INTERACTIONS Drug-drug interaction studies were conducted in patients with normal renal function. Patients with impaired renal function may have increased concentrations of ganciclovir and the coadministered drug following concomitant administration of Ganciclovir Injection Drug-drug interaction studies were conducted in patients with normal renal function. Patients with impaired renal function may have increased concentrations of ganciclovir and the coadministered drug following concomitant administration of Ganciclovir Injection and drugs excreted by the same pathway as ganciclovir. Therefore, these patients should be closely monitored for toxicity of ganciclovir and the coadministered drug. Established and other potentially significant drug interactions conducted with ganciclovir are listed in Table 6 . Established and other potentially significant drug interactions conducted with ganciclovir are listed in Table 6 [see Clinical Pharmacology (12.3) ] .
Table
6. Established and Other Potentially Significant Drug Interactions with Ganciclovir Name of the Concomitant Drug Change in the Concentration of Ganciclovir or Concomitant Drug Clinical Comment Imipenem-cilastatin Unknown Coadministration with imipenem-cilastatin is not recommended because generalized seizures have been reported in patients who received ganciclovir and imipenem-cilastatin. Cyclosporine or amphotericin B Unknown Monitor renal function when Ganciclovir Injection is coadministered with cyclosporine or amphotericin B because of potential increase in serum creatinine [see Warnings and Precautions (5.2)]. Mycophenolate mofetil (MMF) ↔ Ganciclovir (in patients with normal renal function) ↔ MMF (in patients with normal renal function) Based on increased risk, patients should be monitored for hematological and renal toxicity. Other drugs associated with myelosuppression or nephrotoxicity (e.g., dapsone, doxorubicin, flucytosine, hydroxyurea, pentamidine, tacrolimus, trimethoprim/ sulfamethoxazole, vinblastine, vincristine and zidovudine)
Unknown
Because of potential for higher toxicity, coadministration with Ganciclovir Injection should be considered only if the potential benefits are judged to outweigh the risks. Didanosine ↔ Ganciclovir ↑ Didanosine Patients should be closely monitored for didanosine toxicity (e.g., pancreatitis). Probenecid ↑ Ganciclovir Ganciclovir Injection dose may need to be reduced. Monitor for evidence of ganciclovir toxicity. Imipenem-cilastatin: Seizures were reported in patients receiving ganciclovir and imipenem-cilastatin. Concomitant use is not recommended unless the potential benefits outweigh the risks. (7) Cyclosporine or amphotericin B: When coadministered with ganciclovir, the risk of nephrotoxicity may be increased. Monitor renal function. (5.2, 7) Mycophenolate mofetil (MMF): When coadministered with ganciclovir, the risk of hematological and renal toxicity may be increased. Monitor for ganciclovir and MMF toxicity. (7) Other drugs associated with myelosuppression or nephrotoxicity: Due to potential for increased toxicity, such drugs should be considered for concomitant use with ganciclovir only if the potential benefits are judged to outweigh the risks. (7) Didanosine: Ganciclovir coadministered with didanosine may increase didanosine levels. Monitor for didanosine toxicity (e.g., pancreatitis). (7) Probenecid: May increase ganciclovir levels. Monitor for evidence of ganciclovir toxicity. (7)
Ganciclovir Injection Ganciclovir Injection is contraindicated in patients who have experienced a clinically significant hypersensitivity reaction (e.g., anaphylaxis) to ganciclovir, valganciclovir, or any component of the formulation. Hypersensitivity to ganciclovir or valganciclovir. ( 4 )
AND PRECAUTIONS Renal Impairment: Increased serum creatinine levels have been observed with the use of ganciclovir, particularly in elderly patients and transplant recipients receiving concomitant nephrotoxic drugs. Monitor renal function during therapy with ganciclovir, particularly in elderly patients and in patients taking other nephrotoxic drugs, and reduce dosage in patients with renal impairment. ( 5.2 )
