Two medicines, side by side
Acyclovir vs ganciclovir
Acyclovir is labeled for herpes and shingles; ganciclovir has no indication this site maps. Their labels share no use, so they are not alternatives to each other. Drugs@FDA records approvals of acyclovir since 1982 and of ganciclovir since 1989. Pharmacies paid $0.0962 per acyclovir 400 mg tablet and $91.24 per gram (Zirgan 0.15% ophthalmic gel) (NADAC, October 7, 2026); the strengths differ and one is a brand and one a generic, so the two prices are not like for like. In FDA's classes, acyclovir is a herpes zoster virus nucleoside analog dna polymerase inhibitor and ganciclovir a cytomegalovirus nucleoside analog dna polymerase inhibitor.
Check it at the source: the acyclovir FDA label on DailyMed (effective July 24, 2026); the ganciclovir FDA label on DailyMed (effective January 9, 2026).
Highlights of the acyclovir record
Acyclovir (Zovirax) · label of July 24, 2026
Used for
From the label: indicationsHerpes Zoster Infections: Acyclovir tablets are indicated for the acute treatment of herpes zoster (shingles). Genital Herpes: Acyclovir tablets are indicated for the treatment of initial episodes and the management of recurrent episodes of genital herpes. Chickenpox: Acyclovir tablets are indicated for the treatment of chickenpox (varicella).
On the market
- Earliest approval on file
- March 29, 1982
- Generic labelers
- 66 labelers
- Pharmacy cost
- $0.0962 per tablet
Supply and safety
- Shortage
- No current entry
- Recalls
- 12
Highlights of the ganciclovir record
Ganciclovir (Cytovene) · label of January 9, 2026
HEMATOLOGIC TOXICITY, IMPAIRMENT OF FERTILITY, FETAL TOXICITY, MUTAGENESIS AND CARCINOGENESIS
Hematologic Toxicity: Granulocytopenia, anemia, thrombocytopenia, and pancytopenia have been reported in patients treated with Ganciclovir for Injection [see Warnings and Precautions ( 5.1 )].
Used for
From the label: indicationsGanciclovir for Injection is a deoxynucleoside analogue cytomegalovirus (CMV) DNA polymerase inhibitor indicated for the: • treatment of CMV retinitis in immunocompromised adult patients, including patients with acquired immunodeficiency syndrome (AIDS). ( 1.1 ) • prevention of CMV disease in adult transplant recipients at risk for CMV disease. […]
On the market
- Earliest approval on file
- June 23, 1989
- Generic labelers
- 6 labelers
- Pharmacy cost
- $91.24 per gram
Supply and safety
- Shortage
- No current entry
- Recalls
- 2
Source: FDA drug labels via openFDA (Acyclovir label of July 24, 2026, Ganciclovir label of January 9, 2026); NDC Directory, Drugs@FDA, NADAC, FDA shortages and recalls (October 8, 2026)
How do acyclovir and ganciclovir differ on the record?
In FDA's classes, acyclovir is a herpes zoster virus nucleoside analog dna polymerase inhibitor and ganciclovir a cytomegalovirus nucleoside analog dna polymerase inhibitor.
Half-life, in each label's words: Acyclovir, “Mean half-life after oral doses of 300 mg/m 2 and 600 mg/m 2 in pediatric patients aged 7 months to 7 years was 2.6 …”; Ganciclovir, “Half-life was 3.5 ± 0.9 hours (n=98) following intravenous administration.”
Only the ganciclovir label carries a boxed warning.
Generics: acyclovir since 1997; ganciclovir since 2003 (Drugs@FDA).
| Acyclovir | Ganciclovir | |
|---|---|---|
| Labeled for | Herpes and shingles | n/a |
| Pharmacologic class | Herpes Simplex Virus Nucleoside Analog DNA Polymerase Inhibitor, Herpes Zoster Virus Nucleoside Analog DNA Polymerase Inhibitor, Herpesvirus Nucleoside Analog DNA Polymerase Inhibitor | Cytomegalovirus Nucleoside Analog DNA Polymerase Inhibitor, Nucleoside Analog Antiviral |
| How it works (label) | n/a | Ganciclovir is an antiviral drug with activity against CMV [see Microbiology ( 12.4 )]. |
| Half-life (label) | Mean half-life after oral doses of 300 mg/m 2 and 600 mg/m 2 in pediatric patients aged 7 months to 7 years was 2.6 hours (range 1.59 to 3.74 hours). | Half-life was 3.5 ± 0.9 hours (n=98) following intravenous administration. |
| Earliest approval on file (Drugs@FDA) | March 29, 1982 | June 23, 1989 |
| First generic approved | April 22, 1997 | July 16, 2003 |
| Generic labelers (NDC) | 66 labelers | 6 labelers |
| Pharmacy cost (NADAC, each one's most listed form; strengths differ) | $0.0962 per tablet (Acyclovir 400 mg tablet) | $91.24 per gram (Zirgan 0.15% ophthalmic gel) |
| 12-month price change | +5% | -0.2% |
| Boxed warning | No | Yes |
| Shortage now | No current entry | No current entry |
| Recalls recorded | 12 | 2 |
| FAERS reports (a report is not proof of cause; counts follow how widely a medicine is used) | 114,717 | 10,882 |
| DEA schedule | none | none |
Source: Drugs@FDA, FDA NDC Directory, CMS NADAC of October 7, 2026, FDA shortages and recalls, FAERS via openFDA (FDA files October 8, 2026)
What next?
- Alternatives to acyclovir
- every medicine labeled for the same conditions