Pediatric Patients 2 to less than 12 years of age and 12 to 14 years of age with body weight less than 50 kg

If patient response is inadequate and the patient is able to tolerate the initial intravenous maintenance dose, the maintenance dose may be increased by 1 mg/kg steps. If patient response is inadequate and the patient is able to tolerate the oral maintenance dose, the dose may be increased by 1 mg/kg steps or 50 mg steps to a maximum of 350 mg every 12 hours. If patients are unable to tolerate the initial intravenous maintenance dose, reduce the dose by 1 mg/kg steps. If patients are unable to tolerate the oral maintenance dose, reduce the dose by 1 mg/kg or 50 mg steps.

Pediatric patients 12 to 14 years of age weighing greater than or equal to 50 kg and 15 years of age and older regardless of body weight:

Use the optimal method for titrating dosage recommended for adults [see Dosage and Administration (2.3)].

Overview

The most frequently reported adverse reactions (see Table 4) in the adult therapeutic trials were visual disturbances (18.7%), fever (5.7%), nausea (5.4%), rash (5.3%), vomiting (4.4%), chills (3.7%), headache (3.0%), liver function test increased (2.7%), tachycardia (2.4%), hallucinations (2.4%). The adverse reactions which most often led to discontinuation of voriconazole therapy were elevated liver function tests, rash, and visual disturbances [see Warning and Precautions (5.1, 5.4) and Adverse Reactions (6.1)].

The data described in Table 4 reflect exposure to voriconazole in 1655 patients in nine therapeutic studies. This represents a heterogeneous population, including immunocompromised patients, e.g., patients with hematological malignancy or HIV and non-neutropenic patients. This subgroup does not include healthy subjects and patients treated in the compassionate use and non-therapeutic studies. This patient population was 62% male, had a mean age of 46 years (range 11–90, including 51 patients aged 12–18 years), and was 78% White and 10% Black. Five hundred sixty one patients had a duration of voriconazole therapy of greater than 12 weeks, with 136 patients receiving voriconazole for over six months. Table 4 includes all adverse reactions which were reported at an incidence of ≥2% during voriconazole therapy in the all therapeutic studies population, studies 307/602 and 608 combined, or study 305, as well as events of concern which occurred at an incidence of <2%.

In study 307/602, 381 patients (196 on voriconazole, 185 on amphotericin B) were treated to compare voriconazole to amphotericin B followed by other licensed antifungal therapy (OLAT) in the primary treatment of patients with acute IA. The rate of discontinuation from voriconazole study medication due to adverse reactions was 21.4% (42/196 patients). In study 608, 403 patients with candidemia were treated to compare voriconazole (272 patients) to the regimen of amphotericin B followed by fluconazole (131 patients). The rate of discontinuation from voriconazole study medication due to adverse reactions was 19.5% out of 272 patients. Study 305 evaluated the effects of oral voriconazole (200 patients) and oral fluconazole (191 patients) in the treatment of EC. The rate of discontinuation from voriconazole study medication in Study 305 due to adverse reactions was 7% (14/200 patients). Laboratory test abnormalities for these studies are discussed under Clinical Laboratory Values below.

Serious Adverse Reactions and Adverse Reactions Leading to Discontinuation

In clinical studies, serious adverse reactions occurred in 46% (48/105) of VFEND treated pediatric patients. Treatment discontinuations due to adverse reactions occurred in 12 /105 (11%) of all patients. Hepatic adverse reactions (i.e. ALT increased; liver function test abnormal; jaundice) 6% (6/105) accounted for the majority of VFEND treatment discontinuations.

Most Common Adverse Reactions

The most common adverse reactions occurring in ≥5% of pediatric patients receiving VFEND in the pooled pediatric clinical trials are displayed by body system, in Table 8.

