Benzimidazole derivatives

Albenza

Approved 11 Jun 1996OralTablet

Indications

Albendazole is an anthelmintic drug indicated for: Treatment of parenchymal neurocysticercosis due to active lesions caused by larval forms of the pork tapeworm, Taenia solium . ( 1.1 ) Treatment of cystic hydatid disease of the liver, lung, and peritoneum, caused by the larval form of the dog tapeworm, Echinococcus granulosus . ( 1.2 )

1.1Neurocysticercosis

Albendazole is indicated for the treatment of parenchymal neurocysticercosis due to active lesions caused by larval forms of the pork tapeworm, Taenia solium .

1.2Hydatid Disease

Albendazole is indicated for the treatment of cystic hydatid disease of the liver, lung, and peritoneum, caused by the larval form of the dog tapeworm, Echinococcus granulosus .

Contraindications

Albendazole is contraindicated in patients with known hypersensitivity to the benzimidazole class of compounds or any components of albendazole. Patients with known hypersensitivity to the benzimidazole class of compounds or any components of albendazole.

Warnings and precautions

Bone Marrow Suppression: Fatalities have been reported due to bone marrow suppression; monitor blood counts in all patients at the beginning of each 28-day cycle of therapy, and every 2 weeks while on therapy. Discontinue albendazole if clinically significant changes in blood counts occur. ( 5.1 , 5.4 ) Embryo-fetal Toxicity: Obtain pregnancy test in women of reproductive potential prior to therapy and avoid usage in pregnant women except in clinical circumstances where no alternative management is appropriate.

Discontinue therapy if pregnancy occurs and apprise patient of potential hazard to the fetus. ( 5.2 ) Risk of Neurologic Symptoms: Neurocysticercosis patients may experience cerebral hypertensive episodes, seizures or focal neurologic deficits after initiation of therapy; begin appropriate steroid and anticonvulsant therapy. ( 5.3 ) Risk of Retinal Damage in Retinal Cysticercosis: Cases of retinal involvement have been reported; examine the patient for the presence of retinal lesions before initiating therapy for neurocysticercosis.

( 5.4 ) Hepatic Effects. Elevations of liver enzymes may occur. Monitor liver enzymes before the start of each treatment cycle and at least every 2 weeks while on albendazole therapy and discontinue if clinically significant elevations occur. ( 5.5 )

At a glance

Brand name: Albenza
Active substance: albendazole
Drug class: Benzimidazole derivatives
Route: Oral
Dosage form: Tablet
Applicant: Impax Labs Inc
Status: Discontinued
FDA approval: 11 Jun 1996
Application: NDA020666-001
RxCUI: 151717

Indications

1.1Neurocysticercosis

Albendazole is indicated for the treatment of parenchymal neurocysticercosis due to active lesions caused by larval forms of the pork tapeworm, Taenia solium .

1.2Hydatid Disease

Albendazole is indicated for the treatment of cystic hydatid disease of the liver, lung, and peritoneum, caused by the larval form of the dog tapeworm, Echinococcus granulosus .

Warnings and precautions

Interactions

Dexamethasone: Steady-state trough concentrations of albendazole sulfoxide were about 56% higher when dexamethasone was coadministered with each dose of albendazole. ( 7.1 ) Praziquantel: In the fed state increased mean maximum plasma concentration and area under the curve of albendazole sulfoxide by about 50% in healthy subjects. ( 7.2 ) Cimetidine: Increased albendazole sulfoxide concentrations in bile and cystic fluid by about 2-fold in hydatid cyst patients.

( 7.3 ) Theophylline: Albendazole induces cytochrome P450 1A in human hepatoma cells; therefore, it is recommended that plasma concentrations of theophylline be monitored during and after treatment. ( 5.5 , 7.4 )

7.1Dexamethasone

Steady-state trough concentrations of albendazole sulfoxide were about 56% higher when 8 mg dexamethasone was co-administered with each dose of albendazole (15 mg/kg/day) in 8 neurocysticercosis patients.

7.2 Praziquantel In the fed state, praziquantel (40 mg/kg) increased mean maximum plasma concentration and area under the curve of albendazole sulfoxide by about 50% in healthy subjects (n = 10) compared with a separate group of subjects (n = 6) given albendazole alone. Mean T max and mean plasma elimination half-life of albendazole sulfoxide were unchanged. The pharmacokinetics of praziquantel were unchanged following co-administration with albendazole (400 mg).

7.3Cimetidine

Albendazole sulfoxide concentrations in bile and cystic fluid were increased (about 2-fold) in hydatid cyst patients treated with cimetidine (10 mg/kg/day) (n = 7) compared with albendazole (20 mg/kg/day) alone (n = 12). Albendazole sulfoxide plasma concentrations were unchanged 4 hours after dosing.

7.4Theophylline Following

a single dose of albendazole (400 mg), the pharmacokinetics of theophylline (aminophylline 5.8 mg/kg infused over 20 minutes) were unchanged. Albendazole induces cytochrome P450 1A in human hepatoma cells; therefore, it is recommended that plasma concentrations of theophylline be monitored during and after treatment.

Pregnancy and breastfeeding

8.1Pregnancy Risk Summary

There are limited data on use of albendazole in pregnant women to inform a drug-associated risk of major birth defects and miscarriage. In published studies, single-dose albendazole exposure during pregnancy did not show evidence of an increased risk of adverse maternal or fetal outcomes; however, this finding cannot be extrapolated to multiple-dose exposures ( see Data ). In animal reproductive studies, oral administration of albendazole during gestation caused embryotoxicity and skeletal malformations in pregnant rats (at oral doses of 0.10 times and 0.32 times the recommended human dose based on body surface area in mg/m 2 ) and pregnant rabbits (at oral doses of 0.60 times the recommended human dose based on body surface area in mg/m 2 ).

