Ans: c (3 weeks) Ref: Park 20th ed p 278Leprosy is a highly infectious disease of low pathogenicity. It is effectively made non-infectious by treatment with rifampicin for 3 weeks and by dapsone for 90 days. Local application of rifampicin (drops or spray) may destroy all the bacilli with in 8 days.Chemotherapy for leprosy- WHO recommendationsMULTIBACILLARY LEPROSY12 months to he completed within 18 months Rifampicin - 600mg once monthly under supervisionClofazimine - 300 mg once monthly under supervision - 50 mg daily self administered Dapsone 100 - mg daily self administeredPAUCIBACILLARY LEPROSY6 months to he completed within 9 months Rifampicin 600mg once monthly supervised Dapsone 100 mg daily self administered.PAUCIBACILLARY LEPROSY SINGLE LESION -* Ofloxacin 400 mg (Single dose)* Rifampicin 600 mg* Minocycline lOOmgAnti-leprotic drugs1) RIFAMPICIN -It is bactericidal to M.leprae and rapidly renders leprosy patients non contagious.Up to 99.99% M.leprae are killed in 3-7 days.MOA- Rifampicin binds to the bacterial DNA-dependent RN A polymerase and thereby inhibits RNA synthesis.Other indications include tuberculosis, prophylaxis of meningococ-cal and H.influenza meningitis and carrier state, combined with doxy-cycline in brucellosis, 2nd/3rd choice drug in MRSA, diphtheroids and legionella.Adverse effectsImparts a harmless orange color to urine, sweat, tears, and contact lenses.Rashes, thrombocytopenia and nephritis. Cholestatic jaundice and occasionally hepatitis. Rifampicin commonly causes light-chain proteinuria. If administered less often than twice weekly, rifampicin causes a flu-like syndrome characterized by fever, chills, myalgia, anemia, and thrombocytopenia and sometimes is associated with acute tubu-lar necrosis. Rifampicin strongly induces most Cytochrome P450 isoforms.2) DAPSONE (DPS): Dapsone (di amino di phenyl sulfone) like the sulfonamides inhibits folate synthesis.It is leprostatic at low concentrations and at relatively higher con-centrations arrests the growth of many other bacteria sensitive to sulfonamides.Other uses -1) In combination with pyrimethamine, Dapsone is used for treatment of chloroquine-resistant malaria.2) It is used to prevent and treat Pneumocystis jiroveci pneumonia in AIDS patients.Adverse effects:Many patients develop some hemolysis, particularly if they have glucose-6-phosphate dehydrogenase deficiency. Methemoglobinemia is common.Gastrointestinal intolerance, fever, pruritus and various rashes also occur. Allergic rashes, fixed drug eruption hypermelanosis, photo toxicity, and exfoliative dermatitis are the various cutaneous reactions seen.CLOFAZIMINEIt is a dye with leprostatic and anti-inflammatory properties.Its mechanism of action is unknown but may involve DNA binding.Adverse effectsSkin- The most prominent untoward effect is skin discoloration ranging from red-brown to nearly black.Dryness of skin and itching is also seenAcneiform eruptions and photoxicity have been noted.GIT- Gastrointestinal intolerance occurs occasionally.Other antibiotics used are ofloxacin, minocycline and clarithromycin