Mechanism of Action
ALBENZA binds to the colchicine-sensitive site of β-tubulin inhibiting their polymerization into microtubules. The decrease in microtubules in the intestinal cells of the parasites decreases their absorptive function, especially the uptake of glucose by the adult and larval forms of the parasites, and also depletes glycogen storage. Insufficient glucose results in insufficient energy for the production of adenosine trisphosphate (ATP) and the parasite eventually dies.
Mechanism of Resistance
Parasitic resistance to Extender is caused by changes in amino acids that result in changes in the β-tubulin protein. This causes reduced binding of the drug to β-tubulin.
In the specified treatment indications Extender appears to be active against the larval forms of the following organisms:
What is the most important information I should know about Extender?
Extender should not be used during pregnancy, unless there is no alternate treatment. You may need to have a negative pregnancy test before starting this treatment.
13.1 Carcinogenesis, Mutagenesis, Impairment of Fertility
Long-term carcinogenicity studies were conducted in mice and rats.
No evidence of increased incidence of tumors was found in the mice or rats at up to 400 mg/kg/day or 20 mg/kg/day respectively (2 times and 0.2 times the recommended human dose on a body surface area basis).
In genotoxicity tests, Extender was found negative in an Ames Salmonella/Microsome Plate mutation assay, Chinese Hamster Ovary chromosomal aberration test, and in vivo mouse micronucleus test. In the in vitro BALB/3T3 cells transformation assay, Extender produced weak activity in the presence of metabolic activation while no activity was found in the absence of metabolic activation.
Extender d >2 ).
Extender has been proven to be efficacious for gnathostomiasis, with cure rates of over 90% at a dose of 400 mg bd for 21 days. Small studies of ivermectin 200 µg/kg either as a stat dose or on two consecutive days seem to show similar efficacy to Extender. Initial treatment is not always successful and second courses of treatment have been needed in some cases. Either Extender or ivermectin may be used sequentially in such patients. Further trials are needed to determine whether relapse rates are lower with combination drugs than with monotherapy. Follow-up should be for at least 1 year. 19,20
Where can I get more information?
Your pharmacist can provide more information about Extender.
Extender ↔ food
Moderate Food Interaction
Food significantly increases the absorption of Extender. You should take each dose of Extender with a meal. Taking it on an empty stomach may lead to inadequate blood levels and reduced effectiveness of the medication. Grapefruit juice can also increase the absorption of Extender.
Pharmacology and toxicology
Extender is a highly effective broad-spectrum anthelmintic, structurally related to mebendazole. It also kills the parasite through inhibition of the glucose uptake. It is the first-line drug for the treatment of alveolar forms of echinococcosis (Echinococcus multilocularis), and also for the advanced cystic forms (Echinococcus granulosus). During a mass drug administration for lymphatic filiriasis in Ghana, 50 women were inadvertently (because their pregnancy was not recognized) treated with ivermectin and Extender; their pregnancy outcomes were compared with those of 293 women with a recognized pregnancy who were not treated. Of the 39 children who were exposed during the first trimester, 1 congenital malformation (a hearing impairment), versus 5 of the untreated group, was reported. The authors concluded that there was no evidence of increased risk after exposure to ivermectin and Extender ( Gyapong 2003 ). One Down syndrome was observed in a small prospective study of Extender (n = 12) and flubendazole (n = 11) ( Choi 2005 ). No malformations were observed among 24 children born after first-trimester exposure to Extender in a prospective study ( Reuvers-Lodewijks 1999 ).
Thiabendazole is indicated for the treatment of strongyloidiasis, larva migrans cutanea, and trichinosis. There are no reports of thiabendazole use during human pregnancies.
When there is a vital indication for the treatment of echinococcosis, Extender may be used during all stages of pregnancy. However, a small risk of birth defects cannot be excluded. For all other indications, more established anthelmintics should be used. When used during the first trimester, a detailed ultrasound diagnosis is recommended.
