- Acyclic guanosine analog that competes with deoxyguanosine triphosphate to inhibit viral DNA polymerase
- Resistance mediated by mutation in or decrease of thymidine kinase
- Good penetration into CNS and vitreous if administered intravenously, though not orally
- Adverse drug reactions include:
- Acute kidney injury from crystal deposition, so maintain hydration
- Phlebitis
- Neurotoxicity, with lethargy, confusion, tremor, myoclonus, agitation, hallucinations, and extrapyramidal symptoms
