Valganciclovir
Brand names: Valganciclovir, VALGANCICLOVIR HYDROCHLORIDE, VALGANCICLOVIR, Valcyte
Boxed warning
BOXED WARNING WARNING: HEMATOLOGIC TOXICITY, IMPAIRMENT OF FERTILITY, FETAL TOXICITY, MUTAGENESIS AND CARCINOGENESIS • Hematologic Toxicity: Severe leukopenia, neutropenia, anemia, thrombocytopenia, pancytopenia, bone marrow aplasia and aplastic anemia have been reported in patients treated with valganciclovir tablets [see Warnings and Precautions ( 5.1 )]. • Impairment of Fertility: Based on animal data, valganciclovir tablets may cause temporary or permanent inhibition of spermatogenesis [see Warnings and Precautions ( 5.2 )]. • Fetal Toxicity: Based on animal data, valganciclovir tablets have the potential to cause birth defects in humans [see Warnings and Precautions ( 5.3 )]. • Mutagenesis and Carcinogenesis: Based on animal data, valganciclovir tablets have the potential to cause cancers in humans [see Warnings and Precautions ( 5.4 )]. WARNING: HEMATOLOGIC TOXICITY, IMPAIRMENT OF FERTILITY, FETAL TOXICITY, MUTAGENESIS AND CARCINOGENESIS See full prescribing information for complete boxed warning. • Hematologic Toxicity: Severe leukopenia, neutropenia, anemia thrombocytopenia, pancytopenia, bone marrow aplasia and aplastic anemia have been reported in patients treated with valganciclovir tablets ( 5.1 ). • Impairment of Fertility: Based on animal data, valganciclovir tablets may cause temporary or permanent inhibition of spermatogenesis ( 5.2 ). • Fetal Toxicity: Based on animal data, valganciclovir tablets have the potential to cause birth defects in humans ( 5.3 ). • Mutagenesis and Carcinogenesis: Based on animal data, valganciclovir tablets have the potential to cause cancers in humans ( 5.4 ).
Warnings
5 WARNINGS AND PRECAUTIONS • Hematologic toxicity: Severe leukopenia, neutropenia, anemia, thrombocytopenia, pancytopenia, bone marrow depression, and aplastic anemia have occurred with the use of valganciclovir tablets or ganciclovir. Avoid valganciclovir tablets use if absolute neutrophil count is less than 500 cells/µL, platelet count is less than 25,000/µL, or hemoglobin is less than 8 g/dL. Use with caution in pre-existing cytopenias and when receiving myelosuppressive drugs or irradiation. Monitor with frequent testing of platelet and complete blood counts ( 5.1 ). • Impairment of fertility: Based on animal studies, valganciclovir tablets may cause temporary or permanent inhibition of spermatogenesis ( 5.2 ). • Fetal toxicity: Based on animal studies, valganciclovir tablets may cause fetal harm. Females of reproductive potential should use effective contraception during and following treatment and males should practice barrier contraception during and following treatment (5.3 ). • Mutagenicity and carcinogenicity: Based on animal studies, valganciclovir tablets are potentially mutagenic and carcinogenic ( 5.4 ). • Acute renal failure: Acute renal failure may occur in elderly patients (with or without reduced renal function), patients who receive concomitant nephrotoxic drugs, or inadequately hydrated patients. Use with caution in elderly patients or those taking nephrotoxic drugs, reduce dosage in patients with renal impairment, and monitor renal function ( 2.5 , 5.5 , 8.5 , 8.6 , 12.3 ). 5.1Hematologic Toxicity Severe leukopenia, neutropenia, anemia, thrombocytopenia, pancytopenia, bone marrow aplasia, and aplastic anemia have been reported in patients treated with valganciclovir tablets or ganciclovir. Valganciclovir tablets should be avoided if the absolute neutrophil count is less than 500 cells/µL, the platelet count is less than 25,000/µL, or the hemoglobin is less than 8 g/dL. Valganciclovir tablets should also be used with caution in patients with pre-existing cytopenias, or who have received or who are receiving myelosuppressive drugs or irradiation. Cytopenia may occur at any time during treatment and may worsen with continued dosing. Cell counts usually begin to recover within 3 to 7 days after discontinuing drug. Due to the frequency of neutropenia, anemia, and thrombocytopenia in patients receiving valganciclovir tablets [see Adverse Reactions ( 6.1 )], complete blood counts with differential and platelet counts should be performed frequently, especially in patients in whom ganciclovir or other nucleoside analogues have previously resulted in leukopenia, or in whom neutrophil counts are less than 1000 cells/μL at the beginning of treatment. Increased monitoring for cytopenias may be warranted if therapy with oral ganciclovir is changed to valganciclovir tablets, because of increased plasma concentrations of ganciclovir after valganciclovir tablets administration [see Clinical Pharmacology ( 12.3 )]. 5.2 Impairment of Fertility Based on animal data with ganciclovir, valganciclovir tablets at the recommended human doses 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 use of valganciclovir tablets [see Use in Specific Populations ( 8.1, 8.3 ), Nonclinical Toxicology ( 13.1 )]. 