The Pharmacokinetics of Pregabalin in Breast Milk, Plasma, and Urine of Healthy Postpartum Women.

BACKGROUND: Limited data exist on the presence of pregabalin in human breast milk of nursing mothers. OBJECTIVES: This study aimed to determine pregabalin concentrations in breast milk, estimate the infant daily pregabalin dose from nursing mothers, and evaluate pregabalin pharmacokinetic data in lactating women (≥ 12 weeks postpartum). METHODS: In this multiple-dose, open-label, pharmacokinetic study, 4 doses of pregabalin 150 mg were administered orally at 12-hour intervals. Urine, blood, and breast milk samples were collected up to 12, 24, and 48 hours, respectively, following the fourth dose. Pharmacokinetic parameters were estimated using noncompartmental methods. Adverse events were monitored throughout. RESULTS: Ten healthy lactating women (age 24-37 years) received pregabalin. Geometric mean pregabalin Cmaxss and AUCτ values in breast milk were approximately 53% and 76%, respectively, of those for plasma. The mean amount of pregabalin in breast milk recovered in a 24-hour period after the last dose was 574 µg (range, 270-1720 µg), which is approximately 0.2% of the administered daily maternal dose of 300 mg. The estimated average daily infant dose of pregabalin from breast milk was 0.31 mg/kg/day, which would be approximately 7% (23% coefficient of variation) of the body weight normalized maternal dose. Approximately 89% of the dose administered was recovered in urine. Renal clearance averaged 68.2 mL/min. Adverse events were of mild or moderate severity. CONCLUSION: Lactation appears to have had little influence on pregabalin pharmacokinetics. Overall, the estimated dose of pregabalin in breastfed children of women receiving pregabalin is low. Pregabalin was well tolerated in lactating women. DECLARATION OF CONFLICTING INTERESTS: The authors declared the following potential conflicts of interest with respect to the research, authorship, and/or publication of this article: Peter A. Lockwood, Lynne Pauer, Joseph M. Scavone, Maud Allard, Laure Mendes da Costa, Tanja Alebic-Kolbah, Anna Plotka, Christine W. Alvey, and Marci L. Chew were all full-time employees of Pfizer at the time the study was completed and hold stock and/or stock options in Pfizer. FUNDING: The authors disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: This study was sponsored by Pfizer, which was involved in the study design, the collection, analysis, and interpretation of the data, the writing of the report, and the decision to submit the paper for publication. Medical writing support was provided by Penny Gorringe, MSc, of Engage Scientific Solutions and funded by Pfizer.

Effect of the gastrointestinal prokinetic agent erythromycin on the pharmacokinetics of pregabalin controlled-release in healthy individuals: a phase I, randomized crossover trial.

BACKGROUND AND OBJECTIVES: The controlled-release (CR) formulation of pregabalin is designed to remain in the stomach for a prolonged period while slowly releasing pregabalin for absorption in the small intestine. This study evaluated the effect of the gastrointestinal prokinetic agent, erythromycin, on the pharmacokinetics of a single dose of pregabalin CR 330 mg administered following an evening meal and the safety and tolerability of a single dose of pregabalin CR 330 mg when administered with and without multiple doses of erythromycin 500 mg. METHODS: This was a phase I, open-label, randomized, two-period, two-treatment crossover study. Participants received (in a randomized sequence) a single oral dose of pregabalin CR 330 mg alone and pregabalin CR 330 mg co-administered with multiple doses of erythromycin 500 mg. The CR formulation was administered immediately following a standardized 600-750 calorie 30 % fat evening meal. Erythromycin 500 mg was administered orally approximately 1 h prior to pregabalin CR, as well as 6 and 12 h following the first erythromycin dose. Blood samples were collected up to 48 h post-pregabalin CR dose. Pharmacokinetic parameters were estimated from concentration-time data using standard noncompartmental methods. Adverse events were monitored throughout. RESULTS: Eighteen healthy participants (aged 19-52 years) received pregabalin CR. Co-administration of pregabalin CR with erythromycin resulted in a 17 % decrease in total exposure [area under the plasma concentration-time curve from zero to infinity (AUC∞)] and a 13 % decrease in peak plasma concentrations (C max) relative to pregabalin CR administered alone. The 90 % CI for the ratio of the adjusted geometric mean AUC∞ was 76.5-89.2 % (outside the 80-125 % range prespecified for bioequivalence). Adverse events were of mild to moderate severity and the adverse event profile was similar for pregabalin CR administered with and without erythromycin. CONCLUSION: Co-administration of multiple high doses of erythromycin resulted in 17 % lower pregabalin exposure for a single dose of pregabalin CR 330 mg than for pregabalin CR 330 mg administered alone. Although the two treatments did not achieve formal bioequivalence, the impact of co-administered erythromycin treatment was small and not considered clinically relevant.

