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Hancu G, Modroiu A. Chiral Switch: Between Therapeutical Benefit and Marketing Strategy. Pharmaceuticals (Basel) 2022; 15:ph15020240. [PMID: 35215352 PMCID: PMC8877306 DOI: 10.3390/ph15020240] [Citation(s) in RCA: 33] [Impact Index Per Article: 16.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2022] [Revised: 02/13/2022] [Accepted: 02/16/2022] [Indexed: 11/16/2022] Open
Abstract
Chirality of pharmaceutical substances is an important aspect in drug research because it determines how enantiomers will interact with chiral biological targets. Enantiomers of a chiral drug can have different pharmacokinetic and pharmacological profiles; consequently, using a single pure enantiomer instead of a racemate can enhance the effectiveness and/or safety of the treatment. The tendencies of modern pharmaceutical industry regarding the current market of chiral drugs are divided between the chiral switch of previously used racemates and the development of new enantiopure drugs. The term chiral switch refers to the replacement on the market of a previously approved racemate with its single enantiomer version. The potential advantages of chiral switch can be related to a higher therapeutic index due to better potency, selectivity and fewer adverse effects, faster onset of action and exposure of the patient to lower drug dosages. However, chiral switch is also a strategy that permits manufacturers to keep market exclusivity for chiral pharmaceuticals that have lost their patent protection, even if the pure enantiomers have not demonstrated higher effectiveness or safety profile compared with the racemates.
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Clark SM, Dunn HE, Hankins GDV. A review of oral labetalol and nifedipine in mild to moderate hypertension in pregnancy. Semin Perinatol 2015; 39:548-55. [PMID: 26344738 DOI: 10.1053/j.semperi.2015.08.011] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Hypertension is the most commonly encountered medical condition in pregnancy, contributing significantly to maternal and perinatal morbidity and mortality. Mild to moderate hypertension in pregnancy is defined as systolic blood pressure of 140-159 mmHg or diastolic blood pressure of 90-109 mmHg (7-9% of pregnancies). When treating hypertension in pregnancy, not only do physiologic changes of pregnancy have an effect on the pharmacokinetics and pharmacodynamics of the drugs used, but the pathophysiology of hypertensive disorders of pregnancy also have an effect. To date, evidence is lacking on the pharmacokinetics and pharmacodynamics of commonly used antihypertensive drugs, which often times leads to suboptimal treatment of hypertensive pregnant women. When considering which agents to use for treatment of mild to moderate hypertension, specifically in gestational and chronic hypertension, oral labetalol and nifedipine are valid options. An overview of the profile for use, safety, and current pharmacokinetic data for each agent is presented here.
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Affiliation(s)
- Shannon M Clark
- Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, The University of Texas Medical Branch-Galveston, 301 University Blvd., Route 0587, Galveston, TX 77550.