5.1 Hematologic Toxicity Granulocytopenia (neutropenia), anemia, thrombocytopenia and pancytopenia have been observed in patients treated with ganciclovir. The frequency and severity of these events vary widely in different patient populations <span class="opacity-50 text-xs">[see Adverse Reactions ( 6.1 )]</span> . Ganciclovir is not recommended if the absolute neutrophil count is less than 500 cells/mL, hemoglobin is less than 8 g/dL, or the platelet count is less than 25,000 cells/mL. Ganciclovir should also be used with caution in patients with pre-existing cytopenias and in patients receiving myelosuppressive drugs or irradiation. Granulocytopenia (neutropenia) usually occurs during the first or second week of treatment but may occur at any time during treatment. Cell counts usually begin to recover within 3 to 7 days after discontinuing drug. Colony-stimulating factors have been shown to increase neutrophil and white blood cell counts in patients receiving ganciclovir solution for treatment of CMV retinitis. Due to the frequency of neutropenia, anemia and thrombocytopenia in patients receiving ganciclovir <span class="opacity-50 text-xs">[see Adverse Reactions ( 6.1 )]</span> , complete blood counts with differential and platelet counts should be performed frequently in all patients, especially in patients with renal impairment and in patients in whom ganciclovir or other nucleoside analogues have previously resulted in leukopenia, or in whom neutrophil counts are less than 1000 cells/mL at the beginning of treatment <span class="opacity-50 text-xs">[see Dosage and Administration ( 2.2 )]</span> .
5.2 Renal Impairment Ganciclovir should be used with caution in patients with impaired renal function because the half-life and plasma/serum concentrations of ganciclovir will be increased due to reduced renal clearance. If renal function is impaired, dosage adjustments are recommended <span class="opacity-50 text-xs">[see Dosage and Administration ( 2.5 ), Use in Specific Populations ( 8.5 , 8.6 )]</span> . Increased serum creatinine levels have been reported in elderly patients and in transplant recipients receiving concomitant nephrotoxic medications (i.e., cyclosporine and amphotericin B). Monitoring renal function during therapy with ganciclovir is essential, especially for elderly patients and those patients receiving concomitant agents that may cause nephrotoxicity <span class="opacity-50 text-xs">[see Dosage and Administration ( 2.5 ), Drug Interactions ( 7 ), Use in Specific Populations ( 8.5 ]</span> .
5.3 Impairment of Fertility Based on animal data and limited human data, ganciclovir at the recommended human dose (RHD) may cause temporary or permanent inhibition of spermatogenesis in males, and may cause suppression of fertility in females. Advise patients that fertility may be impaired with the use of ganciclovir <span class="opacity-50 text-xs">[see Use in Specific Populations ( 8.1 , 8.3 ), Nonclinical Toxicology ( 13.1 )]</span>.
5.4 Fetal Toxicity Ganciclovir may cause fetal toxicity when administered to pregnant women based on findings in animal studies. Systemic exposure of ganciclovir in animals at approximately 2 times the RHD caused fetal growth retardation, embryolethality, teratogenicity, and/or maternal toxicity. Teratogenic changes in animals included cleft palate, anophthalmia/microphthalmia, aplastic organs (kidney and pancreas), hydrocephaly and brachygnathia. Women of childbearing potential should be advised to use effective contraception during treatment and for at least 30 days following treatment with ganciclovir. Similarly, men should be advised to practice barrier contraception during and for at least 90 days following treatment with ganciclovir <span class="opacity-50 text-xs">[see Use in Specific Populations ( 8.1 , 8.3 ), Nonclinical Toxicology ( 13.1 )]</span>.
5.5 Mutagenesis and Carcinogenesis Animal data indicate that ganciclovir is mutagenic and carcinogenic. Ganciclovir should therefore be considered a potential carcinogen in humans <span class="opacity-50 text-xs">[see Dosage and Administration ( 2.7 ), Nonclinical Toxicology ( 13.1 )]</span> .
