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Sultan K, Zamir A, Ashraf W, Imran I, Saeed H, Rehman AU, Majeed A, Rasool MF. Clinical pharmacokinetics of terbutaline in humans: a systematic review. NAUNYN-SCHMIEDEBERG'S ARCHIVES OF PHARMACOLOGY 2023; 396:213-227. [PMID: 36227333 DOI: 10.1007/s00210-022-02304-5] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/01/2022] [Accepted: 10/05/2022] [Indexed: 01/29/2023]
Abstract
Terbutaline is used for the management of bronchospasm associated with asthma, bronchitis, emphysema, and chronic obstructive pulmonary disease. A systematic review would be beneficial to assess the impact of routes of administration, stereoisomerism, disease states, smoking, age, exercise, and chronobiology on pharmacokinetics (PK) of terbutaline in humans. PubMed and Google Scholar databases were searched to screen all the relevant articles consisting of at least one of the PK parameters after administration of oral, inhaled, and intravenous (IV) terbutaline in humans. Oral studies of terbutaline depicted a linear relationship between plasma concentration (Cp) and the administered dose. The IV studies demonstrated multi-exponential behavior for disposition and renal clearance. Higher systemic availability was observed with inhaled as compared to oral route, and chrono-pharmacokinetic behavior was notable. Time to reach maximum plasma concentration (Tmax) was prolonged, and maximum plasma concentration (Cmax) was lowered after exercise. The primary route of excretion in chronic kidney disease (CKD) patients is reported to be nonrenal. In pregnant women, the Cp of terbutaline is lowered and clearance is increased. The addition of theophylline to terbutaline did not affect the PK of terbutaline; hence, both can be used without dose adjustment. This review summarizes all the available PK parameters of terbutaline, and it may be helpful for researchers in the development and evaluation of PK models as well as in designing optimal dosage regimens in different clinical conditions.
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Affiliation(s)
- Khadeeja Sultan
- Department of Pharmacy Practice, Faculty of Pharmacy, Bahauddin Zakariya University, Multan, 60800, Pakistan
| | - Ammara Zamir
- Department of Pharmacy Practice, Faculty of Pharmacy, Bahauddin Zakariya University, Multan, 60800, Pakistan
| | - Waseem Ashraf
- Department of Pharmacology, Faculty of Pharmacy, Bahauddin Zakariya University, Multan, 60800, Pakistan
| | - Imran Imran
- Department of Pharmacology, Faculty of Pharmacy, Bahauddin Zakariya University, Multan, 60800, Pakistan
| | - Hamid Saeed
- Allama Iqbal Campus, University College of Pharmacy, University of the Punjab, Lahore, 54000, Pakistan
| | - Anees Ur Rehman
- Department of Pharmacy Practice, Faculty of Pharmacy, Bahauddin Zakariya University, Multan, 60800, Pakistan
| | - Abdul Majeed
- Department of Pharmacy Practice, Faculty of Pharmacy, Bahauddin Zakariya University, Multan, 60800, Pakistan
| | - Muhammad Fawad Rasool
- Department of Pharmacy Practice, Faculty of Pharmacy, Bahauddin Zakariya University, Multan, 60800, Pakistan.
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Oral Drug Delivery: Conventional to Long Acting New-Age Designs. Eur J Pharm Biopharm 2021; 162:23-42. [PMID: 33631319 DOI: 10.1016/j.ejpb.2021.02.008] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2020] [Revised: 01/16/2021] [Accepted: 02/14/2021] [Indexed: 12/13/2022]
Abstract
The Oral route of administration forms the heartwood of the ever-growing tree of drug delivery technology. It is one of the most preferred dosage forms among patients and controlled release community. Despite the high patient compliance, the deliveries of anti-cancerous drugs, vaccines, proteins, etc. via the oral route are limited and have recorded a very low bioavailability. The oral administration must overcome the physiological barriers (low solubility, permeation and early degradation) to achieve efficient and sustained delivery. This review aims at highlighting the conventional and modern-age strategies that address some of these physiological barriers. The modern age designs include the 3D printed devices and formulations. The superiority of 3D dosage forms over conventional cargos is summarized with a focus on long-acting designs. The innovations in Pharmaceutical organizations (Lyndra, Assertio and Intec) that have taken giant steps towards commercialization of long-acting vehicles are discussed. The recent advancements made in the arena of oral peptide delivery are also highlighted. The review represents a comprehensive journey from Nano-formulations to micro-fabricated oral implants aiming at specific patient-centric designs.