| | - Holly E Dunn
- Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, The University of Texas Medical Branch-Galveston, 301 University Blvd., Route 0587, Galveston, TX 77550
| | - Gary D V Hankins
- Department of Obstetrics and Gynecology, Division of Maternal-Fetal Medicine, The University of Texas Medical Branch-Galveston, 301 University Blvd., Route 0587, Galveston, TX 77550
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Fischer JH, Sarto GE, Hardman J, Endres L, Jenkins TM, Kilpatrick SJ, Jeong H, Geller S, Deyo K, Fischer PA, Rodvold KA. Influence of gestational age and body weight on the pharmacokinetics of labetalol in pregnancy. Clin Pharmacokinet 2014; 53:373-83. [PMID: 24297680 PMCID: PMC4310214 DOI: 10.1007/s40262-013-0123-0] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/26/2022]
Abstract
BACKGROUND AND OBJECTIVES Labetalol is frequently prescribed for the treatment of hypertension during pregnancy; however, the influence of pregnancy on labetalol pharmacokinetics is uncertain, with inconsistent findings reported by previous studies. This study examined the population pharmacokinetics of oral labetalol during and after pregnancy in women receiving labetalol for hypertension. METHODS Data were collected from 57 women receiving the drug for hypertension from the 12th week of pregnancy through 12 weeks postpartum using a prospective, longitudinal design. A sparse sampling strategy guided collection of plasma samples. Samples were assayed for labetalol by high-performance liquid chromatography. Estimation of population pharmacokinetic parameters and covariate effects was performed by nonlinear mixed effects modeling using NONMEM. The final population model was validated by bootstrap analysis and visual predictive check. Simulations were performed with the final model to evaluate the appropriate body weight to guide labetalol dosing. RESULTS Lean body weight (LBW) and gestational age, i.e. weeks of pregnancy, were identified as significantly influencing oral clearance (CL/F) of labetalol, with CL/F ranging from 1.4-fold greater than postpartum values at 12 weeks' gestational age to 1.6-fold greater at 40 weeks. Doses adjusted for LBW provide more consistent drug exposure than doses adjusted for total body weight. The apparent volumes of distribution for the central compartment and at steady-state were 1.9-fold higher during pregnancy. CONCLUSIONS Gestational age and LBW impact the pharmacokinetics of labetalol during pregnancy and have clinical implications for adjusting labetalol doses in these women.
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Affiliation(s)
- James H Fischer
- Department of Pharmacy Practice, College of Pharmacy, University of Illinois at Chicago, 833 S Wood Street, Room 164, Chicago, IL, 60612, USA,
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Carvalho TMDJP, Cavalli RDC, Marques MP, Da Cunha SP, Baraldi CDO, Lanchote VL. Stereoselective analysis of labetalol in human plasma by LC-MS/MS: application to pharmacokinetics. Chirality 2009; 21:738-44. [PMID: 19006203 DOI: 10.1002/chir.20673] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/07/2022]
Abstract
Labetalol is clinically available as a mixture of two racemates (four stereoisomers). The stereoisomer (R,R) has as main activity the beta1-antagonism and the stereoisomer (S,R) is highly selective for the alpha1 adrenoceptor and is responsible for most of the alpha-blocker activity. In the present investigation, a method for the analysis of labetalol stereoisomers in human plasma was developed and applied to pharmacokinetic studies. Plasma samples (0.5 ml) were extracted with methyl tert-butyl ether at pH 9.5. The four labetalol stereoisomers were analyzed by LC-MS/MS on a Chirobiotic V column using a mobile phase consisting of methanol, acetic acid, and diethylamine, with a recovery of more than 90% for all four. The quantitation limit was 0.5 ng/ml and linearity was observed at 250 ng/ml plasma for each stereoisomer. Studies of precision and accuracy presented coefficients of variation and percentage inaccuracy of less than 15%, indicating that the method is precise and accurate. The method was applied to the study of the kinetic disposition of labetalol over a period of 12 h after oral administration of a single 100 mg dose to a hypertensive pregnant woman. The clinical study revealed stereoselectivity in the pharmacokinetics of labetalol, with a lower plasma proportion for the active stereoisomers (R,R)-labetalol and (S,R)-labetalol. The stereoselectivity observed after oral administration is due to the hepatic metabolism and the first pass effect, with an AUC(R,R)/AUC(S,S) ratio of 0.5.
