Albendazole is a broad-spectrum, synthetic benzimidazole-derivative anthelmintic. Albendazole interferes with the reproduction and survival of helminths by inhibiting the formation of microtubules from tubulin. This leads to an impaired uptake of glucose, a depletion of glycogen stores, and results in the worm’s death. Albendazole is used in the treatment of dog and pork tapeworm-causing diseases, including hydatid disease and neurocysticercosis. Albendazole may also be used to treat a variety of other roundworm infections.
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. It is useful for giardiasis, trichuriasis, filariasis, neurocysticercosis, hydatid disease, pinworm disease, and ascariasis, among others
Mechanism of Action of Albendazole
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.
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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 concern than does the 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 the 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.
Indications of Albendazole
- Ascariasis
- Hookworm infection
- Pinworm infection (Enterobius vermicularis)
- Cutaneous larva migrans
- Capillariasis
- Cysticercus cellulosae
- Echinococcus
- Enterocolitis
- Filariasis, elephantiasis
- Giardiasis
- Gnathostomiasis
- Hookworm infection (Necator or Ancylostoma)
- Hydatid disease
- Liver fluke
- Loiasis
- Microsporidiosis
- Neurocysticercosis
- Strongyloidiasis
- Trichinosis
- Trichostrongylosis
- Visceral larva migrans, toxicariasis
- Whipworm Infection
- Hydatid disease caused by Echinococcus granulosus
- Neurocysticercosis caused by Taenia solium
- Other specified protozoal diseases
- Other uses of albendazole is also effective in treating infections caused by other parasites including Taenia saginata (beef tapeworm), Trichinella spiralis(pork worm), Trichuris trichiura (whipworm), Enterobius vermicularis(pinworm), Strongyloides stercoralis (threadworm), Ascaris lumbricoides(roundworm), Ancylostoma duodenale (hookworm), and Necator americanus(hookworm).
Nematodes
- Ascariasis, which can be cured with a single dose of albendazole.
- Baylisascariasis, caused by the raccoon roundworm. Corticosteroids are sometimes added in cases of eye and CNS infections. Enterobiasis (pinworm infection)
- Filariasis; since albendazole’s disintegration of the microfilarie (“pre-larva”) can cause an allergic reaction, antihistamines or corticosteroids are sometimes added to treatment. In cases of lymphatic filariasis (elephantiasis) caused by Wuchereria bancrofti or Brugia malayi, albendazole is sometimes given as an adjunct to ivermectin or diethylcarbamazine in order to suppress microfilaremia. It can also be given for loa filariasis as an adjunct or replacement to diethylcarbamazine. Albendazole has an embryotoxic effect on Loa loa adults and thus slowly reduces microfilaremia.
- Gnathostomiasis when caused by Gnathostoma spinigerum. Albendazole has a similar effectiveness to ivermectin in these cases, though it needs to be given for 21 days rather than the 2 days needed for ivermectin.
- Gongylonemiasis
- Hookworm infections, including cutaneous larva migrans caused by hookworms in the Ancylostoma genus. A single dose of albendazole is sufficient to treat intestinal infestations by A. duodenale or Necator americanus
- Intestinal capillariasis, as an alternative to mebendazole
- Mansonelliasis when caused by Mansonella perstans. Albendazole works against the adult worms but not against the younger microfilariae.
- Oesophagostomumiasis, when caused by Oesophagostomum bifurcum
- Strongyloidiasis, as an alternative to ivermectin or thiabendazole. Albendazole can be given with diethylcarbamazine to lower microfilaremia levels.
- Toxocariasis, also called “visceral larva migrans”, when caused by the dog roundworm Toxocara canis or cat roundworm T. catis. Corticosteroids can be added in severe cases, and surgery might be required to repair the secondary damage.
- Trichinosis, when caused by Trichinella spiralis or T. pseudospiralis. Albendazole has a similar efficacy to thiabendazole, but fewer side effects. It works best when given early, acting on the adult worms in the intestine before they generate larva that can penetrate the muscle and cause a more widespread infection. Corticosteroids are sometimes added on to prevent inflammation caused by dying larva.
- Trichostrongyliasis, as an alternative to pyrantel pamoate. A single dose is sufficient for treatment.
- Trichuriasis (whipworm infection), sometimes considered as an alternative to mebendazole and sometimes considered to be the drug of choice. Only a single dose of albendazole is needed. It can also be given with ivermectin.