5.3 Fetal Toxicity Ganciclovir may cause fetal toxicity when administered to pregnant women based on findings in animal studies. When given to pregnant rabbits at dosages resulting in 2-times the human exposure (based on AUC), ganciclovir caused malformations in multiple organs of the fetuses. Maternal and fetal toxicity were also observed in pregnant mice and rabbits. Therefore, valganciclovir has the potential to cause birth defects. Pregnancy should be avoided in female patients taking valganciclovir tablets and in females with male partners taking valganciclovir tablets. Females of reproductive potential should be advised to use effective contraception during treatment and for at least 30 days following treatment with valganciclovir tablets. Similarly, males should be advised to practice barrier contraception during and for at least 90 days following treatment with valganciclovir tablets [see Dosage and Administration (2.6), Use in Specific Populations ( 8.1, 8.3 ), Nonclinical Toxicology ( 13.1 )]. 5.4 Mutagenesis and Carcinogenesis Animal data indicate that ganciclovir is mutagenic and carcinogenic. Valganciclovir tablets should therefore be considered a potential carcinogen in humans [see Dosage and Administration ( 2.6 ), Nonclinical Toxicology ( 13.1 )]. 5.5 Acute Renal Failure Acute renal failure may occur in: • Elderly patients with or without reduced renal function. Caution should be exercised when administering valganciclovir tablets to geriatric patients, and dosage reduction is recommended for those with impaired renal function [see Dosage and Administration ( 2.5 ), Use in Specific Populations ( 8.5 , 8.6 )]. • Patients receiving potential nephrotoxic drugs. Caution should be exercised when administering valganciclovir tablets to patients receiving potential nephrotoxic drugs. • Patients without adequate hydration. Adequate hydration should be maintained for all patients.
Contraindications
4 CONTRAINDICATIONS Valganciclovir tablets are contraindicated in patients who have had a demonstrated clinically significant hypersensitivity reaction (e.g., anaphylaxis) to valganciclovir, ganciclovir, or any component of the formulation [see Adverse Reactions ( 6.1 )]. Hypersensitivity to valganciclovir or ganciclovir ( 4 )
Overdose
10 OVERDOSAGE Experience With Valganciclovir Tablets: One adult developed fatal bone marrow depression (medullary aplasia) after several days of dosing that was at least 10-fold greater than recommended for the patient’s estimated degree of renal impairment. An overdose of valganciclovir tablets could also possibly result in increased renal toxicity [see Dosage and Administration ( 2.5 ), Use in Specific Populations ( 8.6 )]. Because ganciclovir is dialyzable, dialysis may be useful in reducing serum concentrations in patients who have received an overdose of valganciclovir tablets [see Clinical Pharmacology ( 12.3 )]. Adequate hydration should be maintained. The use of hematopoietic growth factors should be considered [see Clinical Pharmacology ( 12.3 )]. Experience with Intravenous Ganciclovir: Reports of overdoses with intravenous ganciclovir have been received from clinical trials and during postmarketing experience. The majority of patients experienced one or more of the following adverse events: Hematological toxicity: pancytopenia, bone marrow depression, medullary aplasia, leukopenia, neutropenia, granulocytopenia Hepatotoxicity: hepatitis, liver function disorder Renal toxicity: worsening of hematuria in a patient with pre-existing renal impairment, acute renal failure, elevated creatinine Gastrointestinal toxicity: abdominal pain, diarrhea, vomiting Neurotoxicity: generalized tremor, convulsion
Drug interactions
7 DRUG INTERACTIONS In vivo drug-drug interaction studies were not conducted with valganciclovir. However, because valganciclovir is rapidly and extensively converted to ganciclovir, drug-drug interactions associated with ganciclovir will be expected for valganciclovir tablets. Established and other potentially significant drug interactions conducted with ganciclovir are listed in Table 9. Table 9 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 Zidovudine ↓ Ganciclovir ↑ Zidovudine Zidovudine and valganciclovir tablets each have the potential to cause neutropenia and anemia Probenicid ↑ Ganciclovir Patients taking probenicid and valganciclovir tablets should be monitored for evidence of ganciclovir toxicity Mycophenolate Mofetil (MMF) ↔ Ganciclovir (in patients with normal renal function) ↔ MMF (in patients with normal renal function) Patients with renal impairment should be monitored carefully as levels of MMF metabolites and ganciclovir may increase Didanosine ↓ Ganciclovir ↑ Didanosine Patients should be closely monitored for didanosine toxicity • Zidovudine: Potential to cause neutropenia and anemia. Monitor with frequent tests of white blood cell counts with differential and hemoglobin levels (7 ). • Probenecid: May increase ganciclovir levels. Monitor for evidence of ganciclovir toxicity (7 ). • Mycophenolate mofetil (MMF): May increase ganciclovir concentrations and levels of MMF metabolites in patients with renal impairment. Monitor for ganciclovir and MMF toxicity ( 7 ). • Didanosine: May increase didanosine concentrations. Monitor for didanosine toxicity ( 7 ).
