[3] Rare but potentially serious side effects include bone marrow suppression which usually improves on discontinuing the medication.

[28] In January 2025, the Committee for Medicinal Products for Human Use (CHMP) of the European Medicines Agency (EMA) adopted a positive scientific opinion for ivermectin/albendazole for the treatment of infections caused by several types of worm parasites including lymphatic filariasis, a neglected tropical disease.

[19] The most common side effects of albendazole are experienced by over 10% of people and include headache and abnormal liver function.

[30] An estimated 1–10% of people experience abdominal pain, nausea or vomiting, dizziness or vertigo, increased intracranial pressure, meningeal signs, temporary hair loss, and fever.

[31] Fewer than 1% of people get hypersensitivity reactions such as rashes and hives, leukopenias (drop in white blood cell levels) such as agranulocytosis and granulocytopenia, thrombocytopenia (reduced platelet count), pancytopenia (drop in white blood cells, red blood cells, and platelets), hepatitis, acute liver failure, acute kidney injury, irreversible bone marrow suppression, and aplastic anemia.

[29] People receiving albendazole for the treatment of neurocysticercosis can have neurological side effects such as seizures, increased intracranial pressure, and focal signs caused by the inflammatory reaction that occurs when parasites in the brain are killed.

[38] Albendazole sulfoxide is secreted into breast milk at around 1.5% of the maternal dose, though oral absorption is poor enough that it is unlikely to affect nursing infants.

It can manifest with lethargy, loss of appetite, vomiting, diarrhea, intestinal cramps, dizziness, convulsions, and sleepiness.

[38] The antiepileptics carbamazepine, phenytoin, and phenobarbital lower the plasma concentration and half-life of albendazole sulfoxide's R(+) enantiomer.

Finally, long-term administration of the antiretroviral ritonavir, which works as a CYP3A4 inhibitor, decreases the maximum concentration of albendazole in the plasma as well as the AUC.

[3][29] Albendazole leads to impaired uptake of glucose by the larval and adult stages of the susceptible parasites, and depletes their glycogen stores.

[48] To target intestinal parasites, which is the most common indication for prescription, albendazole is taken on an empty stomach to stay within the gut.

[49] Oral absorption of albendazole varies among species, with 1–5% of the drug being successfully absorbed in humans, 20–30% in rats, and 50% in cattle.

[24] Food stimulates gastric acid secretion, lowering the pH and making albendazole more soluble and thus more easily absorbed.

[60] Brand names include: Albenza,[29] Alworm, Andazol, Eskazole, Noworm, Zentel, Alben-G, ABZ, Cidazole, Wormnil etc.

It inhibits division of Wolbachia and Mycobacterium tuberculosis, turning them into a long "filament" shape as they grow and fail to divide.

Since Brugia malayi relies on symbiotic Wolbachia, this would mean that albendazole is targeting both the worm and its essential symbioant.

[61] Albendazole is mainly used in cattle and sheep, but has found some use in cats and dogs as well;[35] it is also used in ratite birds for flagellate parasites and tapeworms.

[1] Albendazole has been used as an antihelminthic and for control of flukes in a variety of animal species, including cattle, sheep, goats, swine, camels, dogs, cats, elephants, poultry, and others.

[39] While it is also associated with bone marrow suppression and toxicity in cats and dogs at high doses, albendazole has a higher margin of safety in other species.

[34] It is marketed for this purpose by Zoetis (formerly Pfizer Animal Health) in numerous countries (including the United States and Canada) as Valbazen in oral suspension and paste formulations;[1][35] by Interchemie in the Netherlands and elsewhere as Albenol-100; by Channelle Animal Health Ltd. in the United Kingdom as Albex; and by Ravensdown in New Zealand (as Albendazole).

In dogs, albendazole sulfoxide is detectable in the plasma for less than 12 hours, but in sheep and goats, it remains at measurable levels for around three days.

Summarized research data relating to the durations of these preslaughter and early pregnancy periods when albendazole should not be administered are found in US FDA NADA 110-048 (cattle) and 140-934 (sheep).

Maximum residue limits (MRLs) for albendazole in food, adopted by the FAO/WHO Codex Alimentarius in 1993, are 5000, 5000, 100, and 100 micrograms per kilogram of body weight (μg/kg) for kidney, liver, fat, and muscle, respectively, and 100 μg/L for milk.