Albendazole

Albendazole comes as a tablet to take by mouth. It is usually taken with food twice a day. When albendazole is used to treat neurocysticercosis, it is usually taken for 8 to 30 days. When albendazole is used to treat cystic hydatid disease, it is usually taken for 28 days, followed by a 14-day break, and repeated for a total of three cycles. Take albendazole at around the same times every day. Follow the directions on your prescription label carefully, and ask your doctor or pharmacist to explain any part you do not understand. Take albendazole exactly as directed. Do not take more or less of it or take it more often than prescribed by your doctor.

If you are giving the medication to a child or if you cannot swallow the tablets whole, you may crush or chew the tablets and swallow with a drink of water.

Take albendazole until you finish the prescription, even if you feel better. If you stop taking albendazole too soon or skip doses, your infection may not be completely treated.

• Albenza^®

Take the missed dose as soon as you remember. Skip the missed dose if it is almost time for your next scheduled dose. Do not take extra medicine to make up the missed dose.

Seek emergency medical attention or call the Poison Help line at 1-800-222-1222.

Contraindications

• Hypersensitivity to benzimidazole derivatives or any component in the formulation.1

Warnings/Precautions

Warnings

Can cause bone marrow suppression, aplastic anemia, and agranulocytosis in patients with or without underlying hepatic dysfunction.1 Reversible leukopenia has occurred in <1% of patients receiving the drug;1 granulocytopenia, pancytopenia, agranulocytosis, or thrombocytopenia reported rarely.1 Rare fatalities reported due to granulocytopenia or pancytopenia.1

Monitor blood counts at the beginning of each 28-day cycle of albendazole treatment and every 2 weeks during treatment.1 Closer monitoring of blood counts is recommended in patients with liver disease, including hepatic echinococcosis, since these individuals may be more susceptible to bone marrow suppression leading to pancytopenia, aplastic anemia, agranulocytosis, and leukopenia.1

Discontinue albendazole if clinically important decreases in blood cell counts occur.1

Teratogenic effects (embryotoxicity, skeletal malformations) reported in rats and rabbits.1

Exclude pregnancy before initiating albendazole.1 Avoid pregnancy during and for at least 1 month after treatment.1 If patient becomes pregnant, immediately discontinue the drug and apprise patient of the potential hazard to the fetus.1 (See Pregnancy under Cautions.)

General Precautions

Adverse CNS effects (e.g., seizures and/or hydrocephalus) resulting from inflammatory reactions to damaged intracerebral cysts may occur when albendazole is used for treatment of neurocysticercosis.5 7 Use appropriate corticosteroid and anticonvulsant treatment as required.1 5 7 8 Consider oral or IV corticosteroid therapy during the first week of treatment to prevent cerebral hypertension.1

Destruction of cysticercal lesions by albendazole may cause retinal damage.1 5 8 Prior to treatment of neurocysticercosis, examine patient for retinal lesions.1 In those with such lesions, weigh the need for treatment against the possibility of irreparable retinal damage.1 5 8

Mild to moderate increases of hepatic enzymes occurred in about 16% of patients in clinical trials.1 Hepatic enzymes generally return to normal when the drug is discontinued, but acute liver failure of uncertain casualty and hepatitis have been reported.1

Perform liver function tests (hepatic transaminase concentrations) prior to each cycle of albendazole treatment and at least every 2 weeks during treatment.1 If hepatic enzymes exceed twice the ULN, consider discontinuing the drug based on the individual patient circumstance.1 Decisions to reinstitute albendazole when hepatic enzymes return to pretreatment levels should be individualized taking into account the risks and benefits of further albendazole treatment.1 If the drug is reinstituted, perform laboratory tests frequently.1

Specific Populations

Category C.1 (See Fetal/Neonatal Morbidity and Mortality under Cautions.)

Use during pregnancy only if benefits justify risks to the fetus and only when no alternative management is appropriate.1

Use in women of childbearing age only after a negative pregnancy test; caution women against becoming pregnant while receiving albendazole and for at least 1 month after completing treatment.1

Discontinue immediately if patient becomes pregnant.1

Distributed into animal milk; not known whether distributed into human milk.1 Use with caution in nursing women.1

Only limited experience in children <6 years of age.1

Has been used for treatment of neurocysticercosis in pediatric patients as young as 1 year of age; efficacy appeared to be similar to that in adults and no unusual problems were reported.1

Has been used without unusual problems for treatment of hydatid disease in infants and young children.1

