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Vfend (Voriconazole) - Warnings and Precautions

 
 



WARNINGS AND PRECAUTIONS

Drug Interactions

See Table 7 for a listing of drugs that may significantly alter voriconazole concentrations. Also, see Table 8 for a listing of drugs that may interact with voriconazole resulting in altered pharmacokinetics or pharmacodynamics of the other drug [see Contraindications (4), and Drug Interactions (7) ].

Hepatic Toxicity

In clinical trials, there have been uncommon cases of serious hepatic reactions during treatment with VFEND (including clinical hepatitis, cholestasis and fulminant hepatic failure, including fatalities). Instances of hepatic reactions were noted to occur primarily in patients with serious underlying medical conditions (predominantly hematological malignancy). Hepatic reactions, including hepatitis and jaundice, have occurred among patients with no other identifiable risk factors. Liver dysfunction has usually been reversible on discontinuation of therapy [see Warnings and Precautions, and Adverse Reactions ].

Monitoring of hepatic function: Liver function tests should be evaluated at the start of and during the course of VFEND therapy. Patients who develop abnormal liver function tests during VFEND therapy should be monitored for the development of more severe hepatic injury. Patient management should include laboratory evaluation of hepatic function (particularly liver function tests and bilirubin). Discontinuation of VFEND must be considered if clinical signs and symptoms consistent with liver disease develop that may be attributable to VFEND [see Warnings and Precautions, Dosage and Administration (2.4, 2.6), and Adverse Reactions ].

Visual Disturbances

The effect of VFEND on visual function is not known if treatment continues beyond 28 days. There have been post-marketing reports of prolonged visual adverse events, including optic neuritis and papilledema. If treatment continues beyond 28 days, visual function including visual acuity, visual field and color perception should be monitored [see Adverse Reactions ].

Pregnancy Category D

Voriconazole can cause fetal harm when administered to a pregnant woman.

In animals, voriconazole administration was associated with teratogenicity, embryotoxicity, increased gestational length, dystocia and embryomortality. Please refer to section 8.1 (Use in Pregnancy) for additional details.

If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patient should be informed of the potential hazard to the fetus.

Arrhythmias and QT Prolongation

Some azoles, including voriconazole, have been associated with prolongation of the QT interval on the electrocardiogram. During clinical development and post-marketing surveillance, there have been rare cases of arrhythmias, (including ventricular arrhythmias such as torsade de pointes), cardiac arrests and sudden deaths in patients taking voriconazole. These cases usually involved seriously ill patients with multiple confounding risk factors, such as history of cardiotoxic chemotherapy, cardiomyopathy, hypokalemia and concomitant medications that may have been contributory.

Voriconazole should be administered with caution to patients with these potentially proarrhythmic conditions.

Rigorous attempts to correct potassium, magnesium and calcium should be made before starting voriconazole [see Clinical Pharmacology ].

Infusion Related Reactions

During infusion of the intravenous formulation of voriconazole in healthy subjects, anaphylactoid-type reactions, including flushing, fever, sweating, tachycardia, chest tightness, dyspnea, faintness, nausea, pruritus and rash, have occurred uncommonly. Symptoms appeared immediately upon initiating the infusion. Consideration should be given to stopping the infusion should these reactions occur.

Laboratory Tests

Electrolyte disturbances such as hypokalemia, hypomagnesemia and hypocalcemia should be corrected prior to initiation of VFEND therapy.

Patient management should include laboratory evaluation of renal (particularly serum creatinine) and hepatic function (particularly liver function tests and bilirubin).

Patients With Hepatic Impairment

It is recommended that the standard loading dose regimens be used but that the maintenance dose be halved in patients with mild to moderate hepatic cirrhosis (Child-Pugh Class A and B) receiving VFEND [see Clinical Pharmacology, and Dosage and Administration ].

VFEND has not been studied in patients with severe cirrhosis (Child-Pugh Class C). VFEND has been associated with elevations in liver function tests and clinical signs of liver damage, such as jaundice, and should only be used in patients with severe hepatic insufficiency if the benefit outweighs the potential risk. Patients with hepatic insufficiency must be carefully monitored for drug toxicity.

Patients With Renal Impairment

In patients with moderate to severe renal dysfunction (creatinine clearance <50 mL/min), accumulation of the intravenous vehicle, SBECD, occurs. Oral voriconazole should be administered to these patients, unless an assessment of the benefit/risk to the patient justifies the use of intravenous voriconazole. Serum creatinine levels should be closely monitored in these patients, and if increases occur, consideration should be given to changing to oral voriconazole therapy [see Clinical Pharmacology, and Dosage and Administration ].