- Giardiasis, as an alternative or adjunct to metronidazole, especially in children
- Microsporidiosis, including ocular microsporidiosis caused by Encephalitozoon hellem or E. cuniculi, when combined with topical fumagillin
- Granulomatous amoebic encephalitis, when caused by the ameba Balamuthia mandrillaris, in combination with miltefosine and fluconazole
- Arthropods
- Crusted scabies, when combined with topical crotamiton and salicylic acid
- Head lice infestation, though ivermectin is much better
- Intestinal myiasis
- Though albendazole is effective in treating many diseases, it is only FDA-approved for treating hydatid disease caused by dog tapeworm larvae and neurocysticercosis caused by pork tapeworm larvae
Contra-Indications of Albendazole
- Reduction in the body’s resistance to infection
- The acquired decrease of all cells in the blood
- Low Blood Counts due to Bone Marrow Failure
- Anemia
- Decreased Neutrophils a Type of White Blood Cell
- Liver Problems
- Abnormal Liver Function Tests
Dosage of Albendazole
Strengths
- Tablet: 200 mg
- Chewable Tablet: 200 mg
Adult dosages
Hookworm Infection (Necator or Ancylostoma)
- US CDC recommendations: 400 mg orally as a single dose
Pinworm Infection (Enterobius vermicularis)
- Some experts recommend 400 mg orally as a single dose; repeat in 2 weeks
Whipworm Infection (Trichuris trichiura)
- US CDC recommendations: 400 mg orally once a day for 3 days
Capillariasis
- US CDC recommendations: 400 mg orally once a day for 10 days
Gnathostomiasis
- US CDC recommendations: 400 mg orally twice a day for 21 days
Clornorchis Sinensis (Liver Fluke)
- US CDC recommendations: 10 mg/kg/day orally for 7 days
Cysticercus cellulosae (Cysticercosis)
- Some experts recommend: 400 mg orally twice a day for 8 to 30 days
Echinococcus Infection
- US CDC recommendations: 400 mg orally twice a day for 1 to 6 months
Loiasis
- US CDC recommendations: 200 mg orally twice a day for 21 days
Microsporidiosis
- Some experts recommend: 400 mg orally twice a day
Neurocysticercosis
- Less than 60 kg: 15 mg/kg/day orally in divided doses twice a day with meals
- Maximum dose: 800 mg/day
- 60 kg or more: 400 mg orally twice a day with meals
- Duration of therapy: 8 to 30 days
Cutaneous Larva Migrans
- US CDC recommendations: 400 mg orally once a day for 3 to 7 days
- 400 mg orally twice a day for 3 to 5 days
Visceral Larva Migrans (Toxicariasis)
- US CDC recommendations: 400 mg orally twice a day for 5 days
Enterocolitis
- Some experts recommend: 400 mg orally as a single dose
Strongyloidiasis
- Some experts recommend: 400 mg orally twice a day for 7 days
Hydatid Disease
- Less than 60 kg: 15 mg/kg/day orally in divided doses twice a day with meals
- Maximum dose: 800 mg/day
- 60 kg or more: 400 mg orally twice a day with meals
- Duration of therapy: 28-day cycle followed by a 14-day drug-free interval, for a total of 3 cycles
Trichinosis
- US CDC recommendations: 400 mg orally twice a day for 8 to 14 days
Trichostrongylosis
- Some experts recommend: 400 mg orally as a single dose
Ascariasis
- US CDC recommendations: 400 mg orally as a single dose
Filariasis
- Some experts recommend: 400 mg orally twice a day for 10 days
Usual Pediatric Dosages
Pinworm Infection (Enterobius vermicularis)
AAP recommendations
- Children less than 20 kg: 200 mg orally as a single dose; repeat in 2 weeks
- Children at least 20 kg: 400 mg orally as a single dose; repeat in 2 weeks
- Some experts recommend 400 mg orally as a single dose; repeat in 2 weeks
Hydatid Disease
- Less than 60 kg: 15 mg/kg/day orally in divided doses twice a day with meals
- Maximum dose: 800 mg/day
- 60 kg or more: 400 mg orally twice a day with meals
- Duration of therapy: 28-day cycle followed by a 14-day drug-free interval, for a total of 3 cycles
Neurocysticercosis
- Less than 60 kg: 15 mg/kg/day orally in divided doses twice a day with meals
- Maximum dose: 800 mg/day
- 60 kg or more: 400 mg orally twice a day with meals
- Duration of therapy: 8 to 30 days
Capillariasis
- US CDC and American Academy of Pediatrics (AAP) recommendations: 400 mg orally once a day for 10
Cutaneous Larva Migrans
US CDC and AAP recommendations
- Older than 2 years: 400 mg orally once a day for 3 days
Cysticercus cellulosae (Cysticercosis)
- Some experts recommend: 15 mg/kg/day orally in divided doses twice a day
- Maximum dose: 800 mg/day
- Duration of therapy: 8 to 30 days
Echinococcus Infection
- US CDC and AAP recommendations: 10 to 15 mg/kg/day orally in divided doses twice a day
- Maximum dose: 800 mg/day
- Duration of therapy: 1 to 6 months
Ascariasis
- US CDC and AAP recommendations: 400 mg orally as a single dose
Filariasis
