Monday, May 24, 2010

Albendazole

MEDICATION SAFETY ISSUES
Sound-alike/look-alike issues:
Albenza® may be confused with Aplenzin™ , Relenza®

International issues:
Albenza® may be confused with Avanza® which is a brand name for mirtazapine in Australia

U.S. BRAND NAMES — Albenza®

PHARMACOLOGIC CATEGORY
Anthelmintic

DOSING: ADULTS
Neurocysticercosis: Oral:
<60 kg: 15 mg/kg/day in 2 divided doses (maximum: 800 mg/day) for 8-30 days
≥ 60 kg: 800 mg/day in 2 divided doses for 8-30 days
Note: Give concurrent anticonvulsant and steroid therapy during first week.

Hydatid: Oral:
<60 kg: 15 mg/kg/day in 2 divided doses (maximum: 800 mg/day)
≥ 60 kg: 800 mg/day in 2 divided doses
Note: Administer dose for three 28-day cycles with a 14-day drug-free interval in between. The manufacturer recommends a total of 3 cycles.

Ancylostoma caninum, Ascaris lumbricoides(roundworm), Ancylostoma duodenale (hookworm), and Necator americanus(hookworm) (unlabeled use): Oral: 400 mg as a single dose

Clonorchis sinensis(Chinese liver fluke) (unlabeled use): Oral: 10 mg/kg for 7 days

Cutaneous larva migrans (unlabeled use): Oral: 400 mg once daily for 3 days

Enterobius vermicularis(pinworm) (unlabeled use): Oral: 400 mg as a single dose; may repeat in 2 weeks

Gnathostoma spinigerum (unlabeled use): Oral: 800 mg/day in 2 divided doses for 21 days

Gongylonemiasis (unlabeled use): Oral: 10 mg/kg/day for 3 days

Mansonella perstans(unlabeled use): Oral: 800 mg/day in 2 divided doses for 10 days

Visceral larva migrans (toxocariasis) (unlabeled use): Oral: 800 mg/day in 2 divided doses for 5 days

Cysticercus cellulosae(unlabeled use): Oral: 800 mg/day in 2 divided doses for 8-30 days; may be repeated as necessary

Disseminated microsporidiosis (unlabeled use): Oral: 800 mg/day in 2 divided doses

Echinococcus granulosus(tapeworm) (unlabeled use): Oral: 800 mg/day in 2 divided doses for 1-6 months

Intestinal microsporidiosis (unlabeled use): Oral: 800 mg/day in 2 divided doses for 21 days

Ocular microsporidiosis (unlabeled use): Oral: 800 mg/day in 2 divided doses, in combination with fumagillin

DOSING: PEDIATRIC

(For additional information see "Albendazole: Pediatric drug information")
Neurocysticercosis: Oral: Refer to adult dosing.

Hydatid: Oral: Refer to adult dosing.

Cysticercus cellulosae(unlabeled use): Oral: 15 mg/kg/day (maximum: 800 mg/day) in 2 divided doses for 8-30 days; may be repeated as necessary

Echinococcus granulosus(tapeworm) (unlabeled use): Oral: 15 mg/kg/day (maximum: 800 mg) divided twice daily for 1-6 months

For the following unlabeled uses, refer to adult dosing:
Ancylostoma caninum, Ascaris lumbricoides (roundworm), Ancylostoma duodenale (hookworm), Clonorchis sinensis, (Chinese liver fluke), cutaneous larva migrans, Enterobius vermicularis (pinworm), Gnathostoma spinigerum, gongylonemiasis, Mansonella perstans, Necator americanus (hookworm), visceral larva migrans (toxocariasis)

DOSING: ELDERLY — Refer to adult dosing.

DOSAGE FORMS — Excipient information presented when available (limited, particularly for generics); consult specific product labeling.

Tablet:
Albenza®: 200 mg

DOSAGE FORMS: CONCISE
Tablet:
Albenza®: 200 mg

GENERIC EQUIVALENT AVAILABLE — No

ADMINISTRATION — Should be administered with a high-fat meal. Administer anticonvulsant and steroid therapy during first week of neurocysticercosis therapy. If patients have difficulty swallowing, tablets may be crushed or chewed, then swallowed with a drink of water.

USE — Treatment of parenchymal neurocysticercosis caused by Taenia solium and cystic hydatid disease of the liver, lung, and peritoneum caused by Echinococcus granulosus

USE - UNLABELED / INVESTIGATIONAL — Albendazole has activity against Ascaris lumbricoides (roundworm); Ancylostoma caninum; Ancylostoma duodenale and Necator americanus (hookworms); cutaneous larva migrans; Enterobius vermicularis (pinworm); Gnathostoma spinigerum; Gongylonema sp; Mansonella perstans (filariasis); Opisthorchis sinensis (liver fluke); visceral larva migrans (toxocariasis); activity has also been shown against the liver fluke Clonorchis sinensis, Giardia lamblia, Cysticercus cellulosae, and Echinococcus multilocularis. Albendazole has also been used for the treatment of intestinal microsporidiosis (Encephalitozoon intestinalis), disseminated microsporidiosis (E. hellem, E. cuniculi, E. intestinalis, Pleistophora sp, Trachipleistophora sp, Brachiola vesicularum), and ocular microsporidiosis (E. hellem, E. cuniculi, Vittaforma corneae).