The following adverse reactions with incidence less than 5% were reported in 105 pediatric patients treated with VFEND:

Blood and Lymphatic System Disorders: anemia, leukopenia, pancytopenia

Cardiac Disorders: bradycardia, palpitations, supraventricular tachycardia

Eye Disorders: dry eye, keratitis

Ear and Labyrinth Disorders: tinnitus, vertigo

Gastrointestinal Disorders: abdominal tenderness, dyspepsia

General Disorders and Administration Site Conditions: asthenia, catheter site pain, chills, hypothermia, lethargy

Hepatobiliary Disorders: cholestasis, hyperbilirubinemia, jaundice

Immune System Disorders: hypersensitivity, urticaria

Infections and Infestations: conjunctivitis

Laboratory Investigations: AST increased, blood creatinine increased, gamma-glutamyl transferase increased

Metabolism and Nutrition Disorders: hypercalcemia, hypermagnesemia, hyperphosphatemia, hypoglycemia

Musculoskeletal and Connective Tissue Disorders: arthralgia, myalgia

Nervous System Disorders: ataxia, convulsion, dizziness, nystagmus, paresthesia, syncope

Psychiatric Disorders: affect lability, agitation, anxiety, depression, insomnia

Respiratory Disorders: bronchospasm, nasal congestion, respiratory failure, tachypnea

Skin and Subcutaneous Tissue Disorders: alopecia, dermatitis (allergic, contact, and exfoliative), pruritus

Vascular Disorders: flushing, phlebitis

Hepatic-Related Adverse Reactions in Pediatric Patients

The frequency of hepatic-related adverse reactions in pediatric patients exposed to VFEND in therapeutic studies was numerically higher than that of adults (28.6% compared to 24.1%, respectively). The higher frequency of hepatic adverse reactions in the pediatric population was mainly due to an increased frequency of liver enzyme elevations (21.9% in pediatric patients compared to 16.1% in adults), including transaminase elevations (ALT and AST combined) 7.6% in the pediatric patients compared to 5.1% in adults.

Clinical Laboratory Values in Pediatric Patients

The overall incidence of transaminase increases >3× upper limit of normal was 27.2% (28/103) in pediatric and 17.7% (268/1514) in adult patients treated with VFEND in pooled clinical trials. The majority of abnormal liver function tests either resolved on treatment with or without dose adjustment or after VFEND discontinuation.

A higher frequency of clinically significant liver laboratory abnormalities, irrespective of baseline laboratory values (>3× ULN ALT or AST), was consistently observed in the combined therapeutic pediatric population (15.5% AST and 22.5% ALT) when compared to adults (12.9% AST and 11.6% ALT). The incidence of bilirubin elevation was comparable between adult and pediatric patients. The incidence of hepatic abnormalities in pediatric patients is shown in Table 9.

Animal Data

Voriconazole was administered orally to pregnant rats during organogenesis (gestation days 6–17) at 10, 30, and 60 mg/kg/day. Voriconazole was associated with increased incidences of the malformations hydroureter and hydronephrosis at 10 mg/kg/day or greater, approximately 0.3 times the recommended human dose (RMD) based on body surface area comparisons, and cleft palate at 60 mg/kg, approximately 2 times the RMD based on body surface area comparisons. 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 were also observed at doses of 10 mg/kg or greater. There was no evidence of maternal toxicity at any dose.

Voriconazole was administered orally to pregnant rabbits during the period of organogenesis (gestation days 7–19) at 10, 40, and 100 mg/kg/day. Voriconazole was associated with increased post-implantation loss and decreased fetal body weight, in association with maternal toxicity (decreased body weight gain and food consumption) at 100 mg/kg/day (6 times the RMD based on body surface area comparisons). Fetal skeletal variations (increases in the incidence of cervical rib and extra sternebral ossification sites) were observed at 100 mg/kg/day.

In a peri- and postnatal toxicity study in rats, voriconazole was administered orally to female rats from implantation through the end of lactation at 1, 3, and 10 mg/kg/day. Voriconazole prolonged the duration of gestation and labor and produced dystocia with related increases in maternal mortality and decreases in perinatal survival of F1 pups at 10 mg/kg/day, approximately 0.3 times the RMD.

Metabolism

In vitro studies showed that voriconazole is metabolized by the human hepatic cytochrome P450 enzymes, CYP2C19, CYP2C9 and CYP3A4 [see Drug Interactions (7)].

In vivo studies indicated that CYP2C19 is significantly involved in the metabolism of voriconazole. This enzyme exhibits genetic polymorphism [see Clinical Pharmacology (12.5)].

