Maloprim - Dapsone

Maloprim, the fixed dose combination of pyrimethamine with dapsone, is not recommended for routine prophylaxis because of the potential for fatal agranulocytosis. 

D Dapson-Fatol GB Maloprim (Glaxo J Protogen (Yoshitomi)... 

Mefloquine, chloroquine, proguanil, and pyrimethamine plus dapsone (Maloprim), alone or in combination are most commonly advised for prophylaxis regimens and doxycycline for special cases (drug resistance or intolerance) primaquine is being re-evaluated. 

A dapsone syndrome was reported in a 30-year-old woman after 4 weeks of treatment with Maloprim and chloroquine base 300 mg/weekly. The symptoms comprised fever, joint and muscle pains, dry cough, and a diffuse red urticarial rash, followed by generalized lym-phadenopathy, a painful exudative tonsillitis, and a prominent atypical lymphocytosis. 

Thong BY, Leong KP, Chug HH. Hypersensitivity syndrome associated with dapsone/pyrimethamine (Maloprim) antimalaria chemoprophylaxis. Ann Allergy Asthma Immunol 2002 88(5) 527-9. 

Trade names Avlosulfon Dapson Dapson-Fatol Maloprim (Combination) Protogen Sulfona Indications Leprosy, dermatitis herpetiformis Category Antibiotic Antimycobacterial Half-life 10-50 hours... 

Sulfonamides or sulfones usually account for most toxicity associated with coadministration of these antifolate drugs (see Chapter 43). The combination of pyrimethamine (25 mg) and sulfa-doxine (500 mg) (fansidar) causes severe and even fatal cutaneous reactions in up to 1 in 5000 people. This combination also has been associated with serum sickness-type reactions, urticaria, exfoliative dermatitis, and hepatitis. Pyrimethamine-sulfadoxine is contraindicated in individuals with previous reactions to sulfonamides, lactating mothers, and infants <2 months of age. Administration of pyrimethamine with dapsone (MALOPRIM, unavailable in the U.S.), occasionally has been associated with agranulocytosis. Higher doses pyrimethamine (75 mg daily) used along... 

An example of sequential blocking is the use of a sulfadiazine with pyrimethamine 9.31) in toxoplasmosis, a protozoal disease (Wettingfeld, Rowe and Eyles, 1956). In this sequence, the sulfonamide blocks the incorporation of / -aminobenzoic acid into dihydrofolic acid, and the pyrimethamine prevents the reduction of this pteridine to tetrahydrofolic acid (Sections 9.3.2 and 9.3.3). In malaria, as early as 1959, Hurly made the observation that pyrimethamine and sulfadiazine potentiated one another to such a degree that the combination could actually cure Pl.falciparum infections. Thus, less than 0.1 m.e.d. (minimal effective dose) of pyrimethamine and 0.25 m.e.d. of sulfadiazine were, together, as effective as 1.0 m.e.d. of either drug separately. In current tropical medicine, Maloprim , a combination of pyrimethamine and dapsone 9.17) (the latter chosen because of its slow rate of excretion which matches that of pyrimethamine), forms an excellent replacement for chloroquine in cases of Pl.falciparum... 

---