Can I take mefloquine daily?

The recommended dosage for malaria prophylaxis is once weekly - see http://www.drugs.com/pro/mefloquine.html

Malaria Prophylaxis

One 250 mg Mefloquine hydrochloride tablet once weekly.

Prophylactic drug administration should begin 1 week before arrival in an endemic area. Subsequent weekly doses should be taken regularly, always on the same day of each week, preferably after the main meal. To reduce the risk of malaria after leaving an endemic area, prophylaxis must be continued for 4 additional weeks to ensure suppressive blood levels of the drug when merozoites emerge from the liver. Tablets should not be taken on an empty stomach and should be administered with at least 8 oz (240 mL) of water.

The WHO recommendations for malaria prophylaxis in Sudan

Malaria risk
Malaria: Malaria risk-predominantly due to P. falciparum-exists throughout the year in the whole country. Risk is low and seasonal in the north. It is higher in the central and southern part of the country. Malaria risk on the Red Sea coast is very limited. Resistance to chloroquine and sulfadoxine-pyrimethamine reported.
Malaria prevention
Recommended prevention: Mosquito bite prevention plus mefloquine, doxycycline or atovaquone+proguanil chemoprophylaxis (select according to reported resistance pattern)