General Pharmacokinetic Characteristics
Posaconazole delayed-release tablets exhibit dose proportional pharmacokinetics after single and multiple dosing up to 300 mg. The mean pharmacokinetic parameters of posaconazole at steady state following administration of posaconazole delayed-release tablets 300 mg twice daily (BID) on Day 1, then 300 mg once daily (QD) thereafter in healthy volunteers and in neutropenic patients who are receiving cytotoxic chemotherapy for AML or MDS or HSCT recipients with GVHD are shown in Table 15.
Table 15: Arithmetic Mean (%CV) of Steady State PK Parameters in Healthy Volunteers and Patients Following Administration of Posaconazole Delayed-Release Tablets (300 mg)300 mg BID on Day 1, then 300 mg QD thereafter
| CV = coefficient of variation expressed as a percentage (%CV); AUC0-T = Area under the plasma concentration-time curve from time zero to 24 hr; Cmax = maximum observed concentration; Cmin = minimum observed plasma concentration; Tmax = time of maximum observed concentration; t½ = terminal phase half-life; CL /F = Apparent total body clearance |
| N
| AUC 0-24 hr (ng·hr/mL)
| Cav Cav = time-averaged concentrations (i.e., AUC0-24 hr/24hr) (ng/mL)
| C max (ng/mL)
| C min (ng/mL)
| Median (minimum-maximum) T max(hr)
| t 1/2 (hr)
| CL/F (L/hr)
|
Healthy Volunteers
| 12
| 51618 (25)
| 2151 (25)
| 2764 (21)
| 1785 (29)
| 4 (3-6)
| 31 (40)
| 7.5 (26)
|
Patients
| 50
| 37900 (42)
| 1580 (42)
| 2090 (38)
| 1310 (50)
| 4 (1.3-8.3)
| -
| 9.39 (45)
|
Absorption:
When given orally in healthy volunteers, posaconazole delayed-release tablets are absorbed with a median Tmax of 4 to 5 hours. Steady-state plasma concentrations are attained by Day 6 at the 300 mg dose (QD after BID loading dose at Day 1). The absolute bioavailability of the oral delayed-release tablet is approximately 54% under fasted conditions. The Cmax and AUC of posaconazole following administration of posaconazole delayed-release tablets is increased 16% and 51%, respectively, when given with a high fat meal compared to a fasted state (see Table 17). In order to enhance the oral absorption of posaconazole and optimize plasma concentrations, posaconazole delayed-release tablets should be administered with food.
Table 17: Statistical Comparison of Plasma Pharmacokinetics of Posaconazole Following Single Oral Dose Administration of 300 mg Posaconazole Delayed-Release Tablet to Healthy Subjects under Fasting and Fed Conditions | GMR=Geometric least-squares mean ratio; CI=Confidence interval |
| Fasting Conditions
| Fed Conditions (High Fat Meal) 48.5 g fat
| Fed/Fasting
|
Pharmacokinetic Parameter
| N
| Mean (%CV)
| N
| Mean (%CV)
| GMR (90% CI)
|
Cmax (ng/mL)
| 14
| 935 (34)
| 16
| 1060 (25)
| 1.16 (0.96, 1.41)
|
AUC0-72hr (hr∙ng/mL)
| 14
| 26200 (28)
| 16
| 38400 (18)
| 1.51 (1.33, 1.72)
|
Tmax Median (Min, Max) reported for Tmax (hr)
| 14
| 5.00 (3.00, 8.00)
| 16
| 6.00 (5.00, 24.00)
| N/A
|
Concomitant administration of posaconazole delayed-release tablets with drugs affecting gastric pH or gastric motility did not demonstrate any significant effects on posaconazole pharmacokinetic exposure (see Table 18).
