insomnia; neuromuscular dysfunction’16
Contraindications‘Acute abdomen; delayed gastric emptying; heart failure secondary to chronic lung disease; phaeochromocytoma’16
CautionSee for Drug Driving advice
LicencingSuppository licensed; rectal use of modified release tablets is an off licence use
BenefitsA transmucosal alternative to oral or subcutaneous morphine
RisksUnpredictability of bioavailability when rectal route used, ‘Delayed absorption of rectal morphine has contributed to respiratory arrest in infants.’3
Cost£19.45 for 12×10 mg suppositories; £5.20 for 60×10 mg modified release tablets