Pharmacokinetics of pregabalin controlled-release in healthy volunteers: effect of food in five single-dose, randomized, clinical pharmacology studies.

BACKGROUND: The pharmacokinetic properties of the immediate-release (IR) and the recently developed controlled-release (CR) formulation of pregabalin are dose proportional. Pregabalin IR can be taken with or without food. OBJECTIVES: This analysis characterizes the effect of food on pregabalin CR. The objectives of this analysis were: (1) to evaluate the effect of administration time and fat or caloric content of an accompanying meal on the pharmacokinetic properties of a single dose of pregabalin CR (330 mg) relative to a single dose of pregabalin IR (300 mg); (2) to evaluate the pharmacokinetic properties of a single dose of pregabalin CR administered fasted relative to a single dose of pregabalin CR administered immediately after food; and (3) to determine the safety and tolerability of single-dose administration of pregabalin CR and IR with and without food. METHODS: The effect of food on the pharmacokinetic properties of pregabalin CR was determined in five phase I, open-label, single-dose, crossover studies (24-28 participants/study). Caloric and fat content of meals were varied and treatments were administered in the morning, at midday, or in the evening. Blood samples were collected up to 48 h post-dose. Pharmacokinetic parameters were estimated from plasma concentration-time data using standard noncompartmental methods. Adverse events were monitored throughout all studies. RESULTS: One hundred and twenty-eight healthy participants (19-54 years of age) received pregabalin. Peak plasma concentrations (C max) were lower for CR than the respective pregabalin IR doses, and time to C max occurred later. When pregabalin CR was administered with food at midday or in the evening, total exposures [area under the plasma concentration-time curve from time zero extrapolated to infinite time (AUC∞)] were equivalent for pregabalin CR and IR formulations regardless of fat or caloric content. When pregabalin CR was administered with an 800-1,000 calorie medium-fat breakfast, AUC∞ was equivalent for pregabalin CR and IR. Bioequivalence criteria for comparison of pregabalin CR after a low- or medium-calorie breakfast relative to pregabalin IR were not met; however, bioavailability of the pregabalin CR vs. IR formulation was relatively high (75-86 %). When pregabalin CR was administered fasted, the AUC∞ was 70-78 % of the AUC∞ of pregabalin CR administered with food and bioequivalence criteria were not met. Additionally, the AUC∞ of the pregabalin CR formulation administered fasted was 62-69 % of that of pregabalin IR administered fasted and bioequivalence criteria were not met. Single-dose pregabalin CR and IR were well tolerated in all studies, with no serious or severe adverse events reported. CONCLUSION: Time of day of administration and the fat and caloric content of the accompanying meal had minimal overall effect on the pharmacokinetic properties and bioavailability of the pregabalin CR formulation.

Pregabalin controlled-release pharmacokinetics in healthy volunteers: analysis of four multiple-dose randomized clinical pharmacology studies.

BACKGROUND: Pregabalin (Lyrica(®)) is approved as an immediate-release (IR) formulation for administration twice (BID) or three times (TID) a day depending on indication. Once daily (QD) dosing may be appropriate for ease of clinical use and patient convenience. OBJECTIVES: The objectives of this analysis were: (1) to evaluate the pharmacokinetics of pregabalin controlled-release (CR) administered with food relative to the pregabalin IR formulation administered fasted; (2) to evaluate the pharmacokinetics of a two-tablet dose of pregabalin CR compared with the equivalent one-tablet dose of pregabalin CR; and (3) to determine the safety and tolerability of multiple-dose administration of pregabalin CR and IR. METHODS: The pharmacokinetic properties of pregabalin CR were determined in four phase I, open-label, multiple-dose crossover studies (18-24 participants/study). Pregabalin CR (82.5, 165, 330 or 660 mg/day) administered QD was compared with pregabalin IR (75, 150, 300 or 600 mg/day, respectively) administered either BID or TID. Blood samples were collected up to 24 h post-dose. Pharmacokinetic parameters were estimated from plasma concentration-time data using standard noncompartmental methods. Adverse events were monitored throughout all studies. RESULTS: Eight-four healthy participants (19-55 years of age) received pregabalin. For all pregabalin CR doses, total exposure was equivalent to the corresponding pregabalin IR dose. Relative bioavailability of pregabalin CR was 93-97 % of pregabalin IR, and bioequivalence criteria with respect to the 24-h steady-state exposure (area under the plasma concentration-time curve from 0 to 24 h [AUC24]) were met. Administration of a two-tablet dose of pregabalin CR was bioequivalent to one-tablet pregabalin CR. The relative bioavailability of two-tablet pregabalin CR was 97-102 % of one-tablet pregabalin CR, and bioequivalence criteria with respect to AUC24 and peak plasma concentrations were met. Pregabalin CR pharmacokinetic parameters were dose proportional following administration of 82.5-660 mg/day pregabalin CR. Pregabalin was well tolerated across studies, with no serious or severe adverse events. CONCLUSION: Total daily exposure with multiple-dose pregabalin CR is equivalent to the corresponding pregabalin IR dose.