The major metabolite of voriconazole is the N-oxide, which accounts for 72% of the circulating radiolabelled metabolites in plasma. Since this metabolite has minimal antifungal activity, it does not contribute to the overall efficacy of voriconazole.

Excretion

Voriconazole is eliminated via hepatic metabolism with less than 2% of the dose excreted unchanged in the urine. After administration of a single radiolabelled dose of either oral or IV voriconazole, preceded by multiple oral or IV dosing, approximately 80% to 83% of the radioactivity is recovered in the urine. The majority (>94%) of the total radioactivity is excreted in the first 96 hours after both oral and intravenous dosing.

As a result of non-linear pharmacokinetics, the terminal half-life of voriconazole is dose dependent and therefore not useful in predicting the accumulation or elimination of voriconazole.

Male and Female Patients

In a multiple oral dose study, the mean Cmax and AUCτ for healthy young females were 83% and 113% higher, respectively, than in healthy young males (18–45 years), after tablet dosing. In the same study, no significant differences in the mean Cmax and AUCτ were observed between healthy elderly males and healthy elderly females (>65 years). In a similar study, after dosing with the oral suspension, the mean AUC for healthy young females was 45% higher than in healthy young males whereas the mean Cmax was comparable between genders. The steady state trough voriconazole concentrations (Cmin) seen in females were 100% and 91% higher than in males receiving the tablet and the oral suspension, respectively.

In the clinical program, no dosage adjustment was made on the basis of gender. The safety profile and plasma concentrations observed in male and female subjects were similar. Therefore, no dosage adjustment based on gender is necessary.

Geriatric Patients

In an oral multiple dose study the mean Cmax and AUCτ in healthy elderly males (≥65 years) were 61% and 86% higher, respectively, than in young males (18–45 years). No significant differences in the mean Cmax and AUCτ were observed between healthy elderly females (≥65 years) and healthy young females (18–45 years).

In the clinical program, no dosage adjustment was made on the basis of age. An analysis of pharmacokinetic data obtained from 552 patients from 10 voriconazole clinical trials showed that the median voriconazole plasma concentrations in the elderly patients (>65 years) were approximately 80% to 90% higher than those in the younger patients (≤65 years) after either IV or oral administration. However, the safety profile of voriconazole in young and elderly subjects was similar and, therefore, no dosage adjustment is necessary for the elderly [see Use in Special Populations (8.5)].

Pediatric Patients

The recommended doses in pediatric patients were based on a population pharmacokinetic analysis of data obtained from 112 immunocompromised pediatric patients aged 2 to less than 12 years and 26 immunocompromised pediatric patients aged 12 to less than 17 years.

A comparison of the pediatric and adult population pharmacokinetic data indicated that the predicted total exposure (AUC12) in pediatric patients aged 2 to less than 12 years following administration of a 9 mg/kg intravenous loading dose was comparable to that in adults following a 6 mg/kg intravenous loading dose. The predicted total exposures in pediatric patients aged 2 to less than 12 years following intravenous maintenance doses of 4 and 8 mg/kg twice daily were comparable to those in adults following 3 and 4 mg/kg IV twice daily, respectively.

The predicted total exposure in pediatric patients aged 2 to less than 12 years following an oral maintenance dose of 9 mg/kg (maximum of 350 mg) twice daily was comparable to that in adults following 200 mg oral twice daily. An 8 mg/kg intravenous dose will provide voriconazole exposure approximately 2-fold higher than a 9 mg/kg oral dose in pediatric patients aged 2 to less than 12 years.

Voriconazole exposures in the majority of pediatric patients aged 12 to less than 17 years were comparable to those in adults receiving the same dosing regimens. However, lower voriconazole exposure was observed in some pediatric patients aged 12 to less than 17 years with low body weight compared to adults [see Dosage and Administration (2.4)].

