Effect of Exercise and Environmental Heat on Theophylline Kinetics

Schlaeffer, Francisc; Engelberg, Isaac S.; Kaplanski, Jacob; Danon, Abraham

doi:10.1159/000194651

Cited by 24 publications

(16 citation statements)

References 14 publications

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“…This is in agreement with the pharmacokinetic literature that has demonstrated no effect of exercise on the metabolism and elimination of drugs, such as caffeine, with a large V d and a low hepatic extraction ratio (13,34,39). However, this is in contrast to previous studies of methylxanthine pharmacokinetics (11,29).…”

Section: Discussionsupporting

confidence: 91%

“…Collomp et al (11) examined caffeine kinetics over an 8-h period at rest and with exercise during the 1st h. Exercise raised the maximal plasma caffeine level and reduced the plasma half-life (t1 ⁄2) and volume of distribution (V d ) yet, remarkably, did not alter the clearance of caffeine (Cl AUC ). Schlaeffer et al (29) studied theophylline kinetics at rest and with two intensities of exercise (light and moderate) in a normal and hot environment: the t1⁄2 was prolonged under all exercise conditions, and V d was decreased by the moderate and light exercise in heat trials. Other studies that have examined the pharmacokinetics of methylxanthines have produced variable results (3,19).…”

mentioning

confidence: 99%

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Effects of exercise and thermal stress on caffeine pharmacokinetics in men and eumenorrheic women

McLean

Graham

2002

Journal of Applied Physiology

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The influence of gender, exercise, and thermal stress on caffeine pharmacokinetics is unclear. We hypothesized that these factors would not have an effect on the metabolism of caffeine. Eight women participated in four 8-h trials and six men participated in two 8-h trials after the ingestion of 6 mg/kg caffeine. The women performed two resting trials (1 in the follicular phase and 1 in the luteal phase of the menstrual cycle) and two exercise trials (90 min of cycling exercise at 65% of maximal O(2) uptake, 1 h after caffeine ingestion) in the follicular phase (1 without and 1 with an additional thermal stress). The men performed one exercise and one resting trial. Menstrual cycle, gender, and exercise, with or without an additional thermal stress, had no effect on the pharmacokinetic measurements or urine caffeine. There was a trend for higher plasma caffeine and lower plasma paraxanthine concentrations in the women. These results confirm that gender, exercise, and thermal stress have no effect on caffeine pharmacokinetics in men and women.

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Section: Discussionsupporting

confidence: 91%

mentioning

confidence: 99%

Effects of exercise and thermal stress on caffeine pharmacokinetics in men and eumenorrheic women

McLean

Graham

2002

Journal of Applied Physiology

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“…139 Theophylline is found mostly in tea and anti-asthma medications. 140 Electrolyte Imbalance. Electrolyte imbalances do not usually occur in trained, acclimatized individuals who engage in physical activity and eat a normal diet.…”

Section: Lack Of Acclimatization Tomentioning

confidence: 99%

National Athletic Trainers' Association Position Statement: Exertional Heat Illnesses

