Which is the drug used for refractory intractable rheumatic chorea?

Explanation

## Correct Answer: D. Sodium valproate Rheumatic chorea (Sydenham's chorea) is a manifestation of acute rheumatic fever (ARF) characterized by involuntary, purposeless movements due to inflammation of the basal ganglia. While most cases resolve spontaneously or respond to first-line agents (NSAIDs, corticosteroids, benzodiazepines), refractory intractable chorea requires second-line pharmacotherapy. **Sodium valproate** is the gold-standard drug for refractory cases because it acts as a broad-spectrum anticonvulsant with multiple mechanisms: GABA enhancement, sodium channel blockade, and histone deacetylase inhibition. These properties stabilize abnormal neuronal firing in the basal ganglia circuits responsible for choreiform movements. In Indian clinical practice, valproate is preferred over other anticonvulsants for chorea because it has a faster onset of action (days to weeks) compared to phenytoin, better tolerability than older agents, and proven efficacy in ARF cohorts. Typical dosing is 15–30 mg/kg/day in divided doses, titrated to therapeutic levels (50–100 µg/mL). It is particularly valuable in children and adolescents with ARF in whom chorea persists despite NSAIDs, corticosteroids, and benzodiazepines. ## Why the other options are wrong **A. Diazepam** — Diazepam is a first-line agent for acute chorea and mild-to-moderate cases, providing symptomatic relief through GABA-A potentiation and muscle relaxation. However, it is NOT suitable for refractory intractable chorea because tolerance develops rapidly, higher doses become ineffective, and it lacks the sustained anticonvulsant properties needed for long-term control of persistent choreiform movements. NBE may trap students who confuse acute management with refractory management. **B. Probenecid** — Probenecid is a uricosuric agent used for chronic gout management and has NO role in treating chorea. It is sometimes confused with anti-rheumatic drugs in ARF, but it does not affect neurological manifestations. This is a distractor that tests whether students understand the distinction between drugs for ARF complications (e.g., carditis, arthritis) and drugs for neurological manifestations (chorea). **C. Haloperidol** — Haloperidol is a first-generation antipsychotic that blocks dopamine and can reduce choreiform movements acutely. However, it is NOT preferred for refractory chorea because of significant adverse effects (tardive dyskinesia, extrapyramidal side effects, neuroleptic malignant syndrome) and poor long-term tolerability in children. Valproate is safer and more effective for sustained control in the ARF population. ## High-Yield Facts - **Sodium valproate** is the second-line drug for refractory Sydenham's chorea when NSAIDs, corticosteroids, and benzodiazepines fail. - **Valproate dosing** in chorea: 15–30 mg/kg/day in divided doses; therapeutic level 50–100 µg/mL. - **First-line agents** for acute chorea: NSAIDs (aspirin), corticosteroids (prednisolone), and benzodiazepines (diazepam); valproate reserved for refractory cases. - **Mechanism in chorea**: Valproate enhances GABA, blocks sodium channels, and stabilizes basal ganglia neuronal firing. - **Haloperidol** is avoided in refractory chorea due to risk of tardive dyskinesia and extrapyramidal effects in long-term use. ## Mnemonics **CHOREA DRUGS (Escalation)** First-line: NSAIDs, Steroids, Benzodiazepines (NSB) → Refractory: Valproate, Haloperidol (VH). Use this to remember that valproate is the preferred second-line agent over haloperidol. **VALPROATE for CHOREA** VAlproate = Versatile Anticonvulsant for refractory chorea (when benzodiazepines fail). Mnemonic: VA-CHOREA. ## NBE Trap NBE pairs benzodiazepines (diazepam) with chorea management to trap students who only know first-line therapy and confuse acute symptomatic relief with refractory management. The question specifically asks for "refractory intractable" chorea, which is the discriminating phrase that rules out diazepam. ## Clinical Pearl In Indian paediatric practice, ARF with refractory chorea is not uncommon in resource-limited settings where acute rheumatic fever remains prevalent. Valproate is preferred because it is affordable, widely available, and has a rapid onset compared to phenytoin—critical factors in managing children who may have already suffered significant morbidity from prolonged chorea. _Reference: Harrison Ch. 375 (Acute Rheumatic Fever); KD Tripathi Ch. 10 (Anticonvulsants); Robbins Ch. 12 (Rheumatic Heart Disease)_