Limited voriconazole trough plasma samples were collected in pediatric patients aged 2 to less than 18 years with IA or invasive candidiasis including candidemia, and EC in two prospective, open-label, non-comparative, multicenter clinical studies. In eleven pediatric patients aged 2 to less than 12 years and aged 12 to 14 years, with body weight less than 50 kg, who received 9 mg/kg intravenously every 12 hours as a loading dose on the first day of treatment, followed by 8 mg/kg every 12 hours as an intravenous maintenance dose, or 9 mg/kg every 12 hours as an oral maintenance dose, the mean trough concentration of voriconazole was 3.6 mcg/mL (range 0.3 to 10.7 mcg/mL). In four pediatric patients aged 2 to less than 12 years and aged 12 to 14 years, with body weight less than 50 kg, who received 4 mg/kg intravenously every 12 hours, the mean trough concentration of voriconazole was 0.9 mcg/mL (range 0.3 to 1.6 mcg/mL) [see Clinical Studies (14.5)].

Patients with Hepatic Impairment

After a single oral dose (200 mg) of voriconazole in 8 patients with mild (Child-Pugh Class A) and 4 patients with moderate (Child-Pugh Class B) hepatic impairment, the mean systemic exposure (AUC) was 3.2-fold higher than in age and weight matched controls with normal hepatic function. There was no difference in mean peak plasma concentrations (Cmax) between the groups. When only the patients with mild (Child-Pugh Class A) hepatic impairment were compared to controls, there was still a 2.3-fold increase in the mean AUC in the group with hepatic impairment compared to controls.

In an oral multiple dose study, AUCτ was similar in 6 subjects with moderate hepatic impairment (Child-Pugh Class B) given a lower maintenance dose of 100 mg twice daily compared to 6 subjects with normal hepatic function given the standard 200 mg twice daily maintenance dose. The mean peak plasma concentrations (Cmax) were 20% lower in the hepatically impaired group. No pharmacokinetic data are available for patients with severe hepatic cirrhosis (Child-Pugh Class C) [see Dosage and Administration (2.5)].

Patients with Renal Impairment

In a single oral dose (200 mg) study in 24 subjects with normal renal function and mild to severe renal impairment, systemic exposure (AUC) and peak plasma concentration (Cmax) of voriconazole were not significantly affected by renal impairment. Therefore, no adjustment is necessary for oral dosing in patients with mild to severe renal impairment.

In a multiple dose study of IV voriconazole (6 mg/kg IV loading dose × 2, then 3 mg/kg IV × 5.5 days) in 7 patients with moderate renal dysfunction (creatinine clearance 30–50 mL/min), the systemic exposure (AUC) and peak plasma concentrations (Cmax) were not significantly different from those in 6 subjects with normal renal function.

However, in patients with moderate renal dysfunction (creatinine clearance 30–50 mL/min), accumulation of the intravenous vehicle, SBECD, occurs. The mean systemic exposure (AUC) and peak plasma concentrations (Cmax) of SBECD were increased 4-fold and almost 50%, respectively, in the moderately impaired group compared to the normal control group.

A pharmacokinetic study in subjects with renal failure undergoing hemodialysis showed that voriconazole is dialyzed with clearance of 121 mL/min. The intravenous vehicle, SBECD, is hemodialyzed with clearance of 55 mL/min. A 4-hour hemodialysis session does not remove a sufficient amount of voriconazole to warrant dose adjustment [see Dosage and Administration (2.6)].

Patients at Risk of Aspergillosis

The observed voriconazole pharmacokinetics in patients at risk of aspergillosis (mainly patients with malignant neoplasms of lymphatic or hematopoietic tissue) were similar to healthy subjects.

Effects of Other Drugs on Voriconazole

Voriconazole is metabolized by the human hepatic cytochrome P450 enzymes CYP2C19, CYP2C9, and CYP3A4. Results of in vitro metabolism studies indicate that the affinity of voriconazole is highest for CYP2C19, followed by CYP2C9, and is appreciably lower for CYP3A4. Inhibitors or inducers of these three enzymes may increase or decrease voriconazole systemic exposure (plasma concentrations), respectively.

