What Are 2 General Factors That Can Influence Drug Metabolism?

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..

What does increased metabolism of a drug mean?

Drug metabolism is the term used to describe the biotransformation of pharmaceutical substances in the body so that they can be eliminated more easily.

What factors affect drug metabolism?

Many factors affect the rate and pathway of metabolism of drugs, and the major influences can be sub-divided into internal (physiological and pathological) and external (exogenous) factors as indicated below: Internal: species, genetic (strain), sex, age, hormones, pregnancy, disease. External: diet, environment.

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.

Where does drug metabolism occur?

Most drugs must pass through the liver, which is the primary site for drug metabolism. Once in the liver, enzymes convert prodrugs to active metabolites or convert active drugs to inactive forms. The liver’s primary mechanism for metabolizing drugs is via a specific group of cytochrome P-450 enzymes.

Does liver damage slow metabolism?

A healthy liver can metabolize fats and toxins easily, resulting in a high-functioning metabolism that burns calories efficiently and a body that’s full of energy. However, if it becomes ‘clogged,’ it is unable to break down fats and harmful substances, and, in effect, creates more fat to store the toxins.

How do drugs affect the liver?

Chronic use of some drugs, such as heroin, inhalants, and steroids (appearance- and performance-enhancing drugs), may lead to significant damage to the liver. This damage can be worse when these drugs are combined with alcohol or other drugs.

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.

What are the two categories 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.

How does liver disease affect drug metabolism?

Cirrhosis causes changes in the architecture of the liver leading to changes in blood flow, protein binding, and drug metabolizing enzymes. Drug metabolizing enzymes are primarily decreased due to loss of liver tissue. However, not all enzyme activities are reduced and some are only altered in specific cases.

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 medications should be avoided with liver disease?

The 10 Worst Medications for Your Liver1) Acetaminophen (Tylenol) … 2) Amoxicillin/clavulanate (Augmentin) … 3) Diclofenac (Voltaren, Cambia) … 4) Amiodarone (Cordarone, Pacerone) … 5) Allopurinol (Zyloprim) … 6) Anti-seizure medications. … 7) Isoniazid. … 8) Azathioprine (Imuran)More items…•Feb 11, 2019

Why are drugs monitored?

The selection of drugs for therapeutic drug monitoring is important as the concentrations of many drugs are not clearly related to their effects. For selected drugs therapeutic drug monitoring aims to enhance drug efficacy, reduce toxicity or assist with diagnosis.

What are the four stages of drug metabolization?

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

Do all drugs undergo first pass metabolism?

All drugs given by the oral route undergo a degree of first pass metabolism either in the gut or the liver, with some drugs being destroyed before they reach the systemic circulation.