Ganciclovir
Ganciclovir is an antiviral medication used to treat or prevent cytomegalovirus (CMV) infections and, as Zirgan eye gel, to treat herpes-related corneal ulcers.
🧬 Where this information comes from Click to expand
The clinical label records used on this page are FDA-filed Structured Product Labeling (SPL) retrieved through openFDA. We identified 9 clinical label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. Forms, routes, brands, labelers, strengths, and NDC product-record counts are built separately from matching FDA National Drug Code Directory records. The linked DailyMed document is a representative official source for verification, not the page’s only clinical source. View the linked label on DailyMed →
⚠️ FDA Boxed Warning — the FDA’s strongest safety alert ▾
Ganciclovir injection carries four serious warnings that the FDA requires to be prominently displayed:
Blood toxicity: Ganciclovir can severely lower white blood cell, red blood cell, and platelet counts — a condition that can be life-threatening. Regular blood tests are required during treatment.
Fertility: Based on animal and limited human data, ganciclovir injection may temporarily or permanently reduce sperm production in men and suppress fertility in women.
Birth defects: Animal studies show ganciclovir can cause serious birth defects. It should not be used during pregnancy unless absolutely necessary, and effective contraception is required during and after treatment.
Cancer risk: Animal studies indicate ganciclovir has the potential to cause cancer in humans. It should be used only when the benefit clearly outweighs this long-term risk.
📖 Ganciclovir: Patient Information Guide
A plain-language walkthrough of Ganciclovir — what it treats, how it works, how it’s taken, side effects, warnings and interactions. Tap any section to expand it.
🎯What it's used for▾
Ganciclovir is an antiviral used across different formulations for distinct viral infections. The approved uses depend on the specific product and route of administration:
- Ganciclovir injection (Cytovene, Ganciclovir, and ganciclovir sodium) is indicated for the treatment of CMV retinitis in immunocompromised adults, including those with AIDS
- Ganciclovir injection is also indicated for the prevention of CMV disease in adult transplant recipients who are at risk
- Zirgan ophthalmic gel is indicated for the treatment of acute herpetic keratitis (corneal ulcers caused by herpes simplex virus) in adults and children aged 2 years and older
⚙️How it works▾
Ganciclovir is a synthetic molecule that closely resembles a natural DNA building block. When it enters a virus-infected cell, a viral enzyme converts it to an active form called ganciclovir triphosphate. This active form blocks the viral DNA polymerase — the enzyme the virus needs to copy its genetic material — effectively stopping the virus from replicating. Because that first activation step depends mainly on a viral enzyme, the drug acts preferentially inside infected cells rather than healthy ones.
Resistance can develop when viruses develop mutations in the genes that encode the enzymes ganciclovir targets, particularly the viral kinase (pUL97) and the viral DNA polymerase (pUL54).
💊How it's taken▾
Ganciclovir injection is always given by slow intravenous infusion over one hour — the rate must not be exceeded to avoid serious toxicity. It is given more frequently during an initial induction phase, then less often as a maintenance dose; the exact schedule depends on whether the goal is treatment or prevention. Zirgan eye gel is applied as drops into the affected eye multiple times daily while awake until the corneal ulcer heals, then tapered for a final week. Dose adjustments are required for patients with reduced kidney function when using the injection form. Always follow your prescriber's exact schedule and never adjust the dose on your own.
🤒Side effects — in detail▾
The most commonly reported side effects with ganciclovir injection include:
- Fever
- Diarrhea
- Nausea
- Low white blood cell count (leukopenia/neutropenia)
- Anemia (low red blood cells)
- Weakness or fatigue (asthenia)
- Headache
- Decreased appetite
- Excessive sweating
- Abdominal pain
Seriously low blood counts — especially white blood cells and platelets — are among the most dangerous effects and require regular blood monitoring. Retinal detachment has also been observed in patients with CMV retinitis, though its connection to the drug is not fully established.
⚠️Warnings & precautions▾
- Blood toxicity: Ganciclovir injection commonly and significantly lowers white blood cells, red blood cells, and platelets. This usually begins in the first two weeks but can happen at any time. It can be life-threatening, and blood counts must be monitored frequently throughout treatment.