The systemic exposure to voriconazole is significantly reduced by the concomitant administration of the following agents and their use is contraindicated:

Rifampin (potent CYP450 inducer)–Rifampin (600 mg once daily) decreased the steady state Cmax and AUCτ of voriconazole (200 mg every 12 hours × 7 days) by an average of 93% and 96%, respectively, in healthy subjects. Doubling the dose of voriconazole to 400 mg every 12 hours does not restore adequate exposure to voriconazole during coadministration with rifampin [see Contraindications (4)].

Ritonavir (potent CYP450 inducer; CYP3A4 inhibitor and substrate)–The effect of the coadministration of voriconazole and ritonavir (400 mg and 100 mg) was investigated in two separate studies. High-dose ritonavir (400 mg every 12 hours for 9 days) decreased the steady state Cmax and AUCτ of oral voriconazole (400 mg every 12 hours for 1 day, then 200 mg every 12 hours for 8 days) by an average of 66% and 82%, respectively, in healthy subjects. Low-dose ritonavir (100 mg every 12 hours for 9 days) decreased the steady state Cmax and AUCτ of oral voriconazole (400 mg every 12 hours for 1 day, then 200 mg every 12 hours for 8 days) by an average of 24% and 39%, respectively, in healthy subjects. Although repeat oral administration of voriconazole did not have a significant effect on steady state Cmax and AUCτ of high-dose ritonavir in healthy subjects, steady state Cmax and AUCτ of low-dose ritonavir decreased slightly by 24% and 14% respectively, when administered concomitantly with oral voriconazole in healthy subjects [see Contraindications (4)].

St. John's Wort (CYP450 inducer; P-gp inducer)–In an independent published study in healthy volunteers who were given multiple oral doses of St. John's Wort (300 mg LI 160 extract three times daily for 15 days) followed by a single 400 mg oral dose of voriconazole, a 59% decrease in mean voriconazole AUC0–∞ was observed. In contrast, coadministration of single oral doses of St. John's Wort and voriconazole had no appreciable effect on voriconazole AUC0–∞. Long-term use of St. John's Wort could lead to reduced voriconazole exposure [see Contraindications (4)].

Significant drug interactions that may require voriconazole dosage adjustment, or frequent monitoring of voriconazole-related adverse reactions/toxicity:

Fluconazole (CYP2C9, CYP2C19 and CYP3A4 inhibitor): Concurrent administration of oral voriconazole (400 mg every 12 hours for 1 day, then 200 mg every 12 hours for 2.5 days) and oral fluconazole (400 mg on day 1, then 200 mg every 24 hours for 4 days) to 6 healthy male subjects resulted in an increase in Cmax and AUCτ of voriconazole by an average of 57% (90% CI: 20%, 107%) and 79% (90% CI: 40%, 128%), respectively. In a follow-on clinical study involving 8 healthy male subjects, reduced dosing and/or frequency of voriconazole and fluconazole did not eliminate or diminish this effect [see Drug Interactions (7)].

Letermovir (CYP2C9/2C19 inducer)–Coadministration of oral letermovir with oral voriconazole decreased the steady state Cmax and AUC0–12 of voriconazole by an average of 39% and 44%, respectively [see Drug Interactions (7)].

Minor or no significant pharmacokinetic interactions that do not require dosage adjustment:

Cimetidine (non-specific CYP450 inhibitor and increases gastric pH)–Cimetidine (400 mg every 12 hours × 8 days) increased voriconazole steady state Cmax and AUCτ by an average of 18% (90% CI: 6%, 32%) and 23% (90% CI: 13%, 33%), respectively, following oral doses of 200 mg every 12 hours × 7 days to healthy subjects.

Ranitidine (increases gastric pH)–Ranitidine (150 mg every 12 hours) had no significant effect on voriconazole Cmax and AUCτ following oral doses of 200 mg every 12 hours × 7 days to healthy subjects.

Macrolide antibiotics–Coadministration of erythromycin (CYP3A4 inhibitor; 1 gram every 12 hours for 7 days) or azithromycin (500 mg every 24 hours for 3 days) with voriconazole 200 mg every 12 hours for 14 days had no significant effect on voriconazole steady state Cmax and AUCτ in healthy subjects. The effects of voriconazole on the pharmacokinetics of either erythromycin or azithromycin are not known.

