Topiramate (Topiramate)
Also sold as: Topamax, Topaz, Topirol, Epitomax
Pregnancy
Cat D
Lactation
Caution
Schedule
H
Forms
Tablet (25mg, 50mg, 100mg, 200mg) +1
Indications
- Migraine prophylaxis (adults)
- Epilepsy — focal (partial) seizures
- Epilepsy — primary generalised tonic-clonic seizures
- Lennox-Gastaut syndrome (adjunctive)
- Weight loss (off-label, in combination with phentermine)
Adult Dosing
Migraine prophylaxis
25 mg once daily at night for week 1, then 25 mg twice daily for week 2, increasing to 50 mg twice daily (target dose 50–100 mg/day in divided doses)
Ongoing; reassess after 3–6 months
Slow titration is essential to minimise cognitive side effects. Takes 4–8 weeks to assess prophylactic efficacy.
Focal (partial) seizures — monotherapy or adjunctive
Start 25 mg once daily; increase by 25–50 mg/day every 1–2 weeks to 100–200 mg twice daily
Maintenance: 100–200 mg twice daily
Higher doses (>400 mg/day) do not improve seizure control and increase side effects.
Generalised tonic-clonic seizures
As above; target 200–400 mg/day in two divided doses
Long-term maintenance
Pediatric Dosing
Use sprinkle capsule for young children who cannot swallow tablets. Titrate slowly to minimise side effects.
Renal Dose Adjustment
| CrCl / eGFR | Dose Adjustment |
|---|---|
| CrCl ≥70 mL/min | Standard dose |
| CrCl <70 mL/min | Reduce dose by 50% and titrate slowly |
| Haemodialysis | Supplemental dose required after each session |
Hepatic Adjustment
Use with caution in hepatic impairment; clearance may be reduced. No specific dose defined — titrate to response.
Pregnancy & Lactation
Pregnancy: Category D
Associated with increased risk of oral clefts (cleft lip/palate) and foetal growth restriction. Avoid in pregnancy, especially first trimester. Use effective contraception — but note topiramate reduces OCP efficacy at doses >200 mg/day. Prescribe non-hormonal contraception.
Lactation: Caution
Excreted in breast milk. Monitor infant for drowsiness and poor feeding. Weigh benefits vs risks with the mother.
Top Drug Interactions
| Interacting Drug | Effect | Severity |
|---|---|---|
| Combined oral contraceptive pill (OCP) | Topiramate induces CYP3A4 at doses >200 mg/day, reducing OCP efficacy — risk of unintended pregnancy | Major |
| Valproate (sodium valproate) | Mutual reduction of each other's levels; combination increases risk of hyperammonaemia and encephalopathy | Moderate |
| Phenytoin / carbamazepine | Enzyme inducers reduce topiramate plasma levels by up to 50% — may need higher topiramate dose | Moderate |
| Lithium | Topiramate may reduce lithium levels — monitor lithium concentration | Moderate |
| Carbonic anhydrase inhibitors (acetazolamide, zonisamide) | Additive kidney stone risk and metabolic acidosis | Moderate |
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Side Effects
Common
- Cognitive impairment — word-finding difficulty, slowed thinking, memory problems ("Dopamax")
- Paraesthesia (tingling in hands and feet — very common)
- Fatigue, somnolence
- Weight loss (clinically useful in obese patients)
- Anorexia, nausea
- Dizziness
Serious / Discontinue If
- Nephrolithiasis (kidney stones) — carbonic anhydrase inhibition; hydrate well
- Metabolic acidosis (monitor bicarbonate in long-term use)
- Acute angle-closure glaucoma (rare — presents within 1 month of initiation)
- Oligohidrosis with hyperthermia (reduced sweating — especially in children)
- Teratogenicity (oral clefts)
- Suicidal ideation (class warning for all anticonvulsants)
Contraindications
- Pregnancy (especially first trimester — oral cleft risk)
- Known hypersensitivity to topiramate
- Use with caution in patients with history of kidney stones
Available Indian Brands
| Brand | Manufacturer | Price (approx) |
|---|---|---|
| Topamax 25mg | Janssen | ₹125/10 tab |
| Topaz 25mg | Sun Pharma | ₹85/10 tab |
| Topirol 25mg | Cipla | ₹95/10 tab |
Monitoring Required
- Serum bicarbonate (metabolic acidosis — baseline and periodically)
- Eye examination if acute visual disturbance or eye pain (rule out glaucoma)
- Renal function and urine for stones in predisposed patients
- Weight and BMI
- Contraceptive method — confirm adequate non-hormonal contraception in women of childbearing age
- Cognitive function — subjective assessment at each visit
Patient Counseling Points
- Take the dose at the same time each day; take at bedtime to reduce daytime cognitive side effects
- Drink plenty of water (at least 2–3 litres/day) to reduce kidney stone risk
- You may notice difficulty finding words or slowed thinking — this usually improves with time or dose reduction
- Weight loss is expected — monitor your diet
- If you are on the oral contraceptive pill, it may not work properly — use additional contraception (barrier methods)
- Do not stop this medicine suddenly — taper under medical supervision
- Report eye pain or blurred vision urgently (rare glaucoma risk)
- This medicine takes 4–8 weeks to reduce migraine frequency — do not stop prematurely
Stop Googling drug references mid-consultation
EasyClinic auto-flags Topiramate interactions, renal cutoffs, and pregnancy warnings the moment you write the prescription. Built-in safety net for every Indian doctor.
Clinically reviewed by: Dr. Priya Nair, DM Neurology, DM Neurology, Senior Consultant Neurologist
Last reviewed: 2026-04-01
References
- Silberstein SD, et al. Topiramate in migraine prevention. Headache. 2004;44(suppl 1):S25-S32.
- Biton V. Topiramate in epilepsy. Expert Opin Pharmacother. 2007;8(6):811-821.
- Topiramate prescribing information — Janssen India.