c. Cautions and Warnings.
(1) Do not administer to pregnant women, clients with oliguria, liver disease,
heart disease, or allergy to pyrimethamine.
(2)
Overdosage may cause hypotension, arrhythmias of the heart, and
shock.
(3) Because this is a folic acid antagonist, it tends to cause bone marrow
depression when given at high doses. Periodic blood counts should be run. If signs
appear, then the drug dosage should be reduced.
d. Adverse Reactions. Anorexia, vomiting, megaloblastic anemia, and bone
marrow depression with leukopenia and thrombocytopenia have been observed.
e. Supply. Pyrimethamine is supplied in 25-mg tablets.
6-25. SULFADOXINE AND PYRIMETHAMINE
a. Uses. Sulfadoxine and pyrimethamine (Fansidar) is used in the treatment of
plasmodium falciparum malaria in clients in whom chloroquine resistance is suspected
and for the prophylaxis of malaria for travelers to areas where chloroquine-resistant
plasmodium falciparum malaria is endemic.
b. Usual Dosage.
(1) For treatment of malaria, adults take 2 or 3 tablets in a single dose alone
or in sequence with quinine regimen.
(2) For prophylaxis of malaria for travelers in endemic areas, adults take
one tablet one or two days before departure and then take one tablet weekly during the
stay and for 4 to 6 weeks after return.
c. Cautions and Warnings.
(1) Fatalities have been associated with sulfadoxine/pyrimethamine use.
Discontinue use if skin rash appears, if the count of any formed blood elements is
reduced significantly, or if active bacterial or fungal infections occur.
(2) Clients must maintain adequate fluid intake to prevent crystalluria and
stone formation.
(3)
Take contraceptive measures to avoid pregnancy during therapy.
(4)
Avoid breastfeeding during therapy.
MD0913
6-25