Pethidine (Meperidine)

Pethidine (Meperidine) In Dogs & Cats: Uses, Dosage and Side Effects

Overview

• Analgesia is mediated by the mu-opioid receptor.

Uses of Pethidine (Meperidine)

• Management of mild to moderate pain.
• Incorporation into sedative and pre-anaesthetic medication protocols to provide improved sedation and analgesia.

Dose of Pethidine (Meperidine) in Dogs and Cats

Dogs:

• Analgesia: 2–10 mg/kg i.m., s.c. q1–2h depending on pain assessment.

Cats:

• Analgesia: 5–10 mg/kg i.m., s.c. q1–2h depending on pain assessment.

Side Effects of Pethidine (Meperidine) in Dogs and Cats

• Histamine released during i.v.  injection causes hypotension, tachycardia and bronchoconstriction.
• Histamine-mediated reactions may also occur after i.m. injection, resulting in local urticaria.
• Pethidine crosses the placenta and may exert sedative effects in neonates born to bitches treated before parturition.
• Severe adverse effects can be treated with naloxone.

Contraindications of Pethidine (Meperidine) in Dogs and Cats

• Do not give i.v.
• Not advisable to use in animals at risk from histamine release (e.g. some skin allergies,
  asthma, mast cell tumours).

Some Notes:

• Other CNS depressants (e.g. anaesthetics, antihistamines, barbiturates, phenothiazines and tranquillizers) may cause increased CNS or respiratory depression when used
  concurrently with narcotic analgesics.
• Pethidine may produce a serious interaction if administered with monoamine oxidase
  inhibitors (MAOIs).
• The mechanism of this interaction is not clear but effects include coma, convulsions and hyperpyrexia.
• Pethidine has a fast onset (10–15 min) and short duration (45–60 min) of action.
• Frequent redosing is required for analgesia.
• The short duration of action may be desirable in some circumstances (e.g. when rapid recovery is required or in animals with compromised liver function).
• It shares common opioid effects with morphine but also has anticholinergic effects, producing a dry mouth and sometimes an increase in heart rate.
• It causes less biliary tract spasm than morphine, suggesting that it may be useful for the management of pain in dogs and cats with pancreatitis.
• Due to the concentration of commercially available solutions, the injection volume can be 2–3 ml in large dogs, which can cause pain on i.m. injection.