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Strand TE, Khiabani HZ, Boico A, Radiloff D, Zhao Y, Hamilton KL, Christians U, Klawitter J, Noveck RJ, Piantadosi CA, Bell C, Irwin D, Schroeder T. The novel combination of theophylline and bambuterol as a potential treatment of hypoxemia in humans. Can J Physiol Pharmacol 2017; 95:1009-1018. [PMID: 28467859 DOI: 10.1139/cjpp-2016-0635] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/27/2023]
Abstract
Hypoxemia can be life-threatening, both acutely and chronically. Because hypoxemia causes vascular dysregulation that further restricts oxygen availability to tissue, it can be pharmacologically addressed. We hypothesized that theophylline can be safely combined with the β2-adrenergic vasodilator bambuterol to improve oxygen availability in hypoxemic patients. Ergogenicity and hemodynamic effects of bambuterol and theophylline were measured in rats under hypobaric and normobaric hypoxia (12% O2). Feasibility in humans was assessed using randomized, double-blind testing of the influence of combined slow-release theophylline (300 mg) and bambuterol (20 mg) on adverse events (AEs), plasma K+, pulse, blood pressure, and drug interaction. Both drugs and their combination significantly improved hypoxic endurance in rats. In humans, common AEs were low K+ (<3.5 mmol/L; bambuterol: 12, theophylline: 4, combination: 13 episodes) and tremors (10, 0, 14 episodes). No exacerbation or serious AE occurred when drugs were combined. A drop in plasma K+ coincided with peak bambuterol plasma concentrations. Bambuterol increased heart rate by approximately 13 bpm. Drug interaction was present but small. We report promise, feasibility, and relative safety of combined theophylline and bambuterol as a treatment of hypoxemia in humans. Cardiac safety and blood K+ will be important safety endpoints when testing these drugs in hypoxemic subjects.
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Affiliation(s)
- Trond-Eirik Strand
- a Norwegian Armed Forces Medical Services, Institute of Aviation Medicine, 0313 Oslo, Norway
| | - Hasse Z Khiabani
- b Department of Pharmacology, Oslo University Hospital, Rikshospitalet, 0372 Oslo, Norway
| | - Alina Boico
- c Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
| | | | - Yulin Zhao
- c Department of Radiation Oncology, Duke University Medical Center, Durham, NC 27710, USA
| | - Karyn L Hamilton
- e Department of Health and Exercise Science, Colorado State University, Fort Collins, CO 80523, USA
| | - Uwe Christians
- f iC42 Integrated Solutions in Clinical Research and Development, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Jelena Klawitter
- f iC42 Integrated Solutions in Clinical Research and Development, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Robert J Noveck
- g Department of Medicine, Duke University Medical Center, Durham, NC 27710, USA
| | | | - Christopher Bell
- e Department of Health and Exercise Science, Colorado State University, Fort Collins, CO 80523, USA
| | - David Irwin
- i Department of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA
| | - Thies Schroeder
- i Department of Medicine, University of Colorado Denver, Anschutz Medical Campus, Aurora, CO 80045, USA.,j Department of Biochemistry and Pharmacology, University of Mainz, 55128 Mainz, Germany
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Pistolozzi M, Du H, Wei H, Tan W. Stereoselective Inhibition of Human Butyrylcholinesterase by the Enantiomers of Bambuterol and Their Intermediates. Drug Metab Dispos 2014; 43:344-52. [DOI: 10.1124/dmd.114.060251] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
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Comparative pharmacokinetics and bile transformation of R-enantiomer and racemic bambuterol after single-dose intravenous, oral administration in rats and beagle dogs. Eur J Drug Metab Pharmacokinet 2014; 40:453-60. [DOI: 10.1007/s13318-014-0228-3] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2014] [Accepted: 09/23/2014] [Indexed: 11/25/2022]
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Predicting human exposure of active drug after oral prodrug administration, using a joined in vitro/in silico–in vivo extrapolation and physiologically-based pharmacokinetic modeling approach. J Pharmacol Toxicol Methods 2013; 67:203-13. [DOI: 10.1016/j.vascn.2012.12.002] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/09/2012] [Revised: 12/14/2012] [Accepted: 12/16/2012] [Indexed: 11/18/2022]
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Vacondio F, Silva C, Mor M, Testa B. Qualitative structure-metabolism relationships in the hydrolysis of carbamates. Drug Metab Rev 2011; 42:551-89. [PMID: 20441444 DOI: 10.3109/03602531003745960] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022]
Abstract
The aims of this review were 1) to compile a large number of reliable literature data on the metabolic hydrolysis of medicinal carbamates and 2) to extract from such data a qualitative relation between molecular structure and lability to metabolic hydrolysis. The compounds were classified according to the nature of their substituents (R³OCONR¹R²), and a metabolic lability score was calculated for each class. A trend emerged, such that the metabolic lability of carbamates decreased (i.e., their metabolic stability increased), in the following series: Aryl-OCO-NHAlkyl >> Alkyl-OCO-NHAlkyl ~ Alkyl-OCO-N(Alkyl)₂ ≥ Alkyl-OCO-N(endocyclic) ≥ Aryl-OCO-N(Alkyl)₂ ~ Aryl-OCO-N(endocyclic) ≥ Alkyl-OCO-NHAryl ~ Alkyl-OCO-NHAcyl >> Alkyl-OCO-NH₂ > Cyclic carbamates. This trend should prove useful in the design of carbamates as drugs or prodrugs.
