Malaria chloroquine sensitive

Type of Malaria Chloroquine-sensitive Primary Agent(s) Adjunctive/Alternative Agent(s) Chloroquine Primaquine ... 

Mefloquine (t) 21 d) is similar in several respects to quinine although it does not intercalate with plasmodial DNA. It is used for malaria chemoprophylaxis, to treat uncomplicated Plasmodium falciparum (both chloroquine-sensitive and chloroquine resistant) and chloroquine-resistant Plasmodium vivax malaria. Mefloquine is rapidly absorbed from the gastrointestinal tract and its action is terminated by metabolism. When used for prophylaxis, 250 mg (base)/week should be taken, commencing 1-3 weeks before entering and continued for 4 weeks after leaving a malarious area. It should not be given to patients with hepatic or renal impairment. 

Qinghao (Artemisia annua L.) is an important medicinal herb, which has h>een used in the Chinese traditional system of medicine for many centuries. In 1972, Chinese scientists isolated (+)-artemisinin (7, qinghaosu) from the above plant, which is indigenous to China [27-30]. Artemisinin is a sesquiterpene lactone peroxide, whose structure and synthesis have been worked out [27,28]. It has marked activity against both chloroquine-sensitive and resistant strains of Plasmodium falciparum and is particularly suitable for treating cerebral malaria as it is very fast acting [29-31]. 

Quinine (650 mg every 8 honrs for 5 to 7 days) is indicated for the treatment of chloroquine-resistant falciparum malaria, either alone, with pyrimethamine and a sulfonamide, or with a tetracycline. It is also considered as an alternative therapy for chloroquine-sensitive strains of P. falciparum, P. malariae, P. ovale, andP vivax. Mefloquine and clindamycin may also be nsed with quinine, depending on the geographical location in which the malaria was acquired. 

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... 

Prophylaxis for infections with chloroquine-sensitive P. falciparum, P. vivax, P. malariae, and P. ovale... 

Flalofantrine is considered to be an alternative drug for treatment of both chloroquine-sensitive and chloroquine-resistant Plasmodium falciparum malaria, but its efficacy in mefloquine-resistant malaria may be questionable. The drug is metabolized via N-dealkylation to desbutylhalofantrine by CYP3A4 (Fig. 39.14). The metabolite appears to be several-fold more active than the administered drug. 

Among four major Cinchona alkaloids, quinidine and cinchonine were most active in the malaria therapy followed by quinine and cinchonidine. For example, quinidine is two- to threefold more active than quinine in both chloroquine-sensitive and chloroquine-resistant strains of P. falciparum [224]. Due to its cardiac... 

Since that time, artemisinin has been used successfully in many thousand malaria patients throughout the world including those infected with both cldoroquine-sensitive and chloroquine-resistant strains of P falciparum. Artemisinin has progressively estabhshed itself as one of the most potent and effective antimalarial dmg, and is primarily recommended in the treatment of multidrug-resistant strains of P. falciparum. However, the therapeutic... 

Chloroquine is the drug of choice for preventing and treating acute forms of malaria caused by P. vivax, P. malariae, P ovale, as well as sensitive forms of P. falciparum. The mechanism of its action is not completely clear, although there are several hypotheses explaining its antimalarial activity. Chloroquine and its analogs inhibit synthesis of nucleic acids of the parasite by affecting the matrix function of DNA. This happens by preliminary... 

Hydroxychloroquine, like chloroquine, is also used for treating acute forms of malaria caused by P vivax, P. malariae, P. ovale, and also sensitive forms of P. falciparum. It is also effective and safe like chloroquine, although it does not have obvious advantages. The only advantage is that it is somewhat better tolerated. Its use is somewhat more limited than chloroquine. Synonyms of this drug are plaquenil, quensyl, toremonil, and others. 

Once the primary therapeutic objective has been achieved, attention can be focused on such additional considerations as elimination of the gametocytes and the tissue forms of the parasite. Success in these areas would help to ensure that relapses do not occur. Since no latent liver forms are associated with mosquito-induced, drug-sensitive P. falciparum malaria, administration of chloroquine for up to 3 months after the patient leaves a malarious area will usually bring about a complete or radical cure unless the organism is resistant to chloroquine. 

The drug is effective against all four types of malaria with the exception of chloroquine-resistant P. falciparum Chloroquine destroys the blood stages of the infection and therefore ameliorates the clinical symptoms seen in P. malariae, P. vivax, P. ovale, and sensitive P. falciparum forms of malaria. The disease will return in P. vivax and P. ovale malaria, however, unless the liver stages are sequentially treated with primaquine after the administration of chloroquine. Chloroquine also can be used prophylactically in areas where resistance does not exist. In addition to its use as an antimalarial, chloroquine has been used in the treatment of rheumatoid arthritis and lupus erythematosus (see Chapter 36), extraintestinal amebiasis, and photoallergic reactions. 

Chloroquine has been the drug of choice for both treatment and chemoprophylaxis of malaria since the 1940s, but its usefulness against P falciparum has been seriously compromised by drug resistance. It remains the drug of choice in the treatment of sensitive P falciparum and other species of human malaria parasites. 

Chloroquine is the drug of choice in the treatment of nonfalciparum and sensitive falciparum malaria. It rapidly terminates fever (in 24-48 hours) and clears parasitemia (in 48-72 hours) caused by sensitive parasites. It is still used to treat falciparum malaria in some areas with widespread resistance, in particular much of Africa, owing to its safety, low cost, antipyretic properties, and partial activity, but continued use of chloroquine for this purpose is discouraged, especially in nonimmune individuals. Chloroquine has been replaced by other drugs, principally artemisinin-based combination therapies, as the standard therapy to treat falciparum malaria in most endemic countries. Chloroquine does not eliminate dormant liver forms of P vivax and P ovale, and for that reason primaquine must be added for the radical cure of these species. 

Following the development of synthetic antimalarial agents, such as chloroquine and mefloquine, the use of Cinchona alkaloid quinine declined. However, with the emergence of chloroquine-resistant and multiple-drug-resistant strains of malarial parasites, its use has become firmly reestablished. Quinine is the drug of choice for severe chloroquine-resistant malaria due to Plasmodium falciparum. In the U.S., the related alkaloid quinidine is recommended because of its wide availability and use as an antiarrhythmic agent. In many clinics in the tropics, quinine is the only effective treatment for severe malaria unfortunately, decreasing sensitivity of P. falciparum to quinine has already been reported from Southeast Asia. 

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