Valex CR 500 mg

Description

Indications
Valex CR is used for the management of various types of epilepsy, including:

• Partial seizures
• Absence seizures (petit mal)
• Generalized tonic-clonic seizures (grand mal)
• Myoclonic seizures
• Atonic seizures
• Mixed seizures that involve absence attacks
  Additionally, Valex CR is indicated for:
• Prophylaxis of febrile convulsions
• Prevention of post-traumatic epilepsy
  Valex CR is also effective in the treatment of bipolar disorder and in the prevention of migraine attacks.

Note: Always follow the guidance of a registered physician for appropriate use.

Composition

• Sodium Valproate Tablet: Each enteric-coated tablet contains 200 mg of Sodium Valproate BP.
• Sodium Valproate Syrup: Each 5 ml contains 200 mg of Sodium Valproate BP.
• Sodium Valproate Controlled Release 200 mg Tablet: Each enteric-coated controlled release tablet contains 200 mg of Sodium Valproate, composed of 133.2 mg of Sodium Valproate BP and 58 mg of Valproic Acid BP.
• Sodium Valproate Controlled Release 300 mg Tablet: Each enteric-coated controlled release tablet contains 300 mg of Sodium Valproate, composed of 199.8 mg of Sodium Valproate BP and 87 mg of Valproic Acid BP.
• Sodium Valproate Controlled Release 500 mg Tablet: Each enteric-coated controlled release tablet contains 500 mg of Sodium Valproate, composed of 333 mg of Sodium Valproate BP and 145 mg of Valproic Acid BP.
• Sodium Valproate Injection: Each 5 ml injectable solution contains Sodium Valproate equivalent to 500 mg of Valproic Acid BP.

Pharmacology
Sodium Valproate, the active ingredient, is a widely used anti-epileptic drug effective against various types of seizures. Its precise mechanism of action is not fully understood, but it is believed to increase brain levels of gamma-aminobutyric acid (GABA), an inhibitory neurotransmitter. This effect helps in controlling seizures and stabilizing neuronal activity.

Dosage & Administration

• Oral: Valex CR tablets can be taken once or twice daily, while the syrup should be divided into multiple doses.
  Epilepsy:

  • Adults: Start with 600 mg daily in 2 divided doses, preferably after meals. Gradually increase by 200 mg every 3 days, reaching a maximum of 2.5 g daily in divided doses until seizure control is achieved. The usual maintenance dose is between 1-2 g daily (20-30 mg/kg/day).
  • Children (over 20 kg): Start with 400 mg daily in divided doses, increasing as needed (usually 20-30 mg/kg/day), with a maximum dose of 35 mg/kg daily.
  • Children (up to 20 kg): Begin with 20 mg/kg daily in divided doses.
    Febrile Convulsion: 20-30 mg/kg/day, divided into 3 doses.
    Bipolar Disorder:
  • Initial dose: 600 mg daily (20-30 mg/kg/day), divided into 2-3 doses.
  • Maintenance dose: 1000-2000 mg daily.
    Migraine Prophylaxis:
  • 400-600 mg daily, with some individuals requiring 1000-1500 mg daily.

• Injection:

  • Adults: Administered as a slow intravenous injection over 3-5 minutes, usually 400-800 mg based on body weight (up to 10 mg/kg), followed by a continuous or repeated infusion up to a maximum of 2500 mg/day.
  • Children: Initial dose: 20-30 mg/kg/day; maximum dose: 40 mg/kg/day. The injection may be given directly or via infusion using compatible diluents such as 0.9% Sodium Chloride or 5% Dextrose.

Note: Always follow the prescribed dosage as per the advice of a registered physician.

Interaction
Valex CR may act as a non-specific inhibitor of drug metabolism, interacting significantly with medications such as Phenobarbital, Phenytoin, Warfarin, and Aspirin.

Contraindications
Valex CR should not be used by individuals who are hypersensitive to Sodium Valproate or have liver dysfunction. It is also restricted during pregnancy and in women of childbearing potential.

Side Effects
The most common side effects include:

• Anorexia, nausea, and vomiting (these are minimized with enteric-coated tablets).
• CNS effects such as sedation, ataxia, and tremor (typically resolve with dose reduction).
• Occasionally, rash, alopecia, and increased appetite have been observed.
• Hepatic effects, such as elevated liver enzymes, can occur in up to 40% of patients, especially in the first few months of treatment. Rarely, severe hepatic conditions like fulminant hepatitis may develop.
• In children under 2 years or those on multiple anti-epileptic medications, there is an increased risk of hepatic injury, acute pancreatitis, and hyperammonemia.

Pregnancy & Lactation

• Pregnancy: Sodium Valproate crosses the placenta, and its use during the first trimester has been associated with neural tube defects such as anencephaly and spina bifida. Pregnant women should be offered serum alpha-fetoprotein testing.
• Lactation: Sodium Valproate is excreted in breast milk, but the risk to the infant is minimal. Nonetheless, breastfeeding mothers should use caution.

Precautions & Warnings

• Liver function should be monitored before and during the first 6 months of treatment, particularly in patients at higher risk.
• Ensure no significant bleeding risks before starting treatment or major surgery.
• Special care is needed in patients with renal impairment, during pregnancy and breastfeeding, and in individuals with systemic lupus erythematosus.
• Sudden discontinuation of Valex CR should be avoided.
• Valex CR is partially eliminated in the urine as a ketone metabolite, which may interfere with urine ketone tests.

Therapeutic Class

• Primary anti-epileptic drugs.

Storage Conditions
Store below 30°C. Keep away from light and moisture. Keep out of the reach of children.