Pharmacokinetics

1. Discuss the four main processes that make up pharmacokinetics (absorption, distribution, metabolism, and excretion), and appropriately apply these processes to clinical usefulness.

•Drug absorption: the movement of a drug from its site of administration into the blood

◦Rate of absorption determines how soon effects begin

◦Amount of absorption helps determine how intense the effects will be

◦Commonly used routes of absorption: Intravenous (IV), Intramuscular (IM), Subcutaneous(SubQ) and Oral (p.o.)

•Drug distribution: the movement of drugs throughout the body

•Drug metabolism: a.k.a. Biotransformation; the enzymatic alteration of drug structure, most often takes place in the liver

•Drug excretion: the removal of drugs from the body; can exit body through urine, sweat, saliva, breast milk and expired air

2. Discuss the advantages and disadvantages of the various techniques of drug administration as they relate to pharmacokinetics, noting especially any barriers to absorption associated with intravenous, intramuscular, and oral administration. Students should also compare oral administration with parenteral administration.

Comparing oral and parenteral administration:

•Because of ease, convenience and relative safety, oral is preferred.

•People would want parenteral if:

◦Emergencies required rapid onset of drug action

◦Situations where plasma drug levels might be tightly controlled

◦Treatment with drugs that would be destroyed by gastric acidity, digestive enzymes, or hepatic enzymes if given orally.

◦Treatment with drugs that would cause severe local injury if administered by mouth

◦Treating a systemic disorder with drugs that cannot cross membranes

◦Treating conditions for which patients with prolonged effects of a depot preparation might be desirable

◦Treating patients who cannot/will not take drugs orally

LOOK @ TABLE 4-1

3.Relate the six steps of the nursing process to the administration of medications. List the Six Rights of Drug Administration and the patient's rights regarding medications administered by healthcare providers.

•Verify identity of the patient

•Read the medication label carefully

•Verify dosage calculations

•Implement any special handling the drug may require

•Don't administer any drug if you don't understand the reason of its use Drug

•Patient

•Dose

•Route

•Time

•Documentation

Patients have the right to deny their medication

4.Discuss the purpose of pre-administration assessment.

Has 3 purposes: collecting data to evaluate therapeutic responses, identifying high risk patients and assessing the patients capacity for self-care.

5. Discuss the analysis of the data and development of nursing diagnoses to:

(1) judge the appropriateness of the prescribed regimen

(2) identify health problems the drug might cause

(3) determine the patient's capacity for self-care.

(1) Judging the appropriateness of the prescribed regimen: You should question the drugs appropriateness if the drug has no actions that are known to benefit individuals with the patient's medical diagnosis, if the patient failed to respond to the drug in the past, if the patient had a serious adverse reaction to the drug in the past, or if the patient has a condition or is using a drug that contraindicates the prescribed drug. If any of these conditions apply, you should con

(2) Identify health problems the drug might cause: Analysis must identify potential adverse effects and drug interactions. This is accomplished by integrating knowledge of the drug under consideration and the data collected during assessment. Knowledge of the drug itself will indicate adverse effects that practically all patients are likely to experience. Date on the individual patient will indicate additional adverse effects and interactions to which the particular patient is predisposed. Once potential adverse effects and interactions have been identified, pertinent nursing diagnoses can be easily formulated.

For example: if treatment is likely to cause respiratory depression, an appropriate nursing diagnosis would be "risk for impaired gas exchange related to drug therapy."

(3) Determine the patient's capacity for self-care: The analysis must characterize the patient's capacity for self-care. It should indicate potential impediments to self care (eg, visual impairment, reduced manual dexterity, impaired cognitive function, insufficient understanding of the prescribed regimen) so that these factors can be addressed in the care plan. To varying degrees, nearly all patients will be unfamiliar with self-medication and the drug regimen. Accordingly, a nursing diagnosis applicable to almost every patient is "knowledge deficit related to the drug regimen." P.g. 11

6. Develop a plan of care that does the following:

(1) defines the goal of drug therapy

(2) is prioritized based on the drug under consideration and the patient's unique characteristics

(3) identifies nursing interventions based on

[a] drug administration

[b] interventions to enhance therapeutic effects

[c] interventions to minimize adverse effects and interactions

[d] patient education

(4) establishes objective criteria for evaluation

SAME AS NUMBER 7 in INTRO to PHARM 1st Objective.

