Filariasis Medication

Updated: Oct 09, 2017
  • Author: Brian F Lich, MD; Chief Editor: Pranatharthi Haran Chandrasekar, MBBS, MD  more...
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Medication

Medication Summary

Patients with asymptomatic microfilaremia in lymphatic filariasis can be treated on an outpatient basis. Supervision of oral DEC therapy is recommended for patient compliance with therapy and for the management of febrile reactions in heavily infected patients. Inpatient care may initially be required for adenolymphangitis (ADL) and chronic filariasis.

Mass drug administration in filariasis reduces the transmission of filarial infection and disease morbidity by decreasing the burden of microfilaremia, resulting in suboptimal levels for transmission by disease vectors. [48, 49, 50, 51, 52, 53]

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Antihelminthics

Class Summary

Antihelminthic agents include the macrocyclic lactone derivative ivermectin, piperazine derivatives, and benzimidazole derivatives.

The biochemical pathways of parasites differ from those of their human host. Thus, the toxicity of anthelminthic agents can be directed at the parasite or its egg or larvae. The antiparasitic actions of these drugs vary and include the following:

- Inhibition of microtubules, causing irreversible block of glucose uptake

- Tubulin polymerization inhibition

- Depolarization of neuromuscular blockade

- Cholinesterase inhibition

- Increased cell membrane permeability, resulting in intracellular calcium loss

- Vacuolization of the schistosome tegument

- Increased cell membrane permeability to chloride ions via alteration of chloride channels

Ivermectin (Mectizan)

Ivermectin is a potent microfilaricide against W bancrofti and O volvulus; however, it has limited macrofilaricidal activity. [74]

Ivermectin exerts its antiparasitic action by acting as a potent agonist at gamma-aminobutyric acid (GABA) receptors and potentiating the inhibitory signals sent to motor neurons, thus paralyzing the parasite. Because GABA is confined to the CNS in humans and ivermectin does not cross the blood-brain barrier, the drug has no paralytic action in humans.

Diethylcarbamazine (Hetrazan)

Diethylcarbamazine (DEC) is commonly used in lymphatic filariasis and acts as both a microfilaricidal and macrofilaricidal agent. Its precise mechanism of action is not understood, but it has been shown to induce immobilization of microfilariae by using hyperpolarization effects to decrease muscle activity. Alteration of the surface membrane also occurs, with enhanced destruction by the host's immune system. Evidence exists that DEC may enhance adhesion of granulocytes via antibody-dependent and -independent mechanisms. Hypotheses also include interference by microfilarial intracellular processing and transport of specific macromolecules by DEC. [75]

Concurrent administration of corticosteroids should be considered with DEC treatment to minimize the allergic manifestations secondary to the disintegration of microfilariae, particularly in O volvulus and L loa infections.

Suramin

Suramin is an antitrypanosome and an anthelminthic. Its use is restricted because of its intrinsic toxicity and the frequency with which associated complications occur. The WHO has advised that it only be considered for the curative treatment of individuals in areas without transmission of onchocerciasis, in individuals leaving an endemic area, and in individuals with severe hyperreactive onchodermatitis if their symptoms are not adequately controlled with ivermectin.

The WHO has recommended that suramin not be used to treat onchocerciasis in individuals who are elderly or infirm or in patients with severe liver or renal disease. The drug is not recommended for children younger than 10 years, in totally blind persons (unless they require relief from intensely itchy lesions), in lightly to moderately infected people with no symptoms and whose eyes are not at risk, or in pregnant women (who should be treated after delivery).

Mebendazole

Mebendazole causes worm death by selective and irreversible blockade of uptake of glucose and other nutrients in a susceptible adult intestine where helminths dwell. 

Albendazole

Albendazole is a broad-spectrum anthelmintic. It decreases adenosine triphosphate (ATP) production in worms, causing energy depletion, immobilization, and, finally, death.

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Antibiotics

Class Summary

These agents may provide an alternative to traditional antihelminthics.

Doxycycline (Doxy 100, Vibramycin, Doryx, Monodox, Alodox)

Doxycycline is a broad-spectrum, synthetically derived, bacteriostatic antibiotic in the tetracycline class. In filariasis, it is primarily used to target Wolbachia, an endosymbiotic bacterium in onchocerciasis and lymphatic filariasis. Doxycycline is almost completely absorbed, concentrates in bile, and is excreted in urine and feces as a biologically active metabolite in high concentrations.

Doxycycline inhibits protein synthesis and, thus, bacterial growth by binding to 30S and possibly 50S ribosomal subunits of susceptible bacteria. It may block dissociation of peptidyl transfer RNA (t-RNA) from ribosomes, causing RNA-dependent protein synthesis to arrest.

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