Ocular Toxicity (ocular + toxicity)

Distribution by Scientific Domains

Selected Abstracts

Ocular toxicity of fluoroquinolones

Andrew M Thompson FRANZCO
Abstract The ocular toxicity of fluoroquinolones and the risks of their use in the treatment of ocular infection were reviewed. Systematic identification, selection, review and synthesis of published English-language studies relating to fluoroquinolone use and safety in animals and humans was conducted. Although not free of complications, fluoroquinolones are generally safe when used to treat ocular infection. Ocular toxicity appears to be dose-dependent and results from class-effects and specific fluoroquinolone structures. Phototoxicity and neurotoxicity have been reported, and toxic effects on ocular collagen may be associated with Achilles tendinopathy. Corneal precipitation may provide an advantageous drug depot but delay healing and result in corneal perforation in approximately 10% of cases. Although human toxicity studies are limited, the current recommended dose for intracameral injection of ciprofloxacin is less than 25 ,g. Intravitreal injections of ciprofloxacin 100 ,g, ofloxacin 50 ,g/mL, trovafloxacin 25 ,g or less, moxifloxacin 160 ,g/0.1 mL or less and pefloxacin 200 ,g/0.1 mL are considered safe. [source]

Ocular complications of neurological therapy

S. Hadjikoutis
Treatments used for several neurological conditions may adversely affect the eye. Vigabatrin-related retinal toxicity leads to a visual field defect. Optic neuropathy may result from ethambutol and isoniazid, and from radiation therapy. Posterior subcapsular cataract is associated with systemic corticosteroids. Transient refractive error changes may follow treatment with acetazolamide or topiramate, and corneal deposits and keratitis with amandatine. Intraocular pressure can be elevated in susceptible individuals by anticholinergic drugs, including oxybutynin, tolterodine, benzhexol, propantheline, atropine and amitriptyline, and also by systemic corticosteroids and by topiramate. Nystagmus, diplopia and extraocular muscle palsies can occur with antiepileptic drugs, particularly phenytoin and carbamazepine. Ocular neuromyotonia can follow parasellar radiation. Congenital ocular malformations can result from in utero exposure to maternally prescribed sodium valproate, phenytoin and carbamazepine. Neurologists must be aware of potential ocular toxicity of these drugs, and appropriately monitor for potential adverse events. [source]

Biowaiver monographs for immediate release solid oral dosage forms: ethambutol dihydrochloride,,

C. Becker
Abstract Literature data relevant to the decision to allow a waiver of in vivo bioequivalence (BE) testing for the approval of immediate release (IR) solid oral dosage forms containing ethambutol dihydrochloride as the only active pharmaceutical ingredient (API) are reviewed. Ethambutol dihydrochloride is a Biopharmaceutics Classification System (BCS) Class III drug with permeability properties approaching the border between BCS Class I and III. BE problems of ethambutol formulations containing different excipients and different dosages forms have not been reported and hence the risk of bioinequivalence caused by excipients is low. Ethambutol has a narrow therapeutic index related to ocular toxicity. However, as long as the prescribers' information of the test product stipulates the need for regular monitoring of ocular toxicity, the additional patient risk is deemed acceptable. It is concluded that a biowaiver can be recommended for IR solid oral dosage forms provided that the test product (a) contains only excipients present in ethambutol IR solid oral drug products approved in ICH or associated countries, for instance as presented in this paper, (b) complies with the criteria for "very rapidly dissolving" and (c) has a prescribers' information indicating the need for testing the patient's vision prior to initiating ethambutol therapy and regularly during therapy. 2007 Wiley-Liss, Inc. and the American Pharmacists Association J Pharm Sci 97:1350,1360, 2008 [source]

Animal models for the treatment of bacterial keratitis

Rabbit models of bacterial keratitis have been used to evaluate the efficacy of anti-infectives in the clinical treatment of bacterial keratitis. These models can determine: 1) ocular toxicity and tolerance of anti-infectives to ocular tissue, 2) penetration of anti-infectives into the cornea, and 3) anti-bacterial efficacy of the anti-infectives to corneal bacterial pathogens. The current presentation will cover the structure and limitations of rabbit bacterial keratitis modeling using published data. Topics will include statistical design, the choice of bacterial pathogens, and positive aspects for possible systemic anti-infective development. [source]