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Affiliation(s)
- Federica Vacondio
- Dipartimento Farmaceutico, Università degli Studi di Parma, Parma, Italy.
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Abstract
Kolinesteraze: struktura, uloga, inhibicijaAcetilkolinesteraza (AChE; E.C. 3.1.1.7) i butirilkolinesteraza (BChE; E.C. 3.1.1.8) enzimi su koji se zbog svoje uloge u organizmu intenzivno istražuju unutar područja biomedicine i toksikologije. Iako strukturno homologni, ovi enzimi razlikuju se prema katalitičkoj aktivnosti, odnosno specifičnosti prema supstratima koje mogu hidrolizirati te selektivnosti za vezanje mnogih liganada. U ovom radu dan je pregled dosadašnjih istraživanja kolinesteraza i njihovih interakcija s ligandima i inhibitorima te su izdvojene aminokiseline aktivnog mjesta koje sudjeluju u tim interakcijama.
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Tran PHL, Choe JS, Tran TTD, Park YM, Lee BJ. Design and mechanism of on-off pulsed drug release using nonenteric polymeric systems via pH modulation. AAPS PharmSciTech 2011; 12:46-55. [PMID: 21161457 DOI: 10.1208/s12249-010-9562-1] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2010] [Accepted: 11/30/2010] [Indexed: 11/30/2022] Open
Abstract
The aim was to design a pH-sensitive pulsatile drug delivery system that allows for an on-off pulsed release of a drug using polyacrylic acid (PAA) blended with ethyl cellulose (EC) in different ratios. PAA, a polyelectrolyte polymer, exhibits a highly coiled conformation at low pH but a highly extended structure at high pH. Fumaric acid, which is an internal acidifying agent, was incorporated into the hydroxypropyl methylcellulose-based core tablets to create an acidic microenvironmental pH (pH(M)). The concentration of fumaric acid inside the core tablet and the ratio of PAA/EC in the coating layer were very crucial in modulating drug release behaviors. When the fumaric acid was retained in the core tablet, it gave a more acidic pH(M), so that the PAA was kept in a highly coiled state in the coated film, which hindered drug release ("off" release pattern). Interestingly, the release profiles of the drug and fumaric acid from coated tablets showed the on-off pulsed pattern upon dissolution. Imaging analyses using scanning electron microscopy, near-infrared imaging, confocal laser scanning microscopy, and Fourier transform infrared spectroscopy confirmed this on-off release behavior of the drug and fumaric acid from coated tablets.
