Abstract:
WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT:Performance-enhancing dietary supplements have not been clinically tested for safety or efficacy. In clinical trials performed under resting conditions, performance-enhancing supplements raise blood pressure and affect glucose homeostasis. The effect of exercise on the pharmacokinetics and pharmacodynamics of stimulant herbals is unknown. WHAT THIS STUDY ADDS:Supplement-induced effects on blood pressure and glucose levels are not ameliorated by exercise. Exercise does not affect the kinetics of stimulant ingredients, caffeine and synephrine. Performance-enhancing supplement use modestly improves exercise tolerance. AIMS Dietary supplements (DS) promoted to enhance athletic performance often contain herbal sympathomimetics such as Citrus aurantium (synephrine) and caffeine. We aimed to characterize the pharmacology of a performance-enhancing DS in the setting of exercise. METHODS:Ten healthy adults (three women) aged 20-31 years participated in a three-arm, double-blind, placebo-controlled, crossover study. Subjects ingested one dose of DS (Ripped Fuel Extreme Cut(R) with 21 mg synephrine and 304 mg caffeine by analysis) under resting conditions and 1 h prior to moderately intense exercise (30 min on cycle ergometer at 75-80% HR(max)), with a placebo (PLC)/exercise control. Plasma synephrine and caffeine concentrations were measured over 12 h, and vital signs, serum electrolytes, oxygen consumption and perceived exercise exertion were monitored. RESULTS:No significant adverse events occurred. Synephrine and caffeine pharmacokinetics were unaffected by exercise. Post-exercise diastolic blood pressure was higher after DS (peak mean 71.7 +/- 8.7 mmHg) than PLC (63.0 +/- 4.9 mmHg) (p = 0.007). There were no substantial treatment-related differences in post-exercise HR, systolic blood pressure, or temperature. Postprandial plasma glucose increased to 121.0 +/- 31.6 mg dl(-1) with DS and exercise vs. 103.7 +/- 25.5 mg dl(-1) with PLC and exercise (P = 0.004). No treatment differences in exercise-related oxygen consumption, serum lactate, or insulin were observed. Exercise was rated less difficult with DS than PLC (P = 0.001). CONCLUSIONS:Blood pressure and plasma glucose increased post-exercise with DS use, which could be detrimental in some people. Exercise was perceived as less strenuous after DS, presumably due to the stimulant effects of caffeine.
journal_name
Br J Clin Pharmacoljournal_title
British journal of clinical pharmacologyauthors
Haller CA,Duan M,Jacob P 3rd,Benowitz Ndoi
10.1111/j.1365-2125.2008.03144.xsubject
Has Abstractpub_date
2008-06-01 00:00:00pages
833-40issue
6eissn
0306-5251issn
1365-2125pii
BCP3144journal_volume
65pub_type
杂志文章abstract:WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT:The dominant health economic units upon which new treatment funding decisions are made are the incremental cost per life year gained (LYG) or the cost per quality-adjusted life year (QALY) gained. Neither of these units modifies the amount of health gained, by the amount of heal...
journal_title:British journal of clinical pharmacology
pub_type: 杂志文章
doi:10.1111/j.1365-2125.2007.02996.x
更新日期:2008-02-01 00:00:00
abstract:PURPOSE:Prescribed daily dose (PDD), the number of doses prescribed to be taken per day, is used to calculate medication adherence using pharmacy claims data. PDD can be substituted by (i) one dose per day (1DD), (ii) an estimate based on the 75th percentile of days taken by patients to refill a script (PDD75 ) or (iii...
journal_title:British journal of clinical pharmacology
pub_type: 杂志文章
doi:10.1111/bcp.14468
更新日期:2020-07-08 00:00:00
abstract::The effects of single doses of anhydrous caffeine (250 mg and 500 mg) and placebo on physiological, psychological measures and subjective feelings were studied in a double-blind, cross-over study in nine healthy subjects who had abstained from caffeine-containing beverages for 24 h before each occasion. Caffeine and c...
journal_title:British journal of clinical pharmacology
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1111/j.1365-2125.1986.tb02883.x
更新日期:1986-07-01 00:00:00
abstract::Residual effects of brotizolam (0.25 mg) and flurazepam (30 mg) were studied in healthy young adults. Performance and subjective assessments were observed from 7 to 8 h after overnight ingestion, and effects were compared with that of placebo. Visuo-motor coordination, visuo-mental processing time, visuo-motor reactio...
