NURS 1550- Distribution, Biotranformation, and Excretion of Drugs

Drug absorption

The movement of a drug from its site of administration into the blood.

Drug distribution

The movement of drugs throughout the body.

Drug metabolism

Also known as biotransformation, it is the enzymatic alteration of drug structure.

Drug excretion

The removal of drugs from the body.

Rate of dissolution

The speed at which a drug dissolves in the body.

Surface area

The amount of area available for drug absorption.

Blood flow

The rate at which blood carries drugs to tissues and organs.

Lipid solubility

The ability of a drug to dissolve in fat.

pH partitioning

The movement of a drug between acidic and basic environments.

Blood-brain barrier

A barrier that prevents most drugs from passing through capillary cells in the central nervous system.

Placental drug transfer

The movement of drugs across the placenta to the fetus.

Protein binding

The reversible attachment of a drug to albumin in the blood.

Drug half-life

The time required for the amount of drug in the body to decrease by 50%.

Glomerular filtration

The first step in renal drug excretion, where drugs are filtered out of the blood in the kidneys.

Passive tubular reabsorption

The movement of drugs from the renal tubules back into the blood.

Active tubular secretion

The active transport of drugs from the blood into the renal tubules for excretion.

pH-dependent ionization

The ionization of drugs in the urine based on the pH of the urine.

Competition for active tubular transport

The competition between drugs for transporters in the renal tubules.

Pediatric patients

Patients younger than 16 years old who respond differently to medications than adults.

Older adult patients

Patients who are older and generally more sensitive to drugs than younger adults.

Placebo effect

Any response that a patient has to a placebo is based solely on his or her psychologic reaction to the idea of taking a medication and not to any direct physiologic or biochemical action of the placebo itself.

Positive but realistic assessment

Nurses need to present a positive but realistic assessment of the effects of therapy.

Placebos in clinical trials

Placebos are primarily used for the control groups in clinical trials.

Nocebo effect

The nocebo effect refers to the negative effects that can occur when a patient expects or believes that a treatment will have negative side effects.

Variability in Absorption

Variability in absorption refers to the differences in how drugs are absorbed into the bloodstream.

Bioavailability

Bioavailability refers to the ability of a drug to reach the systemic circulation from its site of administration.

Ability of the drug to reach the systemic circulation from its site of administration

This refers to the drug's ability to be absorbed into the bloodstream and distributed throughout the body.

Variability in absorption with oral preparations

Variability in absorption occurs primarily with oral preparations rather than with parenteral administration.

Tablet disintegration time, enteric coatings, and sustained-release formulations

These factors can affect the variability in absorption of oral medications.

Other causes of variable absorption

Changes in gastric pH, diarrhea, constipation, and food in the stomach can also cause variability in absorption.

Genetics and Pharmacogenomics

Genetics and pharmacogenomics refer to the study of how genes affect individual drug responses.

Altered drug metabolism

Altered drug metabolism refers to changes in the way the body processes and eliminates drugs.

Warfarin, succinylcholine, isoniazid, cytochrome P450

These are examples of drugs and enzymes that can be affected by genetic variations and alter drug metabolism.

Altered drug targets

Genetic variations can alter the structure of drug receptors, affecting how drugs interact with the body.

Other ways genetics can influence drug responses

Some genetically determined drug responses are based on factors other than changes in drug metabolism or drug targets.

Gender

Gender can influence drug responses, such as alcohol being metabolized more slowly by women than by men.

Race

Race can influence drug responses due to genetic variations.

Psychosocial factors

Psychosocial factors, such as comorbidities and psychologic state, can influence drug responses.

Diet

Diet can influence drug responses, such as starvation reducing protein binding of drugs.

Drug interactions

Drug interactions occur when one drug alters the effects of another drug.

Promoting adherence

Promoting adherence refers to strategies to help patients take their medications as prescribed.

Simplified drug regimens

Simplified drug regimens can help promote adherence by making it easier for patients to remember and take their medications.

Clear and concise verbal and written instructions

Clear and concise instructions can help patients understand how to take their medications correctly.

Appropriate dosage form

Using the appropriate dosage form can make it easier for patients to take their medications.

Clearly labeled and easy-to-open containers

Clearly labeled and easy-to-open containers can help patients easily access and identify their medications.

Daily reminders

Daily reminders can help patients remember to take their medications.

Support system

Having a support system can help patients stay motivated and accountable for taking their medications.

Frequent monitoring

Frequent monitoring can help healthcare providers assess a patient's adherence to medication therapy.

Promoting adherence with unintentional nonadherence

Unintentional nonadherence refers to situations where patients forget or unintentionally miss doses of their medications.

Intravenous

Intravenous administration results in the fastest and most complete absorption of a drug.

Intramuscular

Intramuscular administration is a route of administration where the drug is injected into the muscle.

Subcutaneous

Subcutaneous administration is a route of administration where the drug is injected into the fatty tissue just below the skin.

Oral

Oral administration is a route of administration where the drug is taken by mouth.

Sustained-release capsules

Sustained-release capsules are formulations that release the drug slowly over an extended period of time.

Cost of sustained-release capsules

Sustained-release capsules are usually more costly than regular pills.

Crushing sustained-release capsules

Sustained-release capsules should not be crushed for appropriate absorption to take place.

Regular intervals for sustained-release capsules

Sustained-release capsules need to be taken at regular intervals throughout the day.

Slow drug metabolism

Slow drug metabolism refers to a decreased ability of the body to metabolize drugs.

Drug half-life

Drug half-life refers to the time it takes for half of the drug to be eliminated from the body.

Medication adherence

The act of consistently taking prescribed medications as directed by a healthcare professional.

Simplified regimen

A treatment plan that reduces the number of doses per day to improve medication adherence.

Visiting healthcare professional

A healthcare provider who can assist the patient with medication administration, but may not be available multiple times a day.

Independence in self-care

Allowing the patient to take responsibility for their own medication management to the extent possible.

Clear and concise instructions

Providing treatment plan information in a straightforward and easily understandable manner.

Forgetfulness

The problem of unintentionally failing to remember to take prescribed medications.

Difficulty swallowing

A potential barrier to medication adherence, but not directly related to forgetfulness.