Anti-Parasite Drugs
Anti-malarial drugs
These drugs target various stages of the malaria parasite life cycle.
Chloroquine
This drug raises the pH of parasitic vacuoles inhibiting haem-polymerase.
This stops the parasite feeding in RBCs, stopping the life cycle.
It is used for malaria prophylaxis and acute attacks.
Resistance to chloroquine is emerging in many species of P. falciparum. In these cases, mefloquine is used to treat chloroquine-resistance strains.
Side effects
Headache
Contraindicated in epilepsy
Unfortunately, resistance to chloroquine is emerging in many species of P. Falciparum.
Mefloquine
This acts similarly to chloroquine and is used for prophylaxis and treatment of chloroquine-resistance strains
Side effects
Dizziness
Psychiatric signs (suicidal thoughts)
It is contraindicated in epilepsy
Artemisinins – Dihydroartemisin, artensuante
These are semi-synthetic drugs which are used in combination therapy to treat P. falciparum.
– These drugs are converted to dihydroartemisinin, which leads to the generation of free radicals to kill the parasite.
Side effects
GI upset
Dizziness
Quinine
This interferes with the erythrocytic stage of the parasite by inhibiting its ability to metabolise haemoglobin.
It used in the management of P. falciparum when artemisinins are not available.
Side effects
Produces curare-like effects on skeletal muscle, tinnitus and visual disturbances
Blackwater fever, a haemolytic crisis that occasionally complicates malaria infection.
- Large numbers of red blood cells undergo haemolysis releasing haemoglobin into the bloodstream
- This can cause an AKI.
Proguanil
This is a prodrug whose active metabolite inhibits dihydrofolate reductase to stop parasite DNA synthesis.
It is commonly used in combination with chloroquine or atovaquone (electron transport chain inhibitor).
Fansidar
This is Pyrimethamine (inhibits dihydrofolate reductase) and Sulfadoxine (inhibits dihydropteroate synthase)
It acts to prevent folic acid synthesis in order prevent DNA synthesis
Side effects
Megaloblastic anaemia
Folate deficiency
Drugs against other parasites
Mebendazole
This drug is used to treat many parasitic worm infections including threadworms, hookworms and giardia.
It inhibits the synthesis of microtubules which stops the uptake of glucose and nutrients, killing the helminth.
Side effects
GI upset
Hepatotoxicity
Praziquantel
This drug is used to treat schistosomiasis, potentially by increasing cell permeability to Ca2+ ions, leading to parasite paralysis (exact mechanism of action unknown).
Side effects
GI upset
CNS disturbance (dizziness, headache)
Ivermectin
This is a drug which is used against parasites like head lice and scabies. It opens Cl- channels, causing cell hyperpolarisation and death.
Side effects
CNS depression
Ataxia
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