- Some experts recommend: 400 mg orally twice a day for 10 days
Hookworm Infection (Necator or Ancylostoma)
- US CDC and AAP recommendations: 400 mg orally as a single dose
Enterocolitis
- Some experts recommend: 400 mg orally once as a single dose
Loiasis
- US CDC and AAP recommendations: 200 mg orally twice a day for 21 days
Visceral Larva Migrans (Toxicariasis)
- US CDC and AAP recommendations: 400 mg orally twice a day for 5 days
Strongyloidiasis
- Some experts recommend: 400 mg orally twice a day for 7 days
Trichinosis
- US CDC and AAP recommendations: 400 mg orally twice a day for 8 to 14 days
Trichostrongylosis
- Some experts recommend: 400 mg orally as a single dose with food
Whipworm Infection (Trichuris trichiura)
- US CDC and AAP recommendations: 400 mg orally once a day for 3 days
Gnathostomiasis
- US CDC and AAP recommendations: 400 mg orally twice a day for 21 days
Clornorchis Sinensis (Liver Fluke)
- US CDC and AAP recommendations: 10 mg/kg/day orally for 7 days
Microsporidiosis
- Some experts recommend: 15 mg/kg/day orally in divided doses twice a day
- Maximum dose: 800 mg/day
Side Effects of Albendazole
The most common
- Abdominal or stomach pain
- Dizziness
- thinning or loss of the hair
- Nausea
- liver problems,
- stomach pain,
- vomiting,
- a headache,
- increased intracranial pressure,
- meningeal signs,
- reversible hair loss or thinning, and
- fever.
Common
- chills or fever
- a headache, severe and throbbing
- joint or back pain
- muscle aching or cramping
- muscle pains or stiffness
- chest pressure or squeezing pain in the chest
- discomfort in arms, shoulders, neck or upper back
- excessive sweating
- feeling of heaviness, pain, warmth and/or swelling in a leg or in the pelvis
- sudden tingling or coldness in an arm or leg
- sudden slow or difficult speech
- sudden drowsiness or need to sleep
- fast breathing
- sharp pain when taking a deep breath
- fast or slow heartbeat
- coughing up blood
- rust colored urine
- decreased amount of urine
Rare
- Anxiety
- change in vision
- chest pain or tightness
- confusion
- a cough
- Agitation
- arm, back, or jaw pain
- blurred vision
- chest pain or discomfort
- convulsions
- extra heartbeats
- fainting
- hallucinations
- a headache
- irritability
- lightheadedness
- mood or mental changes
- muscle pain or cramps
- muscle spasm or jerking of all extremities
Interactions of Albendazole
The antiepileptics carbamazepine, phenytoin, and phenobarbital lower the plasma concentration and the half-life of albendazole sulfoxide’s R(+) enantiomer.
| Drug | Change in AUC | Change in Cmax |
|---|---|---|
| Carbamazepine | 49% decrease | 50–63% decrease |
| Phenobarbitol | 61% decrease | 50–63% decrease |
| Phenytoin | 66% decrease | 50–63% decrease |
The antacid cimetidine heightens serum albendazole concentrations, increases the half-life of albendazole, and doubles albendazole sulfoxide levels in bile. It was originally thought to work by increasing albendazole bioavailability directly; however, it is now known that cimetidine inhibits the breakdown of albendazole sulfoxide by interfering with CYP3A4. The half-life of albendazole sulfoxide thus increases from 7.4 hours to 19 hours. This might be a helpful interaction on more severe cases because it boosts the potency of albendazole. Paradoxically, cimetidine also inhibits the absorption of albendazole by reducing gastric acidity.
Several other interactions exist. Corticosteroids increase the steady-state plasma concentration of albendazole sulfoxide; dexamethasone, for example, can increase the concentration by 56% by inhibiting the elimination of albendazole sulfoxide. The anti-parasitic praziquantel increases the maximum plasma concentration of albendazole sulfoxide by 50%, and the anti-parasitic levamisole increases the AUC(total drug exposure) by 75%. Grapefruit inhibits the metabolism of albendazole within the intestinal mucosa. 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.
Pregnancy & Lactation of Albendazole
FDA Pregnancy Catagory D
Pregnancy
Albendazole is a pregnancy class D drug in Australia and pregnancy class C in the United States. It is contraindicated in the first trimester of pregnancy and should be avoided up to one month before conception. While studies in pregnant rats and rabbits have shown albendazole to be teratogenic, albendazole has been found to be safe in humans during the second and third trimesters. It can, however, possibly cause infantile eczema when given during pregnancy.
Albendazole sulfoxide is secreted into breast milk at around 1.5% of the maternal dose, through oral absorption is poor enough that it is unlikely to affect nursing infants.
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