- Kidney damage: The drug is cleared almost entirely by the kidneys; impaired kidney function causes drug levels to build up, increasing toxicity risk. Elderly patients and those taking other kidney-stressing drugs (such as cyclosporine or amphotericin B) face the highest risk — kidney function must be monitored throughout.
- Fertility effects: Ganciclovir injection may temporarily or permanently reduce sperm production in men and suppress fertility in women. Discuss this risk with your doctor before starting treatment.
- Pregnancy and birth defects: Animal data show potential for serious birth defects. Effective contraception is required during and after treatment (at least 30 days for women, 90 days for men using barrier contraception).
- Cancer risk: Animal data indicate a potential to cause cancer in humans. This drug is reserved for situations where benefits clearly outweigh risks.
🔀What it interacts with▾
Ganciclovir injection can interact with several other medications, sometimes seriously. Key interactions include:
- Imipenem-cilastatin: Generalized seizures have been reported — combined use is not recommended
- Cyclosporine and amphotericin B: Increase the risk of kidney damage; kidney function must be monitored closely
- Mycophenolate mofetil (MMF): Combined use raises the risk of blood and kidney toxicity; both drugs need monitoring
- Didanosine: Ganciclovir can raise didanosine levels, increasing the risk of pancreatitis
- Probenecid: Can raise ganciclovir blood levels; watch for signs of ganciclovir toxicity
- Other bone-marrow-suppressing or kidney-toxic drugs (e.g., dapsone, doxorubicin, zidovudine, vincristine, flucytosine, pentamidine, trimethoprim/sulfamethoxazole, hydroxyurea, tacrolimus, vinblastine): Combined use should only occur when benefits outweigh the added risks
This is not a complete list of interactions. Always talk with your doctor or pharmacist before starting, stopping, or changing any medication.
📋Before taking it▾
- Tell your doctor if you have ever had a serious allergic reaction (such as anaphylaxis) to ganciclovir or valganciclovir — ganciclovir injection is contraindicated in this case
- Tell your doctor if you have kidney disease or reduced kidney function — dose adjustment is required and monitoring is essential
- Females who could become pregnant must have a pregnancy test before starting ganciclovir injection and use effective contraception during treatment and for at least 30 days afterward
- Males should use barrier contraception during treatment and for at least 90 days after, given the potential for mutagenic effects
- Do not breastfeed while using ganciclovir injection — the drug may pass into milk and harm a nursing infant
- Safety and effectiveness of ganciclovir injection have not been established in children — discuss risks and benefits carefully with a specialist
- Older adults are at higher risk of kidney-related side effects and should be monitored especially closely
- If you have low blood counts or take other drugs that suppress the bone marrow, discuss added risks with your doctor before starting
🚑If you take too much▾
Taking too much ganciclovir injection can cause serious, potentially fatal harm. Reported effects of overdose include severe suppression of blood cell production (bone marrow failure), liver damage, kidney injury, stomach and gut symptoms (abdominal pain, vomiting, diarrhea), and seizures. Because ganciclovir can be removed from the blood by dialysis, this may be used to lower drug levels after an overdose; staying well hydrated and using blood-cell growth factors are also part of overdose management.
📡Pharmacodynamics — effects in the body▾
Ganciclovir works by blocking the viral DNA polymerase enzyme that cytomegalovirus (and herpes simplex virus, in the case of Zirgan) needs to copy its DNA. This stops viral replication — described as virustatic activity — meaning it halts the virus from spreading rather than directly killing existing virus particles. The effect is preferentially concentrated in virus-infected cells because the drug's activation depends largely on a viral enzyme.
🔬Pharmacokinetics — how your body processes it▾
When given intravenously, ganciclovir distributes widely through the body, reaching cerebrospinal fluid (the fluid around the brain and spinal cord) at levels roughly 24–70% of those in the blood. It is not significantly bound to proteins in the blood. The body does not substantially metabolize ganciclovir; instead, about 91% of the drug is excreted unchanged by the kidneys. The half-life — the time it takes for blood levels to fall by half — is about 3.5 hours in people with normal kidney function, but rises significantly when kidney function is reduced. Hemodialysis can reduce ganciclovir blood levels by about 50%.