Effects of Voriconazole on Other Drugs

In vitro studies with human hepatic microsomes show that voriconazole inhibits the metabolic activity of the cytochrome P450 enzymes CYP2C19, CYP2C9, and CYP3A4. In these studies, the inhibition potency of voriconazole for CYP3A4 metabolic activity was significantly less than that of two other azoles, ketoconazole and itraconazole. In vitro studies also show that the major metabolite of voriconazole, voriconazole N-oxide, inhibits the metabolic activity of CYP2C9 and CYP3A4 to a greater extent than that of CYP2C19. Therefore, there is potential for voriconazole and its major metabolite to increase the systemic exposure (plasma concentrations) of other drugs metabolized by these CYP450 enzymes.

The systemic exposure of the following drug is significantly increased by coadministration of voriconazole and their use is contraindicated:

Sirolimus (CYP3A4 substrate)–Repeat dose administration of oral voriconazole (400 mg every 12 hours for 1 day, then 200 mg every 12 hours for 8 days) increased the Cmax and AUC of sirolimus (2 mg single dose) an average of 7-fold (90% CI: 5.7, 7.5) and 11-fold (90% CI: 9.9, 12.6), respectively, in healthy male subjects [see Contraindications (4)].

Coadministration of voriconazole with the following agents results in increased exposure to these drugs. Therefore, careful monitoring and/or dosage adjustment of these drugs is needed:

Alfentanil (CYP3A4 substrate)–Coadministration of multiple doses of oral voriconazole (400 mg every 12 hours on day 1, 200 mg every 12 hours on day 2) with a single 20 mcg/kg intravenous dose of alfentanil with concomitant naloxone resulted in a 6-fold increase in mean alfentanil AUC0–∞ and a 4-fold prolongation of mean alfentanil elimination half-life, compared to when alfentanil was given alone [see Drug Interactions (7)].

Fentanyl (CYP3A4 substrate): In an independent published study, concomitant use of voriconazole (400 mg every 12 hours on Day 1, then 200 mg every 12 hours on Day 2) with a single intravenous dose of fentanyl (5 µg/kg) resulted in an increase in the mean AUC0–∞ of fentanyl by 1.4-fold (range 0.81- to 2.04-fold) [see Drug Interactions (7)].

Oxycodone (CYP3A4 substrate): In an independent published study, coadministration of multiple doses of oral voriconazole (400 mg every 12 hours, on Day 1 followed by five doses of 200 mg every 12 hours on Days 2 to 4) with a single 10 mg oral dose of oxycodone on Day 3 resulted in an increase in the mean Cmax and AUC0–∞ of oxycodone by 1.7-fold (range 1.4- to 2.2-fold) and 3.6-fold (range 2.7- to 5.6-fold), respectively. The mean elimination half-life of oxycodone was also increased by 2.0-fold (range 1.4- to 2.5-fold) [see Drug Interactions (7)].

Cyclosporine (CYP3A4 substrate)–In stable renal transplant recipients receiving chronic cyclosporine therapy, concomitant administration of oral voriconazole (200 mg every 12 hours for 8 days) increased cyclosporine Cmax and AUCτ an average of 1.1 times (90% CI: 0.9, 1.41) and 1.7 times (90% CI: 1.5, 2.0), respectively, as compared to when cyclosporine was administered without voriconazole [see Drug Interactions (7)].

Methadone (CYP3A4, CYP2C19, CYP2C9 substrate)–Repeat dose administration of oral voriconazole (400 mg every 12 hours for 1 day, then 200 mg every 12 hours for 4 days) increased the Cmax and AUCτ of pharmacologically active Rmethadone by 31% (90% CI: 22%, 40%) and 47% (90% CI: 38%, 57%), respectively, in subjects receiving a methadone maintenance dose (30–100 mg every 24 hours). The Cmax and AUC of (S)-methadone increased by 65% (90% CI: 53%, 79%) and 103% (90% CI: 85%, 124%), respectively [see Drug Interactions (7)].

Tacrolimus (CYP3A4 substrate)–Repeat oral dose administration of voriconazole (400 mg every 12 hours × 1 day, then 200 mg every 12 hours × 6 days) increased tacrolimus (0.1 mg/kg single dose) Cmax and AUCτ in healthy subjects by an average of 2-fold (90% CI: 1.9, 2.5) and 3-fold (90% CI: 2.7, 3.8), respectively [see Drug Interactions (7)].

