Proguanil

Proguanil (chlorguanide, chloroguanide) is a prophylactic antimalarial drug.

Proguanil is effective against sporozoites.

Proguanil hydrochloride is marketed as Paludrine by AstraZeneca.

Mechanism
It works by stopping the malaria parasite, Plasmodium falciparum and Plasmodium vivax, from reproducing once it is in the red blood cells.

It does this by inhibiting the enzyme dihydrofolate reductase, which catalyzes the formation of tetrahydrofolate, the main one carbon unit carrier in our body, required for dTMP and purine base synthesis.

Combinations
Proguanil is usually taken in combination with another anti-malarial drug such as atovaquone (e.g., in the drug Malarone) or chloroquine.

Malarone has fewer side effects than mefloquine, but can be more expensive because it is taken daily.

Proguanil is taken with atovaquone for chloroquine-resistant and multidrug resistant strains of P. falciparum and P. vivax. Proguanil combined with atovaquone is sold under the tradename Malarone (GlaxoSmithKline)

Precautions
General precaution regarding Proguanil involves watching out for feelings of sullenness and anxiety to a level that is outside the ordinary, when taking over a period of several months. These may come on gradually and may not be immediately attributable to anything in particular.