📦How to store it▾
Store vials at 20° to 25°C (68° to 77°F) . Store reconstituted solution in the vial at 25°C (77°F) for no longer than 12 hours. Do not refrigerate or freeze.
📄 Written from Ganciclovir’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Every point is grounded in that labeling — nothing is invented. How we use AI →
Supplements & herbs that interact with Ganciclovir
17 supplements and herbal products have documented interactions with Ganciclovir in the licensed clinical database we use. Most are manageable — but your pharmacist should know about everything you take, including vitamins and herbals.
- Major · 1
- Moderate · 7
- Minor · 9
Educational information from a licensed clinical database (Natural Medicines) — see our data sources & update cadence. Not medical advice: an interaction being documented does not mean it will happen to you; do not start or stop medications or supplements without professional guidance.
🩺 Pharmacist Counseling Corner
Quick, plain-English answers to the questions patients ask most about Ganciclovir — the kind of thing our pharmacy team would talk through with you at the counter.
Why has my doctor prescribed ganciclovir — what exactly does it do? ▾
What side effects should I actually watch out for? ▾
Can I take my other medications alongside ganciclovir? ▾
Is it safe to use if I'm pregnant or planning to become pregnant? ▾
I have kidney disease — does that affect how I use ganciclovir? ▾
Will ganciclovir affect my fertility? ▾
Is Ganciclovir available over the counter? ▾
When was Ganciclovir first available? ▾
Who makes Ganciclovir? ▾
💬 Answers drafted from Ganciclovir’s FDA-approved label information, summarized in plain language with AI, and reviewed by our pharmacy team before publication. Grounded in that labeling — nothing is made up. How we use AI →
🧰 Keep exploring
💊 How Ganciclovir comes
Ganciclovir is available in 2 forms. Different forms and brands can have different approved uses, doses, schedules, and directions. Follow the instructions for your exact product, and do not switch forms without guidance from your prescriber or pharmacist.
Injection
How this form is used
- Treatment of CMV retinitis in immunocompromised adults, including patients with AIDS
- Prevention of CMV disease in adult transplant recipients at risk for CMV disease
- Given only by slow intravenous infusion over one hour — never by rapid or bolus injection, never into muscle or under the skin
- Infusion site should be in a vein with good blood flow to reduce irritation; a plastic cannula is preferred
- Adequate hydration must be maintained throughout treatment
- Dose must be adjusted for patients with reduced kidney function — creatinine clearance guides dosing
Eye ointment
How this form is used
- Zirgan is used to treat acute herpetic keratitis (dendritic ulcers caused by the herpes simplex virus) in adults and children aged 2 years and older
- Zirgan: apply one drop into the affected eye five times per day (roughly every 3 hours while awake) until the corneal ulcer heals
- Zirgan: after the ulcer heals, continue one drop three times per day for 7 more days
📊 Ganciclovir across the U.S. market
How Ganciclovir appears in the FDA’s National Drug Code Directory — including its dosage forms, strengths, brand names, manufacturers, and FDA-listed product records. These are directory records, not sales or prescription volume.
FDA-listed product records by dose form (tablet variants merged) — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
Also listed with the FDA, not a patient dose form: Powder (4) — bulk drug substance sold to compounders/manufacturers and multi-item kits. These aren’t counted in the dose-form total above.
Share of FDA-listed product records by manufacturer — FDA National Drug Code Directory. Record counts are not sales or prescription volume.
📈 How widely Ganciclovir is used
A general measure of how commonly Ganciclovir is prescribed, based on Medicaid — one of the largest public drug programs. The figure below is prescriptions filled in Q1–Q4 2025, summed across every form and brand of the drug.
Think of this as a proxy for how widely Ganciclovir is used, drawn from freely available public data. Medicaid is just one program — these numbers don’t include Medicare, other government coverage, or commercial and cash-pay prescriptions, so real-world use is higher than what’s shown here.
How commonly is Ganciclovir prescribed? Of the 1,596 medications we measure, Ganciclovir ranks #1,177 by Medicaid prescriptions — more than 26% of them.
