Major
Gabapentin × Morphine
Gabapentinoids (antiepileptics)×Natural opium alkaloids
Mechanism
Gabapentin reduces morphine clearance and potentiates CNS depression. FDA issued a 2019 warning about increased respiratory depression risk with the combination.
Symptoms
Drowsiness, slowed breathing (rate below 12/min), cyanosis of lips. Severe cases include respiratory arrest. Older patients: fall risk.
Management
The combination is possible in neuropathic or palliative pain. Keep doses minimal, start low. Provide naloxone to the patient and family. Monitor respiratory rate and saturation.