CPJE Secrets 2026: General Antivirals

What toxicity do all antivirals used to treat herpes share?

Renal toxicity (nephrotoxicity)

What is the differences between HSV-1 and HSV-2?

HSV-1: cold sores, fever blisters

HSV-2: genital

Treatment of HSV and VZV Only

Zovirax (acyclovir) dose dependent on virus/form

• Oral HSV: 200-400mg PO 5 times daily x 7-10 d

• Oral VZV: 600-800mg PO 5 times daily x 10 d

• IV: 13 mg/kg per dose q8h x 7 d

• Cream: 6 applications/day x 7 d

Valtrex (valacyclovir) 1 g TID for 7-14 days

• Valtrex is the prodrug of Zovirax!

Treatment of CMV

Cytovene, Cymevene (ganciclovir)

5 mg/kg IV ; PO form not readily bioavailable

Valcyte (valganciclovir) 900mg PO QD

• Valcyte is the prodrug of Cytovene! It is way more bioavailable and rapidly converted, use this.

Treatment of CMV Retinitis

Intraocular AND systemic Cymevene. Implants no longer made.

Other ocular antivirals: trifluoride 1%, idoxuridine 0.1%, vidarabine 3% ointments

Look out for bone marrow suppression!

Suppression of CMV After Transplant

Prevymis (letermovir)

Drug-Resistant Treatments for HSV, VZV, CMV

Foscavir (foscarnet) IV 60mg/kg q8h

• If Zovirax/Cytovene resistant HSV, VZV, CMV

Vistide (cidofovir) IV 5mg/kg qwk

• If Zovirax/Cytovene/Foscavir resistant HSV, CMV

Treatment of HSV, VZV, and Zoster

Denavir (penciclovir)

Famvir (famciclovir) 500mg PO TID x 7 d OR full 1500mg once

• Famvir is the prodrug for Denavir!

Treatment of Influenza

Tamiflu (oseltamivir) 75mg PO BID x 5 d

• Prevention: 75mg PO QD for 10 d

• Only for patients 1 year old and up

Xofluza (baloxavir) 40mg PO once for patients 40-80kg; 80 mg PO once for heavier

• Only for patients 12 years and up

Relenza (zanamivir) 10mg inhaled BID for 5 d

• Prevention: 10 mg QD for 10 d

• Only for patients 7 years and up

Rapivab (peramivir) 600mg IV once within 2 days of symptoms

• Only for patients 18 years and up

Treatment of COVID-19

Paxlovid (nirmatrelvir/ritonavir) 2 tab nirmatrelvir + 1 tab ritonavir PO BID x 5 d

• For ages 12 and up, at least 40kg

• CI: renal failure

Lagevrio (molnupiravir) 800mg (4 200mg capsules) PO q12h x 5 days

• Use in patients under 18 can affect bone/cartilage growth

• CI: pregnancy

Veklury (remdesivir) IV only, requires 3 days administration