Artesunate and Amodiaquine combination therapy
The widespread emergence of resistance to older antimalarials (like chloroquine) led to the need for newer, more effective therapies. The World Health Organization (WHO) has since recommended the use of artemisinin-based combination therapies (ACTs) for the treatment of uncomplicated P. falciparum malaria. AS-AQ is one of the ACTs.
Mechanism of Action
Artesunate: This is derived from the plant Artemisia annua. It is a water-soluble, semi-synthetic derivative of artemisinin. It rapidly reduces the number of parasites in the first 3 days of treatment, which results in quick relief from clinical symptoms. Its action is based on producing free radicals which damage the malaria parasite.
Amodiaquine: This is a 4-aminoquinoline compound, similar to chloroquine but effective against chloroquine-resistant strains. It is believed to interfere with the parasite's digestion of hemoglobin in its intraerythrocytic life cycle stage. Its action extends longer than that of artesunate, effectively clearing any remaining parasites.
Benefits of Combination
The combination reduces the risk of resistance because the drugs have different mechanisms of action.
Artesunate provides rapid symptomatic relief, while amodiaquine ensures that any residual parasites are eliminated.
Dosage and Administration
The therapy is usually administered once daily for three days. The exact dosage and duration may vary based on age, weight, and specific recommendations of the health agency.
Side Effects
Most side effects are mild and can include headache, dizziness, loss of appetite, weakness, and gastrointestinal disturbances. There are concerns about liver toxicity with amodiaquine, but when used in combination with artesunate for short periods, this risk is considered to be low.
Resistance
As with all antimalarials, there's concern about the development of drug resistance. Using them in combination helps to delay the onset of resistance. Still, it's essential to monitor for resistance and adjust treatment recommendations as necessary.
Contraindications
It's essential to check for any contraindications or drug interactions before starting therapy. People with known allergies to either component should not take this combination. Additionally, individuals with certain liver conditions or with a history of liver issues might be advised against taking amodiaquine.