Artemisinins

Artemisinins carry an endoperoxide bridge. In infected red cells, heme iron splits this bridge, releasing free radicals and reactive oxygen species that damage parasite proteins and nucleic acids. They clear blood-stage parasites within 2 to 3 days, including chloroquine-resistant P. falciparum, and kill gametocytes, but miss the dormant liver forms. Artemether and artesunate both become dihydroartemisinin (DHA).

• ArtemetherAlways given with lumefantrine: artemether clears most parasites fast and slowly eliminated lumefantrine kills the rest. WHO recommends it for falciparum malaria in early pregnancy, including the first trimester.
• ArtesunateWHO's first choice for severe malaria in adults, children and pregnant women, preferred over quinine. Where full care is out of reach, one IM dose, or a rectal dose in young children, is given before referral.

• Severe malaria (IV or IM artesunate)
• Uncomplicated falciparum malaria, in ACT combinations

• Delayed hemolytic anemia after treatmentKnown forSerious
• Headache
• Dizziness
• Loss of appetite
• Nausea, vomiting and abdominal pain
• Low white cell count
• Jaundice and raised liver enzymes
• Rash and itching
• Long QT interval (with some partner drugs)Serious
• Anaphylaxis and other allergic reactionsSerious

What the class has in common. Each drug's card has its own, and Known for marks what an exam expects you to know.

• Never used alone for uncomplicated malaria: a longer-acting partner drug (an ACT) clears the rest and protects against resistance.
• After IV artesunate, finish with a full oral ACT course, and check hemoglobin for 4 weeks for delayed hemolysis.
• They miss vivax and ovale liver forms: add an 8-aminoquinoline such as primaquine to prevent relapse.
• Enzyme inducers such as rifampicin, carbamazepine and phenytoin lower their levels and can cause treatment failure.

Written for biofideX in plain words, after checking these references:

• Artesunate for injection: label (FDA)
• Artemether and lumefantrine tablets: label (DailyMed)
• Artesunate (NCI Thesaurus)
• WHO guidelines for malaria (WHO)

For learning pharmacology, not for treatment decisions: no doses are given, and a prescriber, pharmacist or the product's own label is the word on any one patient. Spotted a mistake? Tell us and we'll correct it.