ADVERSE REACTIONS SIGNIFICANT
>10%:
Central nervous system: Headache (11% neurocysticercosis; 1% hydatid)
Hepatic: LFTs increased (16% hydatid; <1% neurocysticercosis)

1% to 10%:
Central nervous system: Intracranial pressure increased (up to 2%), dizziness (≤ 1%), fever (≤ 1%), vertigo (≤ 1%), meningeal signs (1%)
Dermatologic: Alopecia (<1% to 2%)
Gastrointestinal: Abdominal pain (up to 6%), nausea/vomiting (4% to 6%)

<1% (Limited to important or life-threatening symptoms): Acute liver failure, acute renal failure, aplastic anemia, agranulocytosis, erythema multiforme, granulocytopenia, hepatitis, hypersensitivity reaction, leukopenia, neutropenia, pancytopenia, rash, Stevens-Johnson syndrome, thrombocytopenia, urticaria

CONTRAINDICATIONS — Hypersensitivity to albendazole, benzimidazoles, or any component of the formulation

WARNINGS / PRECAUTIONS
Concerns related to adverse effects: Bone marrow suppression: Agranulocytosis, aplastic anemia, granulocytopenia, leukopenia, and pancytopenia have occurred leading to fatalities (rare); use with caution in patients with hepatic impairment (more susceptible to hematologic toxicity). Discontinue therapy in all patients who develop clinically significant decreases in blood cell counts. Transaminase elevations: Reversible elevations in hepatic enzymes have been reported. Patients with abnormal LFTs and hepatic echinococcosis are at an increased risk of hepatotoxicity. Discontinue therapy if LFT elevations are >2 times the upper limit of normal; may consider restarting treatment (with frequent monitoring of LFTs) when hepatic enzymes return to pretreatment values.

Disease-related concerns: Neurocysticercosis: Appropriate use: Corticosteroids should be administered before or upon initiation of albendazole therapy to minimize inflammatory reactions and prevent cerebral hypertension. Anticonvulsant therapy should be used concurrently during the first week of therapy to prevent seizures. If retinal lesions exist, weigh risk of further retinal damage due to albendazole-induced changes to the retinal lesion vs benefit of disease treatment.

METABOLISM / TRANSPORT EFFECTS — Substrate (minor) of CYP1A2, 3A4; Inhibits CYP1A2 (weak)

DRUG INTERACTIONS
Aminoquinolines (Antimalarial): May decrease the serum concentration of Anthelmintics. Risk C: Monitor therapy

ETHANOL / NUTRITION / HERB INTERACTIONS — Food: Albendazole serum levels may be increased if taken with a fatty meal (increases the oral bioavailability by up to 5 times).

PREGNANCY RISK FACTOR — C (show table)

PREGNANCY IMPLICATIONS — Albendazole has been shown to be teratogenic in laboratory animals and should not be used during pregnancy, if at all possible. Women should be advised to avoid pregnancy for at least 1 month following therapy. Discontinue if pregnancy occurs during treatment.

LACTATION — Excretion in breast milk unknown/not recommended

DIETARY CONSIDERATIONS — Should be taken with a high-fat meal.

PRICING — (data from drugstore.com)
Tablets (Albenza)
200 mg (12): $26.99

MONITORING PARAMETERS — Monitor fecal specimens for ova and parasites for 3 weeks after treatment; if positive, retreat; LFTs and CBC with differential at start of each 28-day cycle and every 2 weeks during therapy (more frequent monitoring for patients with liver disease); pregnancy test

INTERNATIONAL BRAND NAMES — ABZ (IN); Acure (PK); Albatel (TH); Alben (BR); Albenzol (EC); Albex (AE, BH, CY, EG, IL, IQ, IR, JO, KW, LB, LY, OM, QA, SA, SY, YE); Albezole (IN); Alfuca (TH); Almex (MY); Alminth (IN); Alzental (AE, BH, CY, EG, IL, IQ, IR, JO, KW, LB, LY, OM, QA, SA, SG, SY, YE); Alzol (TH); Bendex-400 (ZA); Benzol (PH); Bruzol (MX); Ceprazol (CN); Champs D-Worm 6 (MY); Ciclopar (CO); Dalben (HR); Digezanol (MX); Emanthal (IN); Eskasole (MX); Eskazole (AT, AU, DE, ES, GB, IL, JP, NL); Fintel (PE); Gascop (MX); Helmiben (UY); Helmidazole (AE, BH, CY, EG, IL, IQ, IR, JO, KW, LB, LY, OM, QA, SA, SY, YE); Labenda (TH); Lomsin (MX); Lurdex (MX); Mebenix (BR); Mesin-C (MY); Nemozole (IN); Pantex (PY); Paranthil (ZA); Parhel (CR, DO, GT, HN, NI, PA, SV); Rotopar (EC); Sioban (IN); Valbazen Vet (NO); Vastus (AR); Vemizol (MY); Vermin Plus (MX); Zeben (TH); Zela (TH); Zentab (TH); Zentel (AE, AU, BB, BF, BG, BH, BJ, BM, BR, BS, BZ, CH, CI, CL, CN, CR, CY, CZ, DO, EG, ET, FR, GH, GM, GN, GR, GT, GY, HN, IL, IQ, IR, IT, JM, JO, KE, KP, KW, LB, LR, LY, MA, ML, MR, MU, MW, MX, MY, NE, NG, NI, NL, OM, PA, PE, PH, PL, PR, PT, QA, SA, SC, SD, SL, SN, SR, SV, SY, TH, TN, TT, TZ, UG, VE, YE, ZA, ZM, ZW)

MECHANISM OF ACTION — 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.

PHARMACODYNAMICS / KINETICS
Absorption: Poor; may increase up to 5 times when administered with a fatty meal

Distribution: Well inside hydatid cysts and CSF

Protein binding: 70%

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

Half-life elimination: 8-12 hours

Time to peak, serum: 2-5 hours

Excretion: Urine (<1% as active metabolite); feces

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