Ganciclovir sodium is often administered in intraocular doses of 200 to 2000 μg for the treatment of cytomegalovirus retinitis.1 The higher dose has been advocated because it is believed that it may be more efficacious and result in a reduced risk of cytomegalovirus resistance.1 Ganciclovir is commercially available in a 500-mg vial and, therefore, further dilution is required for intraocular injection. It is standard practice for pharmacies to refrigerate reconstituted ganciclovir for future injections.2 Sterile water is used for reconstitution because paraben preservatives in bacteriostatic water for injection may cause precipitation. Stability is not a problem because reconstituted ganciclovir can be stored for up to 60 days at 4°C.2,3
We report the appearance of crystals (Figure) in syringes of ganciclovir sodium, 2000 μg/0.05 mL, after storage for as little as 24 hours in the refrigerator at 4°C. The crystals dissolve within 4 hours at room temperature.
Fiscella RG, Goldstein D, Labib S, Sarris H. The Formation of Crystals in Ganciclovir Used for Intraocular Injection. Arch Ophthalmol. 1997;115(7):945-946. doi:10.1001/archopht.1997.01100160115034