ZOLEFIMIDAZ 400 TABLETS

Indications

• Helminth infections
• Strongyloidiasis
• Hydatid disease
• Tapeworm infections
• Hookworm infections
• Schistosomiasis

Dosage

Children: For children aged 2–17 years: 400 mg twice daily for 3 days. The dose may be repeated after 3 weeks if necessary. Alternatively, for hookworm infections: 7.5 mg/kg twice daily (maximum per dose 400 mg) for 28 days, followed by a 14-day break, repeated for up to 2–3 cycles.

Adults: For Adult patients, the dosage is typically 400 mg taken by mouth as a single dose or as directed by a healthcare professional based on the specific condition being treated.

Mechanism of action

Albendazole works by inhibiting the polymerization of tubulin into microtubules, disrupting the cytoplasmic structure of the helminths, and thereby inhibiting their motility and reproduction.

Pharmacodynamics

Albendazole exhibits its anthelmintic activity through the inhibition of glucose uptake, leading to depletion of glycogen stores in the worms, ultimately resulting in their death. It is effective against a wide range of parasites.

Pharmacokinetics

Albendazole is rapidly absorbed and is metabolized in the liver to its primary active metabolite, albendazole sulfoxide. Its bioavailability is increased when taken with fatty meals. The drug is primarily excreted in the urine and has a half-life that varies based on individual metabolism.

Adverse effects

• Gastro-intestinal upset
• Lightheadedness
• Pruritus

Interactions

• Levamisole may moderately decrease the exposure to albendazole
• Ritonavir may decrease the exposure to albendazole

Precautions

• Treatment must be given under careful patient supervision
• Stop at the first sign of cerebral involvement

Pregnancy

Refer to BNF for specific guidance.

Breast-feeding

Refer to BNF for specific guidance.

Storage

Store in a cool, dry place away from light.

Formulations

• Tablets
• Suspension

Mechanism of action

Albendazole causes degenerative alterations in the tegument and intestinal cells of the worm by diminishing its energy production, ultimately leading to immobilization and death of the parasite. It works by binding to the colchicine-sensitive site of tubulin, thus inhibiting its polymerization or assembly into microtubules. As cytoplasmic microtubules are critical in promoting glucose uptake in larval and adult stages of the susceptible parasites, the glycogen stores of the parasites are depleted. Degenerative changes in the endoplasmic reticulum, the mitochondria of the germinal layer, and the subsequent release of lysosomes result in decreased production of adenosine triphosphate (ATP), which is the energy required for the survival of the helminth. Benzimidazoles produce many biochemical changes in susceptible nematodes, eg, inhibition of mitochondrial fumarate reductase, reduced glucose transport, and uncoupling of oxidative phosphorylation ... /but/ the primary action ... /should be/ to inhibit microtubule polymerization by binding to beta-tubulin. The selective toxicity of these agents derives from the fact that specific, high-affinity binding to parasite beta-tubulin occurs at much lower concn than does binding to the mammalian protein ... Benzimidazole-resistant Haemonchus contortus display reduced high-affinity drug binding to beta-tubulin and alterations in beta-tubulin isotype gene expression that correlate with drug resistance ... Two identified mechanisms of drug resistance in nematodes involve both a progressive loss of "susceptible" beta-tubulin gene isotypes together with emergence of a "resistant" isotype with a conserved point mutation that encodes a tyrosine instead of phenylalanine at position 200 of beta-tubulin. While this mutation may not be required for benzimidazole resistance in all parasites, eg, Giardia lamblia, benzimidazole resistance in parasitic nematodes is unlikely to be overcome by novel benzimidazole analogs, because tyrosine also is present at position 200 of human beta-tubulin. /Benzimidazoles/ Although the exact mechanism of action of albendazole has not been fully elucidated, the principal anthelmintic effect of benzimidazoles, including albendazole, appears to be the specific, high-affinity binding of the drug to free beta-tubulin in parasite cells, resulting in selective inhibition of parasite microtubule polymerization, and inhibition of microtubule-dependent uptake of glucose. Benzimidazole drugs bind to the beta-tubulin of parasites at much lower concentrations than to mammalian beta-tubulin protein; the drugs do not inhibit glucose uptake in mammals, and do not appear to have any effect on blood glucose concentrations in humans The mode of action of albendazole is by binding strongly with the tubulin in the cells of nematodes. The intestinal cells of the nematode are particularly affected, resulting in a loss of absorptive function which causes the nematodes to starve to death.

Pharmacodynamics

Albendazole is a broad-spectrum anthelmintic. The principal mode of action for albendazole is by its inhibitory effect on tubulin polymerization which results in the loss of cytoplasmic microtubules.