Sulfadoxine & Pyrimethamine (SP)
Each tablet contains Sulfadoxine BP 500mg and Pyrimethamine BP25mg
Sulfadoxine is a long acting sulphonamide which inhibits production of nucleic acids in sensitive micro-organisms including the malaria causing plasmodium species. This is achieved by inhibition of dihydropteroate synthase, an enzyme required for bacterial utilization of para-aminobenzoic acid for the synthesis of folic acid.
Pyrimethamine is an antimalarial drug which inhibits the enzyme dihydrofolate reductase essential in the production of nucleic acids in the parasite. When used in combination the two drugs potentiate each other since two successive steps in the production of nucleic acids are inhibited leading to the death of the parasites.
There is no pharmacokinetics interaction between sulfadoxine and pyrimethamine. Sulfadoxine is readily absorbed after oral administration. Peak plasma levels of between 56 and 71 mcg/ml are reached in 2.5 to 6 hours after an oral dose of 500mg. sulfadoxine is widely distributed into tissues and fluids. Plasma protein binding is 90-95%. It is excreted slowly in the urine without being metabolized.
Pyrimethamine is completely absorbed after oral administration. Peak serum concentration (Cmax) is achieved in 1.5 to 8 hours after an oral dose of 25 mg. Pyrimethamine is mainly concentrated in liver, spleen, kidney and lungs. Plasma binding is 80-90%. Pyrimethamine is metabolized in the liver and slowly excreted through the kidney.
Both Pyrimethamine and Sulfadoxine cross the placenta into the foetal circulation and are excreted into the breast milk.
Orodar tablets are used for Intermittent Preventive Therapy (IPTp) of malaria in pregnant women, along with other preventive and control measures. Intermittent Preventive Therapy is recommended in areas where transmission of P.falciparum is high or stable
- All pregnant women in stable and high malaria transmission areas should receive at least two doses of Orodar at separate occasions after quickening: one dose during the second trimester of pregnancy and another during the third trimester. One single dose of Orodar is 3 tablets. IPTp doses should best be linked to scheduled antenatal clinic visits
- Women known to be HIV-infected or unknown HIV status living in area of high HIV prevalence (>10% among pregnant women) should receive at least 3 doses.
- Pregnant women who are HIV positive and are also taking ARVs should receive IPTp
- Pregnant women who are HIV positive and are on daily Co-trimoxazole chemoprophylaxis should not be given Orodar
IPTp doses should be given at an interval of at least 4 weeks
Gastrointestinal disorders like nausea, vomiting and diarrhea.
Skin rashes and other allergic reactions like Stevens-Johnsons syndrome. If these occur Orodar should not be used again
In rare cases, depression of haematopoiesis and megaloblastic anaemia may occur.
Known hypersensitivity to sulphonamides or pyrimethamine
The medication must be immediately withdrawn if skin reactions occur.
Impaired renal function
Adequate fluid intake is necessary with this medication
While on the medication, if coughing and shortness of breath occurs, Orodar should be stopped immediately