Effects of varying degrees of renal impairment on the pharmacokinetics of duloxetine: analysis of a single-dose phase I study and pooled steady-state data from phase II/III trials.
ABSTRACT Duloxetine is indicated for patients with a variety of conditions, and some of these patients may have mild to moderate degrees of renal impairment. Renal impairment may affect the pharmacokinetics of a drug by causing changes in absorption, distribution, protein binding, renal excretion or nonrenal clearance. As duloxetine is highly bound to plasma proteins and its metabolites are renally excreted, it is prudent to evaluate the effect of renal insufficiency on exposure to duloxetine and its metabolites in the systemic circulation.
The aim of this study was to evaluate the effects of varying degrees of renal impairment on duloxetine pharmacokinetics in a single-dose phase I study and using pooled steady-state pharmacokinetic data from phase II/III trials.
In the phase I study, a single oral dose of duloxetine 60 mg was given to 12 subjects with end-stage renal disease (ESRD) and 12 matched healthy control subjects. In the phase II/III trials (n = 463 patients), duloxetine 20-60 mg was given as once- or twice-daily doses. Duloxetine and metabolite concentrations in plasma were determined using liquid chromatography with tandem mass spectrometry. Noncompartmental methods (phase I: duloxetine and its metabolites) and population modelling methods (phase II/III: duloxetine) were used to analyse the pharmacokinetic data.
The maximum plasma concentration (C(max)) and the area under the plasma concentration-time curve (AUC) of duloxetine were approximately 2-fold higher in subjects with ESRD than in healthy subjects, which appeared to reflect an increase in oral bioavailability. The C(max) and AUC of two major inactive conjugated metabolites were as much as 2- and 9-fold higher, respectively, reflecting reduced renal clearance of these metabolites. Population pharmacokinetic results indicated that mild or moderate renal impairment, assessed by creatinine clearance (CL(CR)) calculated according to the Cockcroft-Gault formula, did not have a statistically significant effect on pharmacokinetic parameters of duloxetine. Values for the apparent total body clearance of duloxetine from plasma after oral administration (CL/F) in subjects with ESRD were similar to CL/F values in patients with normal renal function or with mild or moderate renal impairment.
Dose adjustments for duloxetine are not necessary for patients with mild or moderate renal impairment (CL(CR) > or =30 mL/min). For patients with ESRD or severe renal impairment (CL(CR) <30 mL/min), exposures of duloxetine and its metabolites are expected to increase; therefore, duloxetine is not generally recommended for these patients.
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ABSTRACT: The pharmacokinetics and safety of duloxetine were evaluated in a single-blind, placebo-controlled, escalating multiple-dose study in 12 healthy male subjects. In the treatment group (n = 8), duloxetine was administered orally at a starting dose of 20 mg twice daily (bid) and escalated at weekly intervals to 30 mg bid, then to 40 mg bid. The observed plasma concentration-time data at all three dose levels were adequately described by a one-compartment model with a first-order absorption rate constant. The mean oral clearance, apparent volume of distribution, and half-life values were 114 L/h (range: 44 to 218 L/h), 1943 L (range: 803 to 3531 L), and 12.5 h (range: 9.2 to 19.1 h), respectively. Somnolence, nausea, and dry mouth were observed following the initial dose, but they resolved with continuing drug administration. Duloxetine was not associated with clinically significant changes in blood pressure (BP) or heart rate (HR) measured in the standing position. However, in recumbent position, small increases in systolic (< or = 9 mmHg) and diastolic (< or = 5 mmHg) BP and small decreases in HR (< or = 6 beats/min) were observed. Abrupt discontinuation of duloxetine was associated with a small increase in mean HR (< or = 12 beats/min). In 3 subjects, abrupt discontinuation was also associated with transient sleep disturbance. No clinically important changes in electrocardiograms, cardiac intervals, clinical laboratory tests, and neurological functions were observed. These results indicate that duloxetine exhibits linear pharmacokinetics with respect to dose and duration of treatment and that a multiple oral dose regimen starting at 20 mg bid and gradually escalating up to 40 mg bid was generally well tolerated.The Journal of Clinical Pharmacology 02/2000; 40(2):161-7. · 2.84 Impact Factor
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ABSTRACT: Several putative phase I duloxetine metabolites, 4-hydroxy-, 5-hydroxy-, 6-hydroxy-, 5-hydroxy-6-methoxy-, 6-hydroxy-5-methoxy-, 5,6-dihydroxy-, and 4,6-dihydroxyduloxetine were synthesized, and their phase II metabolite as glucuronide or sulfate conjugates were also synthesized. Their in vitro binding activities were compared to that of parent compound duloxetine.Bioorganic & Medicinal Chemistry Letters 08/2004; 14(13):3481-6. · 2.34 Impact Factor
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ABSTRACT: Duloxetine, a potent dual reuptake inhibitor of serotonin and norepinephrine currently undergoing clinical investigation for treatment of depression and stress urinary incontinence, has the potential to act as both a substrate and an inhibitor of cytochrome P4502D6 (CYP2D6). Our objectives were to determine the effect of duloxetine on the pharmacokinetics of desipramine, a tricyclic antidepressant metabolized by CYP2D6 (study 1), and the effect of paroxetine, a potent CYP2D6 inhibitor, on duloxetine pharmacokinetics (study 2). Subjects were healthy men and women between 21 and 63 years old. All subjects were genotypically CYP2D6 extensive metabolizers. In study 1, 50 mg of desipramine was administered as a single dose alone and in the presence of steady-state duloxetine 60 mg twice daily. In study 2, steady-state pharmacokinetics of duloxetine 40 mg once daily were determined in the presence and absence of steady-state paroxetine 20 mg once daily. Duloxetine increased the maximum plasma concentration of desipramine 1.7-fold and the area under the concentration-time curve 2.9-fold. Paroxetine increased the maximum plasma concentration of duloxetine and the area under the concentration-time curve at steady state 1.6-fold. Reports of adverse events were similar whether duloxetine was administered alone or in combination with desipramine or paroxetine. Duloxetine 60 mg twice daily is a moderately potent CYP2D6 inhibitor, intermediate between paroxetine and sertraline. The potent CYP2D6 inhibitor paroxetine has a moderate effect on duloxetine concentrations. The results of these 2 studies suggest that caution should be used when CYP2D6 substrates and inhibitors are coadministered with duloxetine.Clinical Pharmacology & Therapeutics 04/2003; 73(3):170-7. · 6.85 Impact Factor