Utilization by Ganciclovir product
Pick a product to see its own Medicaid numbers. Each chip is one clinical product — a specific strength & dosage form as defined by RxNorm — with brand-name and generic versions combined.
ganciclovir 0.0015 MG/MG Ophthalmic Gel Most dispensed
Summed across the 1 of 2 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 388052
ganciclovir 500 MG Injection
Summed across the 2 of 10 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 310442
10 ML ganciclovir 50 MG/ML Injection
Summed across the 1 of 4 listed NDC products with Medicaid activity — every brand and generic of this exact strength & form. RxNorm 1999531
Shares are of the Medicaid prescriptions shown here. Product grouping follows RxNorm (the National Library of Medicine’s drug terminology), so “one product” means one strength & dosage form regardless of manufacturer. Dollar figures are gross Medicaid reimbursement before mandatory rebates — rebates (often large, especially for brand-name drugs) are confidential, so actual net cost to Medicaid is lower than shown.
Source: Medicaid State Drug Utilization Data (CMS), aggregated by generic ingredient — summed across every NDC (all brands, strengths, salt forms and dosage forms) of Ganciclovir, and across all states and both fee-for-service and managed-care claims. A general popularity signal; it excludes Medicare, commercial insurance and cash prescriptions, so it is not total U.S. use. Based on the 4 of 16 listed Ganciclovir NDCs with Medicaid activity.
🔍 Compare Ganciclovir products
A representative set of FDA-listed product records for Ganciclovir — across manufacturers, strengths, and dosage forms, grouped by form with each product’s manufacturer and how the FDA approved it. The same medicine may be made and packaged by different companies, so a single drug can have many directory entries. (It’s also why a refill can look different — a new shape, color, or box — even though it contains the same medication.)
| Strength | Route | Manufacturer / Labeler | Category ⓘ | Details |
|---|---|---|---|---|
| 💊Eye ointment | ||||
| 1.5 mg/g | Ophthalmic | Bausch & Lomb Incorporated × 2 listings | NDA | View NDC → |
| 💊Injection | ||||
| 500 mg/10 mL | Intravenous | Endo USA, Inc. | ANDA | View NDC → |
| 1 kg/kg | — | Excella GmbH Co. KG × 2 listings | BULK INGREDIENT | View NDC → |
| 2 mg/mL | Intravenous | Exela Pharma Sciences, Llc | NDA | View NDC → |
| 500 mg/10 mL | Intravenous | Fresenius Kabi USA, LLC × 6 listings | ANDA | View NDC → |
| 500 mg/10 mL | Intravenous | H2-Pharma, LLC | NDA | Find on DailyMed ↗ |
| 50 mg/mL | Intravenous | Hikma Pharmaceuticals USA Inc. × 2 listings | ANDA | View NDC → |
| 500 mg/10 mL | Intravenous | Par Pharmaceutical, Inc. | ANDA | View NDC → |
| 500 mg/10 mL | Intravenous | Pharmascience Inc. × 2 listings | ANDA | View NDC → |
| 50 mg/mL | Intravenous | Sagent Pharmaceuticals × 2 listings | ANDA | View NDC → |
| 500 mg/10 mL | Intravenous | Slate Run Pharmaceuticals, LLC × 2 listings | ANDA | View NDC → |
| 500 mg/10 mL | Intraventricular | Slate Run Pharmaceuticals, LLC | ANDA | View NDC → |
| 💊Bulk drug substance | ||||
| 50 kg/50 kg | — | Aurobindo Pharma Limited | BULK INGREDIENT | View NDC → |
| 1 kg/kg | — | Corden Pharma Colorado, Inc. | BULK INGREDIENT | View NDC → |
| 1 kg/kg | — | Excella GmbH & Cp. KG × 2 listings | BULK INGREDIENT | View NDC → |
Showing 27 of 27 products — FDA National Drug Code Directory. See every product, package size and price: browse all 27 Ganciclovir NDCs →
📈 What people report — real-world data (FDA FAERS)
After a medicine reaches the market, patients, doctors and drugmakers can send the FDA reports of problems they think may be linked to it. Here’s what’s been reported for Ganciclovir — a signal of what to watch for, not proof the drug caused it.
