albendazole

Albendazole is an anthelmintic medication used to treat neurocysticercosis and hydatid disease caused by infections of tapeworm larvae. Anthelmintics are a class of medications used to treat parasitic worm infestations in the intestines, liver, lung and peritoneum, the membrane that encloses the abdominal organs. Albendazole is a broad spectrum anthelmintic, also used off-label in many different types of worm infections.

Albendazole kills adult parasitic worms and their larvae by making degenerative changes in their external surface (tegument) and intestinal cells. These changes inhibit their ability to absorb glucose from the host and convert it into adenosine triphosphate (ATP), the form of energy they use to survive and grow, eventually leading to the immobilization and death of the parasites.

Albendazole is approved by the FDA to treat the following:

• Neurocysticercosis: Cysticercosis is an infection of muscle, brain or other tissue by larval cysts of the pork tapeworm, Taenia solium, and neurocysticercosis affects the brain and central nervous system. Eating uncooked/undercooked infected pork causes intestinal tapeworm infection (taeniasis), but not cysticercosis. The T. solium eggs are shed in the stool of the infected person, and cysticercosis spreads from ingesting food or water contaminated by T. solium eggs, which can be avoided by practicing good hygiene. Cysticercosis is more common in countries where pigs are allowed to roam freely and eat human feces and where hygiene practices are poor.
• Hydatid disease: Hydatid disease or cystic echinococcosis is caused by the larval cysts of Echinococcus granulosus, a type of intestinal tapeworm dogs get when they eat infected organs of other animals. The eggs are shed in their stools which contaminate the ground and various farm animals and humans can contract hydatid infection when they ingest food or water contaminated by the eggs. The eggs hatch and lodge in various tissues, most commonly in the lungs and liver.

Off-label uses of albendazole include the following worm infections:

• Eosinophilic enterocolitis caused by Ancylostoma caninum
• Ascariasis cause by intestinal roundworm Ascaris lumbricoides
• Hookworm infections (Ancylostoma duodenale or Necator americanus)
• Clonorchiasis caused by liver fluke, Clonorchis sinensis
• Opisthorciasis caused by liver fluke, Opisthorchis viverrini
• Trichostrongylosis caused by Trichostrongylus species
• Capillariasis caused by Capillaria species
• Trichuriasis caused by whipworms, Trichuris trichiura
• Cutaneous larva migrans caused by dog and cat hookworms Ancylostoma braziliense and Ancylostoma caninum
• Visceral larva migrans (toxocariasis) caused by dog and cat roundworms Toxocara canis and T. cati
• Enterobiasis caused by pinworms Enterobius vermicularis
• Gnathostomiasis caused by Gnathostoma spinigerum
• Microsporidiasis caused by unicellular spore-forming parasites
• Giardiasis caused by Giardia duodenalis
• Gongylonemiasis caused by Gongylonema species
• Oesophagostomiasis caused by Oesophagostomum bifurcum
• Trichinellosis caused by Trichinella spiralis

• Do not use albendazole in patients with known hypersensitivity to benzimidazole class of compounds, albendazole or any of its components
• Albendazole can cause bone marrow suppression and lower the counts of all types of blood cells, particularly in patients with impaired liver function; monitor blood counts in all patients at the beginning of each 28-day cycle of therapy, and every 2 weeks while on therapy; discontinue therapy if blood counts drop significantly
• Albendazole can lead to elevated liver enzymes; monitor levels and discontinue therapy if liver enzymes are higher than two times the upper normal limit and consider restarting treatment when they return to normal levels
• Albendazole can worsen neurocysticercosis symptoms in the first week of therapy or may uncover pre-existing neurocysticercosis when treated for other infections; patients should be concurrently treated with corticosteroids and anticonvulsants as required
• Patients should be examined for retinal lesions from cysticercosis before starting treatment for neurocysticercosis; albendazole can damage the retina if retinal lesions are present
• Theophylline levels should be monitored in patients concurrently treated with theophylline

Common side effects of albendazole include:

• Abnormal liver function tests
• Abdominal pain
• Nausea
• Vomiting
• Headache

Less common side effects of albendazole include:

• Dizziness
• Vertigo
• Reversible hair loss (alopecia)
• Increase in intracranial pressure
• Signs of irritation of meninges, the membrane that covers the brain and spinal cord
• Fever