Uses
1 INDICATIONS & USAGE Valganciclovir tablets, USP are a cytomegalovirus (CMV) nucleoside analogue DNA polymerase inhibitor indicated for: Adult Patients ( 1.1 ) • Treatment of CMV retinitis in patients with acquired immunodeficiency syndrome (AIDS). • Prevention of CMV disease in kidney, heart, and kidney-pancreas transplant patients at high risk. Pediatric Patients ( 1.2 ) • Prevention of CMV disease in heart transplant patients at high risk. 1.1 Adult Patients Treatment of Cytomegalovirus (CMV) Retinitis : Valganciclovir tablets, USP are indicated for the treatment of CMV retinitis in patients with acquired immunodeficiency syndrome (AIDS) [see Clinical Studies ( 14.1)]. Prevention of CMV Disease : Valganciclovir tablets, USP are indicated for the prevention of CMV disease in kidney, heart, and kidney-pancreas transplant patients at high risk (Donor CMV seropositive/Recipient CMV seronegative [D+/R-]) [see Clinical Studies ( 14.1 )]. 1.2 Pediatric Patients Prevention of CMV Disease : Valganciclovir tablets, USP are indicated for the prevention of CMV disease in heart transplant patients (4 month to 16 years of age) at high risk [see Clinical Studies ( 14.2 )]. Pediatric use information for pediatric kidney transplant patients ages 4 months to 16 years and for pediatric heart transplant patients ages 1 to less than 4 months is approved for Roche Palo Alto LLC' s VALCYTE (valganciclovir hydrochloride) tablets. However, due to Roche Palo Alto LLC' s marketing exclusivity rights, this drug product is not labeled with that pediatric information.
Dosage forms & strengths
2 DOSAGE & ADMINISTRATION Adult Dosage (2.2) Treatment of CMV retinitis Induction: 900 mg (two 450 mg tablets) twice a day for 21 days Maintenance: 900 mg (two 450 mg tablets) once a day Prevention of CMV disease in heart or kidney-pancreas transplant patients 900 mg (two 450 mg tablets) once a day within 10 days of transplantation until 100 days post-transplantation Prevention of CMV disease in kidney transplant patients 900 mg (two 450 mg tablets) once a day within 10 days of transplantation until 200 days post-transplantation Pediatric Dosage (2.3) Prevention of CMV disease in heart transplant patients 4 months to 16 years of age Dose once a day within 10 days of transplantation until 100 days post-transplantation according to dosage algorithm (note the calculation of creatinine clearance using a modified Schwartz formula in children) • Valganciclovir tablets should be taken with food ( 2.1 , 12.3 ). • Valganciclovir tablets should not be broken or crushed ( 2.6 ). • Adult patients should use valganciclovir tablets, not valganciclovir for oral solution ( 2.1 ). • Adults with renal impairment: Adjust dose based on creatinine clearance. For adult patients receiving hemodialysis a dose recommendation cannot be given ( 2.5 , 8.6, 12.3 ). 2.1 General Dosing Information • Adult patients should use valganciclovir tablets, not valganciclovir for oral solution. • Valganciclovir tablets should be taken with food [see Clinical Pharmacology ( 12.3 )]. 2.2 Recommended Dosage in Adult Patients with Normal Renal Function For dosage recommendations in adult patients with renal impairment [see Dosage and Administration ( 2.5 )]. Treatment of CMV Retinitis: • Induction: The recommended dosage is 900 mg (two 450 mg tablets) taken orally twice a day for 21 days. • Maintenance: Following induction treatment, or in adult patients with inactive CMV retinitis, the recommended dosage is 900 mg (two 450 mg tablets) taken orally once a day. Prevention of CMV Disease: • For adult patients who have received a heart or kidney-pancreas transplant, the recommended dosage is 900 mg (two 450 mg tablets) taken orally once a day starting within 10 days of transplantation until 100 days post-transplantation. • For adult patients who have received a kidney transplant, the recommended dosage is 900 mg (two 450 mg tablets) taken orally once a day starting within 10 days of transplantation until 200 days post-transplantation. 