For malaria prophylaxis with chloroquine, what is the correct regimen for a trip of three weeks, given OTC packaging of 20 tablets?

• A. 310 mg once weekly, started 1 week before entering endemic area and continued for 4 weeks after leaving. Supply 20 tablets
• B. 300 mg daily starting the day of travel
• C. 150 mg weekly for 2 weeks
• D. 310 mg daily during the trip only

Answer: (A)

Weekly dosing with chloroquine is used for malaria prevention. The idea is to keep protective drug levels in the body throughout exposure and for a tail after leaving the endemic area, so you don’t have gaps in protection.

For a three‑week trip, start one week before you enter the endemic area, take a dose once weekly during the trip (three doses), and continue for four weeks after you return. That makes eight weekly doses in total. The OTC packaging provides 20 tablets, so you have more than enough to cover those eight weekly doses.

Each dose is taken as one 310 mg tablet, so eight doses fit easily within the package. This approach is preferred over daily regimens, which aren’t necessary for prophylaxis and could increase the risk of side effects; the weekly schedule with a pre-travel and post-travel tail is the standard practice for chloroquine prophylaxis.