GABAPENTIN

Background and Date of Approval

Gabapentin is an anticonvulsant medication that received FDA approval on December 30, 1993. It is indicated for the treatment of neuropathic pain, anxiety disorders, and seizures, including those associated with epilepsy.

Uses

Gabapentin is used to treat various conditions, including neuropathic pain, anxiety disorders, and seizures. It is used to manage postherpetic neuralgia in adults, a type of nerve pain following a shingles infection. It is also used as adjunctive therapy for partial onset seizures, with and without secondary generalisation, in adults and pediatric patients aged 3 years and older with epilepsy. Gabapentin is prescribed for other forms of neuropathic pain and seizure management, as it helps regulate nerve activity and alleviate symptoms.

How is it administered?

In the case of tablets, Gabapentin is typically started at a low dose, such as 300 mg on Day 1 for Postherpetic Neuralgia, with gradual increases over several days. For capsules, the starting dose is similar, and adjustments are made based on the patient's response and condition. Gabapentin doses should be adjusted in patients with reduced renal function, regardless of tablet or capsule form.

Side Effects

Side effects are unwanted symptoms caused by medicines. Although all drugs can cause side effects, not everyone experiences them. Common side effects of Gabapentin: Dizziness Somnolence (sleepiness) Peripheral edema (swelling) Fatigue Nausea and vomiting Ataxia (lack of coordination) Diarrhea Dry mouth Constipation Weight gain Tremor Pharyngitis (sore throat) Diplopia (double vision) and amblyopia (blurred vision) Serious side effects of Gabapentin: Jaundice (yellowing of the skin or eyes) Rhabdomyolysis (muscle breakdown) Hepatobiliary disorders (liver problems) Elevated creatine kinase and liver function tests Movement disorders Agitation Angioedema (swelling beneath the skin) Erythema multiforme Stevens-Johnson syndrome (severe skin reaction) Abrupt discontinuation reactions (anxiety, insomnia, pain, sweating, nausea)

Warnings

Drug reaction with eosinophilia and systemic symptoms (DRESS) (Multiorgan hypersensitivity): Discontinue the medication if an alternative etiology is not established. Anaphylaxis and angioedema: Discontinue and immediately evaluate the patient. Driving impairment (Somnolence/Sedation and Dizziness): Warn patients not to drive until they can assess their ability to drive or operate heavy machinery. Increased seizure frequency: Abruptly discontinuing the medication may increase seizure frequency in patients with seizure disorders. Suicidal Behavior and Ideation: Monitor patients for suicidal thoughts or behaviours. Neuropsychiatric adverse reactions in children 3 to 12 years of age: Monitor patients closely for neuropsychiatric events.

Precautions

Gabapentin can cause serious reactions like DRESS (multiorgan hypersensitivity), anaphylaxis, and angioedema, so you should discontinue it immediately if these occur. It can impair your ability to drive or operate heavy machinery, and you should use it cautiously with other sedatives. Abrupt discontinuation may increase your seizure risk, and it may increase the likelihood of suicidal thoughts or behaviour, especially in patients with epilepsy. Children may experience neuropsychiatric issues like emotional lability and hostility, and long-term use requires monitoring for potential tumour risk and unexplained deaths in epilepsy patients.

Word of Advice

Patients taking gabapentin should monitor closely for signs of serious reactions including rash, difficulty breathing, or swelling, and seek immediate medical attention if these occur. Driving or operating heavy machinery should be avoided until the patient is certain the medication does not impair their abilities. Discontinuation of gabapentin requires gradual tapering under doctor's direction to prevent seizures. Patients should inform their doctor of any mood changes or suicidal thoughts during treatment.

References

1. https://www.accessdata.fda.gov/drugsatfda_docs/label/2017/020235s064_020882s047_021129s046lbl.pdf 2. asaei R, Katta S, Patel P, Saadabadi A. Gabapentin. https://pubmed.ncbi.nlm.nih.gov/29630280/ 3. Backonja M, Glanzman RL. Gabapentin dosing for neuropathic pain: evidence from randomized, placebo-controlled clinical trials. https://pubmed.ncbi.nlm.nih.gov/12637113/ 4. https://www.ema.europa.eu/en/medicines/human/referrals/neurontin

Frequently Asked Questions

Is gabapentin a very strong painkiller?

Gabapentin is not considered a very strong painkiller, but it is a medication commonly used to manage nerve-related pain and control seizures.

Is gabapentin good for anxiety?

Gabapentin is not primarily used to treat anxiety, but it may be prescribed off-label in some cases to help manage anxiety symptoms. It is mainly used to treat nerve pain and seizures. Always consult your doctor for advice on appropriate treatments for anxiety.

What is the best time to take Gabapentin?

The best time to take gabapentin depends on your doctor's advice and your condition. It is often taken in divided doses throughout the day, with or without food. Your doctor will recommend a schedule based on your needs and treatment plan.

What are the possible side effects of gabapentin?

Common side effects of gabapentin include dizziness, drowsiness, and swelling in the hands or feet. Less common effects can include blurred vision, weight gain, and mood changes. Always consult a healthcare provider if any side effects occur.

Is gabapentin a muscle relaxer?

Gabapentin is not a muscle relaxer, but it is an anticonvulsant used to treat nerve pain and control seizures.

Available Brands 42

Written By: Muskan Patel, M.Pharm

Reviewed By: Dr. Vishwa Patel, MBBS