Doxycycline malaria

Phillips MA, Kass RB. User acceptability patterns for mefloquine and doxycycline malaria chemoprophylaxis. I Travel Med 1996 3(l) 40-5. 

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. 

Malaria (doxycycline only) Prophylaxis of malaria due to Plasmodium falciparum in short-term travelers (less than 4 months) to areas with chloroquine and/or pyrimethamine-sulfadoxine resistant strains. 

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

Tetracyclines remain the agents of choice in rickettsial infections, and are also used in chlamydial, vibrio, mycoplasmal and spirochaetal infections, brucellosis and the management of chronic bronchitis and acne. They are used in combination with other agents in the treatment of malaria and amoe-biasis, and doxycycline is used for prophylaxis of malaria. 

Quinine sulfate is appropriate first-line therapy for uncomplicated falciparum malaria except when the infection was transmitted in an area without documented chloroquine-resistant malaria. Quinine is commonly used with a second drug (most often doxycycline or, in children, clindamycin) to shorten quinine s duration of use (usually to 3 days) and limit toxicity. Quinine is less effective than chloroquine against other human malarias and is more toxic. Therefore, it is not used to treat infections with these parasites. 

Primaquine has been studied as a daily chemoprophylactic agent. Daily treatment with 30 mg (0.5 mg/kg) of base provided good levels of protection against falciparum and vivax malaria. However, potential toxicities of long-term use remain a concern, and primaquine is generally recommended for this purpose only when mefloquine, Malarone, and doxycycline cannot be used. 

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. 

Esophageal ulceration occurred in two adults taking doxycycline as malaria chemoprophylaxis (13). 

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. 

Some in vitro studies have demonstrated that azithromycin is active against chloroquine-sensitive and -resistant strains of Plasmodium falciparum [285]. A trial using daily azithromycin at a dose of 250 mg as a malaria prophylaxis in volunteers has shown azithromycin to be protective against P. falciparum challenge [286,287]. A randomized, placebo-controlled, double-blind study of malaria prophylaxis compared two regimens of azithromycin versus daily doxycycline for a period of 10 weeks in western Kenya [287]. Both regimens with daily azithromycin and doxycycline provided effective prophylaxis of falciparum malaria in this trial. A potential advantage of azithromycin over doxycycline for malaria prophylaxis is... 

Tetracycline antibiotics such as doxycycline are also slow-acting schizonticides which have proven to be useful in prophylaxis of malaria and in treatment as one component of combination chemotherapy (80). 

Prevosto, J.M. Beraud, B. Cheminel, V. Gaillard, Y Mounier, C. Chaulet, J.F. Determination of doxycycline in human plasma and urine samples by high performance liquid chromatography. Application for drug monitoring in malaria chemoprophylaxis. Ann.Biol.Clin.(Paris), 1995, 53, 29-32... 

Selective uses Specific tetracycUnes are used in the treatment of gastrointestinal ulcers caused by Helicobacter pylori (tetracycline), in Lyme disease (doxycycline), and in the meningococcal carrier state (minocycline). Doxycycline is also used for the prevention of malaria and in the treatment of amebiasis (Chapter 53). Demeclocycline inhibits the renal actions of ADH and is used in the management of patients with ADH-secreting tumors (Chapter 15). 

Clinical use The main use of quinine is in P falciparum infections resistant to chloroquine. Quinine is sometimes used with doxycycline to shorten the duration of therapy and limit toxicity. Quinidine, the dextrorotatory stereoisomer of quinine, is used intravenously in the USA for treatment of severe falciparum malaria. To delay emergence of resistance, the drugs should not be used routinely for prophylaxis. 

Kotecka B, Edstein M D, Rieckmann K H (1996). Chloroquine bioassay of plasma specimens obtained from soldiers on cholo quine plus doxycycline for malaria priphy-laxis. Int. J. Parasitol. 26 1325-1329. 

In a study in 13 patients with acute falciparum malaria, the addition of intravenous doxycycline to treatment with intravenous quinine did not affect quinine pharmacokinetics, when compared with 13 patients taking... 

---