Potential Adverse Consequences of Combination Therapy with Gabapentin and Pregabalin

Gabapentinoids comprise the medications gabapentin and pregabalin. These were designed to not only look chemically like the central inhibitory neurotransmitter gamma-aminobutyric acid (GABA) but also act like it. The prototype gabapentin was primarily introduced to be used as antiepileptic medication. Today, both chemicals are not only utilized as adjunct antiepileptics in focal (aware and impaired awareness) seizures but are also used in several neuropathic pain conditions and other clinical indications. Their use has skyrocketed in the past few years and this has brought forward more instances of adverse effects and errors in prescribing practices. We describe here a case of a female patient with a history of diabetes, diabetic neuropathy, and hypertension being prescribed both gabapentin and pregabalin concomitantly which led to adverse effects like drowsiness, dizziness, fatigue, and ataxia. Once the patient medication profile was revisited, the pharmacy staff was able to identify the therapeutic duplications (gabapentin and pregabalin). The physician was contacted and pregabalin was discontinued. This led to the disappearance of the adverse effects. The dose of the existing gabapentin was increased to control the symptoms of diabetic neuropathy. This report sheds light on the importance of responsible prescribing, efficient checking of medication profiles on the level of dispensing pharmacies, and timely follow-up to patients to keep the patients safe and their medical conditions under check.