Description

Pregabalin, marketed under the brand name Lyrica among others, is a medication used to treat epilepsy, neuropathic pain, fibromyalgia, restless leg syndrome, and generalized anxiety disorder. Its use in epilepsy is an add-on therapy for partial seizures. When used before surgery, it reduces pain but results in greater sedation and visual disturbances. It is taken by mouth.

Common side effects include headache, dizziness, sleepiness, confusion, trouble with memory, poor coordination, dry mouth, the problem with vision, and weight gain. Serious side effects may include angioedema, drug misuse, and increased suicide risk. When pregabalin is taken at high doses over a long period of time, addiction may occur, but if taken at usual doses the risk is low. Use during pregnancy or breastfeeding is of unclear safety. Pregabalin is a gabapentinoid and acts by inhibiting certain calcium channels.

Pregabalin was approved for medical use in the United States in 2004. It was developed as a successor to gabapentin. It is available as a generic medication in a number of countries, including the United States as of 2019. In the US the wholesale costs are about US$11 per month as of October 2019. While in the United Kingdom a similar dose costs the NHS about £6 as of 2018.[15] In 2016, it was the 83rd most prescribed medication in the United States with more than 9 million prescriptions. In the US, Pregabalin is a Schedule V controlled substance under the Controlled Substances Act of 1970

Medical uses

Seizures

Pregabalin is useful when added to other treatments when those other treatments are not controlling partial epilepsy. Its use alone is less effective than some other seizure medications. It is unclear how it compares to gabapentin for this use.

Neuropathic pain

The European Federation of Neurological Societies recommends pregabalin as a first-line agent for the treatment of pain associated with diabetic neuropathy, post-herpetic neuralgia, and central neuropathic pain. A minority obtain a substantial benefit, and a larger number obtain a moderate benefit. It is given equal weight as gabapentin and tricyclic antidepressants as a first-line agent; however, the latter is less expensive as of 2010. Evidence does not support it being useful in sciatica or low back pain.

Pregabalin’s use in cancer-associated neuropathic pain is controversial. There is no evidence for its use in the prevention of migraines and gabapentin has also been found not to be useful. It has been examined for the prevention of post-surgical chronic pain, but its utility for this purpose is controversial.

Pregabalin is generally not regarded as efficacious in the treatment of acute pain. In trials examining the utility of pregabalin for the treatment of acute post-surgical pain, no effect on overall pain levels was observed, but people did require less morphine and had fewer opioid-related side effects. Several possible mechanisms for pain improvement have been discussed.

Anxiety disorders

Pregabalin is moderately effective and is safe for the treatment of generalized anxiety disorder. The World Federation of Biological Psychiatry recommends pregabalin as one of several first-line agents for the treatment of generalized anxiety disorder but recommends other agents such as SSRIs as first-line treatment for obsessive-compulsive disorder and post-traumatic stress disorder. It appears to have anxiolytic effects similar to benzodiazepines with less risk of dependence.

The effects of pregabalin appear after 1 week of use and are similar in effectiveness to lorazepam, alprazolam, and venlafaxine, but pregabalin has demonstrated superiority by producing more consistent therapeutic effects for psychosomatic anxiety symptoms. Long-term trials have shown continued effectiveness without the development of tolerance, and, in addition, unlike benzodiazepines, it has a beneficial effect on sleep and sleeps architecture, characterized by the enhancement of slow-wave sleep. It produces less severe cognitive and psychomotor impairment compared to those drugs; it also has a low potential for abuse and dependence and may be preferred over the benzodiazepines for these reasons.

A 2019 review found that pregabalin reduces symptoms, and was generally well tolerated.

Other uses

Evidence finds little benefit and significant risk in those with chronic low back pain. Evidence of benefit in alcohol withdrawal is poor as of 2016.

Adverse effects

Exposure to pregabalin is associated with weight gain, sleepiness and fatigue, dizziness, leg swelling, disturbed vision, loss of coordination, and euphoria. It has an adverse effect profile similar to other central nervous system depressants. Adverse drug reactions associated with the use of pregabalin include:

  • Very common (>10% of people with pregabalin): dizziness, drowsiness.
  • Common (1–10% of people with pregabalin): blurred vision, diplopia, increased appetite, and subsequent weight gain, euphoria, confusion, vivid dreams, changes in libido (increase or decrease), irritability, ataxia, attention changes, feeling high, abnormal coordination, memory impairment, tremors, dysarthria, parasthesia, vertigo, dry mouth and constipation, vomiting and flatulence, erectile dysfunction, fatigue, peripheral edema, feeling the effects of drunkenness, abnormal walking, asthenia, nasopharyngitis, increased creatine kinase level.
  • Infrequent (0.1–1% of people with pregabalin): depression, lethargy, agitation, anorgasmia, hallucinations, myoclonus, hypoaesthesia, hyperaesthesia, tachycardia, excessive salivation, hypoglycemia, sweating, flushing, rash, muscle cramp, myalgia, arthralgia, urinary incontinence, dysuria, thrombocytopenia, kidney calculus
  • Rare (<0.1% of people with pregabalin): neutropenia, first-degree heart block, hypotension, hypertension, pancreatitis, dysphagia, oliguria, rhabdomyolysis, suicidal thoughts or behavior.