Albendazole was also associated with maternal toxicity in rabbits (at doses of 0.60 times the recommended human dose based on body surface area in mg/m 2 ) ( see Data ). Albendazole should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Albendazole should not be used in pregnant women except in clinical circumstances where no alternative management is appropriate. If a patient becomes pregnant while taking this drug, albendazole should be discontinued immediately.

If pregnancy occurs while taking this drug, the patient should be apprised of the potential hazard to the fetus. The estimated background risk of major birth defects and miscarriage for the indicated population is unknown. In the U.S. general population, the estimated background risk of major birth defects and miscarriage in clinically recognized pregnancies is 2 to 4% and 15 to 20%, respectively. Data Human Data A Cochrane review could not provide sufficient evidence of the impact of antihelminthics (including albendazole) on the pregnancy outcomes of low birthweight, perinatal mortality and preterm birth.

In a large trial of about 2507 women, albendazole use during the second or third trimester of pregnancy had no overall effect on birth weight, perinatal mortality, or congenital anomalies. With a limited sample size and single-does exposure, another study could not rule out a two-fold increased risk of major malformations [4.7% vs. 2.2%; OR 2.2 (95% confidence interval (CI) 0.5 to 10.1); p = 0.26]. Animal Data Albendazole has been shown to be teratogenic (to cause embryotoxicity and skeletal malformations) in pregnant rats and rabbits.

The teratogenic response in the rat was shown at oral doses of 10 and 30 mg/kg/day (0.10 times and 0.32 times the recommended human dose based on body surface area in mg/m 2 , respectively) during gestation days 6 to 15 and in pregnant rabbits at oral doses of 30 mg/kg/day (0.60 times the recommended human dose based on body surface area in mg/m 2 ) administered during gestation days 7 to 19. In the rabbit study, maternal toxicity (33% mortality) was noted at 30 mg/kg/day.

In mice, no teratogenic effects were observed at oral doses up to 30 mg/kg/day (0.16 times the recommended human dose based on body surface area in mg/m 2 ), administered during gestation days 6 to 15.

Adverse reactions

Adverse reactions 1% or greater in hydatid disease: abnormal liver function tests, abdominal pain, nausea/vomiting, reversible alopecia, headache, dizziness/vertigo, fever. ( 6.1 ) Adverse reactions 1% or greater in neurocysticercosis: headache, nausea/vomiting, raised intracranial pressure, meningeal signs. ( 6.1 ) To report SUSPECTED ADVERSE REACTIONS, contact Amneal Pharmaceuticals at 1-877-835-5472 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch.

6.1Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice. The adverse reaction profile of albendazole differs between hydatid disease and neurocysticercosis. Adverse reactions occurring with a frequency of 1% or greater in either disease are described in Table 2 below.

These symptoms were usually mild and resolved without treatment. Treatment discontinuations were predominantly due to leukopenia (0.7%) or hepatic abnormalities (3.8% in hydatid disease). The following incidence reflects adverse reactions that were reported to be at least possibly or probably related to albendazole. T able 2: Adverse Reaction Incidence 1% or Greater in Hydatid Disease and Neurocysticercosis A dverse Reaction H ydatid Disease N eurocysticercosis G astrointestinal Abdominal Pain 6 0 Nausea 4 6 Vomiting 4 6 G eneral disorders and administration site conditions Fever 1 0 Investigations Elevated Hepatic Enzymes 16 less than 1 N ervous system disorders Dizziness 1 less than 1 Headache 1 11 Meningeal Signs 0 1 Raised Intracranial Pressure 0 2 Vertigo 1 less than 1 Skin and subcutaneous tissue disorders Reversible Alopecia 2 less than 1 The following adverse events were observed at an incidence of less than 1%: Blood and Lymphatic System Disorders: There have been reports of leukopenia, granulocytopenia, pancytopenia, agranulocytosis, or thrombocytopenia [see Warnings and Precautions (5.1) ] .

Immune System Disorders: Hypersensitivity reactions, including rash and urticaria.

6.2Postmarketing Experience

The following adverse reactions have been identified during post-approval use of albendazole. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure. Blood and Lymphatic System Disorders: Aplastic anemia, bone marrow suppression, neutropenia. Eye Disorders: Vision blurred. Gastrointestinal Disorders: Diarrhea.

General System Disorders: Asthenia. Hepatobiliary Disorders: Elevations of hepatic enzymes, hepatitis, acute liver failure. Musculoskeletal and Connective Tissue Disorders: Rhabdomyolysis. Nervous System Disorders: Somnolence, convulsion. Renal and Urinary Disorders: Acute renal failure. Skin and Subcutaneous Tissue Disorders: Erythema multiforme, Stevens-Johnson syndrome.

Albenza

Indications

1.1Neurocysticercosis

1.2Hydatid Disease

Contraindications

Warnings and precautions

At a glance

Two medicines in one question?

Albenza

Indications

1.1Neurocysticercosis

1.2Hydatid Disease

Contraindications

Warnings and precautions

At a glance

Two medicines in one question?

5.1Bone Marrow Suppression

5.2Embryo-fetal Toxicity

5.3Risk of Neurologic Symptoms in Neurocysticercosis

5.4Risk of Retinal Damage in Patients with Retinal Neurocysticercosis

5.5Hepatic Effects

5.6Unmasking of Neurocysticercosis in Hydatid Patients

Interactions

7.1Dexamethasone

7.3Cimetidine

7.4Theophylline Following

Pregnancy and breastfeeding

8.1Pregnancy Risk Summary

Adverse reactions

6.1Clinical Trials Experience

6.2Postmarketing Experience

Composition

Official product information