journal_title:British journal of clinical pharmacology
pub_type: 临床试验,杂志文章
doi:10.1111/j.1365-2125.1983.tb02309.x
更新日期:1983-01-01 00:00:00
abstract::1. The absorption and disposition of paracetamol was investigated in 10 healthy male Thai vegetarians and 10 similar non-vegetarians following an oral dose of 20 mg kg-1. 2. The absorption rate of paracetamol was significantly impaired in the vegetarians compared with the non-vegetarians as shown by a lower mean Cmax ...
journal_title:British journal of clinical pharmacology
pub_type: 杂志文章
doi:10.1111/j.1365-2125.1993.tb04223.x
更新日期:1993-09-01 00:00:00
abstract::1 Two antitussive agents (+/-)-glaucine phosphate and codeine phosphate have been compared with placebo with respect to ventilation, ventilatory response to carbon dioxide, pulse, blood pressure, digit symbol substitution, sedation score and the Zahlen-Verbindung test performance in ten healthy volunteers (22-36 years...
journal_title:British journal of clinical pharmacology
pub_type: 临床试验,杂志文章
doi:10.1111/j.1365-2125.1982.tb02028.x
更新日期:1982-10-01 00:00:00
abstract::Plasma and synovial fluid concentrations of the enantiomers of flurbiprofen were measured in 15 rheumatoid patients receiving 100 mg racemic flurbiprofen twice daily. Pharmacokinetic parameters showed considerable variability within the group of patients, although differences in S(+)/R(-) plasma concentration ratios w...
journal_title:British journal of clinical pharmacology
pub_type: 杂志文章
doi:10.1111/j.1365-2125.1991.tb03865.x
更新日期:1991-01-01 00:00:00
abstract:AIMS:In the Swiss heroin substitution trials, patients are treated with self-administered diacetylmorphine (heroin). Intravenous administration is not possible in patients that have venosclerosis. Earlier studies have demonstrated that oral diacetylmorphine may be used, although it is completely converted to morphine p...
journal_title:British journal of clinical pharmacology
pub_type: 杂志文章
doi:10.1111/j.1365-2125.2008.03286.x
更新日期:2008-12-01 00:00:00
abstract::1. The pharmacokinetics of physostigmine were investigated in a three-way cross-over design in six healthy, male volunteers comparing a physostigmine transdermal system (PTS), an oral solution and an i.v. infusion. 2. A single application of the patch over 24 h produced detectable plasma drug concentrations after a me...
journal_title:British journal of clinical pharmacology
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1111/j.1365-2125.1995.tb04410.x
更新日期:1995-01-01 00:00:00
abstract::1 Six previously untreated emergency admissions to hospital with severe hypertension were given oral treatment with labetalol. 2 Pre-treatment diastolic BP exceeded 130 mmHg, and clinical evidence of either accelerated hypertension or encephalopathy was present. 3 Hypotensive response after treatment followed two patt...
journal_title:British journal of clinical pharmacology
pub_type: 杂志文章
doi:
更新日期:1979-01-01 00:00:00
abstract:AIMS:Three 'weak' opioid analgesics in association with paracetamol are marketed in France as step 2 analgesics: dextropropoxyphene, tramadol and codeine. These combinations are involved in several adverse drug reactions (ADRs), but no data are available about their comparative reporting rate. The aim was to compare th...
journal_title:British journal of clinical pharmacology
pub_type: 杂志文章
doi:10.1111/j.1365-2125.2009.03472.x
更新日期:2009-09-01 00:00:00
abstract::1. The effects of chronic dosing with N-acetylcysteine (NAC), on nitrate-induced haemodynamic changes during the acute and chronic treatment of healthy volunteers with glyceryl trinitrate (GTN) patches (Transiderm nitro) has been investigated. 2. Seven volunteers were treated in a double-blind randomised crossover man...
journal_title:British journal of clinical pharmacology
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1111/j.1365-2125.1989.tb03522.x
更新日期:1989-10-01 00:00:00
abstract::1. Changes in undergraduate medical education will involve the development of a core curriculum of material of essential knowledge and of the skills for self directed learning both as a student and a postgraduate. A survey of departments or individuals teaching clinical pharmacology and therapeutics was conducted to c...
