Doctor Won't Prescribe Gabapentin And Lyrica Together

Answer

Thanks so much for reaching out to us! We answered a question very similar to this not too long ago, and in it, we described why it's very uncommon that gabapentin and Lyrica (pregabalin) would be used together.

In a nutshell, Lyrica (pregabalin) and gabapentin are very similar drugs (both are classified as gabapentinoids), and essentially work the same way.

Although the precise mechanism by which both drugs work isn't completely known, they are thought to work at least partially by binding to a specific site on the alpha-2-delta subunit of voltage-gated calcium channels in the brain and spinal cord. This has multiple effects, including altering the release of glutamate, which causes a reduction in the sensation of pain.

Two big differences between Lyrica and gabapentin, however, are their potencies and duration of action:

• Lyrica (pregabalin) is more rapidly absorbed than gabapentin and tends to work faster. It is also more potent. Animal studies have reported that it is likely 3-10 times as potent as gabapentin.
• Lyrica (pregabalin) can often be dosed less frequently due to its longer duration of action.

Now, I won't go too in-depth here regarding the differences between these drugs because that's not what you asked about. I'll focus on their combined use and why your doctor is hesitant to prescribe both together.

Concerns Combining Gabapentin And Lyrica

As mentioned, Lyrica and gabapentin are both gabapentinoids and work in a similar manner. In most cases, taking both together would be considered a duplication of therapy, similar to how taking two different antihistamines, like Claritin and Zyrtec, would be considered a duplication of therapy.

The primary concern here is although some very small studies have shown that the combination of Lyrica and gabapentin can be effective in treating neuropathic pain, the use of both medications together may increase the risk of side effects, such as:

• Sedation
• Dizziness
• Shortness of breath
• Headache
• Dry mouth
• Nausea
• Speech problems
• Difficulty concentrating
  
• Confusion

Adding concern to this is the fact that Lyrica is a federally assigned controlled substance (Schedule V) and gabapentin is a Schedule V controlled substance in some states (e.g., Alabama, Kentucky, Michigan, Virginia, West Virginia, etc...). I can certainly understand your doctor being hesitant to prescribe two drugs with the potential of abuse and misuse where there is no clear evidence that their combined use is safe and effective.

I did mention that there are some studies that show some preliminary evidence of benefit with combined use. One such study stated the following:

Despite their [gabapentin and pregabalin] similarities, they have been used in combination in both clinical and research situations, and have been noted to have a synergistic effect in pain control without concern for clinically significant pharmacokinetic interactions. This combined approach can be made use of to reduce the dose of an individual agent, its side effects, and to enhance therapeutic response compared to a single agent.

Pharmacist Thoughts

To reiterate, I can understand why your doctor wouldn't want to prescribe both gabapentin and Lyrica. While there is some evidence for combined use, there is little data available to properly evaluate the safety and efficacy of the regimen. Throw in the fact that you're talking about controlled substances, it makes it more reasonable not to potentially over-prescribe.

I don't know your medical or medication history, so the following are just some general thoughts for you. I would think the safer, and more evidence-based approach would be to try either gabapentin or Lyrica and dose-titrate up until you (hopefully) achieve a clinical response.

You mentioned you tried gabapentin at 400mg and Lyrica at 75mg. Both drugs can be dosed far higher (pregabalin has been studied up to 600mg per day and gabapentin up to 3,600mg per day), so that may be an option for you.

There are certainly other drugs indicated for the treatment of neuropathic pain that may be of benefit to you as well, such as venlafaxine, duloxetine, and amitriptyline.

Final Words

Thanks so much again for reaching out.

I am sorry to hear of the problems you are having treating your pain. I hope you are able to have a discussion with your doctor to come up with a treatment plan that brings you closer to some kind of relief.