Related Experiment Video
Updated: Aug 6, 2026
07:51
High-throughput Identification of Synergistic Drug Combinations by the Overlap2 Method
Published on: May 21, 2018
Use of single doses and rapid sampling to detect interactions with cimetidine
European Journal of Clinical Pharmacology
|January 1, 1984
Summary
A single dose of cimetidine significantly altered theophylline elimination in most subjects. This study suggests a rapid screening method for detecting drug interactions between cimetidine and theophylline.
Area of Science:
- Pharmacology
- Drug Interactions
- Clinical Pharmacology
Background:
- Cimetidine is known to interact with theophylline.
- Understanding the pharmacokinetics of drug interactions is crucial for patient safety.
Purpose of the Study:
- To demonstrate the drug interaction between cimetidine and theophylline using a single dose of cimetidine.
- To evaluate a potential rapid screening method for detecting this interaction.
Main Methods:
- Eleven healthy subjects received theophylline infusions on two occasions.
- Plasma theophylline levels were monitored frequently.
- A single oral dose of cimetidine (400 mg) was administered during one of the theophylline infusions.
Main Results:
- A deflection in the theophylline elimination curve was observed in 9 out of 11 subjects after cimetidine administration.
- This indicates a significant alteration in theophylline metabolism or elimination.
Conclusions:
- A single dose of cimetidine can effectively demonstrate an interaction with theophylline.
- This approach may serve as a rapid screening tool for identifying cimetidine-theophylline interactions.
Related Concept Videos
01:11Bioavailability Study Design: Single Versus Multiple Dose Studies
Bioavailability studies are essential for understanding how a drug is absorbed, distributed, metabolized, and excreted in the body. These studies assess the extent and rate at which the active pharmaceutical agent becomes available at the site of action. The design of bioavailability studies can involve single-dose or multiple-dose regimens, each with distinct advantages and limitations.Single-dose studies are the preferred approach due to their simplicity and reduced drug exposure for...
01:30Measurement of Bioavailability: Pharmacokinetic Methods
Pharmacokinetics is a vital branch of pharmacology that examines how drugs are absorbed, distributed, metabolized, and excreted by the body. Two key methodologies in pharmacokinetics are plasma drug concentration studies and urinary drug excretion analyses, both of which provide critical insights into a drug's therapeutic efficacy and bioavailability.Plasma Drug Concentration-Time StudiesPlasma drug concentration-time studies involve analyzing blood samples at specific intervals to quantify...
01:20Measurement of Bioavailability: Pharmacodynamic Methods
Pharmacodynamic methods provide insights into a drug's effects on physiological processes over time and play a crucial role in understanding bioavailability and therapeutic efficacy. These methods can be broadly classified into acute pharmacological and therapeutic response approaches, each with distinct mechanisms and applications.The acute pharmacological response method directly correlates a drug's physiological effects, such as ECG or pupil diameter changes, to its time course in the body.
01:26Therapeutic Drug Monitoring: Drug Analysis Methods
Therapeutic Drug Monitoring (TDM) is a clinical practice that measures specific drug levels in a patient's blood or body tissues to tailor drug therapy effectively. This monitoring is critical for managing drugs with narrow therapeutic indices like digoxin and phenytoin, ensuring they are both safe and effective. For instance, monitoring theophylline levels in asthma patients involves precision and sensitivity to adjust doses according to individual responses to therapy, ensuring efficacy and...
01:08Effect of Hepatic Disease on Pharmacokinetics: Dose Adjustments Due to Hepatic Impairment
Hepatic impairment, characterized by decreased liver function, does not uniformly mandate adjustments in drug dosage. Whether dosage modifications are necessary depends on various factors related to the drug's metabolism and elimination pathways. If a drug is primarily excreted via the kidneys and bypasses significant hepatic processing, if it undergoes minimal metabolic transformation in the liver, or if it is volatile and primarily expelled through the lungs, dose adjustments may not be...
01:14Pharmacokinetic–Pharmacodynamic Relationship: Duration of Dose-Effect Relationship
For drugs producing a quantal response, onset occurs when plasma concentration reaches a minimum effective level (Cmin). The drug's action duration depends on how long the plasma concentration remains above Cmin.Two primary factors influence this duration: dose size and the rate of drug removal from the action site. Both depend on the drug's redistribution to poorly perfused tissues and elimination processes. A larger dose promotes rapid onset and prolongs the effect's duration.Consider a...