Experience in patients ≥65 years of age is limited.1 Has been used without unusual problems for treatment of neurocysticercosis or hydatid disease in geriatric adults.1

Individuals with hepatic impairment are at increased risk for hepatotoxicity and bone marrow suppression during albendazole treatment.1

Discontinue albendazole if hepatic enzymes exceed twice the ULN or if clinically important decreases in blood cell counts occur.1

Not studied, but clearance of albendazole unlikely to be affected.1

Common Adverse Effects

Treatment of hydatid disease: Abnormal liver function test results, abdominal pain, nausea, vomiting, reversible alopecia, headache, dizziness.1

Treatment of neurocysticercosis: Headache, nausea, vomiting, raised intracranial pressure, meningeal signs.1

Absorption

Bioavailability

Poorly absorbed from GI tract because of low aqueous solubility.1

Rapidly converted to active metabolite (albendazole sulfoxide) before reaching systemic circulation.1 Peak plasma concentrations of albendazole sulfoxide attained 2–5 hours after a dose.1

Food

Oral bioavailability enhanced by coadministration with fatty meal (estimated fat content 40 g); plasma concentrations up to fivefold higher compared with administration in fasted state.1

Distribution

Extent

Widely distributed throughout body.1 Detected in urine, bile, liver, cyst wall, cyst fluid, and CSF.1

Plasma Protein Binding

70% bound to plasma protein.1

Elimination

Metabolism

Rapidly converted in liver to active metabolite (albendazole sulfoxide) which is responsible for anthelmintic activity.1 Further metabolized to albendazole sulfone and other primary oxidative metabolites.1

Elimination Route

Albendazole is undetectable in urine; <1% of albendazole sulfoxide detectable in urine.1 Albendazole sulfoxide partially eliminated in bile.1

Half-life

Albendazole sulfoxide: 8–12 hours.1

Special Populations

Patients with extrahepatic obstruction: Increased albendazole sulfoxide serum concentration and prolonged half-life.1 Elimination half-life may be 31.7 hours.1

Patients with renal impairment: Pharmacokinetics not studied to date.1

Geriatric patients: Pharmacokinetics not fully evaluated; data from patients up to 79 years of age with hydatid cysts suggest pharmacokinetics similar to young, healthy adults.1

Albendazole is used to treat neurocysticercosis, an infection of the nervous system caused by pork tapeworms. albendazole is also used to treat cystic hydatid disease of the liver, lung, and peritoneum, an infection caused by dog tapeworms.

Albendazole is used to treat infections caused by worms. It works by keeping the worm from absorbing sugar (glucose), so that the worm loses energy and dies.

albendazole is available only with your doctor's prescription.

• Anthelmintic

Active metabolite, albendazole sulfoxide, causes selective degeneration of cytoplasmic microtubules in intestinal and tegmental cells of intestinal helminths and larvae; glycogen is depleted, glucose uptake and cholinesterase secretion are impaired, and desecratory substances accumulate intracellulary. ATP production decreases causing energy depletion, immobilization, and worm death.

Absorption

Poor from the GI tract; may increase up to 5 times when administered with a fatty meal

Distribution

Widely distributed throughout the body including urine, bile, liver, cyst wall, cyst fluid, and CSF

Metabolism

Hepatic; extensive first-pass effect; pathways include rapid sulfoxidation to active metabolite (albendazole sulfoxide [major]), hydrolysis, and oxidation

Excretion

Urine (<1% as active metabolite); feces

Time to Peak

Serum: 2 to 5 hours for the metabolite

Half-Life Elimination

8 to 12 hours (albendazole sulfoxide)

Protein Binding

70%

Systemic availability, rate of absorption, and the elimination half-life of albendazole sulfoxide are increased in patients with extrahepatic obstruction.

Hydatid disease: Treatment of cystic hydatid disease of the liver, lung, and peritoneum caused by the larval form of the dog tapeworm, Echinococcus granulosus.

Neurocysticercosis: Treatment of parenchymal neurocysticercosis due to active lesions caused by larval forms of the pork tapeworm, Taenia solium.

Aminoquinolines (Antimalarial): May decrease the serum concentration of Anthelmintics. Monitor therapy

CarBAMazepine: May decrease serum concentrations of the active metabolite(s) of Albendazole. Monitor therapy

Grapefruit Juice: May increase serum concentrations of the active metabolite(s) of Albendazole. Monitor therapy

PHENobarbital: May decrease serum concentrations of the active metabolite(s) of Albendazole. Monitor therapy

Phenytoin: May decrease serum concentrations of the active metabolite(s) of Albendazole. Monitor therapy

Adverse events were observed in animal reproduction studies. Albendazole should not be used during pregnancy, if at all possible. The manufacturer recommends a pregnancy test prior to therapy in women of reproductive potential. Women should be advised to avoid pregnancy during and for at least 1 month following therapy. Discontinue if pregnancy occurs during treatment.

