Podcast
Questions and Answers
What is the effect of alkalinization of urine on the clearance of acidic drugs?
What is the effect of alkalinization of urine on the clearance of acidic drugs?
How do NSAIDs, such as indomethacin, affect the excretion of certain drugs?
How do NSAIDs, such as indomethacin, affect the excretion of certain drugs?
What is the effect of amphetamine on the absorption of tetracycline?
What is the effect of amphetamine on the absorption of tetracycline?
Why does alkalinization of urine increase the clearance of acidic drugs?
Why does alkalinization of urine increase the clearance of acidic drugs?
Signup and view all the answers
What is the effect of reducing renal blood flow on the excretion of certain drugs?
What is the effect of reducing renal blood flow on the excretion of certain drugs?
Signup and view all the answers
What is the mechanism by which alkalinization of urine increases the clearance of acidic drugs?
What is the mechanism by which alkalinization of urine increases the clearance of acidic drugs?
Signup and view all the answers
Why do NSAIDs, such as indomethacin, increase the toxicity of certain drugs?
Why do NSAIDs, such as indomethacin, increase the toxicity of certain drugs?
Signup and view all the answers
What is the effect of reducing renal vasodilatory prostaglandins on the excretion of certain drugs?
What is the effect of reducing renal vasodilatory prostaglandins on the excretion of certain drugs?
Signup and view all the answers
What is the effect of alkalinization of urine on the toxicity of acidic drugs?
What is the effect of alkalinization of urine on the toxicity of acidic drugs?
Signup and view all the answers
Why do acidic drugs have a higher clearance in alkaline urine?
Why do acidic drugs have a higher clearance in alkaline urine?
Signup and view all the answers
Study Notes
Pharmacokinetic Interactions
- Any drug, chemicals, or food can affect pharmacokinetic processes.
- Pharmacokinetic interactions involve absorption, distribution, metabolism, and elimination (ADME) processes.
Absorption
- Most interactions in the gut result in decreased rather than increased absorption.
- Either the rate or the total amount of absorbed drug can be reduced.
- Induction or inhibition of drug transporter proteins can affect absorption.
Distribution
- P-glycoproteins play a crucial role in the distribution of drugs into the brain and maintaining the blood-brain barrier (BBB).
- Inhibitors of these transporters can increase the uptake of drug substrates into the brain.
Metabolism
- Metabolism involves chemical alteration of drugs to make them more easily excreted by the kidneys.
- The liver is the primary site of metabolism, with enzymes found in the endoplasmic reticulum of liver cells.
- Phase I metabolism involves oxidation, reduction, and hydrolysis reactions.
- Phase II metabolism involves conjugation reactions with glucuronic acid, sulfuric acid, and other substances.
- CYP450 mixed-function oxidases are responsible for 40-50% of metabolism, with isoenzymes CYP1A, CYP2C19, CYP2D6, and CYP3A4 being the most important.
Enzyme Induction
- Changes in enzyme induction can affect drug metabolism.
- Verapamil increases dofetilide blood level by increasing hepatic blood flow and absorption rate.
- Grapefruit juice inhibits CYP450 isoenzyme CYP3A4 in the gut, reducing the metabolism of oral calcium channel blockers.
Enzyme Inhibition
- Enzyme inhibitors can decrease the rate of drug metabolism.
- Examples of enzyme inducers include rifampicin, barbiturates, phenytoin, carbamazepine, and cigarette smoking.
Elimination
- Changes in renal blood flow can affect elimination.
- Alkalinization of urine can increase the excretion of basic drugs.
- NSAIDs such as indomethacin can reduce excretion and increase the toxicity of certain drugs.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
This quiz covers pharmacokinetic interactions, including the effects of medications on the body and how they interact with each other. Learn about the concepts of pharmacokinetics and how they apply to real-world scenarios.