Casa¹,

DeMartini²,

Bergeron³

et al. 2015

Journal of Athletic Training

168

353

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Objective: To present recommendations for the prevention, recognition, and treatment of exertional heat illnesses and to describe the relevant physiology of thermoregulation.Background: Certified athletic trainers evaluate and treat heat-related injuries during athletic activity in ''safe'' and highrisk environments. While the recognition of heat illness has improved, the subtle signs and symptoms associated with heat illness are often overlooked, resulting in more serious problems for affected athletes. The recommendations presented here provide athletic trainers and allied health providers with an integrated scientific and practical approach to the prevention, recognition, and treatment of heat illnesses. These recommendations can be modified based on the environmental conditions of the site, the specific sport, and individual considerations to maximize safety and performance.Recommendations: Certified athletic trainers and other allied health providers should use these recommendations to establish on-site emergency plans for their venues and athletes. The primary goal of athlete safety is addressed through the prevention and recognition of heat-related illnesses and a welldeveloped plan to evaluate and treat affected athletes. Even with a heat-illness prevention plan that includes medical screening, acclimatization, conditioning, environmental monitoring, and suitable practice adjustments, heat illness can and does occur. Athletic trainers and other allied health providers must be prepared to respond in an expedient manner to alleviate symptoms and minimize morbidity and mortality.Key Words: heat cramps, heat syncope, heat exhaustion, heat stroke, hyponatremia, dehydration, exercise, heat tolerance H eat illness is inherent to physical activity and its incidence increases with rising ambient temperature and relative humidity. Athletes who begin training in the late summer (eg, football, soccer, and cross-country athletes) experience exertional heat-related illness more often than athletes who begin training during the winter and spring. [1][2][3][4][5] Although the hot conditions associated with late summer provide a simple explanation for this difference, we need to understand what makes certain athletes more susceptible and how these illnesses can be prevented. PURPOSEThis position statement provides recommendations that will enable certified athletic trainers (ATCs) and other allied health providers to (1) identify and implement preventive strategies that can reduce heat-related illnesses in sports, (2) characterize factors associated with the early detection of heat illness, (3) provide on-site first aid and emergency management of athletes with heat illnesses, (4) determine appropriate return-toplay procedures, (5) understand thermoregulation and physiologic responses to heat, and (6) recognize groups with special concerns related to heat exposure. ORGANIZATIONThis position statement is organized as follows:1. Definitions of exertional heat illnesses, including exerciseassociated muscle (heat) cramps, he...

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“…Since theophylline elimination can be influenced by diet (Kappas el al., 1976) and exercise (Schlaeffer et al, 1984), feeding and exercise schedules were kept rigorously constant from one week before the first trial through the course of the entire study. The ponies received approximately 3 kg of bran and oat mash twice weekly, while the thoroughbreds received 6 kg daily.…”

Section: Animalsmentioning

confidence: 99%

The lack of effect of inoculation with equine influenza vaccine on theophylline pharmacokinetics in the horse

Horner²,

Blay³

et al. 1986

Vet Pharm & Therapeutics

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Several studies conducted during the past few years have shown that the pharmacokinetics of a variety of drugs may be altered following viral infection or vaccination. The elimination of drugs which are extensively metabolized, such as theophylline, may be prolonged, especially following exposure to RNA viruses such as Type A influenza or similar orthomyxoviruses. The purpose of this study was to determine whether vaccination of horses with equine influenza virus affected pharmacokinetic parameters describing the distribution and elimination of intravenously administered theophylline. Three thoroughbred horses and three ponies were vaccinated with a trivalent vaccine containing inactivated strains of A/Equi 1 (Prague), A/Equi 2 (Miami) and A/Equi 2 (Kentucky 81). Antibody titre, serum interferon concentrations, and the pharmacokinetic parameters t1/2 beta, Vc, Vd(ss), Vd(area) and ClB were measured at various intervals after vaccination. Antibody titre increased substantially in only two animals, while plasma interferon was detectable in low concentrations in four subjects. There was no significant change in any parameter describing the pharmacokinetics of theophylline when measured 2, 6, or 12 days after vaccination. It is suggested that the failure of vaccination to substantially increase plasma interferon concentrations, and thereby alter theophylline elimination, was related to the use of an inactivated viral vaccine, the only type available for vaccination of horses against infection with equine influenza. Regular use of such vaccines, as is required by most Racing Authorities, is therefore unlikely to affect drug withdrawal times.

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Effect of Exercise and Environmental Heat on Theophylline Kinetics

Cited by 24 publications

References 14 publications

Effects of exercise and thermal stress on caffeine pharmacokinetics in men and eumenorrheic women

Effects of exercise and thermal stress on caffeine pharmacokinetics in men and eumenorrheic women

National Athletic Trainers' Association Position Statement: Exertional Heat Illnesses

The lack of effect of inoculation with equine influenza vaccine on theophylline pharmacokinetics in the horse

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