Antifilarial and Leishmaniasis Drugs

Filariasis is an infection disease caused by the parasitism of filaria in the human lymphatic system. Anti-filariasis drugs mainly include diethylcarbamazine, furapyrimidone and suramin sodium. Piperazine derivatives diethylcarbamazine can kill the microfilaria of Brugia malayi, Wuchereria bancrofti, Brugia timori and loa as well as Onchocerca volvulus. Diethylcarbamazine is the drug of choice for the treatment of lymphatic filariasis since 1947. It can also be used to for the treatment of onchocerciasis and Loa filariasis.

Leishmaniasis is still mainly seen in tropical and subtropical regions due to that the media of this disease, Leeches are living in these areas. Infection is caused by the presence of the amastigote type of Leishmania in the reticuloendothelial cells. The media in eastern hemisphere is sandflies while the media in Western Hemisphere is longipalpis genus. The storage hosts are usually rodents and other small animals.

Human organs, skin, mucous membranes or skin infections range from mild and self-limiting to severe mixed. The visceral leishmaniasis, namely black sickness caused by the Leishmania donovani is a potentially fatal infection disease in immunocompromised patients. It may maintain the dormant stage under the circumstances of normal immune function for many years and will only appear upon the suppression of host immune system caused by various kinds of reasons. But there are also many cases in which patients with no apparent immune suppression also got visceral leishmaniasis.

Visceral leishmaniasis often has slow and gradual onset, manifested as fever, weight reduction, hepatosplenomegaly and liver dysfunction, hypoalbuminemia, hypergammaglobulinemia, pancytopenia, bleeding, lymph node enlargement and so on. Some patients in epidemic area are asymptomatic or only have mild symptoms, although undergone no treatment, having no infection development; however, on the other hand, infection may also be lethal especially for immunocompromised patients. Malnutrition is also significant risk factors that contributed to the development of visceral leishmaniasis.

The Mucocutaneous leishmaniasis in South American is mainly caused by the Brazilian Leishmania. Treatment should be given because the development of the mouth, palate, pharynx and nasal ulcer can often result in a significant change in the face. Cutaneous leishmaniasis (oriental sore) is caused by tropical or large Leishmania (Old World leishmaniasis) and Brazil, Mexico or Peru Rouly Leishmania donovani (Western Hemisphere leishmaniasis). This disease can still be observed to as north as Texas states in US. It first appears a small nodule in insect biting site; then ulceration or crusting occurs with extremely slow healing rate. Taking tissue sample from the edge of the skin ulcer can often enable the observation of Leishmania.

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