Orfiril 150 (Sodium Valproate)

Orfiril 150 is an antiepileptic drug that acts on neuronal excitability to control various seizure types.

• Generalised tonic‑clonic seizures: reduces frequency and severity of convulsive episodes.
• Absence seizures: helps achieve seizure‑free periods in patients with typical absence epilepsy.
• Myoclonic seizures: diminishes myoclonic jerks and improves daily functioning.
• Lennox‑Gastaut syndrome: contributes to overall seizure control in this severe epilepsy syndrome.
• Bipolar disorder (off‑label): stabilises mood and prevents manic episodes when prescribed by a psychiatrist.

• Sodium valproate increases brain gamma‑aminobutyric acid (GABA) concentrations by inhibiting GABA transaminase and enhancing GABA synthesis, while also blocking voltage‑gated sodium channels and modulating NMDA‑mediated glutamate transmission. These actions collectively raise the seizure threshold and dampen neuronal hyper‑excitability.

Adverse reactions to sodium valproate may vary in frequency and severity.

Common Side Effects

• Nausea or vomiting: mild gastrointestinal upset.
• Tremor: fine shaking of the hands.
• Weight gain: gradual increase in body weight.
• Hair loss: diffuse thinning of scalp hair.
• Drowsiness: transient sedation.
• Elevated liver enzymes: mild, often reversible changes.

Serious or Rare Side Effects

• Hepatic failure: severe liver injury, especially in young children.
• Pancreatitis: inflammation of the pancreas with abdominal pain.
• Thrombocytopenia: low platelet count leading to bleeding risk.
• Hyperammonemia: elevated blood ammonia causing confusion.
• Severe skin reactions: Stevens‑Johnson syndrome or toxic epidermal necrolysis.
• Birth defects: teratogenic risk when used during pregnancy.

When prescribing sodium valproate, clinicians should consider several safety aspects.

• Liver function monitoring: assess baseline enzymes and repeat periodically.
• Pregnancy risk: avoid use in women of childbearing potential unless no alternative exists.
• Drug interactions: review concomitant medications for potential PK/PD effects.
• Renal function: adjust dosing in severe impairment.
• Hematologic monitoring: check complete blood count for thrombocytopenia.
• Store at below 25°C: keep in the original container, protect from moisture and direct sunlight.

Sodium valproate interacts with several medicines, requiring careful management.

Major Interactions (Avoid)

• Carbamazepine: may reduce valproate levels and increase hepatotoxic risk.
• Phenobarbital: can lower valproate concentrations, diminishing efficacy.
• Rifampicin: induces metabolism, leading to sub‑therapeutic levels.

Moderate Interactions (Monitor Closely)

• Oral contraceptives: valproate may increase hormone levels, altering contraceptive effectiveness.
• Warfarin: enhanced anticoagulant effect may require INR monitoring.
• Lamotrigine: risk of severe skin reactions when combined.
• Topiramate: may increase risk of hyperammonemia.
• Acetaminophen: high doses can raise liver enzyme levels.