• Discuss specific use of drug and side effects with patient as it relates to treatment. (HCAHPS: During this hospital stay, were you given any medicine that you had not taken before? Before giving you any new medicine, how often did hospital staff tell you what the medicine was for? How often did hospital staff describe possible side effects in a way you could understand?)

• Patient may experience headache, abdominal pain, vomiting, or nausea. Have patient report immediately to prescriber signs of infection, signs of bleeding (vomiting blood or vomit that looks like coffee grounds; coughing up blood; hematuria; black, red, or tarry stools; bleeding from the gums; abnormal vaginal bleeding; bruises without a reason or that get bigger; or any severe or persistent bleeding), signs of liver problems (dark urine, fatigue, lack of appetite, nausea, abdominal pain, light-colored stools, vomiting, or jaundice), or severe loss of strength and energy (HCAHPS).

• Educate patient about signs of a significant reaction (eg, wheezing; chest tightness; fever; itching; bad cough; blue skin color; seizures; or swelling of face, lips, tongue, or throat). Note: This is not a comprehensive list of all side effects. Patient should consult prescriber for additional questions.

Intended Use and Disclaimer: Should not be printed and given to patients. This information is intended to serve as a concise initial reference for healthcare professionals to use when discussing medications with a patient. You must ultimately rely on your own discretion, experience and judgment in diagnosing, treating and advising patients.

Avoid being near people who have colds, the flu, or other contagious illnesses. Contact your doctor at once if you develop signs of infection.

US CDC recommendations: 400 mg orally as a single dose

Some experts recommend: 400 mg orally twice a day for 10 days

Comments: Recommended for infection due to Mansonella perstans

US CDC recommendations: 400 mg orally twice a day for 5 days

Comments:
-Recommended for visceral toxocariasis
-Optimum duration of therapy is unknown; some clinicians recommend 20 days of therapy.

Some experts recommend: 400 mg orally twice a day for 7 days

Comments:
-Recommended as alternative therapy
-May be necessary to repeat or prolong therapy or use other agents in immunocompromised patients or patients with disseminated disease

US CDC recommendations: 400 mg orally once a day for 3 days

US CDC recommendations: 400 mg orally twice a day for 1 to 6 months

Comments:
-Recommended for cystic echinococcosis in patients with small cysts or multiple cysts in several organs; treatment depends on the WHO classification of the cysts; this drug is not appropriate for all forms of the infection.
-This drug has been administered before surgery to facilitate safe surgical manipulation of cysts by inactivating protoscolices, altering cyst membrane integrity, and reducing cyst turgidity.

US CDC and AAP recommendations:
Older than 2 years: 400 mg orally once a day for 3 days

Comments (US CDC): This drug is contraindicated in children younger than 2 years; may use topical agents in such patients

Case Report (n=1)
11 months: 2.5 mL (suspension: 200 mg/5 mL) orally twice a day for 3 days

US CDC and AAP recommendations: 10 mg/kg/day orally for 7 days

Comments: Recommended as alternative therapy

Data not available

Administration advice:
-Administer with food; oral bioavailability enhanced when administered with fatty meal (estimated fat content 40 g).
-May crush or chew tablets and swallow with a drink of water; chewable tablets also available for patients unable to swallow tablet whole.

Storage requirements:
-Store at 20C to 25C (86F to 77F).

General:
-Current guidelines should be consulted for additional information.
-Safety uncertain in patients younger than 6 years; studies using this drug in children as young as 1 year suggest that it is safe.
-According to WHO guidelines for mass prevention campaigns, this drug can be used in children as young as 1 year; many children younger than 6 years have used this drug (at reduced dose) in such campaigns.

Monitoring:
-General: Pregnancy test in women of reproductive potential (before starting therapy)
-Hematologic: Blood counts in all patients (at the start of each 28-day treatment cycle and every 2 weeks while on therapy)
-Hepatic: Liver enzymes/transaminases in all patients (at the start of each 28-day treatment cycle and at least every 2 weeks during therapy)
-Ocular: For retinal lesions (before starting therapy for neurocysticercosis)