Albendazole

Albendazole

Systematic (IUPAC) name
Methyl [6-(propylthio)-1H-benzoimidazol-2-yl]carbamate
Identifiers
CAS number	54965-21-8
ATC code	P02CA03 QP52AC11
PubChem	2082
DrugBank	APRD00782
ChemSpider	1998
Chemical data
Formula	C12H15N3O2S
Mol. mass	265.333 g/mol
SMILES	eMolecules & PubChem
Pharmacokinetic data
Bioavailability	?
Metabolism	oxidation of sulfur atom to sulfoxide, the active metabolite
Half life	About 8.5 hours
Excretion	?
Therapeutic considerations
Pregnancy cat.	D
Legal status	prescription
Routes	only oral route
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Albendazole, marketed as Albenza, Eskazole, Zentel and Andazol, is a member of the benzimidazole compounds used as a drug indicated for the treatment of a variety of worm infestations. Although this use is widespread in the United States, the U.S. Food and Drug Administration (FDA) has not approved albendazole for this indication. It is marketed by GlaxoSmithKline.

Main uses

It is effective (first line of treatment) against:

• Flatworms
  • Flukes/trematodes
  • Tapeworm/cestodes
    • Echinococcosis^[1]
• Nematodes
  • Hookworms
  • Roundworms
  • Whipworms
  • Threadworms or pinworms

Other uses

Discarded bottles of albendazole distributed in Africa

In Africa, albendazole (donated by GlaxoSmithKline) is being used to treat lymphatic filariasis as part of efforts to stop transmission of the disease.^[2] In sub-Saharan Africa, albendazole is used in conjunction with ivermectin, and elsewhere in the world, the medicine is used in combination with diethylcarbamazine.^[2]

In Brazil and other countries it is used against giardiasis^[3].

Mode of action

As a vermicidal, albendazole causes degenerative alterations in the tegument and intestinal cells of the worm by binding to the colchicine-sensitive site of tubulin, thus inhibiting its polymerization or assembly into microtubules. The loss of the cytoplasmic microtubules leads to impaired uptake of glucose by the larval and adult stages of the susceptible parasites, and depletes their glycogen stores. 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. Due to diminished energy production, the parasite is immobilized and eventually dies.

Albendazole also has been shown to inhibit the enzyme fumarate reductase, which is helminth-specific. This action may be considered secondary to the effect on the microtubules due to the decreased absorption of glucose. This action occurs in the presence of reduced amounts of nicotinamide-adenine dinucleotide in reduced form (NADH), which is a coenzyme involved in many cellular oxidation-reduction reactions.

Albendazole has larvicidal effects in necatoriasis and ovicidal effects in ascariasis, ancylostomiasis, and trichuriasis.

Dosage

Hydatid disease:

• Patients 60 kg or greater: 400 mg twice daily, with meals.
• Patients less than 60 kg: 15 mg/kg/day given in divided doses twice daily with meals (maximum total daily dose 800 mg).
• Treatment interval: 28-day cycle followed by a 14-day albendazole-free interval, for a total of 3 cycles.

NOTE: When administering albendazole in the pre- or post-surgical setting, optimal killing of cyst contents is achieved when 3 courses of therapy have been given.

Neurocysticerosis:

• Patients 60 kg or greater: 400 mg twice daily, with meals.
• Patients less than 60 kg: 15 mg/kg/day given in divided doses twice daily with meals (maximum total daily dose 800 mg).
• Treatment interval: 8–30 days.

Note: Patients being treated for neurocysticercosis should receive appropriate steroid and anticonvulsant therapy as required. Oral or intravenous corticosteroids should be considered to prevent cerebral hypertensive episodes during the first week of treatment.

Filaria

Single dose of 400 mg. For Filariaris, note that Albendazole kills the adult worms - which if taken continuously can lead to damage in the lymphatic system.

Side effects

Albendazole may cause dizziness, headache, fever, nausea, vomiting, or temporary hair loss.

In rare cases it may cause persistent sore throat, severe headache, seizures, vision problems, yellowing eyes or skin, dark urine, stomach pain, easy bruising, mental/mood changes, very stiff neck, change in amount of urine. Allergic reactions are also possible.

CBC and hepatic functions have to be obtained regularly in patients receiving Albendazole.

Drug interactions

Antiepileptics

The drugs Carbamazepine, Phenytoin and Phenobarbital lower the plasmatic concentration and the half life of albendazole.^[4]

Antacids/histamine H₂ antagonists

The drug cimetidine heightens serum albendazole concentrations, and increases the half life of albendazole.^[5]

This might be a helpful interaction on more severe cases, because it boosts the potency of albendazole.^[6]

Contraindications

Hypersensitivity to the benzimidazole class of compounds.

Pregnancy class

D (Australia) - Do not take when pregnant, and do not become pregnant for one month after taking this drug. Pharmacokinetic studies have shown that trace amounts of albendazole appears in semen. Given this potential for teratogenicity, the manufacturers advise that the male sexual partner should also use adequate protection.

See also

• Mebendazole
• Eradication of infectious disease
• Neglected diseases

References

External links

• Prescribing information
• The Carter Center Lymphatic Filariasis Elimination Program