valganciclovir and Retinitis

Valganciclovir HCl (VGH) is the widely used drug for the treatment of cytomegalovirus (CMV) retinitis infection with an induction dose of 900 mg per oral (p.o.) twice a day and a maintenance dose of 900 mg (p.o.). This required dose of the drug also leads to multiple side effects due to repeated administration. The research was highlighted to develop, formulate, optimize, and evaluate single-core osmotic pump (SCOP) tablet of VGH with the dose of 450 mg to reduce dosing frequency and associated side effects. The decrease in dose also minimizes the hepatic and nephrotic load. The optimized batch of the formulation was subjected to comparative in vitro and in vivo evaluation. The tablet core composition is the primary influencer of the drug delivery fraction in a zero order, whereas the membrane characteristics control the drug release rate. In vivo pharmacokinetic studies revealed that the newly developed osmotic formulation has controlled zero-order release for 24 h with a single dose of 450 mg while the marketed formulation requires twice administration within 24 h to maintain the plasma concentration in the therapeutic window. The pharmacokinetic study demonstrated that the developed formulation has the area under curve (AUC) of 58.415 µg h/ml with single dose while the marketed formulation shows the AUC of about 37.903 µg h/ml and 31.983 µg h/ml for first and second dose, respectively. The large AUC demonstrates the extended release of drug with a single dose and effective plasma concentration. Hence, the developed formulation can be a promising option for the treatment of CMV retinitis with the minimum dose and dosing frequency.

Topics: Administration, Oral; Cytomegalovirus Infections; Drug Delivery Systems; Humans; Retinitis; Tablets; Valganciclovir

A case report of recurrent unilateral granulomatous iridocyclitis with ocular hypertension without retinitis caused by cytomegalovirus (CMV) in an immunocompetent patient.. Aqueous humor was analysed by multiplex PCR to detect viral DNA, and real-time PCR was used to evaluate virus copies before and after anti-virus treatments. Inflammation of the anterior chamber was evaluated by a laser flare photometry.. Genomic DNA of CMV - but not of other herpes viruses - was detected in the aqueous humor. Quantitative real-time PCR revealed 2.3 x 10(5) copies/ml of CMV DNA from the specimen. Oral valganciclovir was added to the ongoing treatment, which consisted of topical corticosteroid, timolol and latanoprost as well as systemic acetazolamide, resulting in the reduction of aqueous flare correlated with the reduction of virus copies in aqueous humor.. In this case of CMV-related iridocyclitis in an immunocompetent patient, specific additional anti-viral therapy was effective in controlling inflammation of anterior chamber but, as is so often the case, it was unable to control intraocular pressure. We show that inflammatory activity correlated well with the number of virus copies in the aqueous humor.

Topics: Aged; Antihypertensive Agents; Antiviral Agents; Aqueous Humor; Cytomegalovirus; Cytomegalovirus Infections; DNA, Viral; Drug Therapy, Combination; Eye Infections, Viral; Fluorophotometry; Ganciclovir; Gene Dosage; Glucocorticoids; Humans; Intraocular Pressure; Iridocyclitis; Male; Ocular Hypertension; Polymerase Chain Reaction; Retinitis; Valganciclovir