The first drug to be FDA-approved for fibromyalgia (FMS) was Lyrica (pregabalin), which was already on the market as an anti-epileptic (seizure) drug, or an AED. Lyrica is closely related to an older AED called Neuronton (gabapentin), which is sometimes prescribed off-label for FMS.
AEDs, like all medications, come with risks and potential side effects. People with fibromyalgia often take a combination of drugs, which creates a risk of negative interactions. It's important to understand the possible problems associated with each drug you take to minimize your risk of serious problems.
Anti-Epileptics as Painkillers
AEDs combat seizures by dampening seizure-causing impulses in the brain. However, certain AEDs, such as Lyrica and Neurontin, also affect neurotransmitters (chemical messengers in the brain) that send pain signals around the nervous system and are believed to be dysregulated in FMS.
The use of Lyrica for FMS pain, as well as pain from post-herpetic shingles and neuropathy, is well-supported by clinical studies, which have continued since the drug's 2007 approval for FMS. Research shows that it's effective long-term at decreasing pain and improving sleep.
Neurontin is less well-studied, with a 2011 review of FMS drugs stating that only one study showed it was significantly more effective than placebo. However, many people with this condition say Neurontin is effective for them. Sometimes Neurontin is prescribed instead of Lyrica because of financial considerations -- because Lyrica is newer and no generic form is available, it's considerably more expensive than generic gabapentin.
AED Risks: Suicide, Overdose, Withdrawal
In 2008, the FDA announced that Lyrica, Neurontin, and other AEDs double the risk of suicidal thoughts and behaviors. The agency stopped just short of ordering a Black Box Warning, which is the most serious warning label for drugs marketed in the US.
If you're taking these drugs, you and the people close to you should be aware of the risks and the behavioral changes associated with thoughts of suicide. These resources from the About.com Depression site can help:
Suicide Crisis Hotlines (US):
- 1-800-273-8255
- 1-800-784-2433
Overdose is also a risk of AEDs. It's important to follow your doctor's dosage instructions and not take too much of these drugs.
Depending on the drug, AED overdose symptoms may include:
- Severely slurred speech
- Dizziness
- Sleepiness
- Sluggishness
- Diarrhea
- Numbness in the limbs
- Tremors & other involuntary movements
Other symptoms may occur as well. If you suspect an AED overdose, get medical attention right away.
Another risk of AEDs is withdrawal symptoms. If you want to stop taking one of these drugs, you need to talk to your doctor about how to wean off it safely in order to avoid potentially dangerous problems.
Withdrawal symptoms include:
- Seizure
- Insomnia
- Nausea
- Headaches
- Diarrhea
These symptoms are not due to addiction, as these drugs are not habit-forming. However, people with a history of drug or alcohol abuse may have a higher chance of abusing Lyrica.
AED Side Effects
Allergic reactions are possible with any medication. You should notify your doctor right away if you develop a rash, hives, itching, or swelling in your face, lips or tongue.
Both Lyrica and Neurontin have high rates of side effects, according to a review published in The Journal of Pain.
Side effects that are common to both drugs and don't usually require medical attention include:
- Constipation
- Nausea
- Weight gain
Weight gain causes many people to discontinue these medications due to its effects on health and/or self-esteem.
Other side effects, both minor and serious, vary by drug. You can get more information here:
Drug Interactions
AEDs can cause problems when combined with other medications. It's important for you to let your doctor and pharmacist know about all your medications (prescription and over-the-counter), dietary supplements or herbal treatments you take, and any use of tobacco, alcohol or recreational drugs.
Drugs that can interact badly with both Lyrica and Neurontin include:
- Hydrocodone
- Morphine
Neurontin can also interact negatively with the over-the-counter painkiller Aleve (naproxen).
These interactions with painkillers could be a problem for people who continue to have pain while taking an AED.
As with side effects, other interactions vary by drug. You can get more information by clicking on the "Interactions" tabs on these pages:
Reducing Your Risk
To reduce the risks associated with AEDs, you should carefully follow dosage instructions, talk to your doctor about weaning if it becomes necessary, and let your doctor and pharmacist know what else you may be taking.
It's also important to make sure the people around you are aware of the suicide risk associated with these medications.
To help you keep track of possible side effects, it can help to print out a list and keep it somewhere visible. This is especially true when you begin a new drug.
Are AEDs Right for You?
The decision to take an AED is best made by you and your doctor, while taking into consideration your diagnoses, symptoms, lifestyle factors and overall health.
AEDs don't work the same for everyone with FMS. It can take time to find a drug regimen that works for you. Keeping the lines of communication with your doctor open can help with this process.
Sources:
Arnold LM, et al. Clinical therapeutics. 2012 Apr 14. [Epub ahead of print] Safety profile and tolerability of up to 1 year of pregabalin treatment in 3 open-label extension studies in patients with fibromyalgia.
Baidya DK, et al. Journal of anaesthesiology, clinical pharmacology. Pregabalin in acute and chronic pain.
Pfizer Inc. All rights reserved. Lyrica Indication and Important Safey Information. and Highlights of Prescribing Information. Accessed May 2012.
Roth T, et al. Arthritis care & research. 2012 Apr;64(4):597-606. doi: 10.1002/acr.21595. Effect of pregabalin on sleep in patients with fibromyalgia and sleep maintenance disturbance: A randomized, placebo-controlled, 2-way crossover polysomnography study.
Siler AC, et al. The journal of pain. 2011 Apr;12(4):407-15. Systematic review of the comparative effectiveness of antiepileptic drugs for fibromyalgia.
Smith B, et al. Drug class reviews (Internet). 2011 Apr. Drug Class Review: Drugs for Fibromyalgia: Final Original Report
