FB - Pharmacokinetics I Flashcards
What are the four fundamental principles of pharmacokinetics in medicines?
Absorption, Distribution, Metabolism, Excretion (ADME)
What does the absorption rate constant (Ka) indicate in pharmacokinetics?
The rate at which a drug is absorbed into the bloodstream
Define the ‘therapeutic window’ in pharmacology.
The range of drug concentrations in the body that is effective without being toxic
What are some common dosage regimens in pharmacotherapy?
Intermittent dosing, continuous infusion, slow release formulations
Why are slow release medications beneficial?
They help maintain drug concentrations within the therapeutic window for longer periods
What are the two types of intravenous dosing?
Intermittent injection and continuous infusion
What is the purpose of therapeutic drug monitoring (TDM)?
To optimize drug dosages for effective treatment, especially in patients with varying pathophysiological conditions
How are drug dosages adjusted?
Based on factors like patient’s age, weight, renal function, and the drug’s pharmacokinetic properties
How does the body’s absorption of a drug relate to its pharmacological effect?
Faster absorption generally leads to a quicker onset of the drug’s effect
What factors influence a drug’s distribution in the body?
Blood flow to tissues, tissue binding, and the drug’s lipid solubility
How does metabolism affect a drug’s activity in the body?
Metabolism can either activate a prodrug, inactivate an active drug or generate pharmacologically active metabolite(s)
What role does excretion play in pharmacokinetics?
It removes the drug or its metabolites from the body, ending its action
What is the significance of the half-life (t½) of a drug?
It indicates the time it takes for the drug’s plasma concentration to reduce by half
How does renal function affect drug excretion?
Impaired renal function can lead to reduced drug clearance and increased risk of toxicity
Why is patient compliance important in pharmacotherapy?
Non-compliance can lead to suboptimal therapeutic outcomes or increased risk of adverse effects
What are the challenges associated with high-frequency dosing regimens?
They can be inconvenient and increase the risk of non-compliance
What is the advantage of intermittent injection in IV dosing?
It allows control over drug concentrations and can prevent toxicity
How does continuous infusion benefit patients?
It maintains a constant drug concentration in the bloodstream
What is the importance of the loading dose in pharmacokinetics?
It rapidly achieves the desired therapeutic concentration of a drug in the body
How does the concept of a therapeutic window guide dosage adjustment?
It helps in maintaining drug concentrations within a safe and effective range
What factors are considered in therapeutic drug monitoring?
Drug levels, patient’s clinical response, potential side effects, drug-drug interactions
Why is monitoring renal function important in drug dosing?
To adjust dosages in patients with renal impairment and avoid toxicity
How can drug interactions influence pharmacokinetics?
They can alter absorption, metabolism, and excretion, affecting drug efficacy and safety
What is the impact of liver function on drug metabolism?
Impaired liver function can reduce drug clearance and increase the risk of adverse effects
