Drug reference

Albendazole

Anthelmintic

Also known as Albendazole sulfoxide, Albenza, Zentel

START

Confirm parasitic infection (stool microscopy, serology, imaging for cysts). Baseline CBC, LFTs. Pregnancy test for women of childbearing potential. For neurocysticercosis: start corticosteroids 1-2 days before albendazole.

TYPICAL MAX

800 mg/day (400 mg BID). Do not exceed.

STOP IF

ALT/AST >3x ULN, neutropenia <1000/uL, severe hypersensitivity, suspected aplastic anemia, pregnancy

WATCH

LFTs at baseline and every 2 weeks during prolonged therapy, CBC (neutropenia), pregnancy status, seizure frequency (neurocysticercosis)

CDSCO approvedSchedule HJan AushadhiNPPA price-controlledATC P02CA03

Dose laddermg/d

Renal dose adjustmenteGFR mL/min/1.73m²

KDIGO 2024 + manufacturer label

Pharmacokineticsplasma · t hours

ONSET: 53min · absorption onset
PEAK: 3.5h · 2-5 h (active sulfoxide metabolite)
t½: 10h · 8-12 h (sulfoxide metabolite)
DURATION: 4w · 28-day cycle (hydatid disease)

EXCRETION

Biliary/fecal major; minimal renal; hepatic metabolism to active

route + CYP

INTERACTIONS

2 major

SEVERE in our sources

PREGNANCY

Avoid in pregnancy (esp. first trimester) — teratogenic/embryotoxic in animals at low multiples of the human dose. FDA: obtain a pregnancy test before therapy; effective contraception during and for 1 month after. Single-dose deworming exposure has not shown increased fetal risk in published studies.

FDA category + note

Top interactionssee all 12 →

CladribineSevereDatabaseDDInter
ClozapineSevereDatabaseDDInter

Available in India

852 branded formulations and 13 fixed-dose combinations. Look up specific brands in the Drugs workspace.

Jan Aushadhi — generic available at GoI pharmacies

Mechanism

Albendazole is a broad-spectrum benzimidazole anthelmintic that inhibits parasite microtubule polymerization by binding to beta-tubulin. This binding prevents the assembly of alpha- and beta-tubulin dimers into functional microtubules, disrupting cellular transport, nutrient uptake, and structural integrity of the parasite. The drug also inhibits glucose uptake by the parasite, depleting glycogen stores. Albendazole itself has limited systemic bioavailability; its active metabolite, albendazole sulfoxide (formed by hepatic flavin monooxygenases and cytochrome P450 enzymes), is responsible for the systemic anthelmintic activity.

Indications

Neurocysticercosis (Taenia solium larval cysts in brain/muscle) — in combination with corticosteroids and anticonvulsantsHydatid disease (Echinococcus granulosus) — cysts in liver, lung, peritoneumSoil-transmitted helminthiasis (Ascaris lumbricoides, hookworm — Ancylostoma/Necator, Trichuris trichiura)Strongyloidiasis (Strongyloides stercoralis)Enterobiasis (pinworm — Enterobius vermicularis)Cutaneous larva migransFilariasis (lymphatic — Wuchereria bancrofti, Brugia malayi; loiasis — Loa loa — adjunctive)Giardiasis (Giardia lamblia/intestinalis — off-label)

Dosing

Adult: Hydatid disease: ≥60 kg: 400 mg PO BID with meals x 28 days, then 14-day albendazole-free interval; repeat for 3 cycles. <60 kg: 15 mg/kg/day (max 800 mg/day) divided BID. Neurocysticercosis: same dosing x 8-30 days with corticosteroids. STH: 400 mg PO single dose. Enterobiasis: 400 mg PO single dose; repeat in 2 weeks. Strongyloidiasis: 400 mg PO BID x 7 days.
Pediatric: Hydatysticercosis (≥1 year): 15 mg/kg/day (max 800 mg) divided BID x 8-30 days. STH (≥1 year): 400 mg PO single dose. Enterobiasis: 400 mg single dose; repeat in 2 weeks. <2 years: 200 mg single dose for STH.
Renal adjustment: No adjustment required; minimal renal excretion.
Hepatic adjustment: Monitor LFTs closely; reduced hepatic metabolism may increase toxicity. Use caution in hepatic impairment.
Geriatric: No specific adjustment; monitor LFTs and CBC.
Max dose: 800 mg/day (400 mg BID)

Pharmacokinetics

Onset

Parasite killing occurs over days to weeks; clinical improvement in STH within 48-72 hours.

Peak effect

Oral: peak plasma of active metabolite (albendazole sulfoxide) at 2-5 hours. Food (especially high-fat meal) increases bioavailability 3-5 fold.

Duration

Single-dose STH: days. Hydatid: 28-day cycles. Terminal half-life of sulfoxide metabolite: 8-12 hours.

Half-life

Albendazole parent: ~1 hour. Active sulfoxide metabolite: 8-12 hours.

