Pregabalin vs. Gabapentin: similarities and differences

Similarities of Pregabalin vs. Gabapentin

Pregabalin and Gabapentin are both classified as anticonvulsants or antiepileptic drugs (AEDs) and are both used to treat partial seizures. Pregabalin and Gabapentin are also both approved for the treatment of postherpetic neuralgia in adults. They are also considered first-line medications for the treatment of neuropathic pain following spinal cord injury, and there was no difference in efficacy between the two medications for pain, anxiety, or sleep.

Differences of Pregabalin vs. Gabapentin

However, Pregabalin and Gabapentin are different in terms of indications, dosage used, clinical efficacy and side effects. Below is a brief list about the differences between the two:

Indications

Pregabalin is approved for the treatment of postherpetic neuralgia in adults, neuralgia due to diabetic peripheral neuropathy, neuralgia due to spinal cord injury, fibromyalgia and partial seizures in adults and children as young as 1 month old.

Gabapentin, in addition to being approved for the treatment of postherpetic neuralgia in adults, is also approved for the treatment of partial seizures in adults and children 3 years of age and older, and is often used as an add-on medication for epilepsy. In addition, it is sometimes used off-label for treatments such as prevention of pain conditions (trigeminal neuralgia and neuropathy) and treatment of restless leg syndrome.

Dosage

The table below compares the forms and strengths available for pregabalin and gabapentin:

Pregabalin Dosages

Below are examples of the typical dosages for pregabalin in adults:

• Postherpetic neuralgia: 75–150 mg two times daily or 50–100 mg three times daily; maximum dosage of 600 mg daily
  

• Nerve pain due to diabetic neuropathy: 50–100 mg three times daily; maximum dosage of 600 mg daily
  

• Fibromyalgia: 75–150 mg twice daily; maximum 450 mg daily

• Nerve pain due to spinal cord injury: 75–300 mg two times daily; maximum 600 mg daily
  

• Adjunct treatment of partial seizures: 150–600 mg, divided into two or three doses throughout the day
  

Gabapentin Doses

Here are some examples of the typical doses for gabapentin in adults:

• Postherpetic neuralgia: 300–600 mg three times a day; maximum dosage of 1,800 mg daily
  

• Adjunct treatment of partial seizures: 300–1,200 mg three times daily; maximum dosage of 3,600 mg daily

Clinical Efficacy

Clinical studies have shown Pregabalin to be more effective than Gabapentin in treating partial seizures in patients with epilepsy. However, it was not better than Gabapentin at reducing seizure frequency. Yet another study found Gabapentin to be superior to Pregabalin in the treatment of chronic sciatica. Pregabalin was found to be more effective in reducing pain in a small clinical trial, while Gabapentin was more effective in reducing symptoms of anxiety, insomnia and fatigue in adults suffering from low back pain.

Side Effects

Common side effects of Pregabalin and Gabapentin include dizziness, dry mouth, eye problems, nausea, drowsiness and oedema. However, Pregabalin is more likely to cause weight gain. And both have symptoms of serious adverse reactions that may produce suicidal thoughts or behaviour, respiratory depression, heart problems and severe allergic reactions.

References:

[1] JACQUELINE FRENCH. Adjunctive pregabalin vs gabapentin for focal seizures: Interpretation of comparative outcomes.[J]. Neurology, 2016. DOI:10.1212/WNL.0000000000003118.

[2] YILMAZ B, GOKTEPE A, TAN A. Gabapentin vs. Pregabalin for the Treatment of Neuropathic Pain in Patients with Spinal Cord Injury: A Crossover Study Spinal Kord Yarali Hastalarin Nöropatik Ağri Tedavisinde Gabapentin ve Pregabalin Etkinliğinin Karşilaştirilmasi: Çapraz Çalişma[C]. 1900. DOI:10.5152/tftrd.2015.79069.