Rare side effects of albendazole include:

• Bone marrow depression
• Blood disorders including:
  • Anemia due to lack of red blood cell production (aplastic anemia)
  • Low count of leukocyte immune cells (leukopenia)
  • Low count of neutrophil immune cells (neutropenia)
  • Low blood count of granulocyte immune cells (granulocytopenia)
  • Severely low granulocyte level (agranulocytosis)
  • Low platelet levels (thrombocytopenia)
  • Low count of all types of blood cells (pancytopenia)
• Hypersensitivity reactions including:
  • Rash
  • Hives (urticaria)
• Severe skin reactions including
  • Erythema multiforme
  • Stevens-Johnson syndrome
• Elevation of liver enzymes
• Liver inflammation
• Acute liver failure
• Acute kidney failure

This is not a complete list of all side effects or adverse reactions that may occur from the use of this drug.

Call your doctor for medical advice about serious side effects or adverse reactions. You may also report side effects or health problems to the FDA at 1-800-FDA-1088.

Tablet

• 200 mg

Adult and Pediatric

Neurocysticercosis (Taenia solium Tapeworm)

• Over 60 kg: 400 mg orally twice daily for 8-30 days
• Under 60 kg: 15 mg/kg/day divided twice daily orally for 8-30 days; not to exceed 800 mg/day

Hydatid (Echinococcus Tapeworm)

• Over 60 kg: 400 mg orally twice daily for 28 days, then 14 drug-free days for 3 cycles
• Under 60 kg: 15 mg/kg/day divided twice daily orally, no more than 800 mg/day for 28 days than 14 drug-free days for 3 cycles

Ancylostoma, Ascariasis, Hookworm, Trichostrongylus

• 400 mg orally once

Capillariasis

• 400 mg orally once daily for 10 days

Larva migrans, Cutaneous and Trichuriasis

• 400 mg orally once daily for 3 days

Larva migrans, Visceral

• 400 mg orally once daily for 5 days

Enterobius (Pinworm)

• 400 mg orally once, repeat in 2 weeks

Adult only:

Fluke (Clonorchis sinesis)

• 10 mg/kg orally once daily for 7 days

Gnathostomiasis, Microsporidiosis

• 400 mg twice daily for 21 days

Administration

• Take with food
• If unable to swallow, may crush the tablet and drink with water
• Monitor: complete blood count (CBC), liver function tests

• Albendazole overdose can cause diarrhea, vomiting, increased heart rate and breathing difficulties.
• Overdose is treated with symptomatic and supportive care. In case of overdose, seek medical help or contact Poison Control immediately.

Inform your doctor of all medications you are currently taking, who can advise you on any possible drug interactions. Never begin taking, suddenly discontinue, or change the dosage of any medication without your doctor’s recommendation.

• Albendazole has no known severe interactions with other drugs.
• Serious interactions of albendazole include:
  • ropeginterferon alfa 2b
• Moderate interactions of albendazole include:
  • acalabrutinib
  • fosphenytoin
  • grapefruit
  • phenytoin
• Minor interactions of albendazole include:
  • dexamethasone
  • praziquantel

The drug interactions listed above are not all of the possible interactions or adverse effects. For more information on drug interactions, visit the RxList Drug Interaction Checker.

It is important to always tell your doctor, pharmacist, or health care provider of all prescription and over-the-counter medications you use, as well as the dosage for each, and keep a list of the information.

Check with your doctor or health care provider if you have any questions about the medication.

• Animal tests show that albendazole may cause fetal harm; there are no well-controlled studies on albendazole use in pregnant women.
• Albendazole should be used during pregnancy only if potential benefits outweigh potential fetal risk, and if no alternative treatment is available.
• Women of reproductive potential should begin treatment after a negative pregnancy test.
• Women patients of childbearing age should use contraception for at least 1 month after discontinuation of albendazole therapy.
• If pregnancy occurs while taking albendazole, it should be discontinued immediately, and the patient should be informed of potential risks to the fetus.
• It is not known if albendazole is present in breast milk, however, it is present in animal milk; use with caution in nursing mothers because many drugs are excreted in breast milk.

• Take albendazole exactly as prescribed
• Patients, especially young children, who may find it difficult to swallow the tablet whole may crush or chew and swallow with water
• Store safely away from the reach of children