Doxycycline antimalarial

Some antibiotics, such as the tetracyclines, tetracycline (7), doxycycline (78), and minocycline (17), chloramphenicol (79), and clindamycin (23) have modest antimalarial properties, but are slow-acting. 

Tetracycline and its derivative doxycycline are antibiotics widely used in the treatment of bacterial infections. They also exert an antimalarial activity. Tetracyclines inhibit the binding of aminoacyl-tRNA to the ribosome during protein synthesis. 

Malaria is transmitted from person to person by a certain species of the Anopheles mosquito. The four different protozoans causing malaria are Plasmodium falciparum, P. malariae, P. ovale, and P. vivax. Drugp used to treat or prevent malaria are called anti malarial drags. Three antimalarial drugs are discussed in the chapter chloroquine, doxycycline, and quinine sulfate. Other examples of antimalarial drugs in use today are listed in the Summary Drug Table Antimalarial Drugs. 

Doxycycline - Treatment of malaria (100 mg twice daily for 7 days in combination with other antimalarial agents). 

Clindamycin (see Chapter 44) is slowly active against erythrocytic schizonts and can be used after treatment courses of quinine, quinidine, or artesunate in those for whom doxycycline is not recommended, such as children and pregnant women. Azithromycin (see Chapter 44) also has antimalarial activity and is now under study as an alternative chemoprophylactic drug. Antimalarial activity of fluoroquinolones has been demonstrated, but efficacy for the therapy or chemoprophylaxis of malaria has been suboptimal. 

A lead compound bearing a ferrocenyl moiety at position N(l) was identified. This derivative is more active than Ciprofloxacin and Doxycycline. The activity is remarkably constant regardless of the level of resistance to CQ of the strains. Contrary to other antibiotics, no delayed-death effect was noted. Isobologram analysis showed that this compound exerts an antagonist effect with the main quinoline-containing antimalarials. In vitro results have to be confirmed in vivo to check the bioavailability of the molecule and its potential interest as a new antimalarial [113],... 

Schwartz E, Regev-Yochay G. Primaquine as prophylaxis for malaria for nonimmune travelers A comparison with mefloquine and doxycycline. Clin Infect Dis I999 29(6) 1502-6. Lobel HO, Coyne PE, Rosenthal PJ. Drug overdoses with antimalarial agents prescribing and dispensing errors. JAMA 1998 280(17) 1483. 

Huee antimalarial drags have polycyclic ring systems (Fig. 9-10) in common. The flrst is the common tetracycline anti biotic, doxycycline. The second is one of the newer drags luticated for malaria, halofantrine. The third is the discontinued agent used in the South Pacific, aminoacridine. 

This section consists of antiprotozoal drugs. Note that antimalarials are also antiprotozoals but have been described in a separate section Antibiotics with antiprotozoal activity are not included in this chapter. These include clindamycin, co-trimoxazole/trimethoprim, dapsone, doxycycline and metronidazole ... 

An in vitro study found that doxycycline potentiated the antimalarial activity of atovaquone, but there appears to be no information on the effect of doxycycline on the absorption of atovaquone. A study looking at the population pharmacokinetics of atovaquone in 24 Thai patients found that neither the oral clearance nor the volume of distribution of atovaquone were significantly affected by the concurrent use of tetracycline. ... 

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