Proguanil is a prophylactic antimalarial drug

Antimalarial drug

Antimalarial medications, also known as antimalarials, are designed to prevent or cure malaria. Such drugs may be used for some or all of the following:* Treatment of malaria in individuals with suspected or confirmed infection...

.

Proguanil is effective against sporozoites.

Proguanil hydrochloride is marketed as Paludrine by AstraZeneca

AstraZeneca

AstraZeneca plc is a global pharmaceutical and biologics company headquartered in London, United Kingdom. It is the world's seventh-largest pharmaceutical company measured by revenues and has operations in over 100 countries...

.

Mechanism

It works by stopping the malaria parasite, Plasmodium falciparum

Plasmodium falciparum

Plasmodium falciparum is a protozoan parasite, one of the species of Plasmodium that cause malaria in humans. It is transmitted by the female Anopheles mosquito. Malaria caused by this species is the most dangerous form of malaria, with the highest rates of complications and mortality...

and Plasmodium vivax

Plasmodium vivax

Plasmodium vivax is a protozoal parasite and a human pathogen. The most frequent and widely distributed cause of recurring malaria, P. vivax is one of the four species of malarial parasite that commonly infect humans. It is less virulent than Plasmodium falciparum, which is the deadliest of the...

, from reproducing once it is in the red blood cells.

It does this by inhibiting the enzyme

Enzyme

Enzymes are proteins that catalyze chemical reactions. In enzymatic reactions, the molecules at the beginning of the process, called substrates, are converted into different molecules, called products. Almost all chemical reactions in a biological cell need enzymes in order to occur at rates...

 dihydrofolate reductase

Dihydrofolate reductase

- Function :Dihydrofolate reductase converts dihydrofolate into tetrahydrofolate, a methyl group shuttle required for the de novo synthesis of purines, thymidylic acid, and certain amino acids...

, which catalyzes the formation of tetrahydrofolate, the main one carbon unit carrier in our body, required for dTMP and purine

Purine

A purine is a heterocyclic aromatic organic compound, consisting of a pyrimidine ring fused to an imidazole ring. Purines, including substituted purines and their tautomers, are the most widely distributed kind of nitrogen-containing heterocycle in nature....

 base synthesis.

Combinations

Proguanil is usually taken in combination with another anti-malarial drug such as atovaquone

Atovaquone

Atovaquone is a chemical compound that belongs to the class of naphthalenes. Atovaquone is a hydroxy-1,4-naphthoquinone, an analog of ubiquinone, with antipneumocystic activity. Its average wholesale price is about US$2.13 per standard 250 mg. tablet...

 (e.g., in the drug Malarone) or chloroquine

Chloroquine

Chloroquine is a 4-aminoquinoline drug used in the treatment or prevention of malaria.-History:Chloroquine , N'--N,N-diethyl-pentane-1,4-diamine, was discovered in 1934 by Hans Andersag and co-workers at the Bayer laboratories who named it "Resochin". It was ignored for a decade because it was...

.

Malarone has fewer side effects than mefloquine

Mefloquine

Mefloquine hydrochloride is an orally administered medication used in the prevention and treatment of malaria. Mefloquine was developed in the 1970s at the United States Department of Defense's Walter Reed Army Institute of Research as a synthetic analogue of quinine...

, 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

GlaxoSmithKline

GlaxoSmithKline plc is a global pharmaceutical, biologics, vaccines and consumer healthcare company headquartered in London, United Kingdom...

)

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.

External links

• http://healthlink.mcw.edu/article/979237802.html
• Malarone official website