Table 18: The Effect of Concomitant Medications that Affect the Gastric pH and Gastric Motility on the Pharmacokinetics of Posaconazole Delayed-Release Tablets in Healthy Volunteers Coadministered Drug
| Administration Arms
| Change in Cmax (ratio estimate*; 90% CI of the ratio estimate)
| Change in AUC0-last (ratio estimate Ratio Estimate is the ratio of coadministered drug plus posaconazole to posaconazole alone for Cmax or AUC0-last. ; 90% CI of the ratio estimate)
|
Mylanta® Ultimate strength liquid (Increase in gastric pH)
| 25.4 meq/5 mL, 20 mL
| ↑6% (1.06; 0.90 -1.26)↑
| ↑4% (1.04; 0.90 -1.20)
|
Ranitidine (Zantac®) (Alteration in gastric pH)
| 150 mg (morning dose of 150 mg Ranitidine BID)
| ↑4% (1.04; 0.88 -1.23)↑
| ↓3% (0.97; 0.84 -1.12)
|
Esomeprazole (Nexium®) (Increase in gastric pH)
| 40 mg (QAM 5 days, day -4 to 1)
| ↑2% (1.02; 0.88-1.17)↑
| ↑5% (1.05; 0.89 -1.24)
|
Metoclopramide (Reglan®) (Increase in gastric motility)
| 15 mg four times daily during 2 days (Day -1 and 1)
| ↓14% (0.86, 0.73,1.02)
| ↓7% (0.93, 0.803,1.07)
|
Distribution:
The mean volume of distribution of posaconazole after intravenous solution administration was 261 L and ranged from 226-295 L between studies and dose levels.
Posaconazole is highly bound to human plasma proteins (>98%), predominantly to albumin.
Metabolism:
Posaconazole primarily circulates as the parent compound in plasma. Of the circulating metabolites, the majority are glucuronide conjugates formed via UDP glucuronidation (phase 2 enzymes). Posaconazole does not have any major circulating oxidative (CYP450 mediated) metabolites. The excreted metabolites in urine and feces account for ~17% of the administered radiolabeled dose.
Posaconazole is primarily metabolized via UDP glucuronidation (phase 2 enzymes) and is a substrate for p-glycoprotein (P-gp) efflux. Therefore, inhibitors or inducers of these clearance pathways may affect posaconazole plasma concentrations. A summary of drugs studied clinically with the oral suspension or an early tablet formulation, which affect posaconazole concentrations, is provided in Table 22.
Table 22: Summary of the Effect of Coadministered Drugs on Posaconazole in Healthy Volunteers Coadministered Drug (Postulated Mechanism of Interaction)
| Coadministered Drug Dose/Schedule
| Posaconazole Dose/Schedule
| Effect on Bioavailability of Posaconazole
|
Change in Mean Cmax (ratio estimate Ratio Estimate is the ratio of coadministered drug plus posaconazole to posaconazole alone for Cmax or AUC. ; 90% CI of the ratio estimate)
| Change in Mean AUC (ratio estimate; 90% CI of the ratio estimate)
|
Efavirenz (UDP-G Induction)
| 400 mg QD × 10 and 20 days
| 400 mg (oral suspension) BID × 10 and 20 days
| ↓45% (0.55; 0.47-0.66)
| ↓ 50% (0.50; 0.43-0.60)
|
Fosamprenavir (unknown mechanism)
| 700 mg BID x 10 days
| 200 mg QD on the 1st day, 200 mg BID on the 2nd day, then 400 mg BID x 8 Days
| ↓21% 0.79 (0.71-0.89)
| ↓23% 0.77 (0.68-0.87)
|
Rifabutin (UDP-G Induction)
| 300 mg QD x 17 days
| 200 mg (tablets) QD × 10 days The tablet refers to a non-commercial tablet formulation without polymer.
| ↓ 43% (0.57; 0.43-0.75)
| ↓ 49% (0.51; 0.37-0.71)
|
Phenytoin (UDP-G Induction)
| 200 mg QD x 10 days
| 200 mg (tablets) QD × 10 days
| ↓ 41% (0.59; 0.44-0.79)
| ↓ 50% (0.50; 0.36-0.71)
|
In vitro studies with human hepatic microsomes and clinical studies indicate that posaconazole is an inhibitor primarily of CYP3A4. A clinical study in healthy volunteers also indicates that posaconazole is a strong CYP3A4 inhibitor as evidenced by a >5-fold increase in midazolam AUC. Therefore, plasma concentrations of drugs predominantly metabolized by CYP3A4 may be increased by posaconazole. A summary of the drugs studied clinically, for which plasma concentrations were affected by posaconazole, is provided in Table 23 [see Contraindications (4) and Drug Interactions (7.1) including recommendations].
