Cymevene Special Precautions

General: Cross hypersensitivity: Due to the similarity of the chemical structure of ganciclovir and that of aciclovir and penciclovir, a cross-hypersensitivity reaction between these drugs is possible. Caution should therefore be used when prescribing Ganciclovir (Cymevene) to patients with known hypersensitivity to aciclovir or penciclovir (or to their prodrugs, valaciclovir or famciclovir respectively).
Mutagenicity, teratogenicity, carcinogenicity, fertility and contraception: In animal studies, ganciclovir was found to be mutagenic, teratogenic, carcinogenic and to impair fertility. Ganciclovir (Cymevene) should therefore be considered a potential teratogen and carcinogen in humans with the potential to cause birth defects and cancers. Prior to initiation of ganciclovir treatment, patients should be advised of the potential risks to the fetus and to use contraceptive measures. Based on clinical and nonclinical studies, Ganciclovir (Cymevene) may cause temporary or permanent inhibition of spermatogenesis (see Females and Males of Reproductive Potential, Pregnancy and Lactation under Use in Pregnancy & Lactation, Adverse Reactions, Toxicology: Nonclinical Safety under Actions and Special Instructions for Use, Handling and Disposal under Cautions for Usage).
Myelosuppression: Ganciclovir (Cymevene) should be used with caution in patients with pre-existing hematological cytopenia or a history of drug-related hematological cytopenia and in patients receiving radiotherapy.
Severe leukopenia, neutropenia, anemia, thrombocytopenia, pancytopenia, bone marrow failure and aplastic anemia have been observed in patients treated with Ganciclovir (Cymevene). Therapy should not be initiated if the absolute neutrophil count is less than 500 cells/μL or the platelet count is less than 25,000 cells/μL or the hemoglobin is less than 8 g/dL (see Adverse Reactions).
It is recommended that complete blood counts including platelet counts be monitored in all patients during therapy, particularly in patients with renal impairment and in neonates and infants (see Special Dosage Instructions under Dosage & Administration and Use in Children as follows).
In patients with severe leukopenia, neutropenia, anemia and/or thrombocytopenia, treatment with hematopoietic growth factors and/or the interruption of therapy is recommended (see Adverse Reactions).
Use with other medicines: Seizures have been reported in patients taking imipenem-cilastatin and ganciclovir. Ganciclovir (Cymevene) should not be used concomitantly with imipenem-cilastatin unless the potential benefits outweigh the potential risks (see Interactions).
Zidovudine and Ganciclovir (Cymevene) each have the potential to cause neutropenia and anemia. Some patients may not tolerate concomitant therapy at full dosage (see Interactions).
Didanosine plasma concentrations may increase during concomitant use with Ganciclovir (Cymevene); therefore, patients should be closely monitored for didanosine toxicity (see Interactions).
Concomitant use of other drugs that are known to be myelosuppressive or associated with renal impairment with Ganciclovir (Cymevene) may result in added toxicity (see Interactions).
Drug Abuse and Dependence: No information is available for drug abuse and dependence with Ganciclovir (Cymevene).
Ability to Drive and Use Machines: No studies on the effect on the ability to drive and use machines have been performed. Based on the adverse reaction profile, ganciclovir may have a minor influence on the ability to drive and use machines. Adverse reactions, for example seizures, dizziness and confusion may occur in patients receiving Ganciclovir (Cymevene) (see Adverse Reactions). If they occur, such effects may affect tasks requiring alertness including the patient's ability to drive and operate machinery.
Renal Impairment: In patients with renal impairment, dosage adjustments based on creatinine clearance are required (see Special Dosage Instructions under Dosage & Administration and Pharmacology: Pharmacokinetics: Pharmacokinetics in Special Populations under Actions).
Hepatic Impairment: The safety and efficacy of Ganciclovir (Cymevene) have not been studied in patients with hepatic impairment (see Special Dosage Instructions under Dosage & Administration and Pharmacology: Pharmacokinetics: Pharmacokinetics in Special Populations under Actions).
Use in Children: A higher risk of hematological cytopenias in neonates and infants warrants careful monitoring of blood counts in these age groups. Monitoring of liver function abnormalities, renal function and gastrointestinal fluid loss is also recommended in pediatric patients.
The use of Ganciclovir (Cymevene) in pediatric patients warrants caution due to the potential for long-term carcinogenicity and reproductive toxicity. The benefits of treatment should outweigh the risks (see Toxicology: Nonclinical Safety under Actions).
See Indications/Uses, Special Dosage Instructions under Dosage & Administration, Adverse Reactions and Pharmacology: Pharmacokinetics: Pharmacokinetics in Special Populations under Actions.
Use in the Elderly: See Dosage & Administration and Pharmacology: Pharmacokinetics: Pharmacokinetics in Special Populations under Actions.