Warfarin (CYP2C9 substrate)–Coadministration of voriconazole (300 mg every 12 hours × 12 days) with warfarin (30 mg single dose) significantly increased maximum prothrombin time by approximately 2 times that of placebo in healthy subjects [see Drug Interactions (7)].

Non-Steroidal Anti-Inflammatory Drugs (NSAIDs; CYP2C9 substrates): In two independent published studies, single doses of ibuprofen (400 mg) and diclofenac (50 mg) were coadministered with the last dose of voriconazole (400 mg every 12 hours on Day 1, followed by 200 mg every 12 hours on Day 2). Voriconazole increased the mean Cmax and AUC of the pharmacologically active isomer, S (+)-ibuprofen by 20% and 100%, respectively. Voriconazole increased the mean Cmax and AUC of diclofenac by 114% and 78%, respectively [see Drug Interactions (7)].

No significant pharmacokinetic interactions were observed when voriconazole was coadministered with the following agents. Therefore, no dosage adjustment for these agents is recommended:

Prednisolone (CYP3A4 substrate)–Voriconazole (200 mg every 12 hours × 30 days) increased Cmax and AUC of prednisolone (60 mg single dose) by an average of 11% and 34%, respectively, in healthy subjects [see Warnings and Precautions (5.8)].

Digoxin (P-glycoprotein mediated transport)–Voriconazole (200 mg every 12 hours × 12 days) had no significant effect on steady state Cmax and AUCτ of digoxin (0.25 mg once daily for 10 days) in healthy subjects.

Mycophenolic acid (UDP-glucuronyl transferase substrate)–Voriconazole (200 mg every 12 hours × 5 days) had no significant effect on the Cmax and AUCτ of mycophenolic acid and its major metabolite, mycophenolic acid glucuronide after administration of a 1 gram single oral dose of mycophenolate mofetil.

Two-Way Interactions

Concomitant use of the following agents with voriconazole is contraindicated:

Rifabutin (potent CYP450 inducer)–Rifabutin (300 mg once daily) decreased the Cmax and AUCτ of voriconazole at 200 mg twice daily by an average of 67% (90% CI: 58%, 73%) and 79% (90% CI: 71%, 84%), respectively, in healthy subjects. During coadministration with rifabutin (300 mg once daily), the steady state Cmax and AUCτ of voriconazole following an increased dose of 400 mg twice daily were on average approximately 2 times higher, compared with voriconazole alone at 200 mg twice daily. Coadministration of voriconazole at 400 mg twice daily with rifabutin 300 mg twice daily increased the Cmax and AUCτ of rifabutin by an average of 3-times (90% CI: 2.2, 4.0) and 4 times (90% CI: 3.5, 5.4), respectively, compared to rifabutin given alone [see Contraindications (4)].

Significant drug interactions that may require dosage adjustment, frequent monitoring of drug levels and/or frequent monitoring of drug-related adverse reactions/toxicity:

Efavirenz, a non-nucleoside reverse transcriptase inhibitor (CYP450 inducer; CYP3A4 inhibitor and substrate)–Standard doses of voriconazole and efavirenz (400 mg every 24 hours or higher) must not be coadministered [see Drug Interactions (7)]. Steady state efavirenz (400 mg PO every 24 hours) decreased the steady state Cmax and AUCτ of voriconazole (400 mg PO every 12 hours for 1 day, then 200 mg PO every 12 hours for 8 days) by an average of 61% and 77%, respectively, in healthy male subjects. Voriconazole at steady state (400 mg PO every 12 hours for 1 day, then 200 mg every 12 hours for 8 days) increased the steady state Cmax and AUCτ of efavirenz (400 mg PO every 24 hours for 9 days) by an average of 38% and 44%, respectively, in healthy subjects.

