Gabapentin (brand names: Neurontin, Gralise, Horizant) is a prescription medication primarily used to treat partial seizures (as an add-on therapy for epilepsy) and postherpetic neuralgia (nerve pain after shingles). It’s also commonly prescribed off-label for conditions like neuropathic pain, fibromyalgia, restless legs syndrome, anxiety, and hot flashes.

Key Facts on 300 mg Dosage

• Typical starting dose: 300 mg once daily (often at bedtime) for adults, then titrated up based on response and tolerance (e.g., to 900–3600 mg/day divided into 3 doses).
• Form: Usually oral capsules, tablets, or oral solution.
• How it works: Mimics GABA (a brain calming chemical) to reduce abnormal electrical activity in the brain and nerves, though its exact mechanism isn’t fully understood.
• Onset: Pain relief may take days to weeks; seizure control within hours to days.

Common Side Effects (affecting >10% of users)

• Evidence: From clinical trials (e.g., FDA approval data, Neurontin studies), ~20-30% report dizziness/somnolence at 300 mg initiation. Serious effects are rare (<1%) but dose-dependent.

Warnings & Interactions

• Do not stop abruptly: Can cause seizures or withdrawal (anxiety, insomnia).
• Avoid with: Opioids/alcohol (high respiratory depression risk—FDA black box warning), antacids (reduces absorption), CNS depressants.
• Not for: Children <3 years (seizures), pregnancy (Category C—potential fetal harm), or those with kidney disease (dose adjustment needed).
• Abuse potential: Schedule V controlled substance in the US due to euphoria/misuse at high doses (e.g., >900 mg recreational).

Evidence-Based Sources

• FDA Label: Neurontin Prescribing Info – Details 300 mg pharmacokinetics (half-life ~5-7 hours, renal excretion).
• Cochrane Reviews: Effective for neuropathic pain (NNT=6 for 30% pain reduction; DOI:10.1002/14651858.CD007938.pub4).
• Studies: Randomized trials (e.g., JAMA 1998) show 300 mg BID superior to placebo for postherpetic neuralgia.

Important: This is general info—not medical advice. Consult a doctor/pharmacist for personalized dosing, as 300 mg could be unsafe based on your health (e.g., age, weight, conditions).