Albendazole

Albendazole is a benzimidazole carbamate anthelmintic agent with broad-spectrum activity against intestinal and tissue-dwelling nematodes and cestodes. This synthetic compound demonstrates vermicidal and ovicidal properties by selectively binding to beta-tubulin in parasitic cells, inhibiting microtubule polymerization and disrupting glucose uptake. Its extensive first-pass metabolism produces the active sulfoxide metabolite, which achieves therapeutic concentrations in various tissues, including cysts, making it particularly effective against systemic parasitic infections. The medication represents a cornerstone in antiparasitic therapy due to its proven efficacy, well-established safety profile, and cost-effectiveness in managing helminthic infestations.

Features

• Synthetic benzimidazole derivative with broad anthelmintic spectrum
• Inhibits microtubule assembly through beta-tubulin binding
• Active against larval and adult stages of susceptible parasites
• Produces active sulfoxide metabolite through first-pass metabolism
• Lipophilic properties enabling tissue penetration and cyst fluid concentration
• Available in 200 mg and 400 mg chewable tablets and suspension formulations

Benefits

• Comprehensive Parasite Elimination: Effectively targets both adult worms and larval forms across multiple parasite species
• Tissue Penetration Capability: Achieves therapeutic concentrations in various tissues, including brain, liver, and lung parenchyma
• Proven Clinical Efficacy: Demonstrated high cure rates in numerous clinical trials and decades of practical use
• Convenient Dosage Regimen: Typically administered as single or short-course therapy depending on indication
• Cost-Effective Treatment: Provides affordable therapy for both individual patients and mass drug administration programs
• Well-Tolerated Profile: Generally safe with manageable side effects when used appropriately under medical supervision

Common use

Albendazole is indicated for the treatment of various parasitic infections including neurocysticercosis caused by larval forms of Taenia solium, hydatid disease caused by Echinococcus granulosus, and intestinal infections by Ascaris lumbricoides, hookworm (Ancylostoma duodenale and Necator americanus), Enterobius vermicularis, Trichuris trichiura, and Strongyloides stercoralis. It is also used off-label for cutaneous larva migrans, microsporidiosis, and gnathostomiasis. The World Health Organization includes albendazole in its Model List of Essential Medicines and recommends it for preventive chemotherapy in endemic areas for soil-transmitted helminthiases.

Dosage and direction

Dosage varies according to indication, patient weight, and clinical context. For neurocysticercosis: 15 mg/kg/day (maximum 800 mg) in two divided doses with meals for 8-30 days. For hydatid disease: 15 mg/kg/day (maximum 800 mg) in two divided doses with meals for 28-day cycles followed by 14-day drug-free intervals. For intestinal helminths: single 400 mg dose for adults and children over 2 years (200 mg for children 1-2 years). Administration with fatty meals enhances bioavailability by up to fivefold. Tablets should be chewed or crushed before swallowing if difficulty exists. Complete the full prescribed course unless otherwise directed by a physician.

Precautions

Hepatic function should be monitored before and during therapy, with dosage adjustment in hepatic impairment. Complete blood counts should be performed before treatment and every 2 weeks during prolonged therapy due to potential bone marrow suppression. Use with caution in patients with pre-existing hematological disorders. Effective contraception must be used during treatment and for one month after discontinuation due to teratogenic potential. Corticosteroid therapy should be administered concurrently for neurocysticercosis to prevent inflammatory reactions to dying parasites. Retinal examination is recommended before treatment for ocular involvement.

Contraindications

Absolute contraindications include known hypersensitivity to albendazole, other benzimidazoles, or any component of the formulation. Pregnancy (category C) represents a contraindication due to embryotoxic and teratogenic effects demonstrated in animal studies. Breastfeeding should be avoided during therapy as albendazole is excreted in human milk. The drug is contraindicated in patients with known cirrhosis or significant hepatic impairment. Not recommended for children under one year of age due to insufficient safety data.

Possible side effect

Common adverse reactions (≥1%) include abdominal pain, nausea, vomiting, headache, dizziness, and transient elevation of liver enzymes. Less frequent side effects include leukopenia, thrombocytopenia, pancytopenia, alopecia, fever, skin rash, and pruritus. Rare but serious adverse effects include Stevens-Johnson syndrome, toxic epidermal necrolysis, hepatitis, and acute liver failure. Neurological side effects may include meningeal signs, increased intracranial pressure, and seizures in neurocysticercosis patients. Ocular complications including retinal damage may occur with improper use.

Drug interaction

Cimetidine, dexamethasone, and praziquantel increase plasma levels of albendazole sulfoxide metabolite. Anticonvulsants (carbamazepine, phenytoin, phenobarbital) may decrease albendazole levels. Theophylline levels may be increased when co-administered with albendazole. Potential interaction with warfarin requires close monitoring of coagulation parameters. Concurrent use with other bone marrow suppressants may increase hematological toxicity. Grapefruit juice may inhibit albendazole metabolism and increase bioavailability.

Missed dose

If a dose is missed, take it as soon as remembered unless it is almost time for the next scheduled dose. Do not double the dose to make up for a missed administration. For once-daily dosing regimens, take the missed dose if remembered within 12 hours of the scheduled time. For twice-daily regimens, take the missed dose if remembered within 6 hours. Maintain regular dosing schedule thereafter. Contact healthcare provider for specific guidance if multiple doses are missed.

Overdose

Symptoms of overdose may include severe nausea, vomiting, abdominal cramping, diarrhea, dizziness, and headache. Massive overdose may lead to hepatic impairment, bone marrow suppression, or neurological symptoms. There is no specific antidote for albendazole overdose. Management involves gastric lavage if presented early, activated charcoal administration, and supportive care including monitoring of hematological and hepatic parameters. Hemodialysis is not effective due to high protein binding. Symptomatic treatment should be provided based on clinical manifestations.

Storage

Store at controlled room temperature (20-25°C or 68-77°F) in original container. Protect from light and moisture. Keep tightly closed and away from excessive heat. Do not freeze oral suspension. Keep out of reach of children and pets. Do not use after expiration date printed on packaging. Properly discard any unused medication after completion of therapy. Do not transfer tablets or suspension to other containers as this may affect stability.

Disclaimer

This information is for educational purposes only and does not constitute medical advice. Always consult a qualified healthcare professional for diagnosis and treatment recommendations. Dosage and administration should be determined by a physician based on individual patient characteristics and specific parasitic infection. The prescriber should be aware of the latest clinical guidelines and contraindications. Patient response to therapy should be monitored appropriately, and treatment adjusted based on clinical outcomes and laboratory parameters.

Reviews

Clinical studies demonstrate albendazole efficacy rates of 72-98% for ascariasis, 92-100% for hookworm infection, and 90-100% for enterobiasis. In neurocysticercosis, complete cyst resolution occurs in 50-80% of patients after one cycle, increasing with repeated therapy. Systematic reviews confirm albendazole’s superiority over other anthelmintics for many tissue parasites. The drug has received positive evaluations in WHO treatment guidelines and is considered essential for parasitic disease control programs worldwide. Long-term follow-up studies show sustained efficacy with appropriate dosing regimens and adequate follow-up.