journal_title:British journal of clinical pharmacology
pub_type: 杂志文章
doi:10.1111/j.1365-2125.1994.tb04253.x
更新日期:1994-02-01 00:00:00
abstract:AIMS:New preventative strategies for stroke are required. One promising strategy is uric acid reduction and xanthine oxidase inhibition with allopurinol. We sought to investigate whether allopurinol improves cerebrovascular reactivity (CVR) following subcortical stroke. METHODS:We performed a randomized, double-blind,...
journal_title:British journal of clinical pharmacology
pub_type: 杂志文章,随机对照试验
doi:10.1111/j.1365-2125.2009.03497.x
更新日期:2009-11-01 00:00:00
abstract::1. Metoprolol (ME), pindolol (PI) and propranolol (PR) were studied in nine subjects at different doses and at 'maximum beta-adrenoceptor blockade' at a defined exercise load. Exercise tests were performed after each dosing period; isoprenaline stimulation was studied at the highest dose level. 2. ME and PR reduced he...
journal_title:British journal of clinical pharmacology
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1111/j.1365-2125.1980.tb01769.x
更新日期:1980-10-01 00:00:00
abstract::1. Adrenergic responsiveness may be an important determinant of peripheral resistance in man. We have demonstrated that vascular beta-adrenergic responsiveness is reduced in young borderline hypertensive subjects. A parallel defect in beta-adrenergic mediated adenylyl cyclase activity and beta-adrenoceptor affinity fo...
journal_title:British journal of clinical pharmacology
pub_type: 杂志文章,评审
doi:10.1111/j.1365-2125.1990.tb05469.x
更新日期:1990-01-01 00:00:00
abstract:AIMS:To investigate presence or absence of clinically relevant drug interactions (pharmacokinetic and safety/tolerability) of OBE022 with standard-of-care medicines for preterm labour, enabling coadministration and further clinical development. METHODS:Part A: open-label, randomized, 3-period crossover assessing coadm...
journal_title:British journal of clinical pharmacology
pub_type: 杂志文章,随机对照试验
doi:10.1111/bcp.13925
更新日期:2019-07-01 00:00:00
abstract::WHAT IS ALREADY KNOWN ABOUT THIS SUBJECT * Dihydropyrimidine dehydrogenase (DPD) is the enzyme responsible for the elimination of approximately 80% of the administered dose of 5-fluorouracil (5-FU). * Mutations in the DPD-coding gene have been shown to increase the risk of severe toxicity in 5-FU treated patients. * T...
journal_title:British journal of clinical pharmacology
pub_type: 杂志文章
doi:10.1111/j.1365-2125.2010.03683.x
更新日期:2010-08-01 00:00:00
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journal_title:British journal of clinical pharmacology
pub_type: 杂志文章
doi:10.1111/j.1365-2125.2006.02711.x
更新日期:2006-12-01 00:00:00
abstract:AIMS:5-HT1B-receptor mediated vasoconstriction of cranial arteries is a potential mechanism by which 5-HT1B/1D-receptor agonists such as sumatriptan produce their antimigraine effects. 5-HT1B-receptors exist in other blood vessels which may give rise to unwanted vascular effects. Therefore we examined the distribution ...
journal_title:British journal of clinical pharmacology
pub_type: 杂志文章
doi:10.1046/j.0306-5251.2001.01536.x
更新日期:2002-03-01 00:00:00
abstract::1. A novel formulation of nicardipine (50% standard (short acting), 50% sustained release) was evaluated in mild hypertension in a double-blind, randomized, placebo-controlled study, using clinic measurements (Hawksley) augmented by home recorded blood pressures (Copal UA 251). 2. Nicardipine 60 mg twice daily for 28 ...
journal_title:British journal of clinical pharmacology
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1111/j.1365-2125.1989.tb03418.x
更新日期:1989-05-01 00:00:00
abstract::1 A double-blind trial with parallel treatment groups was conducted to compare the safety and efficacy of mianserin with amitriptyline. 2 This was a six week trial with weekly visits. Measurements at each visit included: 21 item Hamilton Depression (HAMD) Scale. Clinical Global Impression (CGI) Scale and Treatment Eme...