Source: openFDA, from the FDA Adverse Event Reporting System (FAERS). These are voluntary reports — they don’t prove the drug caused the effect, and counts reflect how often something was reported, not how often it actually happens. Reports also often name the very problem the medicine is taken for — a common reason to file one is that the drug didn’t help — so for a pain reliever you may see “pain” high on the list; that points to why the report was filed, not to the drug causing the symptom. This counts every report that lists Ganciclovir in any role, so the total runs higher than the FDA’s official dashboard, which counts only cases where the drug is the suspect. For the authoritative figures, see the FDA FAERS Public Dashboard. Always talk to your pharmacist or doctor.
🏛️ The road to your pharmacy
How Ganciclovir went from FDA review to the pharmacy shelf — the key milestones in its regulatory journey.
Source: Drugs@FDA.
🚨 Recall history
A recall is when a specific batch of a medicine is pulled from the market — usually a manufacturing issue, not a problem with the drug itself. Class I is most serious, Class III least.
Source: openFDA drug enforcement (recall) reports.
RxNorm Concept Web — From Ingredient to Every Form and Strength
This page starts with one ingredient concept (IN). The branches below show its dose-form concepts (SCDF), then the available clinical drug and strength concepts (SCD). Combination products remain separate concepts with their own pages.
RxCUI 4678 4 dose forms · 7 strengths
-
Dose form (SCDF) Drug Implant RxCUI 604019No current FDA listingClinical drug / strength (SCD) 4.5 MGRxCUI 604020 -
Dose form (SCDF) Injection RxCUI 1732140In current FDA listingsClinical drug / strength (SCD) 10 ML ganciclovir 50 MG/MLRxCUI 1999531250 ML ganciclovir 2 MG/MLRxCUI 1872065500 MGRxCUI 310442 -
Dose form (SCDF) Ophthalmic Gel RxCUI 393324In current FDA listingsClinical drug / strength (SCD) 0.0015 MG/MGRxCUI 388052 -
Dose form (SCDF) Oral Capsule RxCUI 372292No current FDA listingClinical drug / strength (SCD) 250 MGRxCUI 314007500 MGRxCUI 200206
Look up RxCUI 4678 in the RxCUI Atlas →
RxNorm is the U.S. National Library of Medicine’s normalized drug vocabulary. Its concept hierarchy can include forms that are not currently marketed; the status on each branch compares that concept with current FDA listings. RxCUIs identify vocabulary concepts, not individual packages or manufacturers.
📦 Supply & shortage status
Whether Ganciclovir is in short supply in the U.S. right now, plus any shortage history the FDA has on record. A shortage usually reflects a manufacturing or demand issue — not a safety problem with the drug.
Source: openFDA, from the FDA Drug Shortages database.
🏷️ Sold under these brand names
🏭 Manufacturers & labelers
🔬 Where this comes from
Core label, product, RxNorm, safety, and utilization data on this page come from the sources identified below. AI-written, editorial, and licensed sections are labeled separately.
How we combine label and product data
HelloPharmacist combines public FDA and NLM records; we don’t author the underlying clinical facts. We identified 9 FDA-filed SPL label sets within the page’s selected clinical scope after exact ingredient or ingredient-combination matching and applicable route/form matching. The representative label is the starting point for the displayed reference monograph; the 12 largest stored in-scope SPL records, which may include that representative, are compared section by section, and the longest available version of each section is retained. Forms, routes, brands, labelers, product-listed strengths, and product-record counts are aggregated separately from ingredient-matched FDA NDC Directory records; package records listed above are associated with the linked SPL; and the normalized concept hierarchy comes from NLM RxNorm.
For canonical ingredient pages, bounded product-attributed indication and administration excerpts may be added to the AI evidence, and the generator is instructed to preserve available product, brand, route, and form qualifiers instead of treating one label as universal. Where a section is identified as AI-written, its plain-language text is generated from bounded label evidence. New draft drug pages remain in the admin review queue before first publication. Exela Pharma Sciences, Llc is the representative DailyMed label linked for verification and dates; it is not the sole source used for the page.
This is general education, not medical advice — always consult your doctor or pharmacist about your medications and any medical condition. For the exact wording of the linked representative label, view that label on DailyMed; some displayed composite sections may come from other in-scope SPL labels. Learn how we use AI and our data sources & update cadence.