Foscarnet adverse reaction

Acyclovir-resistant HSV has been isolated from patients with AIDS. The primary mechanism of resistance appears to be a deficiency in viral thymidine kinase. Strategies that have been employed for management of severe acyclovir-resistant HSV infections include increasing the dose of acyclovir, discontinuing acyclovir, and use of an alternative antiviral agent. Vidarabine and foscarnet, because they do not require phosphorylation by thymidine kinase, are examples of potential alternative agents. A randomized comparison of foscarnet and vidarabine indicated that foscarnet is more effective and associated with fewer adverse reactions than vidarabine. ... 

The primary adverse effect of intravenous cidofovir is a dose-dependent nephrotoxicity. Concurrent administration of other potentially nephrotoxic agents (eg, amphotericin B, aminoglycosides, nonsteroidal anti-inflammatory drugs, pentamidine, foscarnet) should be avoided. Prior administration of foscarnet may increase the risk of nephrotoxicity. Other potential side effects include uveitis, decreased intraocular pressure, and probenecid-related hypersensitivity reactions. Neutropenia and metabolic acidosis are rare. The drug caused mammary adenocarcinomas in rats and is embryotoxic. 

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