Anidulafungin--challenges in development and validation of an LC-MS/MS bioanalytical method validated for regulated clinical studies.

Anidulafungin is a semi-synthetic echinocandin with antifungal activity, usually administered as an intravenous infusion. In order to determine the pharmacokinetics (PK) of anidulafungin in pediatric patients, a sensitive high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) bioanalytical method (M1) was developed and validated for quantification of anidulafungin in plasma. During analysis of incurred samples (samples collected from patients enrolled in a clinical study) an isobaric chromatographic interference was observed. The source of interference was identified as an anidulafungin open-ring form (D1) and its impact on the quantification of anidulafungin was investigated. It was found that accurately quantifying anidulafungin in incurred samples required chromatographic separation of the open-ring form from anidulafungin. The method was redeveloped to achieve the appropriate baseline separation and to avoid experimental conditions that favored opening the anidulafungin ring. The extraction of anidulafungin from plasma by protein precipitation remained unchanged, but the changes in chromatography warranted validation of a new method, M2, 2 years after M1 was validated. Incurred samples from three studies that were previously analyzed by M1 and were within confirmed long-term frozen stability were then reanalyzed by M2. Although the incurred sample reproducibility tests on those samples passed for each of the two methods, comparison of concentrations from the same samples obtained by M1 and M2 revealed that an overestimation of anidulafungin following the M1 method exceeded acceptance criteria. The new HPLC-MS/MS method (M2) is applicable for quantification of anidulafungin within a nominal range 50-20,000 ng/mL and requires a 50 µL human plasma aliquot. A linear, 1/concentration squared weighted, least-squares regression algorithm was used to generate the calibration curve and its parameters were used to quantitate the incurred samples. The inter-assay accuracy in heparin human plasma validation ranged from -4.33 to 0.0386 % and precision was ≤7.32 %. The method M2 was validated for use in regulated bioanalysis and is presently used to quantitate anidulafungin in plasma samples from clinical studies.

Dalbavancin: Quantification in human plasma and urine by a new improved high performance liquid chromatography-tandem mass spectrometry method.

Dalbavancin is a novel second-generation lipoglycopeptide antibiotic with activity against broad range of Gram-positive pathogens. In order to determine the pharmacokinetics (PK) of dalbavancin in pediatric patients, a new High Performance Liquid Chromatography-Tandem Mass Spectrometry (HPLC-MS/MS) bioanalytical method has been developed for quantification of dalbavancin in plasma and in urine. The plasma method was validated for dalbavancin in the linear range from 0.5 µg/mL to 500 µg/mL using 50 µL of K(2) EDTA plasma. For dalbavancin spiked in urine, non-specific binding (NSB) of the drug to polypropylene (PP) urine collection containers was observed. The loss amounted to about 10% per transfer. After successfully establishing the collection/sampling procedure for urine by addition of Triton X-100 to the collection vessels (with a purpose of preventing NSB), the method was validated for dalbavancin in the range from 0.05 µg/mL to 50 µg/mL, using 100 µL of urine. These methods were used to quantify dalbavancin in plasma and urine of hospitalized children in a pediatric dalbavancin PK study. Eighteen percent of the total number of plasma study samples was reassayed for incurred samples reproducibility (ISR) and all the reassayed dalbavancin concentrations were within the ± 20% limits. For urine, all the collected samples were reassayed for ISR and the original dalbavancin concentration was confirmed within the ± 20% limits for 17 (94%) samples; the one remaining urine sample had its reassayed concentration confirmed within ± 25% of the original result.