The pharmacokinetics of adjusted doses of voriconazole and efavirenz were studied in healthy male subjects following administration of voriconazole (400 mg PO every 12 hours on Days 2 to 7) with efavirenz (300 mg PO every 24 hours on Days 1–7), relative to steady state administration of voriconazole (400 mg for 1 day, then 200 mg PO every 12 hours for 2 days) or efavirenz (600 mg every 24 hours for 9 days). Coadministration of voriconazole 400 mg every 12 hours with efavirenz 300 mg every 24 hours, decreased voriconazole AUCτ by 7% (90% CI: -23%, 13%) and increased Cmax by 23% (90% CI: -1%, 53%); efavirenz AUCτ was increased by 17% (90% CI: 6%, 29%) and Cmax was equivalent [see Dosage and Administration (2.7), Contraindications (4), and Drug Interactions (7)].

Phenytoin (CYP2C9 substrate and potent CYP450 inducer)–Repeat dose administration of phenytoin (300 mg once daily) decreased the steady state Cmax and AUCτ of orally administered voriconazole (200 mg every 12 hours × 14 days) by an average of 50% and 70%, respectively, in healthy subjects. Administration of a higher voriconazole dose (400 mg every 12 hours × 7 days) with phenytoin (300 mg once daily) resulted in comparable steady state voriconazole Cmax and AUCτ estimates as compared to when voriconazole was given at 200 mg every 12 hours without phenytoin [see Dosage and Administration (2.7) and Drug Interactions (7)].

Repeat dose administration of voriconazole (400 mg every 12 hours × 10 days) increased the steady state Cmax and AUCτ of phenytoin (300 mg once daily) by an average of 70% and 80%, respectively, in healthy subjects. The increase in phenytoin Cmax and AUC when coadministered with voriconazole may be expected to be as high as 2 times the Cmax and AUC estimates when phenytoin is given without voriconazole [see Drug Interactions (7)].

Omeprazole (CYP2C19 inhibitor; CYP2C19 and CYP3A4 substrate)–Coadministration of omeprazole (40 mg once daily × 10 days) with oral voriconazole (400 mg every 12 hours × 1 day, then 200 mg every 12 hours × 9 days) increased the steady state Cmax and AUCτ of voriconazole by an average of 15% (90% CI: 5%, 25%) and 40% (90% CI: 29%, 55%), respectively, in healthy subjects. No dosage adjustment of voriconazole is recommended.

Coadministration of voriconazole (400 mg every 12 hours × 1 day, then 200 mg × 6 days) with omeprazole (40 mg once daily × 7 days) to healthy subjects significantly increased the steady state Cmax and AUCτ of omeprazole an average of 2 times (90% CI: 1.8, 2.6) and 4 times (90% CI: 3.3, 4.4), respectively, as compared to when omeprazole is given without voriconazole [see Drug Interactions (7)].

Oral Contraceptives (CYP3A4 substrate; CYP2C19 inhibitor)–Coadministration of oral voriconazole (400 mg every 12 hours for 1 day, then 200 mg every 12 hours for 3 days) and oral contraceptive (Ortho-Novum1/35® consisting of 35 mcg ethinyl estradiol and 1 mg norethindrone, every 24 hours) to healthy female subjects at steady state increased the Cmax and AUCτ of ethinyl estradiol by an average of 36% (90% CI: 28%, 45%) and 61% (90% CI: 50%, 72%), respectively, and that of norethindrone by 15% (90% CI: 3%, 28%) and 53% (90% CI: 44%, 63%), respectively in healthy subjects. Voriconazole Cmax and AUCτ increased by an average of 14% (90% CI: 3%, 27%) and 46% (90% CI: 32%, 61%), respectively [see Drug Interactions (7)].

No significant pharmacokinetic interaction was seen and no dosage adjustment of these drugs is recommended:

Indinavir (CYP3A4 inhibitor and substrate)–Repeat dose administration of indinavir (800 mg TID for 10 days) had no significant effect on voriconazole Cmax and AUC following repeat dose administration (200 mg every 12 hours for 17 days) in healthy subjects.

Repeat dose administration of voriconazole (200 mg every 12 hours for 7 days) did not have a significant effect on steady state Cmax and AUCτ of indinavir following repeat dose administration (800 mg TID for 7 days) in healthy subjects.