7. Describe the five diverse and important topics in pharmacology:

(1) landmark drug legislation in the United States that reflects the evolution in our national viewpoint on regulation of the pharmaceutical industry

(2) new drug development (e.g., the cost of more than $800 million to develop a new drug)

(3) the nuances of formulating drug names

(4) over-the-counter drugs

(5) sources of drug information.

All these topics have significant implications for pharmacology and nursing care. Such information requires the profession of nursing and individual nurses to participate in continuing education in pharmacology and its administration.

Already answered in previous objective

8. Discuss Phases I, II, III, and IV of the clinical testing of new drugs. Discuss the ethical and legal implications for the different phases of clinical testing.

Phase I studies involve the use of healthy human volunteers to test the drugs. In Phases II and III, drugs are tested in patients. Upon completion of Phase III, the drug manufacturer applies to the FDA for conditional approval.

Two problems: Information on drug use in women and children have been limited and second, new drugs are likely to have adverse effects that were not detected during clinical trials.

Until recently, FDA barred all women of child-bearing age from Phase I and Phase II trial - even if they're not pregnant and were using birth control. Only women with life-threatening illnesses might respond to the drug under study. Because there's limited information on how women will respond to the drugs, it is hard to dose administration of drug.

9. Explain the purpose of Phase IV clinical studies after regulatory (i.e., FDA) approval. Discuss the important information that can be gained from

Phase IV (postmarketing surveillance) of clinical drug testing and explain the roles and responsibilities of the nurse, nurse practitioner, and physicianin gathering and reporting new data.

It is important for nurses and other healthcare professionals to appreciate the limitation of the drug development process. The problems are of particular concern. First until recently information on drug use in woman and children has been limited. Second, new drugs are likely to have adverse effects that were not detected during clinical trials.

10. Discuss chemical, generic, and proprietary (trade or brand) names of drugs and explain the benefits, if any, of generic drugs over brand-name drugs.

Drugs have three types of names: (1) a chemical name, (2) a generic or nonproprietary name, and (3) a trade or proprietary name.

Chemical name: the chemical name constitutes a description of a drug using the nomenclature of chemistry. A drug's chemical name can be long and complex. Because of their complexity, chemical names are inappropriate for everyday use.

Generic name: the generic name of a drug is assigned by the United States Adopted Names Council. Each drug has only one generic name. The generic name is also known as the nonproprietary name. Generic names are less complex than chemical names.

Trade name: Trade names, also known as proprietary or brand names, are the names under which a drug is marketed. These names are created by drug companies with the intention that they be easy for nurses, physicians, pharmacists, and consumers to recall and pronounce. Trade names must be approved by the FDA. the review process tries to ensure that no two trade names are too similar. *certain active drugs in allegra are different in other countries - some are for allergies some are for migraines.

Do significant difference exist between different brands of the same drug? And if such differneces do exist, do they justify the use of trade names? The answer for both questions is NO!

11. Identify appropriate resources for pharmacology information and patient care and discuss reasons why, in particular, some may be more suitable

than others for a specific purpose (e.g., a specific type of information that is sought).

Newsletters: The Medical Letter on Drugs and Therapeutics is a bimonthly publication that gives current information on drugs. It is available both in print and online.

Prescriber's Letter is a monthly publication with very current information. Unlike The Medical Letter, which usually focuses on just two or three drugs, this newsletter addresses (briefly) most major drug-related developments - from new drugs to FDA warnings to the new uses of older agents. Available both print and online versions

Reference books: the Physicians' Desk Reference, also known as the PDR, is a reference work financed by the pharmaceutical industry. The information on each drug is identical to the FDA- approved information on its package insert. The PDR is annually and it's available online.

Drug Facts and Comparisons is a comprehensive reference that contains monographs on virtually every drug marketed in the United States. Information is provided on drug actions, indications, warnings, precautions, adverse reactions, dosage, and administration. It is available in loose-leaf format (updated monthly) an online format (updated monthly), and a hardcover format (published annually)

The Internet: the internet can be a valuable source of drug information. However, since anyone regardless of qualifications can post information, not everything you find will be accurate. Accordingly, you need to exercise discretion when searching for information.