5.1 Hematologic Toxicity Granulocytopenia (neutropenia), anemia, thrombocytopenia and pancytopenia have been observed in patients treated with ganciclovir. The frequency and severity of these events vary widely in different patient populations <span class="opacity-50 text-xs">[see Adverse Reactions ( 6.1 )]</span> . Ganciclovir is not recommended if the absolute neutrophil count is less than 500 cells/mL, hemoglobin is less than 8 g/dL, or the platelet count is less than 25,000 cells/mL. Ganciclovir should also be used with caution in patients with pre-existing cytopenias and in patients receiving myelosuppressive drugs or irradiation. Granulocytopenia (neutropenia) usually occurs during the first or second week of treatment but may occur at any time during treatment. Cell counts usually begin to recover within 3 to 7 days after discontinuing drug. Colony-stimulating factors have been shown to increase neutrophil and white blood cell counts in patients receiving ganciclovir solution for treatment of CMV retinitis. Due to the frequency of neutropenia, anemia and thrombocytopenia in patients receiving ganciclovir <span class="opacity-50 text-xs">[see Adverse Reactions ( 6.1 )]</span> , complete blood counts with differential and platelet counts should be performed frequently in all patients, especially in patients with renal impairment and in patients in whom ganciclovir or other nucleoside analogues have previously resulted in leukopenia, or in whom neutrophil counts are less than 1000 cells/mL at the beginning of treatment <span class="opacity-50 text-xs">[see Dosage and Administration ( 2.2 )]</span> .
5.2 Renal Impairment Ganciclovir should be used with caution in patients with impaired renal function because the half-life and plasma/serum concentrations of ganciclovir will be increased due to reduced renal clearance. If renal function is impaired, dosage adjustments are recommended <span class="opacity-50 text-xs">[see Dosage and Administration ( 2.5 ), Use in Specific Populations ( 8.5 , 8.6 )]</span> . Increased serum creatinine levels have been reported in elderly patients and in transplant recipients receiving concomitant nephrotoxic medications (i.e., cyclosporine and amphotericin B). Monitoring renal function during therapy with ganciclovir is essential, especially for elderly patients and those patients receiving concomitant agents that may cause nephrotoxicity <span class="opacity-50 text-xs">[see Dosage and Administration ( 2.5 ), Drug Interactions ( 7 ), Use in Specific Populations ( 8.5 ]</span> .
5.3 Impairment of Fertility Based on animal data and limited human data, ganciclovir at the recommended human dose (RHD) may cause temporary or permanent inhibition of spermatogenesis in males, and may cause suppression of fertility in females. Advise patients that fertility may be impaired with the use of ganciclovir <span class="opacity-50 text-xs">[see Use in Specific Populations ( 8.1 , 8.3 ), Nonclinical Toxicology ( 13.1 )]</span>.
5.4 Fetal Toxicity Ganciclovir may cause fetal toxicity when administered to pregnant women based on findings in animal studies. Systemic exposure of ganciclovir in animals at approximately 2 times the RHD caused fetal growth retardation, embryolethality, teratogenicity, and/or maternal toxicity. Teratogenic changes in animals included cleft palate, anophthalmia/microphthalmia, aplastic organs (kidney and pancreas), hydrocephaly and brachygnathia. Women of childbearing potential should be advised to use effective contraception during treatment and for at least 30 days following treatment with ganciclovir. Similarly, men should be advised to practice barrier contraception during and for at least 90 days following treatment with ganciclovir <span class="opacity-50 text-xs">[see Use in Specific Populations ( 8.1 , 8.3 ), Nonclinical Toxicology ( 13.1 )]</span>.
5.5 Mutagenesis and Carcinogenesis Animal data indicate that ganciclovir is mutagenic and carcinogenic. Ganciclovir should therefore be considered a potential carcinogen in humans <span class="opacity-50 text-xs">[see Dosage and Administration ( 2.7 ), Nonclinical Toxicology ( 13.1 )]</span> .