Chemotherapy of Malaria

Chemotherapy for malaria involves the use of antimalarial drugs to treat and prevent the disease caused by the Plasmodium parasite.
The word “chemotherapy” is split as follows: “chemo” means chemical, drug, or medicine, and “therapy” means treatment.
Thus, chemotherapy is defined as the use of chemicals, drugs, or medicines to treat malaria.

Terminology in Chemotherapy of Malaria

1) Blood Schizontocidal Drugs

• Act on asexual parasites in the blood.
  Benefits:
• Cure malaria.
• Reduce morbidity.
• Prevent death and complications.
• Benefit the patient only (not the community).
• Kill merozoites and trophozoites, preventing further development.

2) Tissue Schizontocidal Drugs

• Act on asexual parasites in tissues (liver phase).
  Benefits: Kills hypnozoites and sporozoites.
• Primary tissue schizontocide: Acts on pre-erythrocytic or exo-erythrocytic forms.
• Secondary tissue schizontocide: Acts on secondary pre-erythrocytic or exo-erythrocytic forms.
  Example: Primaquine.

3) Gametocytocidal Drugs

• Destroy the sexual forms of malaria parasites.
  Benefits:
• Protect the community by killing gametocytes.
• Prevent secondary transmission.

Types of Antimalarial Drugs

Blood Schizontocidal Drugs

Destroy asexual forms of malaria parasites in red blood cells.
Examples: Halofantrine, Artemisinin and derivatives (artesunate, dihydroartemisinin, arteether), Sulfonamides, Chloroquine, Amodiaquine, Proguanil, Pyrimethamine + Sulphadoxine (Metakelfin), Mefloquine, and Quinine.

Gametocytocidal Drugs

Target gametocytes in red blood cells.

• Only primaquine is effective.
• Benefits society, not the individual.
• Kills gametocytes and prevents malaria transmission.
• Also kills hypnozoites and sporozoites.

⚠️ Note: Contraindicated in pregnant women, infants, and patients with G6PD deficiency.

Tissue Schizontocidal Drugs

• Only primaquine is effective.
• Kills resting sporozoites in the hypnozoite stage.

Sporontocidal Drugs

• Prevent or interrupt the development of parasites inside mosquitoes after feeding.
• Block the formation of oocysts and sporozoites.
  Examples: Primaquine, Quinocide, Proguanil, and Pyrimethamine.

Aims of Malaria Case Management

1. Provide prompt, complete, and effective treatment to all confirmed cases.
2. Prevent mild cases from progressing to severe or complicated malaria.
3. Prevent deaths due to severe malaria.
4. Prevent malaria transmission.
5. Minimize the spread of drug-resistant parasites by using effective drugs at appropriate dosages.

Types of treatment generally used in malaria cases: PT, RT, MT, and CRT.