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Chou YL, Wu CC, Wang HW. Effects of bambuterol and terbutaline on isolated rat's tracheal smooth muscle. Eur Arch Otorhinolaryngol 2009; 267:1305-11. [PMID: 20012638 DOI: 10.1007/s00405-009-1173-7] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Accepted: 11/26/2009] [Indexed: 11/30/2022]
Abstract
Terbutaline (Bricanyl) and its prodrug Bambuterol (Bambec) are highly potent beta(2)-adrenoceptor agonists often used in asthma patients. Terbutaline in the form of inhaled short-acting bronchodilator relieves asthmatic symptoms. However, the effects of bambuterol given intratracheally have rarely been explored. To verify the effect of bambuterol and terbutaline, which act on the tracheal smooth muscle directly in vitro, we used our preparation to test the effects of bambuterol on isolated rat's tracheal smooth muscle compared with terbutaline. The following assessments of bambuterol and terbutaline were performed: (1) effect on tracheal smooth muscle resting tension; (2) effect on contraction caused by 10(-6) M methacholine as a parasympathetic mimetic; (3) effect of the drugs on electrically induced tracheal smooth muscle contractions. The results indicated that adding bambuterol induced a significant further contraction to 10(-6) M methacholine-induced contraction when the preparation was increased to 10(-4) M. But terbutaline elicited a relaxation response at a dose of 10(-6) M or more. Both bambuterol and terbutaline could inhibit electrical field stimulation (EFS) induced spike contraction. Terbutaline had an anti-cholinergic effect that could relieve asthmatic symptoms. But the effect of bambuterol acting on tracheal smooth muscle directly was controversial.
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Affiliation(s)
- Ying-Liang Chou
- Department of Otolaryngology-Head and Neck Surgery, Tri-Service General Hospital, National Defense Medical Center, No. 325, Sect. 2, Cheng-Gung Road, Neihu District, 114 Taipei, Taiwan, ROC
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Tanino T, Nawa A, Miki Y, Iwaki M. Enzymatic stability of 2′‐ethylcarbonate‐linked paclitaxel in serum and conversion to paclitaxel by rabbit liver carboxylesterase for use in prodrug/enzyme therapy. Biopharm Drug Dispos 2008; 29:259-69. [DOI: 10.1002/bdd.611] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
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12
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Gardiner SJ, Begg EJ. Pharmacogenetics, drug-metabolizing enzymes, and clinical practice. Pharmacol Rev 2006; 58:521-90. [PMID: 16968950 DOI: 10.1124/pr.58.3.6] [Citation(s) in RCA: 235] [Impact Index Per Article: 13.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022] Open
Abstract
The application of pharmacogenetics holds great promise for individualized therapy. However, it has little clinical reality at present, despite many claims. The main problem is that the evidence base supporting genetic testing before therapy is weak. The pharmacology of the drugs subject to inherited variability in metabolism is often complex. Few have simple or single pathways of elimination. Some have active metabolites or enantiomers with different activities and pathways of elimination. Drug dosing is likely to be influenced only if the aggregate molar activity of all active moieties at the site of action is predictably affected by genotype or phenotype. Variation in drug concentration must be significant enough to provide "signal" over and above normal variation, and there must be a genuine concentration-effect relationship. The therapeutic index of the drug will also influence test utility. After considering all of these factors, the benefits of prospective testing need to be weighed against the costs and against other endpoints of effect. It is not surprising that few drugs satisfy these requirements. Drugs (and enzymes) for which there is a reasonable evidence base supporting genotyping or phenotyping include suxamethonium/mivacurium (butyrylcholinesterase), and azathioprine/6-mercaptopurine (thiopurine methyltransferase). Drugs for which there is a potential case for prospective testing include warfarin (CYP2C9), perhexiline (CYP2D6), and perhaps the proton pump inhibitors (CYP2C19). No other drugs have an evidence base that is sufficient to justify prospective testing at present, although some warrant further evaluation. In this review we summarize the current evidence base for pharmacogenetics in relation to drug-metabolizing enzymes.
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Affiliation(s)
- Sharon J Gardiner
- Department of Medicine, Christchurch School of Medicine, Private Bag 4345, Christchurch, New Zealand.
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Gazić I, Bosak A, Sinko G, Vinković V, Kovarik Z. Preparative HPLC separation of bambuterol enantiomers and stereoselective inhibition of human cholinesterases. Anal Bioanal Chem 2006; 385:1513-9. [PMID: 16865342 DOI: 10.1007/s00216-006-0566-3] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2006] [Revised: 05/17/2006] [Accepted: 05/17/2006] [Indexed: 11/29/2022]
Abstract
We separated and characterized the enantiomers of bambuterol (5-[-(tert-butylamino)-1-hydroxyethyl]-m-phenylene-bis(dimethylcarbamate) hydrochloride), which is used in racemic form as a prodrug of terbutaline, a beta(2)-adrenoceptor agonist. The enantioseparation was attempted on several chiral HPLC columns, and the most effective separation was achieved on the amylose-based Chiralpak AD column. Since in vivo conversion of bambuterol into terbutaline involves hydrolysis by butyrylcholinesterase (EC 3.1.1.8), we studied the reaction of enantiomers with eight human BChE variants. Both enantiomers inhibited all studied BChE variants; however, the rate of inhibition with the (R)-enantiomer was about five times faster than with the (S)-enantiomer. (R)-bambuterol inhibition rate constants for homozygous usual (UU), fluoride-resistant (FF) or atypical (AA) variant ranged from 6.4 to 0.11 min(-1)microM(-1). The inhibition rates for heterozygotes were between the respective constants for the corresponding homozygotes.
