Tramadol

Tramadol In Dogs & Cats: Uses, Dosage and Side Effects

Overview

• Metabolites of tramadol act as agonists at all opioid receptors, especially mu receptors.
• The parent compound inhibits noradrenaline and serotonin (5-HT) reuptake, and stimulates pre-synaptic 5-HT release.
• This provides an alternative analgesic pathway involving descending inhibitory pathways within the spinal cord.
• In humans, individuals metabolize tramadol differently, with “good metabolizers” experiencing more opioid-like effects and improved analgesia.
• Whether similar metabolic differences exist in cats and dogs is currently uncertain.

Uses of Tramadol

• Chewable tablets are approved for managing mild acute and chronic soft tissue and musculoskeletal pain in dogs.
• Injectable tramadol is used perioperatively in dogs for acute pain instead of opioids.
• Epidural administration of tramadol in dogs has been attempted, but no clear advantages over systemic administration have been observed.

Dose of Tramadol in Dogs and Cats

Dogs:

• 2–5 mg/kg p.o. q8h, 2 mg/kg i.v.

Cats:

• 2–4 mg/kg p.o. q8h, 1–2 mg/kg i.v., s.c.

Side Effects of Tramadol in Dogs and Cats

• Sedation is possible in dogs with high doses; dysphoria is more common in cats.
• Contraindicated in humans with epilepsy.
• Owners should be informed of a slightly increased risk of seizures in treated animals.

Contraindications of Tramadol in Dogs and Cats

• No information is available.

Some Notes:

• There is increasing literature on pharmacokinetics (PK) and pharmacodynamics (PD) in dogs and cats, but the recommended dose range is largely empirical due to limited combined PK/PD studies.
• PK of sustained-release tramadol tablets investigated in dogs; low plasma concentrations of tramadol and metabolites suggest once-daily dosing unsuitable for analgesia in dogs.
• Tramadol 2 mg/kg provides equivalent analgesia to morphine 0.2 mg/kg i.v. in dogs post-ovariohysterectomy; effective dosing for acute pain management in cats and dogs is 3–4 times daily.
• Tramadol is similar to morphine in action but causes less respiratory depression, sedation, and GI side effects; suitable for oral administration, making it attractive for chronic pain management.
• Cats are more susceptible to tramadol’s dysphoric effects; both dogs and cats may experience nausea, behavioural changes, or sedation with repeated dosing.
• Oral preparations are unpalatable to cats, making administration challenging even with reformulation in gelatin capsules.
• Tramadol can be combined with other analgesic drugs like NSAIDs, amantadine, and gabapentin.
• Potential interactions with drugs inhibiting central 5-HT and noradrenaline reuptake, such as tricyclic antidepressants (e.g., amitriptyline), monoamine oxidase inhibitors (e.g., selegiline), selective serotonin reuptake inhibitors, and some opioids (e.g., fentanyl, pethidine, and buprenorphine).
• Interaction may lead to serotonin syndrome, characterized by seizures and death.
• Signs of serotonin syndrome include hyperthermia, elevated blood pressure, and CNS disturbances like hypervigilance and excitation.
• If signs of serotonin syndrome develop, manage symptoms and discontinue contributing drug treatments.