Drug-Drug Interaction


GABAPENTIN/ALUMINUM; MAGNESIUM-CONTAINING COMPOUNDS

MECHANISM OF ACTION
ALUMINUM OR MAGNESIUM CONTAINING PRODUCTS MAY REDUCE the bioavailability of gabapentin.(1)

DISCUSSION
In 16 subjects, Maalox reduced the bioavailability of gabapentin by about 20%. The reduction was only 5% when gabapentin was administered 2 hours after the Maalox dose. It is for this reason that the manufacturer of gabapentin recommends that it be taken at least 2 hours after the administration of aluminum or magnesium containing products.(1)

CLINICAL EFFECTS
Simultaneous administration of aluminum or magnesium containing products and gabapentin may result in decreased absorption of gabapentin by 20% and reduce its clinical effectiveness.(1)

SEVERITY LEVEL
3-Moderate Interaction: Assess the risk to the patient and take action as needed.

PATIENT MANAGEMENT
If the use of both medications is unavoidable, it is recommended that gabapentin be taken at least 2 hours following the administration of aluminum or magnesium containing products.(1)

PREDISPOSING FACTORS
None determined.

REFERENCE

  1. Neurontin (gabapentin) US prescribing information. Pfizer Inc. April, .Neurontin (gabapentin) US prescribing information. Pfizer Inc. April, 2009.