Table 23: Summary of the Effect of Posaconazole on Coadministered Drugs in Healthy Volunteers and Patients Coadministered Drug (Postulated Mechanism of Interaction is Inhibition of CYP3A4 by posaconazole)
| Coadministered Drug Dose/Schedule
| Posaconazole Dose/ Schedule
| Effect on Bioavailability of Coadministered Drugs
|
Change in Mean Cmax (ratio estimate Ratio Estimate is the ratio of coadministered drug plus posaconazole to coadministered drug alone for Cmax or AUC. ; 90% CI of the ratio estimate)
| Change in Mean AUC (ratio estimate; 90% CI of the ratio estimate)
|
Sirolimus
| 2-mg single oral dose
| 400 mg (oral suspension) BID x 16 days
| ↑ 572% (6.72; 5.62-8.03)
| ↑ 788% (8.88; 7.26-10.9)
|
Cyclosporine
| Stable maintenance dose in heart transplant recipients
| 200 mg (tablets) QD x 10 days The tablet refers to a non-commercial tablet formulation without polymer.
| ↑ cyclosporine whole blood trough concentrations Cyclosporine dose reductions of up to 29% were required
|
Tacrolimus
| 0.05-mg/kg single oral dose
| 400 mg (oral suspension) BID × 7 days
| ↑ 121% (2.21; 2.01-2.42)
| ↑ 358% (4.58; 4.03-5.19)
|
Simvastatin
| 40-mg single oral dose
| 100 mg (oral suspension) QD x 13 days
| Simvastatin ↑ 841% (9.41, 7.13-12.44) Simvastatin Acid ↑ 817% (9.17, 7.36-11.43)
| Simvastatin ↑ 931% (10.31, 8.40-12.67) Simvastatin Acid ↑ 634% (7.34, 5.82-9.25)
|
200 mg (oral suspension) QD x 13 days
| Simvastatin ↑ 1041% (11.41, 7.99-16.29) Simvastatin Acid ↑ 851% (9.51, 8.15-11.10)
| Simvastatin ↑ 960% (10.60, 8.63-13.02) Simvastatin Acid ↑748% (8.48, 7.04-10.23)
|
Midazolam
| 0.4-mg single intravenous dose The mean terminal half-life of midazolam was increased from 3 hours to 7 to 11 hours during coadministration with posaconazole.
| 200 mg (oral suspension) BID x 7 days
| ↑ 30% (1.3; 1.13-1.48)
| ↑ 362% (4.62; 4.02-5.3)
|
0.4-mg single intravenous dose
| 400 mg (oral suspension) BID x 7 days
| ↑62 (1.62; 1.41-1.86)
| ↑524% (6.24; 5.43-7.16)
|
2-mg single oral dose
| 200 mg (oral suspension) QD x 7 days
| ↑ 169% (2.69; 2.46-2.93)
| ↑ 470% (5.70; 4.82-6.74)
|
2-mg single oral dose
| 400 mg (oral suspension) BID x 7 days
| ↑ 138% (2.38; 2.13-2.66)
| ↑ 397% (4.97; 4.46-5.54)
|
Rifabutin
| 300 mg QD x 17 days
| 200 mg (tablets) QD × 10 days
| ↑ 31% (1.31; 1.10-1.57)
| ↑ 72% (1.72;1.51-1.95)
|
Phenytoin
| 200 mg QD PO x 10 days
| 200 mg (tablets) QD x 10 days
| ↑ 16% (1.16; 0.85-1.57)
| ↑ 16% (1.16; 0.84-1.59)
|
Ritonavir
| 100 mg QD x 14 days
| 400 mg (oral suspension) BID x 7 days
| ↑ 49% (1.49; 1.04-2.15)
| ↑ 80% (1.8;1.39-2.31)
|
Atazanavir Atazanavir/ ritonavir boosted regimen
| 300 mg QD x 14 days
| 400 mg (oral suspension) BID x 7 days
| ↑ 155% (2.55; 1.89-3.45)
| ↑ 268% (3.68; 2.89-4.70)
|
300 mg/100 mg QD x 14 days
| 400 mg (oral suspension) BID x 7 days
| ↑ 53% (1.53; 1.13-2.07)
| ↑ 146% (2.46; 1.93-3.13)
|
Additional clinical studies demonstrated that no clinically significant effects on zidovudine, lamivudine, indinavir, or caffeine were observed when administered with posaconazole 200 mg QD; therefore, no dose adjustments are required for these coadministered drugs when coadministered with posaconazole 200 mg QD.
Excretion:
Following administration of posaconazole oral suspension, posaconazole is predominantly eliminated in the feces (71% of the radiolabeled dose up to 120 hours) with the major component eliminated as parent drug (66% of the radiolabeled dose). Renal clearance is a minor elimination pathway, with 13% of the radiolabeled dose excreted in urine up to 120 hours (<0.2% of the radiolabeled dose is parent drug).
Posaconazole delayed-release tablets are eliminated with a mean half-life (t½) ranging between 26 to 31 hours.