ganciclovir

Absorption: IV administration results in complete bioavailability.

Distribution: Widely distributed; enters CSF.

Protein Binding: 1–2%.

Metabolism/Excretion: 90% excreted unchanged by the kidneys.

Half-Life: Adults: 2.9 hr; Children 9 mo–12 yr: 2.4 ±0.7 hr; Neonates: 2.4 hr (↑ in renal impairment).

Time/Action Profile ⬆ ⬇

(antiviral levels)

ROUTE	ONSET	PEAK	DURATION
IV	rapid	end of infusion	12–24 hr

Contraind./Precautions ⬆ ⬇

Contraindicated in:

Hypersensitivity to ganciclovir or acyclovir;
Bone marrow depression or immunosuppression or thrombocytopenia (do not administer if absolute neutrophil count [ANC] <500/mm³ or platelet count <25,000/mm³);
Lactation: Lactation.

Use Cautiously in:

Renal impairment (dose ↓ required if CCr <80 mL/min);
OB: Use during pregnancy only if potential maternal benefit justifies potential fetal risk;
Rep: Women of reproductive potential and men with female partners of reproductive potential;
Geri: Dose recommended in older adults.

Adv. Reactions/Side Effects ⬆ ⬇

CV: arrhythmias, edema, hypertension, hypotension

Derm: alopecia, photosensitivity, pruritus, rash, urticaria

Endo: hypoglycemia

GI: ↑liver enzymes, abdominal pain, GI BLEEDING, nausea, vomiting

GU: ↓fertility, gonadal suppression, hematuria, renal impairment

Hemat: neutropenia, thrombocytopenia, anemia, eosinophilia

Local: pain/phlebitis at IV site

Neuro: abnormal dreams, ataxia, confusion, dizziness, drowsiness, headache, malaise, nervousness, SEIZURES, tremor

Resp: dyspnea

Misc: fever

Interactions ⬆ ⬇

Drug-drug:

Toxicity may be ↑ by probenecid.
↑risk of seizures with imipenem/cilastatin; concurrent use not recommended.
Concurrent use of cyclosporine or amphotericin B↑ risk of nephrotoxicity.
↑risk of nephrotoxicity and hematological toxicity with mycophenolate mofetil.
Concurrent use with dapsone, doxorubicin, flucytosine, hydroxyurea, pentamidine, tacrolimus, trimethoprim/sulfamethoxazole, vinblastine, vincristine, or zidovudine↑ risk of nephrotoxicity and myelosuppression.

Route/Dosage ⬆ ⬇

IV (Adults and Children >3 mo): Induction: 5 mg/kg every 12 hr for 14–21 days. Maintenance regimen: 5 mg/kg/day or 6 mg/kg for 5 days of each wk. If progression occurs, ↑ to every 12 hr regimen. Prevention: 5 mg/kg every 12 hr for 7–14 days, then 5 mg/kg/day or 6 mg/kg for 5 days of each wk.
IV (Neonates ): Congenital CMV infection: 12 mg/kg/day divided every 12 hr for 6 wk.

Renal Impairment

IV (Adults and Children ): Induction: CCr 50–69 mL/min: 2.5 mg/kg/dose every 12 hr; CCr 25–49 mL/min: 2.5 mg/kg/dose every 24 hr; CCr 10–24 mL/min: 1.25 mg/kg/dose every 24 hr; CCr <10 mL/min: 1.25 mg/kg 3 times/wk after hemodialysis; Maintenance: CCr 50–69 mL/min: 2.5 mg/kg/dose every 24 hr; CCr 25–49 mL/min: 1.25 mg/kg/dose every 24 hr; CCr 10–24 mL/min: 0.625 mg/kg/dose every 24 hr; CCr <10 mL/min: 0.625 mg/kg 3 times/wk after hemodialysis.