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Affiliation(s)
- Ivana Gazić
- Ruder Bosković Institute, Bijenicka cesta 54, 10002, Zagreb, Croatia
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Analytical methodology for the detection of β2-agonists in urine by gas chromatography–mass spectrometry for application in doping control. Anal Chim Acta 2000. [DOI: 10.1016/s0003-2670(00)00950-8] [Citation(s) in RCA: 51] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
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Kuusela AL, Marenk M, Sandahl G, Sanderud J, Nikolajev K, Persson B. Comparative study using oral solutions of bambuterol once daily or terbutaline three times daily in 2-5-year-old children with asthma. Bambuterol Multicentre Study Group. Pediatr Pulmonol 2000; 29:194-201. [PMID: 10686040 DOI: 10.1002/(sici)1099-0496(200003)29:3<194::aid-ppul7>3.0.co;2-i] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
The aim of this study was to compare safety and efficacy of bambuterol hydrochloride (10 mg) oral solution administered once daily in the evening with terbutaline sulphate (0.075 mg/kg body weight) oral solution administered three times daily in 2-5-year-old children with asthma. There were two treatment groups: (2/3) of the patients received bambuterol and (1/3) received terbutaline. The study was double-blind, randomized, and of a parallel group design, and it lasted for 3 months after a 2-week run-in period. The primary objective was to evaluate safety (adverse events, and changes in blood pressure, pulse rate, hematology, and clinical chemistry parameters). Plasma concentrations of terbutaline and/or bambuterol were also measured. Evaluation of efficacy (diary card data) was a secondary objective. A total of 155 patients (range, 2-6 years; 3 patients were 6 years old at randomization) were treated with the study drugs; 104 patients received bambuterol and 51 patients received terbutaline. Both treatments showed a good safety profile with respect to clinical and laboratory tests, and they were generally well tolerated. Reported adverse events were mild to moderate. There were no statistically significant differences between treatment groups in any of the efficacy variables (diary variables: peak expiratory flow (PEF), asthma symptoms, restlessness, other reported symptoms, use of inhaled bronchodilators, and nighttime awakenings). For morning PEF, the mean increase from run-in to treatment was 16.9 L/min in the terbutaline group and 23.3 L/min in the bambuterol group. For evening PEF, the mean increase was 20.2 L/min in the terbutaline group and 20.6 L/min in the bambuterol group. In conclusion, once-daily bambuterol is as safe and effective as terbutaline given three times daily. The study also confirmed that bambuterol has a 24-hr duration of action, and therefore its once daily administration, makes it a preferred bronchodilator agent. Pediatr Pulmonol. 2000:29:194-201.