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Affiliation(s)
- Teresa Maria De Jesus Ponte Carvalho
- Department of Clinical, Toxicologic, and Bromatologic Analysis, Faculty of Pharmaceutical Sciences of Ribeirão Preto, University of São Paulo, Ribeirão Preto, Brazil
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Jeong H, Choi S, Song JW, Chen H, Fischer JH. Regulation of UDP-glucuronosyltransferase (UGT) 1A1 by progesterone and its impact on labetalol elimination. Xenobiotica 2008; 38:62-75. [PMID: 18098064 DOI: 10.1080/00498250701744633] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/22/2022]
Abstract
The authors recently reported the increased oral clearance of labetalol in pregnant women. To elucidate the mechanism of the elevated oral clearance, it was hypothesized that female hormones, at the high concentrations attainable during pregnancy, enhance hepatic metabolism of labetalol. Labetalol glucuronidation, which is the major elimination pathway of labetalol, was characterized by screening six recombinant human UGTs (UGT1A1, 1A4, 1A6, 1A9, 2B4, and 2B7) for their capacity to catalyse labetalol glucuronidation. The effect of female hormones (progesterone, oestradiol, oestriol, or oestrone) on the promoter activities of relevant UDP glucuronosyltransferases (UGT) was investigated using a luciferase reporter assay in HepG2 cells. The involvement of oestrogen receptor alpha (ERalpha) and pregnane X receptor (PXR) was examined by co-transfecting ERalpha- or PXR-constructs. UGT1A1 and UGT2B7 were identified as the major UGT enzymes producing labetalol glucuronides (trace amount of glucuronide conjugate was formed by UGT1A9). The activities of the UGT1A1 promoter containing PXR response elements were enhanced by progesterone, but not by oestrogens, indicating PXR-mediated induction of UGT1A1 promoter activity by progesterone. Results from semi-quantitative real-time polymerase chain reaction (PCR) assays are consistent with the above findings. This effect of progesterone on UGT1A1 promoter activities was concentration dependent. Promoter activities of UGT2B7 were not affected by either oestrogens or progesterone. The results suggest a potential role for progesterone in regulating labetalol elimination by modulating the expression of UGT1A1, leading to enhanced drug metabolism during pregnancy.
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Affiliation(s)
- H Jeong
- Department of Pharmacy Practice, College of Pharmacy, Universit of Illinois at Chicago, Chicago, IL 60612, USA
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Zanotti-Cavazzoni SL. Hypertensive Crises. Crit Care Med 2008. [DOI: 10.1016/b978-032304841-5.50037-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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Bazylak G, Aboul-Enein HY. DIRECT SEPARATION OF LABETALOL STEREOISOMERS IN A HIGH PERFORMANCE LIQUID CHROMATOGRAPHY SYSTEM USING HELICALLY SELF-ASSEMBLED CHELATE AS CHIRAL SELECTOR IN THE MOBILE PHASE†. J LIQ CHROMATOGR R T 2007. [DOI: 10.1081/jlc-100101725] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Affiliation(s)
- Grzegorz Bazylak
- a Department of General Chemistry , Institute of Physiology and Biochemistry, Medical University of Lodz , Lindleya 6, Lodz , PL-90-131 , Poland
| | - Hassan Y. Aboul-Enein
- b Bioanalytical and Drug Development Laboratory, Biological and Medical Research Department , King Faisal Specialist Hospital and Research Centre , MBC-03, Riyadh , Kingdom of Saudi Arabia
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Abstract
Stimulating cardiac beta 1-adrenoceptors with oxyfedrine causes dilatation of coronary vessels and positive inotropic effects on the myocardium. beta 1-adrenergic agonists increase coronary blood flow in nonstenotic and stenotic vessels. The main indication for the use of the phosphodiesterase inhibitors pamrinone, mirinone, enoximone and piroximone is acute treatment of severe congestive heart failure. Theophylline is indicated for the treatment of asthma, chronic obstructive pulmonary disease, apnea in preterm infants ans sleep apnea syndrome. Severe arterial occlusive disease associated with atherosclerosis can be beneficially affected by elcosanoids. These drugs must be administered parenterally and have a half-life of only a few minutes. Sublingual or buccal preparations of nitrates are the only prompt method (within 1 or 2 min) of terminating anginal pain, except for biting nifedipine capsules. The short half-life (about 2.5 min) of nitroglycerin (glyceryl trinitrate) makes long term therapy impossible. Tolerance is a problem encountered with longer-acting nitric oxide donors. Knowledge