Drug	Usage	Adult dosage	Cost*	Comments
Chloroquine (Aralen)	In areas with chloroquine-sensitive Plasmodium falciparum; safe option in pregnancy	500 mg orally, once a week; begin therapy two weeks before exposure and continue for four weeks after.	$ 5.26	—
Mefloquine (Lariam)	In areas with chloroquine-resistant P. falciparum; safe option in pregnancy	250 mg orally, once a week; begin therapy two weeks before exposure and continue for four weeks after.	$10.75	Not recommended in patients with seizure disorders, cardiac conduction abnormalities, or psychosis
Doxycycline (Vibramycin)	Alternative to mefloquine in areas with chloroquine- resistant P. falciparum;contraindicated in pregnancy	100 mg orally, once a day; begin therapy two days before exposure and continue for four weeks after.	$ 4.34	Contraindicated in lactating women and children younger than eight years; should be taken with food
Atovaquone/ proguanil (Malarone)	Alternative to mefloquine and adoxycycline in areas with chloroquine-resistant P. falciparum; contraindicated in pregnancy	1 adult tablet (250 mg atovaquone/100 mg proguanil) orally, once a day; begin therapy one to two days before exposure and continue for one week after.	$ 4.70	Contraindicated in severe renal failure (creatinine clearance less than 30 mL per minute); should be taken with food
Primaquine (Palum)	As terminal prophylaxis in those with prolonged exposure to Plasmodium vivax or Plasmodium ovale, or both, or exposure in areas of intense P. vivax transmission; contraindicated in pregnancy	26.3 mg orally, once a day, for 14 days after departure from endemic area	$ 0.90	Contraindicated in patients with G6PD deficiency; for chemoprophylaxis (not yet FDA-approved for this purpose), take 2 tablets daily one day before exposure and continue for seven days after departure from an endemic area