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Affiliation(s)
- A L Kuusela
- Department of Paediatrics, Tampere University Hospital, Tampere, Finland
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Rosenborg J, Larsson P, Nyberg L. Pharmacokinetics of bambuterol during oral administration of plain tablets and solution to healthy adults. Br J Clin Pharmacol 2000; 49:199-206. [PMID: 10718774 PMCID: PMC2014922 DOI: 10.1046/j.1365-2125.2000.00143.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AIMS The pharmacokinetics of orally administered bambuterol were investigated in healthy adult subjects, with particular regard to time to steady state, pharmacokinetic linearity, intraindividual variability for the parent drug and its active beta2-adrenergic metabolite terbutaline and bioequivalence between tablet and solution. METHODS Twenty-six healthy Caucasian subjects were included and 23 (12 women) completed this open, randomised, crossover study. Racemic bambuterol hydrochloride was administered orally as 10 mg, 20 mg, and 10 + 20 mg tablets, and as a solution once daily for 2 weeks at about 19.00 h. Plasma concentrations and urinary recoveries of bambuterol and terbutaline were measured after single doses and during repeated treatments. RESULTS Absorption of bambuterol was biphasic. The initial rate could not be assessed directly, but it was faster than that during the second phase where absorption was rate-limiting for elimination (mean terminal half-life: 16 h). Steady-state AUC(0,24 h) of bambuterol, reached within 1 week, was not dose-linear. Mean terminal half-life of terbutaline was 22 h and steady-state was reached within one week of bambuterol treatment. Contrary to bambuterol, overall pharmacokinetics of terbutaline indicated dose-linearity. Day-to-day intraindividual variation in AUC(0,24 h) of terbutaline, 15% with the tablet, was half that of bambuterol. Urine data indicated that intraindividual variability was slightly smaller with the solution. Tablets were bioequivalent with the solution with regard to terbutaline (90% confidence interval: 87-100%). CONCLUSIONS With oral bambuterol steady state was reached within 1 week. Regarding generated terbutaline, pharmacokinetics judged to be were linear, intraindividual variability of AUC at steady state was on average 15% with the tablet, and tablets were bioequivalent with the solution.
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Affiliation(s)
- J Rosenborg
- Experimental Medicine and Clinical Science, Astra Zeneca R & D, Lund and Division of Biopharmaceutics and Pharmacokinetics, Uppsala University, Uppsala, Sweden.
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Ashani Y. Prospective of human butyrylcholinesterase as a detoxifying antidote and potential regulator of controlled-release drugs. Drug Dev Res 2000. [DOI: 10.1002/1098-2299(200007/08)50:3/4<298::aid-ddr13>3.0.co;2-x] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
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Ahlström H, Alvero J, Alvero R, Espos R, Fajutrao L, Herrera J, Kjellman B, Kubista J, Leviste C, Meyer P, Oldæus G, Siricururat A, Vichyanond P, Wettrell G, Wong E, Laxmyr L, Nyberg L, Olsson H, Weibull E, Rosenborg J. Pharmacokinetics of bambuterol during oral administration to asthmatic children. Br J Clin Pharmacol 1999; 48:299-308. [PMID: 10510139 PMCID: PMC2014342 DOI: 10.1046/j.1365-2125.1999.00028.x] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AIMS To investigate dose proportionality, dosing frequency, and ethnic aspects of the pharmacokinetics of bambuterol in asthmatic children, and to discuss the relationship with previous observations in adults. METHODS Forty-eight children in four different studies completed two double-blind bambuterol treatments each (daily doses of bambuterol hydrochloride): 12 preschool (5 mg x 2 vs 10 mg) and 12 school (10 mg vs 20 mg) Caucasians, 12 preschool (2.5 mg vs 5 mg), and 12 school (10 mg vs 20 mg) Orientals. Peak plasma concentrations and dosing interval area under curve (AUC) of bambuterol and the active metabolite terbutaline were assessed at steady state. Treatment differences were analysed statistically within each study. Differences between the studies and the relation to steady-state AUC in adults were described. RESULTS Dose proportionality was seen for terbutaline but not for bambuterol. Twice-daily dosing (2 x AUC(0,12 h)) could not be shown to differ from once-daily dosing (AUC(0,24 h)) in the preschool Caucasians. Mean AUC of terbutaline was 128 and 242 nmol l-1 h in the preschool Caucasians (5 mg/12 h; 10 mg/24 h), 213 and 406 nmol l-1 h in the Caucasian school children (10 mg; 20 mg), 87.4 and 202 nmol l-1 h in the Oriental preschool children (2.5 mg; 5 mg), and 356 and 640 nmol l-1 h in the Oriental school children (10 mg; 20 mg). Oriental school children had higher plasma concentrations of bambuterol and terbutaline than Caucasian school children. The strict ethnic implication of the difference could not be elucidated, because demographic data were not perfectly matched. Terbutaline AUC was only moderately increased in the Caucasian school children compared with Caucasian adults. The increase was more pronounced in Oriental children and in some preschool Caucasians. The highest concentration of terbutaline, 58 nmol l-1, was seen in an Oriental school child after a 20 mg dose. CONCLUSIONS Caucasian school children can be given bambuterol hydrochloride very much as Caucasian adults, 10 or 20 mg once daily, but Oriental preschool and school children plus preschool Caucasians should be given lower doses.