Bioavailability

Poor: <5% (parent). Improved 3-5x with high-fat meal. Active sulfoxide metabolite is the primary circulating moiety.

Protein binding

~70% (albendazole sulfoxide bound to plasma proteins).

Metabolism

Extensive first-pass hepatic metabolism via flavin monooxygenases (FMO) and CYP450 to active sulfoxide metabolite; further oxidation to inactive sulfone.

Excretion

Biliary/fecal (major); minimal renal excretion.

Contraindications

Hypersensitivity to albendazole or other benzimidazoles
Pregnancy (teratogenic in animals; embryotoxic and fetotoxic)
Cysticercosis involving the eye (ocular cysticercosis — inflammation may damage retina)

Side effects

Common

Elevated liver enzymes (transient, usually asymptomatic)Abdominal pain, nauseaHeadache, dizzinessReversible alopecia (hair loss)Fever

Serious

Bone marrow suppression (neutropenia, pancytopenia, aplastic anemia — rare but fatal)
Hepatotoxicity (acute liver failure, elevated transaminases >3x ULN)
Retinal/periocular damage (in ocular cysticercosis — contraindicated)
Severe hypersensitivity (SJS, TEN)
Teratogenicity (contraindicated in pregnancy)
Cerebral hypertensive episodes (during neurocysticercosis treatment — requires corticosteroid cover)

Pregnancy & lactation

Pregnancy

Lactation

Excreted in breast milk in low concentrations. Caution advised. Consider risk-benefit. Avoid single-day therapy during breastfeeding if possible.

Drug interactions

Cladribine

Severe

Database

Drug interaction classified as: synergy

Source: DDInter

Clozapine

Severe

Database

Drug interaction classified as: synergy

Source: DDInter

Glucocorticoids

Moderate

Textbook

Increased plasma levels of albendazole sulfoxide. In neurocysticercosis, glucocorticoids are often started before albendazole to reduce side effects from inflammatory reactions.

Glucocorticoid therapy is usually begun before initiating albendazole therapy and continued for several days after commencement of therapy to reduce the incidence of side effects resulting from inflammatory reactions.

Source: G&G 14e · p1325-1334

Antiepileptics

Moderate

Database

CYP inducers reduce plasma levels of albendazole sulfoxide by increasing metabolism, potentially reducing anthelmintic efficacy.

Monitor for treatment failure (persistent parasites). May need higher albendazole dose or alternative anthelmintic. Consider switching to non-inducing antiepileptic (valproate, levetiracetam) if feasible.

Source: Kimi deep-research + Cla

Carbamazepine

Moderate

Database

Decreased plasma concentrations of albendazole sulfoxide, potentially leading to reduced therapeutic effect.

Monitor for reduced efficacy of albendazole. Consider increasing albendazole dose if clinically indicated and tolerated, or consider alternative anthelmintic if possible.

Source: DDInter

Cimetidine

Moderate

Database

Cimetidine inhibits metabolism and increases plasma concentration of albendazole active metabolite, potentially increasing efficacy but also toxicity.

May be used therapeutically to increase albendazole levels (e.g., for hydatid disease). Monitor LFTs. If unintended, watch for increased side effects.

Source: Kimi deep-research + Cla

Dexamethasone

Moderate

Database

Dexamethasone increases albendazole sulfoxide plasma levels by ~50% via inhibition of metabolism or displacement from protein binding. Used therapeutically in neurocysticercosis but increases hepatotoxicity risk.

Standard combination for neurocysticercosis. Monitor LFTs closely. Beneficial interaction in this context.

Source: Kimi deep-research + Cla

Grapefruit Juice

Moderate

Database

Grapefruit juice inhibits intestinal CYP3A4 and P-gp, increasing albendazole bioavailability and plasma levels.

Avoid grapefruit juice during albendazole therapy to prevent unpredictable increases in drug levels and toxicity.

Source: Kimi deep-research + Cla

Phenobarbital

Moderate

Database

Decreased plasma concentrations of albendazole sulfoxide, potentially leading to reduced therapeutic effect.

Monitor for reduced efficacy of albendazole. Consider increasing albendazole dose if clinically indicated and tolerated, or consider alternative anthelmintic if possible.

Source: DDInter

Phenytoin

Moderate

Database

Decreased plasma concentrations of albendazole sulfoxide, potentially leading to reduced therapeutic effect.

Monitor for reduced efficacy of albendazole. Consider increasing albendazole dose if clinically indicated and tolerated, or consider alternative anthelmintic if possible.

Source: DDInter

Praziquantel

Moderate

Database

Albendazole increases praziquantel plasma levels (inhibition of metabolism). Combined use enhances cysticidal effect for neurocysticercosis but increases adverse effects.

Standard combination for neurocysticercosis. Monitor LFTs and adverse effects. Ensure corticosteroid cover.

Source: Kimi deep-research + Cla

Ritonavir

Moderate

Database

Potential for increased plasma levels of albendazole sulfoxide.

Caution is advised when using high doses of albendazole together with drugs that inhibit hepatic CYPs, such as ritonavir.

Source: DDInter