Monitoring of Renal Function

Acute renal failure has been observed in patients undergoing treatment with VFEND. Patients being treated with voriconazole are likely to be treated concomitantly with nephrotoxic medications and have concurrent conditions that may result in decreased renal function.

Patients should be monitored for the development of abnormal renal function. This should include laboratory evaluation, particularly serum creatinine.

Monitoring of Pancreatic Function

Patients with risk factors for acute pancreatitis (e.g., recent chemotherapy, hematopoietic stem cell transplantation [HSCT]) should be monitored for the development of pancreatitis during VFEND treatment.

Dermatological Reactions

Serious exfoliative cutaneous reactions, such as Stevens-Johnson syndrome, have been reported during treatment with VFEND. If a patient develops an exfoliative cutaneous reaction, VFEND should be discontinued.

In addition VFEND has been associated with photosensitivity skin reaction. Patients should avoid intense or prolonged exposure to direct sunlight during VFEND treatment. In patients with photosensitivity skin reactions squamous cell carcinoma of the skin and melanoma have been reported during long-term therapy. If a patient develops a skin lesion consistent with squamous cell carcinoma or melanoma, VFEND should be discontinued.

Skeletal Adverse Events

Fluorosis and periostitis have been reported during long-term voriconazole therapy. If a patient develops skeletal pain and radiologic findings compatible with fluorosis or periostitis, voriconazole should be discontinued [see Adverse Reactions ].

USE IN SPECIFIC POPULATIONS

Pregnancy

Pregnancy Category D

Voriconazole can cause fetal harm when administered to a pregnant woman and should not be taken in pregnancy except in patients where the benefit to the mother clearly outweighs the potential risk to the fetus. There are no adequate and well-controlled studies in pregnant women.

If this drug is used during pregnancy, or if the patient becomes pregnant while taking this drug, the patients should be informed of the potential hazard to the fetus [see Warnings and Precautions ].

Animal Data

Voriconazole was teratogenic in rats (cleft palates, hydronephrosis/hydroureter) from 10 mg/kg (0.3 times the recommended maintenance dose (RMD) on a mg/m2 basis) and embryotoxic in rabbits at 100 mg/kg (6 times the RMD). Other effects in rats included reduced ossification of sacral and caudal vertebrae, skull, pubic and hyoid bone, supernumerary ribs, anomalies of the sternebrae and dilatation of the ureter/renal pelvis. Plasma estradiol in pregnant rats was reduced at all dose levels. Voriconazole treatment in rats produced increased gestational length and dystocia, which were associated with increased perinatal pup mortality at the 10 mg/kg dose. The effects seen in rabbits were an increased embryomortality, reduced fetal weight and increased incidences of skeletal variations, cervical ribs and extrasternebral ossification sites.

Nursing Mothers

It is not known whether voriconazole is excreted in human milk. Because many drugs are excreted in human milk and because of the potential for serious adverse reactions in nursing infants from VFEND, a decision should be made whether to discontinue nursing or discontinue the drug, taking into account the importance of the drug to the mother.

Pediatric Use

Safety and effectiveness in pediatric patients below the age of 12 years have not been established.

A total of 22 patients aged 12 to 18 years with invasive aspergillosis were included in the therapeutic studies. Twelve out of 22 (55%) patients had successful response after treatment with a maintenance dose of voriconazole 4 mg/kg q12h.

Sparse plasma sampling for pharmacokinetics in adolescents was conducted in the therapeutic studies [see Clinical Pharmacology ].

There have been postmarketing reports of pancreatitis in pediatric patients.

Geriatric Use

In multiple dose therapeutic trials of voriconazole, 9.2% of patients were ≥65 years of age and 1.8% of patients were ≥75 years of age. In a study in healthy subjects, the systemic exposure (AUC) and peak plasma concentrations (Cmax) were increased in elderly males compared to young males. Pharmacokinetic data obtained from 552 patients from 10 voriconazole therapeutic trials showed that voriconazole plasma concentrations in the elderly patients were approximately 80% to 90% higher than those in younger patients after either IV or oral administration. However, the overall safety profile of the elderly patients was similar to that of the young so no dosage adjustment is recommended [see Clinical Pharmacology ].

Women of Childbearing Potential

Women of childbearing potential should use effective contraception during treatment. The coadministration of voriconazole with the oral contraceptive, Ortho-NovumĀ® (35 mcg ethinyl estradiol and 1 mg norethindrone), results in an interaction between these two drugs, but is unlikely to reduce the contraceptive effect. Monitoring for adverse events associated with oral contraceptives and voriconazole is recommended [see Drug Interactions (7), and Clinical Pharmacology ].

Page last updated: 2013-04-24

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