Pharmacologic Profile

General Use

Acyclovir, famciclovir, and valacyclovir are used in the management of herpes virus infections. Acyclovir and valacyclovir are also used in the management of chickenpox. Oseltamivir is used primarily in the prevention and/or treatment of influenza infection. Foscarnet, ganciclovir, and valganciclovir are used in the prevention and/or treatment of cytomegalovirus (CMV) infection. Entecavir and lamivudine are used for the treatment of hepatitis B infection. Molnupiravir, nirmatrelvir/ritonavir, and remdesivir are used in the treatment of COVID-19 infection.

General Action and Information

Most agents inhibit viral replication.

Contraindications

Previous hypersensitivity.

Precautions

Many antiviral agents require dose adjustment in renal impairment. Acyclovir may cause renal impairment. Acyclovir may cause CNS toxicity. Foscarnet ↑ risk of seizures.

Interactions

Acyclovir may have additive CNS and nephrotoxicity with drugs causing similar adverse reactions. Nirmatrelvir/ritonavir has numerous drug interactions involving the cytochrome P450 system.

Nursing Implications

Assessment

• Assess patient for signs and symptoms of infection before and throughout therapy.
• Assess eye lesions before and daily during therapy.
• Assess lesions before and daily during therapy.

Implementation

• Most systemic antiviral agents should be administered around the clock to maintain therapeutic serum drug levels.

Patient/Family Teaching

• Instruct patient to continue taking medication around the clock for full course of therapy, even if feeling better.
• Advise patient that antivirals do not prevent transmission to others. Precautions should be taken to prevent spread of virus.
• Instruct patient in correct technique for topical or ophthalmic preparations.
• Instruct patient to notify health care provider if symptoms do not improve.

Evaluation/Desired Outcomes

• Prevention or resolution of the signs and symptoms of viral infection. Length of time for complete resolution depends on organism and site of infection.