Question: What Factors Affect Metabolism Of A Drug?

What is the most common medication problem in the elderly?

Warfarin is one of the most common causes of medication-related hospitalizations in older adults.

To reduce the risk of serious problems, one may need to apply extra care in monitoring warfarin effect (via the prothrombin blood test) and extra care in checking for interactions when a new drug is prescribed..

How can you tell if someone is overmedicated?

Recognize the Warning Signs: Knowing symptoms to watch for can help you determine if your loved one may be overmedicated. Potential signs include: drowsiness; physical complications, like dry mouth and ulcers; confusion; withdrawal from family or friends; hallucinations; dizziness or falls; fractures; and seizures.

What are the two most important organs for drug metabolism?

The principal organs of drug metabolism are the liver and (for orally taken drugs) the small intestine.

What factors can affect drug metabolism in an elderly client and why?

Aging results in a number of significant changes in the human liver including reductions in liver blood flow, size, drug-metabolizing enzyme content, and pseudocapillarization. Drug metabolism is also influenced by comorbid disease, frailty, concomitant medicines, and (epi)genetics.

What are the phases of drug metabolism?

Drug metabolism reactions comprise of two phases: Phase I (functionalization) reactions such as oxidation, hydrolysis; and Phase II (conjugation) reactions such as glucuronidation, sulphate conjugation. Oxidation reactions are the most common and vital.

What is the main purpose of drug metabolism?

The majority of metabolic processes that involve drugs occur in the liver, as the enzymes that facilitate the reactions are concentrated there. The purpose of metabolism in the body is usually to change the chemical structure of the substance, to increase the ease with which it can be excreted from the body.

Which drug has highest volume of distribution?

ExamplesDrugVDCommentsWarfarin8 LReflects a high degree of plasma protein binding.Theophylline, Ethanol30 LRepresents distribution in total body water.Chloroquine15000 LShows highly lipophilic molecules which sequester into total body fat.NXY-0598 LHighly charged hydrophilic molecule.

What is considered a high VD?

If the volume of distribution is larger than 42, the drug is thought to be distributed to all tissues in the body, especially the fatty tissue. Some drugs have volume of distribution values greater than 10,000 L! This means that most of the drug is in the tissue, and very little is in the plasma circulating.

What are 2 general factors that can influence drug metabolism?

Various physiological and pathological factors can also affect drug metabolism. Physiological factors that can influence drug metabolism include age, individual variation (e.g., pharmacogenetics), enterohepatic circulation, nutrition, intestinal flora, or sex differences.

What are the 2 phases of drug metabolism?

Phase I and Phase II Drug Metabolism Phase I reactions involve intramolecular modifications: oxidation, reduction, and hydrolysis; whereas phase II reactions result in conjugation of the drug with an endogenous substance by acetylation, glucuronidation, sulfation (also called sulfonation), and methylation.

What are the 3 phases of drug action?

Drug action usually occurs in three phases: Pharmaceutical phase. Pharmacokinetic phase. Pharmacodynamic phase.

Is it safe to take all medications at once?

Risks of Taking Multiple Medicines Because most medicines can have side effects, the more medicines you take, the more likely you will have side effects. Taking certain medicines can also increase the risk for falls. You are at higher risk for drug interactions.

How does weight affect drug effectiveness?

Changes in body weight can influence the amount of medicine you need to take and how long it stays in your body. The circulatory system may slow down, which can affect how fast drugs get to the liver and kidneys.

How does gender affect drug effectiveness?

Physiologic differences between men and women affect drug activity, including pharmacokinetics and pharmacodynamics. Pharmacokinetics in women is affected by lower body weight, slower gastrointestinal motility, less intestinal enzymatic activity, and slower glomerular filtration rate.

What are the four stages of drug metabolization?

The four stages are absorption, distribution, metabolism, and excretion.

How does age affect metabolism of drugs?

Thus, age-related changes in drug metabolism should be considered a typical phenotypic characteristic of the aging process. Generally, older age is associated with increased blood concentrations of drugs and altered metabolism, reduced effectiveness, and increased risk of adverse reactions for many medications (2).

Why is taking multiple medications a problem for the elderly?

Polypharmacy is an area of concern for elderly because of several reasons. Elderly people are at a greater risk for adverse drug reactions (ADRs) because of the metabolic changes and reduced drug clearance associated with ageing; this risk is furthermore exacerbated by increasing the number of drugs used.

How does hydration status affect drugs in the body?

Additionally, an individual’s hydration status can be affected by medications that have the potential to alter thirst sensation, leading to decreased fluid intake, and diuretics, which lead to increased urine output.

How does dehydration affect drug distribution?

Dehydration or reduced rates of blood flow to tissues of distribution can affect the magnitude of the volume of distribution. For example, the LD of a drug with a volume of distribution of 0.3 L/kg of body weight and a target plasma drug concentration of 1 μg/ml is 0.3 mg/kg of body weight.