Availability ⬆ ⬇

(Generic available)

Lyophilized powder for injection: 500 mg/vial
Solution for injection: 50 mg/mL
Premixed infusion: 500 mg/250 mL

Assessment ⬆ ⬇

Diagnosis of CMV retinitis should be determined by ophthalmoscopy before treatment with ganciclovir.
Culture for CMV (urine, blood, throat) may be taken before administration. However, a negative CMV culture does not rule out CMV retinitis. If symptoms do not respond after several wk, resistance to ganciclovir may have occurred. Ophthalmologic exams should be performed weekly during induction and every 2 wk during maintenance or more frequently if the macula or optic nerve is threatened. Progression of CMV retinitis may occur during or after ganciclovir treatment.
Assess for signs of infection (fever, chills, cough, hoarseness, lower back or side pain, sore throat, difficult or painful urination). Notify health care professional if these symptoms occur.
Assess for bleeding (bleeding gums, bruising, petechiae; guaiac stools, urine, and emesis). Avoid IM injections and taking rectal temperatures. Apply pressure to venipuncture sites for 10 min.

Lab Test Considerations:

Verify negative pregnancy test prior to starting therapy.
- Monitor neutrophil and platelet count at least every 2 days during twice daily therapy and weekly thereafter. Granulocytopenia usually occurs during the first 2 wk of treatment but may occur anytime during therapy. Do not administer if ANC <500/mm³ or platelet count <25,000/mm³. Recovery begins within 3–7 days of discontinuation of therapy.
- Monitor BUN and serum creatinine at least once every 2 wk throughout therapy.
- Monitor liver function tests (AST, ALT, serum bilirubin, alkaline phosphatase) periodically during therapy. May cause ↑ levels.
- May cause ↓ blood glucose.

Implementation ⬆ ⬇

Do not confuse Cytovene (ganciclovir) with Cytosar (cytarabine).
- Do not administer SUBQ or IM; severe tissue irritation may result.
IV: Observe infusion site for phlebitis. Rotate infusion site to prevent phlebitis.
- Maintain adequate hydration throughout therapy.

IV Administration:

Prepare solution in a biologic cabinet. Wear gloves, gown, and mask while handling medication. Discard IV equipment in specially designated containers.
Intermittent Infusion: Reconstitution: Reconstitute 500 mg powder for injection with 10 mL of sterile water for injection for a concentration of 50 mg/mL. Do not reconstitute with bacteriostatic water with parabens; precipitation will occur. Shake well to dissolve completely. Discard vial if particulate matter or discoloration occurs. Reconstituted solution is stable for 12 hr at room temperature; do not refrigerate.
- Diluent: Dilute reconstituted solution or solution for injection in 100 mL of D5W, 0.9% NaCl, Ringer’s or LR. Once diluted for infusion, solution should be used within 24 hr. Refrigerate but do not freeze.Concentration: 10 mg/mL.
Rate: Administer slowly, via infusion pump, over 1 hr using an in-line filter. Rapid administration may increase toxicity.

Patient/Family Teaching ⬆ ⬇

Inform patient that ganciclovir is not a cure for CMV retinitis. Progression of retinitis may continue in immunocompromised patients during and after therapy. Advise patients to have regular ophthalmic exams at least every 6 wk. Duration of therapy for CMV prevention is based on the duration and degree of immunosuppression.
Advise patient to notify health care professional if fever; chills; sore throat; other signs of infection; bleeding gums; bruising; petechiae; or blood in urine, stool, or emesis occurs. Caution patient to avoid crowds and persons with known infections. Instruct patient to use soft toothbrush and electric razor. Patient should be cautioned not to drink alcoholic beverages or take products containing aspirin or NSAIDs.
Caution patient to use sunscreen and protective clothing to prevent photosensitivity reactions.
Rep: May cause fetal harm. Advise female patients of reproductive potential to use a nonhormonal method of contraception during and for at least 30 days after last dose and to avoid breastfeeding during therapy. Advise male patients to use condoms during and for at least 90 days after therapy. Inform patients that ganciclovir may cause temporary or permanent female and male infertility.
Emphasize the importance of frequent follow-up exams to monitor blood counts.

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Pronunciation ⬇

Classifications ⬆ ⬇

Indications ⬆ ⬇

Action ⬆ ⬇

Pharmacokinetics ⬆ ⬇