morphine sulphate (Astramorph®, others)
Opioid analgesic
Morphine sulfate is a natural opium alkaloid that increases peripheral venous capacitance and decreases venous return ("chemical phlebotomy"). It promotes analgesia, euphoria, and respiratory and physical depression.
Secondary pharmacologic effects of mophine include depressed responsiveness of alpha adrenergic receptors (producing peripheral vasodilation) and baroreceptor inhibition. In addition, because morphine decreases both preload and afterload, it may decrease myocardial oxygen demand. The properties of this medication make it extremely useful in emergency care.
Morphine is a Schedule II drug.
< 1 minute
2-7 hours
Chest pain associated with myocardial infarction/ischemia
Pulmonary edema, with or without associated pain
Moderate to severe acute and chronic pain
Hypersensitivity to narcotics
Hypovolemia
Hypotension
Head injury or undiagnosed abdominal pain
Patients who have taken MAO inhibitors within 14 days.
Hypotension
Tachycardia or bradycardia
Palpitations
Syncope
Facial flushing
Respiratory depression
Euphoria
Bronchospasm
Allergic reaction.
CNS Depressants may potentiate effects of morphine
Chlorpromazine may potentiate analgesia
MAO inhibitors may cause paradoxical excitation
Various packages including tablets, suppositories, and solution. In emergency care, morphine sulfate is usually administered IV.
Parenteral preparations are available in may strenghts. A common preparation is 10mg in 1 ml ampules and Tubex syringes.
IV: 1-3 mg slow push over 1-5 minutes. Repeat in 5 - 10 minute intervals, titrated to relief of pain.
IV: 0.1 – 0.2 mg/kg , max 15 mg dose
Pregnancy Safety: Category
Narcotics rapidly cross the placenta
Safety in neonates has not been established
Use with caution in the elderly and those with asthma, and in those susceptible to CNS depression.
May worsen bradycardia or heart block in inferior MI (vagotonic effect)
Naloxone should be readily available