<p><strong>For Treatment of Toxoplasmosis</strong>: The dosage of Pyrimethamine for the treatment of toxoplasmosis must be carefully adjusted so as to provide maximum therapeutic effect and a minimum of side effects. At the dosage required, there is a marked variation in the tolerance to the drug. Young patients may tolerate higher doses than older individuals. Concurrent administration of&nbsp;folinic acid&nbsp;is strongly recommended in all patients.<br />
<br />
The adult&nbsp;starting&nbsp;dose is 50 to 75 mg of the drug daily, together with 1 to 4 g daily of a sulfonamide of the sulfapyrimidine type, e.g. sulfadoxine. This dosage is ordinarily continued for 1 to 3 weeks, depending on the response of the patient and tolerance to therapy. The dosage may then be reduced to about one half that previously given for each drug and continued for an additional 4 to 5 weeks.<br />
<br />
The pediatric dosage of Pyrimethamine is 1 mg/kg/day divided into 2 equal daily doses; after 2 to 4 days this dose may be reduced to one half and continued for approximately 1 month. The usual pediatric sulfonamide dosage is used in conjunction with Pyrimethamine.<br />
<br />
<strong>For Treatment of Acute Malaria</strong>: Pyrimethamine is NOT recommended alone in the treatment of acute malaria. Fast-acting schizonticides, such as chloroquine or quinine, are indicated for treatment of acute malaria. However, Pyrimethamine at a dosage of 25 mg daily for 2 days with a sulfonamide will initiate transmission control and suppression of non-falciparum malaria.&nbsp;Pyrimethamine is only recommended for patients infected in areas where susceptible plasmodia exist. Should circumstances arise wherein Pyrimethamine must be used alone in semi- immune persons, the adult dosage for acute malaria is 50 mg for 2 days; children 4 through 10 years old may be given 25 mg daily for 2 days. In any event, clinical cure should be followed by the once-weekly regimen described below for chemoprophylaxis. Regimens which include suppression should be extended through any characteristic periods of early&nbsp;recrudescence&nbsp;and late relapse, i.e., for at least 10 weeks in each case.<br />
<br />
For Chemoprophylaxis of Malaria:</p>

<ul>
	<li><strong>Adults and pediatric patients over 10 years</strong>: 25 mg (1 tablet) once weekly</li>
	<li><strong>Children 4 through 10 years:</strong>&nbsp;12.5 mg (&frac12; tablet) once weekly</li>
	<li><strong>Infants and children under 4 years:</strong>&nbsp;6.25 mg (&frac14; tablet) once weekly.</li>
</ul>