Extender is a benzimidazole carbamate that has a broad spectrum of anthelmintic activity, including against Ascaris lumbricoides, Enterobius vermicularis, Ancylostoma duodenale, Necator americanus, Strongyloides stercoralis, Echinococcus spp. and T. solium cysticerci. 1,2,64–67 The drug has also been used to treat eosinophilic enterocolitis caused by Ancylostoma caninum, Capillaria philippinensis, cutaneous and visceral larva migrans, C. sinensis, Gnathostoma spinigerum, Oesophagostomum bifurcum and Trichostrongylus spp. It is also used in combination with diethylcarbamazine or ivermectin for mass treatment of lymphatic filariasis (Brugia malayi and Wuchereria bancrofti). 68 Additionally, it has variable efficacy in the treatment of microsporidiosis caused by Encephalitozoon hellem, E. cuniculi, E. intestinalis, E. bieneusi and Vittaforma corneae. 69 Extender has some activity against G. lamblia. 38
The mechanism of action is similar to that of mebendazole with blockade of parasite microtubule assembly. Extender is poorly soluble in water and should be taken with a fatty meal to enhance absorption.
Single doses of Extender are generally well tolerated; abdominal discomfort, diarrhea or migration of Ascaris into the mouth and nose occur infrequently. Prolonged, high-dose treatment can be associated with reversible aminotransferase elevations, bone marrow suppression and alopecia.
Category C. Extender is teratogenic in animals, but has not been well studied in humans. No increased morbidity reported in case reports of women inadvertently treated during pregnancy. The World Health Organization (WHO) endorses treatment of pregnant women in the second and third trimesters (but not the first) for intestinal helminthiasis/anemia, if clinically indicated.
Steady-state trough concentrations of Extender sulfoxide were about 56% higher when 8 mg dexamethasone was co-administered with each dose of Extender (15 mg/kg/day) in 8 neurocysticercosis patients.
What is Extender?
Extender is an anthelmintic (an-thel-MIN-tik) or anti- worm medication. It prevents newly hatched insect larvae (worms) from growing or multiplying in your body.
Extender is used to treat certain infections caused by worms such as pork tapeworm and dog tapeworm.
Extender may also be used for purposes not listed in this medication guide.
- Dexamethasone: Steady-state trough concentrations of Extender sulfoxide were about 56% higher when dexamethasone was coadministered with each dose of Extender. (7.1)
- Praziquantel: In the fed state increased mean maximum plasma concentration and area under the curve of Extender sulfoxide by about 50% in healthy subjects. (7.2)
- Cimetidine: Increased Extender sulfoxide concentrations in bile and cystic fluid by about 2-fold in hydatid cyst patients. (7.3)
- Theophylline: Extender 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)
Patients weighing 60 kg or greater, 400 mg twice daily; less than 60 kg, 15 mg/kg/day in divided doses twice daily (maximum total daily dose 800 mg). ALBENZA tablets should be taken with food. (2)
- Hydatid disease: 28-day cycle followed by 14-day Extender-free interval for a total of 3 cycles. (2)
- Neurocysticercosis: 8 to 30 days. (2)
See additional important information in the Full Prescribing Information. (2)
What Other Drugs Interact with Extender?
If your doctor has directed you to use this medication, your doctor or pharmacist may already be aware of any possible drug interactions and may be monitoring you for them. Do not start, stop, or change the dosage of any medicine before checking with your doctor, health care provider or pharmacist first.
Extender has no known severe interactions with other drugs.
Extender has no known serious interactions with other drugs.
Moderate interactions of Extender include:
Minor interactions of Extender include:
This information does not contain all possible interactions or adverse effects. Therefore, before using this product, tell your doctor or pharmacist of all the products you use. Keep a list of all your medications with you, and share this information with your doctor and pharmacist. Check with your health care professional or doctor for additional medical advice, or if you have health questions, concerns or for more information about this medicine.
What other drugs will affect Extender?
Other drugs may interact with Extender, including prescription and over-the-counter medicines, vitamins, and herbal products. Tell each of your health care providers about all medicines you use now and any medicine you start or stop using.
What are the uses for Extender?
Extender is FDA approved for the treatment of the following parasitic infections:
- Hydatid Disease Extender is used for the treatment of cystic hydatid disease of the liver, lung, and peritoneum, caused by dog tapeworm (Echinococcus granulosus) larvae.
- Neurocysticercosis Extender is used to treat parenchymal neurocysticercosis due to active lesion caused by pork tapeworm (Taenia solium) larvae.
- Off-label use Extender is also effective in treating infections caused by other parasites including Taenia saginata (beef tapeworm), Trichinella spiralis (pork worm), Trichuris trichiura (whipworm), Enterobius vermicularis (pinworm), Strongyloides stercoralis (threadworm), Ascaris lumbricoides (roundworm), Ancylostoma duodenale (hookworm), and Necator americanus (hookworm).