Gabapentin: Does it work?
IMPS has noticed an uptick in articles about Gabapentin use by veterinarians. Always the skeptic, IMPS wondered if the benefits of this drug have been over billed
Background
Gabapentin is a drug that was developed in the 1980s with the hope it could be a stand in for the naturally occurring neurotransmitter gamma-aminobutyric acid (GABA). Human use was approved in 1993, though clinical testing was done in both humans and pets prior to that time.
In humans, the primary use is for the treatment of epilepsy and more recently, neuropathic pain (most often associated with diabetic neuropathy). Common side effects are drowsiness and dizziness and/or incoordination.
The side effects in animals are similar to that of humans. However, Gabapentin use in treatment of neuropathic issues in pets has become more common and in some cases it has been recommended as a sedative.
Studies
Epilepsy
A number of controlled studies have been conducted that indicated that Gabapentin can be effective in reducing the number of and time between seizures experienced by epileptic dogs Gabapentin, however, did not reduce the severity of the seizures.
A more recent study with the successor drug Pregabalin ("Lyrica") appeared to show even stronger results for the reduction of seizures.
All of the studies also saw the expected negative side effects, but considered them to be mild. Of note, these studies only had 10 to 20 participants.
Neuropathic pain
There may be additional studies IMPS is not aware of, but the entirety of the basis for using Gabapentin for treatment of neuropathic pain in pets comes from one study done in 2009. Study is probably not the correct term - only three pets participated and there were no controls. However, it was reported that all the pets appeared to have reduced symptoms of pain.
More likely for the uptick in this use in for Gabapentin in pets is the increased use in humans. However, pet parents must understand that drugs can often work differently, if at all, in pets. In the case of Gabapentin, the metabolization of the drug is by a different means in dogs than in humans, so assuming similar effects without proper study is perilous.
General Analgesic
The greatest participation (20 to 60 dogs) in controlled studies was for research into the analgesic effect of Gabapentin. Analgesics act to reduce pain in general, think aspirin or ibuprofen.
Unfortunately, none of these studies showed any significant benefit to the use of Gabapentin. The one area that might be worth further exploration is using Gabapentin post-op. There were some indications it may reduce the amount of morphine necessary in that situation.
Conclusion
Unless a pet is suffering from epilepsy, the use of Gabapentin does not seem warranted. In particular, IMPS is concerned that pet parents might request this drug unnecessarily, hoping it will work miracles on their pet's perceived pain.
That said, if nothing else has had a positive effect, then Gabapentin may be worth a try. Pet parents are advised to keep a close eye on their dog or cat due to the side effects, especially if your home has stairs.
Pet parents should also be aware that Gabapentin is processed through the renal system. Gabapentin should not be used by pets with kidney disease without close monitoring and supervision by a skilled vet and attentive pet parents.
Of critical importance - NEVER give your pet Gabapentin that is intended for human consumption. Those formulations contain xylitol which is highly toxic to dogs!
Bottom line - IMPS thinks Gabapentin and its successors probably are best used for pets with epilepsy.