journal_title:British journal of clinical pharmacology
pub_type: 临床试验,杂志文章
doi:10.1111/j.1365-2125.1983.tb05870.x
更新日期:1983-01-01 00:00:00
abstract:AIMS:To test the hypothesis that inhibition of cytochrome P450 2D6 (CYP2D6) by quinidine increases the antitussive effect of dextromethorphan (DEX) in an induced cough model. METHODS:Twenty-two healthy extensive metaboliser phenotypes for CYP2D6 were studied according to a double-blind, randomised cross-over design af...
journal_title:British journal of clinical pharmacology
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1046/j.1365-2125.1999.00029.x
更新日期:1999-09-01 00:00:00
abstract::Cost-containment measures in healthcare provision include the implementation of therapeutic and generic drug substitution strategies in patients whose condition is already well controlled with pharmacotherapy. Treatment for hypertension is frequently targeted for such measures. However, drug acquisition costs are only...
journal_title:British journal of clinical pharmacology
pub_type: 杂志文章
doi:10.1111/j.1365-2125.2010.03681.x
更新日期:2010-09-01 00:00:00
abstract::1. The pharmacokinetics of butorphanol were evaluated in 18 female volunteers with varying degrees of renal function following a single, 1 mg transnasal dose of butorphanol tartrate. The creatinine clearance (CLCR) values for subjects in the normal (NOR), moderately impaired (MI), and severely impaired (SI) groups wer...
journal_title:British journal of clinical pharmacology
pub_type: 杂志文章
doi:10.1046/j.1365-2125.1996.03327.x
更新日期:1996-05-01 00:00:00
abstract::Theophylline clearance was studied in normal healthy volunteers before and after chronic oral dosing. Oral theophylline clearance showed a significant decrease (P less than 0.001) from 59.3 +/- 6.48 ml/min (mean +/- s.e. mean, n = 10) to 48.0 +/- 6.4 ml/min. Steady-state intravenous clearance decreased by 26 +/- 2% fr...
journal_title:British journal of clinical pharmacology
pub_type: 杂志文章
doi:10.1111/j.1365-2125.1984.tb02385.x
更新日期:1984-05-01 00:00:00
abstract::Ethanol aggravates benzodiazepine-induced central nervous depression by pharmacokinetic and/or pharmacodynamic interactions and Ro 15-1788 reverses promptly the hypnotic effects of benzodiazepines. We therefore studied the acute effects of Ro 15-1788 on the ethanol-induced sedation in six healthy male subjects. Subseq...
journal_title:British journal of clinical pharmacology
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1111/j.1365-2125.1986.tb02929.x
更新日期:1986-11-01 00:00:00
abstract::1. We have investigated the effect of repeated s.c. Org 10172 (a low molecular weight heparinoid; Lomoparan) treatment (1000 anti-Xa units twice daily for 5 days) on antipyrine (500 mg orally) metabolism, and the effect of enzyme induction by pentobarbitone (100 mg for 12 days) on the pharmacokinetics and pharmacodyna...
journal_title:British journal of clinical pharmacology
pub_type: 杂志文章
doi:10.1111/j.1365-2125.1991.tb05608.x
更新日期:1991-07-01 00:00:00
abstract::1. The effects of selective beta-adrenoceptor partial agonist activity on plasma creatine kinase (CK) and skeletal muscle symptoms were studied in normal volunteers. 2. A drug with beta 1-selective partial agonist activity (xamoterol) and one with partial agonist activity acting mainly through beta 2-adrenoceptors (pi...
journal_title:British journal of clinical pharmacology
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1111/j.1365-2125.1990.tb03834.x
更新日期:1990-11-01 00:00:00
abstract:AIMS:The pharmacokinetics and dose proportionality of rizatriptan single oral doses from 2.5 to 15 mg administered as solutions to healthy volunteers were studied. METHODS:In a randomized, crossover study with four periods, twenty-four healthy volunteers (12 males and 12 females) took single oral doses of 2.5, 5, 10, ...
journal_title:British journal of clinical pharmacology
pub_type: 临床试验,杂志文章,随机对照试验
doi:10.1046/j.1365-2125.1999.00917.x
更新日期:1999-04-01 00:00:00