<prompt> Drug of choice for primary prophylaxis for acute rheumatic fever?Erythromycin-1.2 million unitsErythromycin-1.2 lakh unitsBenzathine penicllin-1.2 lakh unitsBenzathine penicillin-1.2 million units  <response>: Prophylaxis of ARF: 1.primary-To stop streptococcal pharyngitis to procede to ARF In this,Antibiotics are given for a week. DOC-injection benzathine penicillin-1.2 million unitswt27kgs;0.6 million unitswt27 kgs. if patient is allergic to penicillins then macrolides are preferred. 2.secondary prophylaxis-To prevent recurrence. given during patient suffering from ARF. DRUG SAME AS PRIMARY-But every 3-4 weeks. if allergic-SULFADIAZINE is given. if also allergic to saulfadiazone,macrolides are preferred. 