Antileprotic drugs

Antileprotic drugs

1. ANTILEPROTIC DRUGS PREPARED BY, Mrs. Rijo lijo

2. INTRODUCTION Leprosy is caused by a slow-growing type of bacteria called Mycobacterium leprae (M. leprae ) Also known as Hansen's disease, after the scientist ho discovered M. leprae in 1873. It primarily affects the skin and the peripheral nerves. Long Incubation period (3 – 5 years ).

3. CLASSIFICATION OF ANTILEPROTIC DRUG

4. DAPSONE Mechanism of action: Dapsone is a sulfone for the primary treatment of Dermatitis herpetiformis and an antibacterial drug for susceptible cases of leprosy. Dapsone is bactericidal as well as bacteriostatic against Mycobacterium leprae . As an antibacterial, dapsone inhibits bacterial synthesis of dihydrofolic acid, via competition with para- aminobenzoate for the active site of dihydropteroate synthetase .

5. PHARMACOKINETICS Absorption: Rapidly and nearly completely absorbed from GI tract. Peak: 2–8 h. Distribution : Distributed to all body tissues; high concentrations in kidney, liver, muscle, and skin; crosses placenta; distributed into breast milk . Metabolism: Metabolized in liver. Elimination : 70–85% excreted in urine; remainder excreted in feces; traces of drug may be found in body for 3 week after discontinuation of repeated doses . Half-Life: 20–30 h.

6. Indication of D apsone : • Leprosy • Pneumocystis carinii pneumonia.

7. Contraindications : Avoid use in cardiac or pulmonary disease, anemia, G6PD deficiency. Methemoglobin reductase deficiency . Hypersensitivity to dapsone or any of its components.

8. DOSAGE Dosing : Oral Leprosy : Oral 1-2 mg/kg/day as single dose in combination with rifampicin. Maximum Dose: 100 mg/day.

9. Pneumocystis Pneumonia Prophylaxis : >1 month: 2 mg/kg/day (up to 100 mg) orally once a day OR 4 mg/kg orally once weekly Maximum dose = 200 mg Adolescents: 100 mg once orally or in two divided doses in single drug treatment OR 50 mg once every day in combination therapy.

10. ADVERSE EFFECT : Dose-related hemolysis. Agranulocytosis. peripheral neuropathy. Nausea. vomiting.

11. abdominal pain. pancreatitis. Vertigo. blurred vision. tinnitus. insomnia. fever.

12. Headache. psychosis. phototoxicity . pulmonary eosinophilia. tachycardia. albuminuria. nephrotic syndrome.

13. hypoalbuminemia without proteinuria. renal papillary necrosis. male infertility. drug-induced lupus erythematosus. infectious mononucleosis-like syndrome. methemoglobinemia . erythema nodosum leprosum .

14. Systemwise adverse reaction Body as a Whole: Hypersensitivity (cutaneous reactions); erythema multiforme . exfoliative dermatitis. toxic epidermal necrolysis [rare ]. allergic rhinitis. urticarial. Fever. infectous mononucleosis-like syndrome.

15. CNS: Headache. nervousness. insomnia. vertigo. paresthesia. muscle weakness.

16. CV: Tachycardia. GI : Anorexia. nausea. vomiting. abdominal pain. toxic hepatitis. cholestatic jaundice (reversible with discontinuation of drug therapy). increased ALT, AST, LDH; hyperbilirubinemia.

17. Hematologic: In patient with or without G6PD deficiency dose-related hemolysis. Heinz body formation. methemoglobinemia with cyanosis. hemolytic anemia. aplastic anemia (rare ). agranulocytosis.

18. Skin : Drug-induced lupus erythematosus. phototoxicity . Special Senses : Blurred vision. tinnitus.

19. Other: Male infertility. sulfone syndrome (fever, malaise, exfoliative dermatitis, hepatic necrosis with jaundice, lymphadenopathy, methemoglobinemia , anemia).

20. NURSES RESPONSIBILITY Assessment & Drug Effects Monitor for therapeutic effectiveness that may not appear for leprosy until after 3–6 months of therapy. Skin lesions respond well; recovery from nerve involvement is usually limited. Lab tests: Perform baseline then weekly CBC during the first month of therapy, at monthly intervals for at least 6 months, and semiannually thereafter. Determine periodic dapsone blood levels. Perform liver function tests in patients who complain of malaise, fever, chills, anorexia, nausea, vomiting, and have jaundice. Dapsone therapy is usually suspended until etiology is identified.

21. Monitor severity of anemia. Nearly all patients demonstrate hemolysis. Manufacturer states that Hg level is generally decreased by 1–2 g/ dL ; reticulocytes increase by 2–12%; RBC life span is shortened; and methemoglobinemia occurs in most patients receiving dapsone . Monitor temperature during first few weeks of therapy. If fever is frequent or severe, leprosy reactional state should be ruled out. Reduction of or interruption of therapy may be sufficient for improvement. Report cyanotic appearance or mucous membranes with brownish hue to physician as possible methemoglobinemia .

22. Patient & Family Education Report symptoms of leprosy that do not improve within 3 months or get worse to physician. Report the appearance of a rash with bullous lesions around elbows and other joints promptly. Drug-induced or worsening skin lesions require withdrawal of dapsone . Report symptoms of peripheral neuropathy with motor loss (muscle weakness) promptly. Do not breast feed while taking this drug without consulting physician.