Related Experiment Video
Updated: Aug 7, 2026
10:05
Testing the Efficacy of Pharmacological Agents in a Pericardial Target Delivery Model in the Swine
Published on: July 7, 2016
The effect of everyday exercise on steady state digoxin concentrations
P D Hall1, W R Garnett, K W Kolb
1University of Texas Health Science Center.
Journal of Clinical Pharmacology
|December 1, 1989
Summary
Everyday exercise significantly impacts serum digoxin concentrations. Digoxin levels changed during rest and exercise, necessitating consideration during interpretation.
Area of Science:
- Pharmacology
- Exercise Physiology
Background:
- Serum digoxin concentration monitoring is crucial for therapeutic drug management.
- Physical activity can influence drug pharmacokinetics, including digoxin.
Purpose of the Study:
- To investigate the impact of a 1-hour walking exercise on serum digoxin levels.
- To determine if exercise alters digoxin concentrations in older adult males.
Main Methods:
- Nine male subjects (58-74 years) with stable digoxin doses underwent three phases: rest, exercise, rest.
- Serum digoxin concentrations were measured every 20 minutes throughout the 3-hour protocol.
- Statistical analysis included repeated measures ANOVA and paired t-tests with Bonferroni correction.
Main Results:
- Serum digoxin concentrations increased by 30% during the initial rest phase.
- Exercise led to a 26.8% decrease in digoxin levels, while subsequent rest increased them by 36.6%.
- Significant changes (P < .01) in digoxin concentrations were observed across all study phases.
Conclusions:
- Physical activity, even light exercise, significantly alters serum digoxin concentrations.
- Clinicians should account for recent physical activity when interpreting digoxin levels.
- Age showed a weak correlation with digoxin concentration changes during exercise.
Related Concept Videos
01:14Time Course of Drug Effect
The progression of a drug's impact can be analyzed by examining both the concentration-time course and the effect-time course. The concentration-time course is determined by the drug's half-life and is influenced by factors such as its pharmacokinetics, including absorption, distribution, metabolism, and elimination. The effect of the drug is often related to its concentration in the plasma and is calculated using the maximum drug effect and the plasma concentration that generates 50 percent of...
01:05Steady State Concentration
A steady state refers to the level of a drug in the body once it has reached an equilibrium between administration and elimination. It represents the point at which the drug administration rate equals the drug elimination rate, resulting in a relatively constant concentration in the body over time. The dynamic equilibrium is crucial to ensure the drug's effectiveness with minimal risk of toxicity.
Most drugs are administered in repeated doses at fixed intervals or through continuous intravenous...
Most drugs are administered in repeated doses at fixed intervals or through continuous intravenous...
01:26Heart Failure Drugs: Inotropic Agents
Positive inotropic agents are commonly used as the first line of treatment for heart failure. One such agent is digoxin, derived from the genus Digitalis, which has been known for centuries but effectively utilized since 1785. However, these cardiac glycosides can have potentially toxic effects due to their mechanism of action, which involves inhibiting Na+/K+-ATPase and increasing contractility. Digoxin is absorbed orally and distributed in various tissues, including the CNS. It has a long...
01:20Exercise and Cardiovascular Response
Exercise significantly impacts cardiovascular response, which is crucial for understanding patient health and designing effective treatment plans.
Light to moderate physical activity initiates a series of interconnected responses in the body. The heart rate modestly increases in anticipation of the workout, followed by widespread vasodilation as oxygen consumption by skeletal muscles increases. This results in decreased peripheral resistance, increased capillary blood flow, and accelerated...
Light to moderate physical activity initiates a series of interconnected responses in the body. The heart rate modestly increases in anticipation of the workout, followed by widespread vasodilation as oxygen consumption by skeletal muscles increases. This results in decreased peripheral resistance, increased capillary blood flow, and accelerated...
01:15Determination of Multiple Dosing Parameters: Steady-State, Minimum and Maximum Concentrations
Gentamicin, an aminoglycoside antibiotic, is commonly administered via intermittent intravenous infusion to treat severe infections. An intermittent one-hour infusion of gentamicin, administered at eight-hour intervals, allows for precise control of plasma drug concentrations, minimizing toxicity while ensuring therapeutic efficacy. Pharmacokinetic principles govern the dynamics of plasma concentrations and can be mathematically described using specific equations.The plasma drug concentration...
01:15Pharmacodynamic Models: Logarithmic Concentration–Effect Model
The log-linear model is a pharmacological framework used to describe the relationship between drug concentration and its effect. This model is particularly relevant when the observed effects range between 20% and 80% of the drug’s maximum effect (Emax), where a near-linear relationship is observed between the log of drug concentration and the measured effect. However, the log-linear model does not predict the maximum possible effect (Emax) or the effect at zero drug concentration, limiting its...