Valex CR
Generic Name
Valex CR
Manufacturer
Square Pharmaceuticals Ltd.
Country
Bangladesh
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Price Details
Current market pricing information
| Variant | Unit Price | Strip Price |
|---|---|---|
| valex cr 200 mg tablet | ৳ 6.00 | ৳ 60.00 |
| valex cr 300 mg tablet | ৳ 9.00 | ৳ 90.00 |
| valex cr 500 mg tablet | ৳ 13.00 | ৳ 130.00 |
Description
Overview of the medicine
Valex CR is an extended-release formulation of Valproic Acid, used to treat epilepsy, manic episodes associated with bipolar disorder, and for migraine prophylaxis. It works by increasing the levels of a natural substance in the brain called gamma-aminobutyric acid (GABA), which helps calm nerve activity.
Uses & Indications
Dosage
Adults
Typically starts at 250-500 mg daily, increased gradually to an effective dose, usually 1000-2500 mg daily in divided doses. Administer Valex CR once or twice daily.
Elderly
Start with a lower dose and titrate slowly with careful monitoring due to potential for reduced hepatic and renal function.
Renal_impairment
Dosage adjustment is generally not necessary, but monitoring of valproate levels and clinical response is recommended.
How to Take
Take Valex CR tablets whole, do not crush or chew. Can be taken with or without food, but taking with food may reduce gastrointestinal upset.
Mechanism of Action
Valproic acid is thought to exert its anticonvulsant effects through several mechanisms, including increasing gamma-aminobutyric acid (GABA) levels in the brain by inhibiting its catabolism and enhancing its synthesis, blocking voltage-gated sodium channels, and modulating T-type calcium channels. This leads to stabilization of neuronal membranes and reduction in neuronal excitability.
Pharmacokinetics
Onset
Onset of anticonvulsant effect can be within days to weeks, depending on titration to therapeutic levels. For CR formulation, sustained effect.
Excretion
Mainly through urine as metabolites, with a small amount excreted in feces. Renal clearance is typically 1-2 mL/min/1.73 m².
Half life
Approximately 9-16 hours in adults, may be shorter in children and longer in hepatic impairment.
Absorption
Valproic acid is rapidly and almost completely absorbed after oral administration. Valex CR, being an extended-release formulation, shows delayed and sustained absorption, resulting in less fluctuation in plasma concentrations.
Metabolism
Primarily hepatic, mainly by glucuronidation and mitochondrial beta-oxidation. Extensive metabolism with less than 3% excreted unchanged.
Side Effects
Contraindications
- Known hypersensitivity to valproic acid or its components
- Hepatic disease or significant hepatic dysfunction
- Urea cycle disorders
- Mitochondrial disorders caused by mutations in the nuclear gene encoding the mitochondrial enzyme polymerase gamma (POLG)
Drug Interactions
Lamotrigine
May increase lamotrigine levels, increasing risk of rash.
Aspirin, Warfarin
Increased risk of bleeding due to valproate's effect on platelet aggregation.
Carbamazepine, Phenytoin, Phenobarbital
May alter valproate levels or increase toxicity of other antiepileptics.
Benzodiazepines, Antidepressants, Alcohol
Increased CNS depressant effects.
Storage
Store below 30°C in a dry place, away from light. Keep out of reach of children.
Overdose
Symptoms include somnolence, heart block, coma, and metabolic acidosis. Management involves supportive care, activated charcoal for recent ingestion, naloxone for CNS depression, and hemodialysis in severe cases to remove valproate.
Pregnancy & Lactation
Pregnancy Category D/X. Valproate is highly teratogenic. Avoid during pregnancy, especially in the first trimester, unless clearly necessary and benefits outweigh risks. Use effective contraception during treatment. Not recommended for use during lactation as valproate is excreted into breast milk.
Side Effects
Contraindications
- Known hypersensitivity to valproic acid or its components
- Hepatic disease or significant hepatic dysfunction
- Urea cycle disorders
- Mitochondrial disorders caused by mutations in the nuclear gene encoding the mitochondrial enzyme polymerase gamma (POLG)
Drug Interactions
Lamotrigine
May increase lamotrigine levels, increasing risk of rash.
Aspirin, Warfarin
Increased risk of bleeding due to valproate's effect on platelet aggregation.
Carbamazepine, Phenytoin, Phenobarbital
May alter valproate levels or increase toxicity of other antiepileptics.
Benzodiazepines, Antidepressants, Alcohol
Increased CNS depressant effects.
Storage
Store below 30°C in a dry place, away from light. Keep out of reach of children.
Overdose
Symptoms include somnolence, heart block, coma, and metabolic acidosis. Management involves supportive care, activated charcoal for recent ingestion, naloxone for CNS depression, and hemodialysis in severe cases to remove valproate.
Pregnancy & Lactation
Pregnancy Category D/X. Valproate is highly teratogenic. Avoid during pregnancy, especially in the first trimester, unless clearly necessary and benefits outweigh risks. Use effective contraception during treatment. Not recommended for use during lactation as valproate is excreted into breast milk.
Frequently Asked Questions
Common questions about this medicine
Pack Sizes
Shelf Life
24 to 36 months from manufacturing date
Availability
Available in pharmacies and hospitals nationwide
Approval Status
Approved in Bangladesh by DGDA
Patent Status
Off-patent (Generic available)
WHO Essential Medicine
YesClinical Trials
Valproic acid has been extensively studied in numerous clinical trials for its efficacy in epilepsy, bipolar disorder, and migraine prophylaxis. Ongoing research explores its potential in other neurological and psychiatric conditions.
Lab Monitoring
- Liver function tests (baseline and periodically, especially during the first 6 months)
- Complete Blood Count (CBC) with platelets (baseline and periodically)
- Serum valproate levels (therapeutic drug monitoring to ensure effective and safe levels)
- Ammonia levels (if hyperammonemia is suspected or unexplained lethargy occurs)
Doctor Notes
- Emphasize the importance of patient counseling on teratogenicity and the need for effective contraception for women of childbearing potential.
- Monitor LFTs and CBC regularly, especially during the initial months of therapy.
- Be vigilant for signs of hepatotoxicity and pancreatitis.
- Valproate is generally dosed to achieve therapeutic serum levels (50-100 mcg/mL).
Patient Guidelines
- Take medication regularly as prescribed; do not stop abruptly without consulting your doctor.
- Report any unusual symptoms like severe abdominal pain, persistent nausea, or yellowing of skin/eyes immediately.
- Do not crush or chew extended-release tablets.
- Use effective contraception if you are a woman of childbearing potential.
Missed Dose Advice
If you miss a dose, take it as soon as you remember. If it is almost time for your next dose, skip the missed dose and resume your regular dosing schedule. Do not take a double dose to make up for a missed one.
Driving Precautions
Valex CR may cause drowsiness, dizziness, or impaired coordination. Patients should be cautioned about operating hazardous machinery, including automobiles, until it is known that they do not experience these adverse reactions.
Lifestyle Advice
- Avoid alcohol consumption as it can worsen side effects and interact with the medication.
- Maintain a balanced diet and regular exercise to manage potential weight gain.
- Report any mood changes or suicidal thoughts to your doctor.
- Discuss all other medications, supplements, and herbal remedies with your doctor to avoid interactions.
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Global Brand Names
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