Medications Used to Treat Herpesvirus Infections

AcyclovirAcyclovir

Active against (in order of potency) HSV type 1 (HSV-1), HSV-2, VZV, and EBV

Minimal activity against CMV

Oral or IV: IV indicated when a higher serum drug level is required, as for herpes simplex encephalitis

Oral: Infrequent

IV: Rarely, renal toxicity due to precipitation of acyclovir crystals in the renal tubules (primarily with IV use); in patients with renal failure, neurologic toxicity; in patients who are immunocompromised, TTP/HUSRarely, renal toxicity due to precipitation of acyclovir crystals in the renal tubules (primarily with IV use); in patients with renal failure, neurologic toxicity; in patients who are immunocompromised, TTP/HUS

CidofovirCidofovir

In vitro inhibition of a broad spectrum of viruses, including HSV-1, HSV-2, VZV, CMV, EBV, KSHV, adenovirus, HPV, poxviruses, and human polyomavirus (JC and BK viruses)

IV: Generally used for CMV, but use limited by renal toxicity

Intravitreal injection: For CMV retinitis

Significant renal toxicity (Fanconi-type syndrome with proteinuria, glucosuria, and bicarbonate wasting)

Famciclovir (prodrug of penciclovir)Famciclovir (prodrug of penciclovir)

Antiviral spectrum similar to acyclovir (strains resistant to acyclovir also resistant to famciclovir)Antiviral spectrum similar to acyclovir (strains resistant to acyclovir also resistant to famciclovir)

Oral: As effective as acyclovir for oral and As effective as acyclovir for oral andgenital herpes and herpes zoster;more bioavailable than acyclovir after oral administration (which is theoretically important for VZV infection);more bioavailable than acyclovir after oral administration (which is theoretically important for VZV infection)

Infrequent

FoscarnetFoscarnet

Active against EBV, KSHV, human herpesvirus 6, acyclovir-susceptible and resistant HSV and VZV, and ganciclovir-susceptible and resistant CMVActive against EBV, KSHV, human herpesvirus 6, acyclovir-susceptible and resistant HSV and VZV, and ganciclovir-susceptible and resistant CMV

IV or intravitreal injection: Efficacy similar to that of ganciclovir for treating and delaying progression of Efficacy similar to that of ganciclovir for treating and delaying progression ofCMV retinitis

Renal toxicity in up to one third of patients if foscarnet is given without adequate hydration, electrolyte imbalances, genital ulcerations (reversible once the medication is stopped)Renal toxicity in up to one third of patients if foscarnet is given without adequate hydration, electrolyte imbalances, genital ulcerations (reversible once the medication is stopped)

Ganciclovir Ganciclovir

In vitro activity against all herpesviruses, including CMV, but HSV strains that are resistant to acyclovir are also cross-resistant to ganciclovirIn vitro activity against all herpesviruses, including CMV, but HSV strains that are resistant to acyclovir are also cross-resistant to ganciclovir

Typically drug of choice for CMV

Used in HIV patients with CMV retinitis

IV form: Most common

Intravitreal injection: For CMV retinitis

Oral: Only 6 to 9% bioavailable; requires 12 capsules/day for a standard dose (1 g tid), limiting its usefulness

Primarily, bone marrow suppression, particularly neutropenia, which sometimes requires treatment*

Idoxuridine (no longer available in the United States)

Active against HSV-1, HSV-2, VZV, vaccinia, and CMV

Topical: Because of its high systemic toxicity, limited to topical ophthalmic treatment of herpes simplex keratoconjunctivitis

Irritation, pain, photophobia, pruritus, inflammation or edema of the eyelids

Rarely, allergic reactions

LetermovirLetermovir

Active against CMV

IV or oral: CMV prophylaxis in bone marrow and renal transplant patients

Nausea, vomiting, diarrhea, peripheral edema, cough, headache, fatigue, abdominal pain

MaribavirMaribavir

Active against CMV

Oral: Used to treat refractory CMV disease

Dysgeusia, diarrhea, nausea, vomiting

PenciclovirPenciclovir

Active against HSV-1, HSV-2, VZV, and EBV

Topical (cream): Used to treat recurrent herpes labialis in adults

Erythema

Trifluridine (trifluorothymidine)Trifluridine (trifluorothymidine)

Active against HSV-1 and HSV-2

Topical: Ophthalmic treatment of primary keratoconjunctivitis and recurrent keratitis or ulceration caused by HSV-1 and HSV-2

(Systemic use precluded by bone marrow suppression)

Ocular stinging, palpebral edema

Less commonly, punctate keratitis, allergic reactions

Valacyclovir (prodrug of acyclovir)Valacyclovir (prodrug of acyclovir)

Antiviral spectrum similar to that of acyclovirAntiviral spectrum similar to that of acyclovir

Oral: 3–5 times more bioavailable than acyclovir3–5 times more bioavailable than acyclovir

Similar to those of acyclovirSimilar to those of acyclovir

TTP/HUS in some patients with advanced HIV and in transplant recipients who receive valacyclovir in higher doses than currently recommended†and in transplant recipients who receive valacyclovir in higher doses than currently recommended†

Valganciclovir (prodrug of ganciclovir)Valganciclovir (prodrug of ganciclovir)

Similar to ganciclovirSimilar to ganciclovir

Oral: More bioavailable than oral ganciclovirMore bioavailable than oral ganciclovir

Similar to ganciclovirSimilar to ganciclovir

Vidarabine (adenine arabinoside, ara-A)

HSV infections

IV form not used anymore because of neurotoxicity

Ophthalmic preparations: Effective for acute keratoconjunctivitis and recurrent superficial keratitis caused by HSV-1 and HSV-2

Superficial punctate keratitis with tearing, irritation, pain, and photophobia