Morphine

What it is used for

• As an analgesic
• As an analgesic
• For post-op pain
• For analgesia
• For analgesia
• For analgesia
• Epidural administration for pain control
• As a preanesthetic in critical patients
• For adjunctive treatment of cardiogenic pulmonary edema
• For analgesia
• For epidural (Adult horses)
• For epidural (Foals)
• For analgesia
• Epidural analgesia
• As a preanesthetic/analgesic (prior to chloralose, barbiturate)
• As an analgesic
• For sedation and analgesia (Rabbits)
• For post-op pain
• As a CRI for acute pain
• For acute pain
• For acute pain
• As a CRI for pain
• Epidural administration for pain control
• Epidural/Spinal administration for pain control
• Epidural administration for pain control
• As a premedicant with acepromazine
• As a preanesthetic in a healthy large breed dog
• Severe sedation/analgesia for minor surgical procedures
• As a preanesthetic in critical patients
• For adjunctive treatment of cardiogenic pulmonary edema
• For treatment of hypermotile diarrhea
• As an antitussive

How it is given

Possible side effects

• Histamine release (hypotension, vasodilation)
• Respiratory depression
• Bronchoconstriction
• CNS depression (dogs, primates) or excitation (cats, horses, ruminants)
• Physical dependence (with chronic use)
• Hyperthermia (cattle, goats, horses, cats)
• Hypothermia (dogs, rabbits)
• Nausea and vomiting
• Decreased intestinal peristalsis and constipation
• Initial defecation (dogs)
• Panting (dogs)
• Bradycardia or tachycardia
• Histamine release (if given rapidly IV)
• Vomiting (common in non-painful pre-operative patients)
• Transient excitation (IV administration)
• Respiratory depression (especially under general anaesthesia)
• Constriction of gastrointestinal sphincters (e.g., pyloric sphincter)
• Reduction in gastrointestinal motility (with prolonged use)
• Neonatal sedation (crosses the placenta)

Cautions & contraindications

• Hypersensitivity to narcotic analgesics
• Patients receiving monoamine oxidase inhibitors (MAOIs)
• Diarrhea caused by a toxic ingestion (until toxin is eliminated)
• Scorpion envenomation (Centruroides spp. - potentiates venom)
• Conditions where vomiting is contraindicated (e.g., raised intraocular pressure)
• **Extreme Caution:** Patients with head injuries, increased intracranial pressure, acute abdominal conditions (e.g., colic - may mask clinical signs), and respiratory disease or acute respiratory dysfunction. **Caution:** Hypothyroidism, severe renal insufficiency (acute uremia), adrenocortical insufficiency (Addison's), and geriatric or severely debilitated patients. > **Important Notes:** > * **IV Administration:** Must be given slowly to avoid significant hypotension and histamine release. > * **Envenomation:** Avoid in envenomation situations, as clinical signs associated with histamine-release can be confused with anaphylaxis. > * **Uremia:** Because of its effects on vasopressin (ADH), urine flow can decrease by up to 90% in dogs given large doses.

Drug interactions

• CNS Depressants (anesthetics, antihistamines, phenothiazines, barbiturates): May cause increased CNS or respiratory depression when used with morphine.
• Diuretics: Opiates may decrease diuretic efficacy in congestive heart failure patients.
• Monoamine Oxidase Inhibitors (MAOIs, e.g., amitraz, selegiline): Use with extreme caution; contraindicated in humans due to risk of severe opiate overdose signs.
• Skeletal Muscle Relaxants: Morphine may enhance neuromuscular blockade.
• Tricyclic Antidepressants (clomipramine, amitriptyline): Morphine may exacerbate the effects of tricyclic antidepressants.
• Warfarin: Opiates may potentiate anticoagulant activity.
• CNS depressants (anaesthetics, antihistamines, barbiturates, phenothiazines, tranquillizers): Increased CNS or respiratory depression

Frequently asked questions