2.3 Recommended Dosage in Pediatric Patients Prevention of CMV Disease in Pediatric Heart Transplant Patients : For pediatric heart transplant patients 4 month to 16 years of age, the recommended once daily mg dose (7x BSA x CrCL) should start within 10 days of transplantation until 100 days post-transplantation. The recommended once daily dosage of valganciclovir is based on body surface area (BSA) and creatinine clearance (CrCl) derived from a modified Schwartz formula, and is calculated using the equation below: Pediatric Dose (mg) = 7 x BSA x CrCl (calculated using a modified Schwartz formula). If the calculated Schwartz creatinine clearance exceeds 150 mL/min/1.73m 2 , then a maximum value of 150 mL/min/1.73m 2 should be used in the equation. The k values used in the modified Schwartz formula are based on pediatric patient age, as shown in Table 1. Mosteller BSA (m 2 ) = √ Height (cm) x weight (kg) 3600 Schwartz Creatinine Clearance (mL/min/1.73m 2 ) = K x Height (cm) Serum Creatinine (mg/dL) Table 1. k Values According to Pediatric Patient Age* k value Pediatric Patient Age 0.33 Infants less than 1 year of age with low birth weight for gestational age 0.45 Infants less than 1 year of age with birth weight appropriate for gestational age 0.45 Children aged 1 to less than 2 years 0.55 Boys aged 2 to less than 13 years Girls aged 2 to less than 16 years 0.7 Boys aged 13 to 16 years * The k values provided are based on the Jaffe method of measuring serum creatinine, and may require correction when enzymatic methods are used 1 Monitor serum creatinine levels regularly and consider changes in height and body weight and adapt the dose as appropriate during prophylaxis period. All calculated doses should be rounded to the nearest 10 mg increment for the actual deliverable dose. If the calculated dose exceeds 900 mg, a maximum dose of 900 mg should be administered. Valganciclovir for oral solution is the preferred formulation since it provides the ability to administer a dose calculated according to the formula above; however, valganciclovir tablets may be used if the calculated doses are within 10% of available tablet strength (450 mg). For example, if the calculated dose is between 405 mg and 495 mg, one 450 mg tablet may be taken. Before prescribing valganciclovir tablets, pediatric patients should be assessed for the ability to swallow tablets. Pediatric use information for pediatric kidney transplant patients ages 4 months to 16 years and for pediatric heart transplant patients ages 1 to less than 4 months is approved for Roche Palo Alto LLC' s VALCYTE (valganciclovir hydrochloride) tablets. However, due to Roche Palo Alto LLC' s marketing exclusivity rights, this drug product is not labeled with that pediatric information. 2.5 Dosage Recommendation for Adult Patients with Renal Impairment Serum creatinine levels or creatinine clearance should be monitored regularly during treatment. Dosage recommendations for adult patients with reduced renal function are provided in Table 2. For adult patients on hemodialysis (CrCl less than 10 mL/min), a dose recommendation for valganciclovir tablets cannot be given [see Use in Specific Populations ( 8.5, 8.6 ), Clinical Pharmacology ( 12.3 )]. Table 2 Dosage Recommendations for Adult Patients with Impaired Renal Function Valganciclovir Tablets 450 mg CrCl* (mL/min) Induction Dose Maintenance/Prevention Dose ≥ 60 900 mg twice daily 900 mg once daily 40 – 59 450 mg twice daily 450 mg once daily 25 – 39 450 mg once daily 450 mg every 2 days 10 – 24 450 mg every 2 days 450 mg twice weekly < 10 (on hemodialysis) not recommended not recommended *An estimated creatinine clearance in adults is calculated from serum creatinine by the following formulas: For males = (140-age [years]) x ( body weight [kg]) (72) x (serum creatinine [mg/dL] For females = 0.85 x male value Dosing in pediatric patients with renal impairment can be done using the recommended equations because CrCl is a component in the calculation [see Dosage and Administration ( 2.3 )]. 2.6 Handling and Disposal Caution should be exercised in the handling of valganciclovir tablets. Tablets should not be broken or crushed. Because valganciclovir is considered a potential teratogen and carcinogen in humans, caution should be observed in handling broken tablets [see Warnings and Precautions ( 5.3, 5.4 )]. Avoid direct contact with broken or crushed tablets with skin or mucous membranes. If such contact occurs, wash thoroughly with soap and water, and rinse eyes thoroughly with plain water. Handle and dispose valganciclovir tablets according to guidelines for antineoplastic drugs because ganciclovir shares some of the properties of antitumor agents (i.e., carcinogenicity and mutagenicity) 2 .