morphine and antispasmodics

N02AG01

Forms & Strengths

Fixed-dose combination products containing an opioid analgesic (morphine) and antispasmodic agents (e.g., belladonna alkaloids, drotaverine, or hyoscine depending on the regional formulation)

Adult Dosing

Dosing must be individualized based on severity of pain, spasm, patient response, and prior opioid exposure
Typically administered orally or rectally as combination tablets, capsules, or suppositories
Administered every 4 to 6 hours as needed for severe visceral pain accompanied by smooth muscle spasm

Pediatric Dosing

Safety and efficacy in pediatric patients have not been established
Use is generally not recommended in children due to the risk of opioid toxicity and anticholinergic adverse effects

Indications

Management of moderate to severe acute visceral pain associated with smooth muscle spasm (e.g., biliary colic, renal colic, gastrointestinal spasm)

Mechanism of Action

Morphine acts as an agonist at mu-opioid receptors in the central nervous system, altering the perception of and response to pain
Antispasmodic component acts directly on smooth muscle or via anticholinergic/antimuscarinic pathways to relieve spasms of the gastrointestinal, biliary, or urinary tracts

Contraindications

Hypersensitivity to morphine, antispasmodic agents, or any component of the formulation
Significant respiratory depression
Acute or severe bronchial asthma or hypercapnia
Known or suspected paralytic ileus or GI obstruction
Angle-closure glaucoma, urinary tract obstruction, or severe hepatic impairment (due to antispasmodic/anticholinergic components)

Adverse Reactions

Central nervous system depression, sedation, dizziness, confusion
Respiratory depression
Constipation, nausea, vomiting, dry mouth
Urinary retention, blurred vision, tachycardia (anticholinergic effects from antispasmodic)
Hypotension, orthostatic hypotension
Risk of dependence, abuse, and tolerance with prolonged use

Drug Interactions

Central nervous system depressants (alcohol, sedatives, hypnotics, anxiolytics, other opioids) increase risk of profound sedation, respiratory depression, coma, and death
Anticholinergic drugs may exhibit additive anticholinergic toxicity (e.g., severe dry mouth, constipation, urinary retention, confusion)
Monoamine oxidase inhibitors (MAOIs) may precipitate severe unpredictable potentiation or serotonin syndrome
Cytochrome P450 inhibitors or inducers may alter the metabolism of the opioid component

Curated Content: Needs Vetting Before Put to Clinical Use