Those being treated for retinal neurocysticercosis can face retinal damage if they are not first checked for ocular cysticeri, since changes to existing lesions in the eye by albendazole can cause permanent blindness. Overdose
Because of its low solubility, albendazole often cannot be absorbed in high enough quantities to be toxic. The oral LD50 of albendazole in rats was found to be 2,500 mg/kg. It takes 20 times the normal dose to kill a sheep, and 30 times the normal dose to kill cattle. Overdose affects the liver, testicles, and GI tract the most. It can manifest with lethargy, loss of appetite, vomiting, diarrhea, intestinal cramps, dizziness, convulsions, and sleepiness. There is no specified antidote. Interactions
The antiepileptics carbamazepine, phenytoin, and phenobarbital lower the plasma concentration and the half life of albendazole sulfoxides R(+) enantiomer. The antacid cimetidine heightens serum albendazole concentrations, increases the half life of albendazole, and doubles albendazole sulfoxide levels in bile. It was originally thought to work by increasing albendazole bioavailability directly; however, it is now known that cimetidine inhibits the breakdown of albendazole sulfoxide by interfering with CYP3A4. The half-life of albendazole sulfoxide thus increases from 7.4 hours to 19 hours. This might be a helpful interaction on more severe cases, because it boosts the potency of albendazole. Paradoxically, cimetidine also inhibits the absorption of albendazole by reducing gastric acidity.Several other interactions exist. Corticosteroids increase the steady-state plasma concentration of albendazole sulfoxide; dexamethasone, for example, can increase the concentration by 56% by inhibiting the elimination of albendazole sulfoxide.
It is also used off-label to treat endoparasites in goats and pigs. Albendazole has been used as an anthelminthic and for control of flukes in a variety of animal species, including cattle, sheep, goats, swine, camels, dogs, cats, elephants, poultry, and others. Side effects include anorexia in dogs and lethargy, depression, and anorexia in cats, with more than 10% of dogs and cats having anorexia. Of dogs and cats, 1–10% experience elevated liver enzymes, nausea, vomiting, and diarrhea. Less than 1% experience neutropenia or aplastic anemia, though these require a use of at least 5 days. While it is also associated with bone marrow suppression and toxicity in cats and dogs at high doses, albendazole has a higher margin of safety in other species. Thus, it is usually only prescribed in cats and dogs when an infection is present that is resistant to the commonly prescribed metronidazole and fenbendazole.It is extensively used for ruminant livestock in Latin America. It is marketed for this purpose by Zoetis (formerly Pfizer Animal Health) in numerous countries (including the United States and Canada) as Valbazen in oral suspension and paste formulations; by Interchemie in the Netherlands and elsewhere as Albenol-100; by Channelle Animal Health Ltd. in the United Kingdom as Albex; and by Ravensdown in New Zealand (as Albendazole).