Antimalarials: Nursing pharmacology

Antimalarials are a group of medications primarily used in the prevention and treatment of malaria, which is caused by Plasmodium spp, a protozoan parasite transmitted by certain Anopheles mosquitoes. In addition, some antimalarials can also be used to treat amebiasis and some autoimmune disorders like systemic lupus erythematosus and rheumatoid arthritis.

The oldest medication of this group is quinine, but its derivative chloroquine is most often used because it has fewer side effects. Other antimalarials include hydroxychloroquine, mefloquine, primaquine, pyrimethamine, and a combination of atovaquone and proguanil. If Plasmodium is resistant to antimalarial therapy, antibiotics like doxycycline, tetracycline, and clindamycin can be used.

Antimalarials are administered orally. Once administered, they work in various ways. Chloroquine, quinine, pyrimethamine, atovaquone, and proguanil all inhibit parasitic DNA synthesis; pyrimethamine, in particular, also inhibits protein synthesis.

Mefloquine and hydroxychloroquine affect the function of lysosomes in the parasitic cell. Finally, primaquine affects the mitochondria of the parasite.

Antimalarials can cause a number of side effects, most commonly of the gastrointestinal tract such as nausea, vomiting, cramps, and anorexia. In addition, clients can develop alopecia, a skin rash, photosensitivity, and hypersensitivity reactions like Stevens-Johnson syndrome and drug reaction with eosinophilia and systemic symptoms or DRESS for short.

Some clients taking antimalarials may also experience neurological side effects, such as headaches, nightmares, and even seizures; and mefloquine has a boxed warning for causing adverse neuropsychiatric reactions like anxiety, depression, hallucinations, and suicidal ideation.