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Affiliation(s)
| | | | - Rita Alvero
- De La Salle University Medical Centre DasmariñasCavite, Philippines
| | - Roberto Espos
- De La Salle University Medical Centre DasmariñasCavite, Philippines
| | | | - Jocelyn Herrera
- De La Salle University Medical Centre DasmariñasCavite, Philippines
| | - Bengt Kjellman
- Department of Paediatrics, Skövde Central HospitalSweden
| | - Josef Kubista
- Department of Paediatrics, Jönköping Central HospitalSweden
| | - Carolina Leviste
- De La Salle University Medical Centre DasmariñasCavite, Philippines
| | - Peter Meyer
- Department of Paediatrics, Helsingborg HospitalSweden
| | - Göran Oldæus
- Department of Paediatrics, Jönköping Central HospitalSweden
| | | | - Pakit Vichyanond
- Department of Paediatrics, Siriraj University HospitalBangkok, Thailand
| | - Göran Wettrell
- Department of Paediatrics, Skövde Central HospitalSweden
| | | | - Lena Laxmyr
- Experimental Medicine, AstraZeneca R&D, Uppsala UniversityLund, Sweden
| | - Lars Nyberg
- Experimental Medicine, AstraZeneca R&D, Uppsala UniversityLund, Sweden
- Division of Biopharmaceutics and Pharmacokinetics, Uppsala UniversityUppsala, Sweden
| | - Håkan Olsson
- Experimental Medicine, AstraZeneca R&D, Uppsala UniversityLund, Sweden
| | - Eva Weibull
- Experimental Medicine, AstraZeneca R&D, Uppsala UniversityLund, Sweden
| | - Johan Rosenborg
- Experimental Medicine, AstraZeneca R&D, Uppsala UniversityLund, Sweden
- Division of Biopharmaceutics and Pharmacokinetics, Uppsala UniversityUppsala, Sweden
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Bang U, Nyberg L, Rosenborg J, Viby-Mogensen J. Pharmacokinetics of bambuterol in subjects homozygous for the atypical gene for plasma cholinesterase. Br J Clin Pharmacol 1998; 45:479-84. [PMID: 9643621 PMCID: PMC1873551 DOI: 10.1046/j.1365-2125.1998.00697.x] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
AIMS It has been assumed that both plasma cholinesterase (EC 3.1.1.8) and oxidative enzymes are needed for optimum formation of the bronchodilator terbutaline from its biscarbamate prodrug bambuterol. The present study aimed at investigating the fate of bambuterol in subjects with deficient plasma cholinesterase but with normal oxidative (CYP2D6) capability. METHODS The pharmacokinetics of bambuterol and terbutaline were studied in four healthy subjects (two men and two women) being homozygous for the atypical gene for plasma cholinesterase. Their oxidative metabolism was apparently good as they were all rapid metabolizers of debrisoquine. Bambuterol hydrochloride 20 mg was given orally once daily for 10 days, and plasma and urine samples were taken for 1.5 days (plasma) and 4.5 days (urine) after administration of the last dose. RESULTS The pharmacokinetic parameters in the present study were grossly similar to those found in a study of bambuterol in subjects with normal plasma cholinesterase activity (N). However, subjects with atypical cholinesterase had a shorter terminal half-life of bambuterol (a measure of uptake rate), 4.8-12.6 h vs 8.3-22.3 h in N, and slightly higher plasma concentrations of bambuterol (average concentrations 1.9-3.7 nmol l(-1) vs 1.5-3.1 nmol l(-1) in N). Peak/trough terbutaline plasma concentrations ratios (2.1-3.2) were somewhat increased, but average plasma concentrations (8.3-14.5 nmol l(-1)) and terminal half-life (16.5-21.8 h) of terbutaline did not differ. CONCLUSIONS In Caucasian populations, one subject out of 2500 is homozygous for the atypical gene for plasma cholinesterase. The atypical enzyme has a much lower affinity for bambuterol than the normal enzyme. Nevertheless, the subjects with atypical cholinesterase were able to produce terbutaline as efficiently as normal subjects. This might be explained by an altered uptake and metabolism in the absence of plasma cholinesterase, or the importance of this enzyme for the formation of terbutaline from bambuterol in vivo may have been overestimated.
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Affiliation(s)
- U Bang
- Department of Anaesthesia, Skejby Sygehus, Aarhus N, Denmark
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