Convulex, Depakote, Epilim
Generic Name
Valproic Acid
Manufacturer
Sanofi, Abbott, Beximco Pharmaceuticals, Square Pharmaceuticals
Country
France, USA, Bangladesh
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Description
Overview of the medicine
Valproic Acid is an anticonvulsant primarily used to treat epilepsy, bipolar disorder, and to prevent migraine headaches. It works by affecting neurotransmitters in the brain.
Uses & Indications
Dosage
Adults
Epilepsy: Initial 10-15 mg/kg/day, increased by 5-10 mg/kg/week to a maximum of 60 mg/kg/day. Bipolar: Initial 750 mg/day in divided doses. Migraine: 250 mg twice daily, may increase up to 1000 mg/day.
Elderly
Lower initial doses and slower titration recommended due to increased sensitivity and potential for adverse effects.
Renal_impairment
No specific dose adjustment typically needed for renal impairment, but caution advised. Monitor plasma concentrations.
How to Take
Administer orally, with or without food. Extended-release tablets should be swallowed whole, not crushed or chewed.
Mechanism of Action
Increases brain levels of GABA, blocks voltage-gated sodium channels, and modulates T-type calcium channels, thereby stabilizing neuronal membranes and reducing seizure activity.
Pharmacokinetics
Onset
Variable, often days to weeks to achieve steady-state therapeutic levels.
Excretion
Primarily renal, with a small amount excreted in feces.
Half life
9-16 hours in adults; shorter in children.
Absorption
Well absorbed orally; peak plasma concentrations reached in 1-4 hours (immediate release) or 3-8 hours (extended release).
Metabolism
Primarily hepatic (glucuronidation, beta-oxidation). Metabolized to several inactive and some active metabolites.
Side Effects
Contraindications
- Hepatic disease or significant hepatic dysfunction
- Known urea cycle disorders
- Hypersensitivity to valproate
- Mitochondrial disorders (e.g., Alpers-Huttenlocher Syndrome)
Drug Interactions
Aspirin
May increase free valproate levels.
Carbapenem antibiotics
May significantly decrease valproate levels, leading to loss of seizure control.
Other AEDs (e.g., Phenytoin, Phenobarbital)
May alter valproate levels or be affected by valproate.
CNS depressants (e.g., Alcohol, Benzodiazepines)
Increased risk of CNS depression.
Storage
Store below 30°C, protect from light and moisture. Keep out of reach of children.
Overdose
Symptoms include somnolence, heart block, deep coma, and liver injury. Management involves supportive care, gastric lavage, and activated charcoal. Naloxone may reverse CNS depression.
Pregnancy & Lactation
Pregnancy Category D (for epilepsy) or X (for migraine prophylaxis). High risk of major birth defects, especially neural tube defects. Use in pregnancy only if potential benefit outweighs risk. Excreted into breast milk; caution advised, monitor infant for adverse effects.
Side Effects
Contraindications
- Hepatic disease or significant hepatic dysfunction
- Known urea cycle disorders
- Hypersensitivity to valproate
- Mitochondrial disorders (e.g., Alpers-Huttenlocher Syndrome)
Drug Interactions
Aspirin
May increase free valproate levels.
Carbapenem antibiotics
May significantly decrease valproate levels, leading to loss of seizure control.
Other AEDs (e.g., Phenytoin, Phenobarbital)
May alter valproate levels or be affected by valproate.
CNS depressants (e.g., Alcohol, Benzodiazepines)
Increased risk of CNS depression.
Storage
Store below 30°C, protect from light and moisture. Keep out of reach of children.
Overdose
Symptoms include somnolence, heart block, deep coma, and liver injury. Management involves supportive care, gastric lavage, and activated charcoal. Naloxone may reverse CNS depression.
Pregnancy & Lactation
Pregnancy Category D (for epilepsy) or X (for migraine prophylaxis). High risk of major birth defects, especially neural tube defects. Use in pregnancy only if potential benefit outweighs risk. Excreted into breast milk; caution advised, monitor infant for adverse effects.
Frequently Asked Questions
Common questions about this medicine
Pack Sizes
Shelf Life
Typically 2-3 years from manufacturing date.
Availability
Pharmacies, Hospitals
Approval Status
FDA Approved
Patent Status
Generic Available
WHO Essential Medicine
YesClinical Trials
Extensive clinical trials support its efficacy in epilepsy, bipolar disorder, and migraine prophylaxis.
Lab Monitoring
- Liver function tests (baseline and periodically, especially during the first 6 months of therapy)
- Complete blood count with platelets (baseline and periodically)
- Serum valproate levels (to ensure therapeutic range)
- Ammonia levels (if encephalopathy suspected)
- Pancreatic enzyme levels (if pancreatitis suspected)
Doctor Notes
- Monitor liver and pancreatic function carefully, especially in pediatric patients and those on multiple AEDs.
- Counsel women of childbearing potential about the significant teratogenic risks and the need for effective contraception.
- Consider therapeutic drug monitoring to maintain levels within the optimal range and minimize adverse effects.
Patient Guidelines
- Do not stop taking this medicine abruptly, as it may lead to increased seizure frequency.
- Report any unusual bleeding, bruising, abdominal pain, or jaundice to your doctor immediately.
- Attend regular blood tests as advised by your doctor.
Missed Dose Advice
Take the missed dose as soon as you remember, unless it is almost time for your next scheduled dose. In that case, skip the missed dose and resume your regular dosing schedule. Do not double the dose.
Driving Precautions
Valproic Acid may cause drowsiness, dizziness, or blurred vision. Avoid driving or operating heavy machinery until you know how this medicine affects you.
Lifestyle Advice
- Avoid alcohol consumption as it may increase side effects like drowsiness and dizziness.
- Inform your doctor about all other medications, including over-the-counter drugs and herbal supplements.
- Maintain a balanced diet and regular exercise.
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Global Brand Names
International brand names for this medicine. Click a brand to search for detailed information.