of the pharmacokinetic properties of vasodilating drugs can prevent a too sudden and severe blood pressure decrease in patients with chronic hypertension. In considering the administration of a second dose, or another drug, the time necessary for the initially administered drug to reach maximal efficacy should be taken into account. In hypertensive emergencies urapidil, sodium nitroprusside, nitroglycerin, hydralazine and phentolamine are the drugs of choice, with the addition of beta-blockers during catecholamine crisis or dissecting aortic aneurysm. Childhood hypertension is most often treated with angiotensin-converting enzyme (ACE) inhibitors or calcium antagonists, primarily nifedipine. Because of the teratogenic risk involved with ACE inhibitors, extreme caution must be exercised when prescribing for adolescent females. The propagation of health benefits to breast-fed infants, combined with more women delaying pregnancy until their fourth decade, has entailed an increase in the need for hypertension management during lactation. Low dose hydrochlorothiazide, propranolol, nifedipine and enalapril or captopril do not pose enough of a risk of preclude breastfeeding in this group. The most frequently used antihypertensive agents during pregnancy are methyldopa, labetalol and calcium channel antagonists. Methyldopa and beta-blockers are the drugs of choice for treating mild to moderate hypertension. Prazosin and hydralazine are used to treat moderate to severe hypertension and hydralazine, urapidil or labetalol are used to treat hypertensive emergencies. The use of overly aggressive antihypertensive therapy during pregnancy should be avoided so that adequate uteroplacental blood flow is maintained. Methyldopa is the only drug accepted for use during the first trimester of pregnancy.
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Affiliation(s)
- R Kirsten
- Department of Clinical Pharmacology, University of Frankfurt, Germany
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Dakers JM, Boulton DW, Fawcett JP. Sensitive chiral high-performance liquid chromatographic assay for labetalol in biological fluids. JOURNAL OF CHROMATOGRAPHY. B, BIOMEDICAL SCIENCES AND APPLICATIONS 1997; 704:215-20. [PMID: 9518153 DOI: 10.1016/s0378-4347(97)00422-2] [Citation(s) in RCA: 17] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The four stereoisomers of the combined alpha- and beta-adrenoceptor antagonist labetalol were separated and quantified at therapeutic concentrations by normal-phase high-pressure liquid chromatography using a chiral stationary phase and fluorescence detection. Drug in plasma or urine was recovered by solid-phase extraction with 83+/-5% efficiency. Limits of detection from biological samples (3 ml) were between 1.5-1.8 ng ml(-1). Intra-day and inter-day variation at 25 ng ml(-1) were < or = 2.7% and < or = 5.80% respectively for all stereoisomers. The assay was applied to an examination of the disposition of labetalol stereoisomers after a single oral dose of racemate to a human volunteer. Labetalol appears to undergo enantioselective metabolism leading to relatively low plasma concentrations of the pharmacologically active enantiomers.
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Affiliation(s)
- J M Dakers
- School of Pharmacy, University of Otago, Dunedin, New Zealand
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Donnelly R, Elliott HL, Meredith PA. Antihypertensive drugs: individualized analysis and clinical relevance of kinetic-dynamic relationships. Pharmacol Ther 1992; 53:67-79. [PMID: 1641402 DOI: 10.1016/0163-7258(92)90044-z] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/28/2022]
Abstract
Individualized approaches to antihypertensive therapy are being widely advocated. Ideally these should incorporate rational prospective methods for drug and dosage selection but progress has been hampered by the paucity of information about dose- (and plasma concentration-) response relationships. However, in several recent clinical studies, concentration-effect analysis has been used to characterize kinetic-dynamic relationships in individual patients for a range of antihypertensive drugs. This approach provides an integrated mathematical description of drug response which has potential utility for quickly identifying poor or nonresponders and for determining individual dose requirements for optimum longterm blood pressure control.
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Affiliation(s)
- R Donnelly
- Department of Medicine and Therapeutics, Gardiner Institute, Western Infirmary, Glasgow, U.K
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