Week 3 Overview of Key Concepts in Pharmacology

Fat-soluble vitamins

A (retinol, retinal, retinoic acid) Nausea, vomiting, headache, dizziness, blurred vision, clumsiness, birth defects, liver problems, possible risk of osteoporosis D (calciferol) Nausea, vomiting, poor appetite, constipation, weakness, weight loss, confusion, heart rhythm problems, deposits of calcium and phosphate in soft tissues

Safe practice alert

ALWAYS CHECK PATIENT ALLERGIES

Routine

Administered until the health care provider discontinues the order, or until a prescribed number of doses or days have occurred. Digoxin 0.125 mg PO daily;

Feverfew

Alleviates and helps prevent migraines; relieves pain of arthritis Increased bleeding; potentiates action of anticoagulants

St. John's Wort

Alleviates mild to moderate depression, anxiety, and sleep disorders Interacts with antidepressants, birth control pills, cyclosporine, digoxin, and human immunodeficiency virus (HIV) and cancer medications

Floor Stock

Although not required by the CSA, many hospitals and clinics require that floor stock of controlled substances be accounted for at the beginning and end of each nursing shift.

Water-Soluble Vitamins

B3 (niacin) Adverse effects: Flushing, redness of the skin, upset stomach B6 (pyridoxine, pyridoxal, and pyridoxamine) Nerve damage to the limbs, which may cause numbness, trouble walking, and pain C (ascorbic acid) Upset stomach, kidney stones, increased iron absorption Folic acid (folate) At high levels, especially in older adults, may hide signs of B12 deficiency

The FDA developed what checklist for use when selecting OTC meds

Choosing the Right Over-the-Counter Medicine

Safe use of OTC medication includes understanding the

Desired effect of the medication Potential side and adverse effects Possible allergic reactions Potential interactions with other medications and herbs Warnings Directions and dosage Features, such as safety caps

The FDA regulates herbs and dietary supplements through the

Dietary Supplement Health and Education Act (DSHEA). This form of regulation is different from that for prescription medications, despite the fact that herbs and prescription medications can act in the human body in the same way

Compliance with these regulations is monitored by the

Drug Enforcement Administration (DEA), an office within the U.S. Department of Justice

Tracking

Every time a controlled substance is purchased or dispensed, an accurate record must be documented. An inventory must be kept of all controlled substances in stock, and this inventory must be reported to the DEA every two years.

OTC medications

Examples are cold medicines, mild analgesics, vitamins, herbal preparations, and sleep aids. The FDA regulates OTC medications relative to safety and recommended dosage, but it does not regulate all supplements.

Nurses need to know why a medication is ordered for certain times and whether the times can be altered:

For example, there is a difference between medications ordered every six hours (q 6 hr.) and those ordered four times per day (qid), even though the four doses of medication are administered in a 24-hour period. A medication ordered q 6 hr. is given at regular intervals around the clock (e.g., at 6 A.M., 12 P.M., 6 P.M., and midnight) to maintain a constant blood level.

Stat

Given immediately and only once in a single dose; frequently given for emergency situations. Diazepam 10 mg IV stat for seizure

One-time/on-call

Given only once at a specified time, often before a diagnostic or surgical procedure. Ativan 1 mg IV on call to surgery

PRN

Given only when the patient requires it. Use is determined by objective and subjective assessment and clinical judgment of the nurse. A PRN medication is administered as needed, but still within identified time constraints. Morphine sulfate 4 mg IV q 2 hr. PRN pain

Saw palmetto

Helps with enlarged prostate and urinary inflammation Interacts with other hormones

Schedule I

High potential for abuse No currently accepted medical use in treatment in the United States Ex: Heroin, LSD, and methaqualone

Schedule II

High potential for abuse; may lead to severe psychological or physical dependence Has a currently accepted medical use with severe restrictions Ex: Morphine, cocaine, methadone, and methamphetamine

Disposal

If a controlled drug needs to be wasted (e.g., only a partial amount is needed for the prescribed dose), two licensed clinical staff members must witness the disposal of the substance and document the wasting of the drug in the appropriate manner.

Ginkgo biloba

Improves memory and mental alertness Increased bleeding; potentiates action of anticoagulants

Ginseng

Increases physical stamina and mental concentration Can increase heart rate and blood pressure; decreases effectiveness of anticoagulants

Schedule V

Low potential for abuse relative to the drugs in schedule IV Has a currently accepted medical use in treatment in the United States Ex: Over-the-counter cough medicines with codeine

Schedule III

Lower potential for abuse compared to the drugs in schedules I and II, in regard to moderate dependence Has a currently accepted medical use Ex: Anabolic steroids, narcotics, such as codeine or hydrocodone with aspirin or acetaminophen, and some barbiturates

Schedule IV

Lower potential for abuse relative to the drugs in schedule III; may lead to limited dependence Has a currently accepted medical use Ex: Pentazocine, meprobamate, diazepam, and alprazolam

Garlic

Lowers blood pressure and cholesterol and triglyceride levels Increased bleeding; potentiates action of anticoagulants

Tablet

Medication is compressed with binding substances and disintegrating agents into a tablet form; may have flavoring added to improve taste; used for oral, sublingual, and buccal routes. Enteric-coated tablets have a special outer covering that delays absorption as the medication dissolves in the intestines.

Capsule

Medications are enclosed in cylindrical gelatin coatings called capsules. Time-release capsules have medication particles encased in smaller casings that deliver medication over an extended period.

Topical

Medications for topical application are applied to a specific skin surface or mucous membrane of a body cavity. Nurses administer medications to the skin and mucous membranes through: Liquids and ointments applied to the eyes Suppositories inserted into the rectum or vagina Fluids instilled into a body cavity, such as the eye, ear, nose, bladder, vagina, or rectum Lotions and ointments applied to any skin surface Spray applied to the throat Absorption is affected by the vascularity of the application site. Topical administration has local effects with systemic effects possible; dose absorption may be unpredictable.

inhalant

Medications inhaled or sprayed into the mouth or nose are called inhalants. Inhalants may have local or systemic effects. Some inhalants or sprays are delivered in fixed doses.

incompatibilitiy

Mixing medications in a solution that causes precipitation, or combining a drug with another drug that causes an adverse chemical reaction is called drug incompatibility. If prescribed medications are not compatible, they should be administered separately following necessary safety measures, such as flushing the intravenous tubing between medications

Oral

Most commonly administered route Abbreviated as PO (Latin: per os, "by mouth") Designed to be swallowed with fluid Safest, most convenient, least expensive method Have slower onset of action than parenteral medications Nurses are responsible for ensuring medications taken orally are swallowed. A patient with: Difficulty swallowing may hold medication in mouth Cognitive or mental health issues may pocket medication in the cheek Certain tablets may be inappropriate for patients with: Nausea or vomiting Simultaneous gastric suctioning Swallowing difficulty Certain procedures scheduled Oral medications may: Irritate gastrointestinal lining Have an unpleasant taste Discolor teeth

Via tube

Oral medication can be administered through nasogastric, gastric, intestinal, and jejunal tubes. Tube placement must be checked before medication administration. Special safety precautions need to be taken to prevent aspiration or clogging of the tube when administering medications through small-bore feeding tubes.

To be considered a legally valid prescription, a medication order from any health care setting must include

Patient's name Date and time the order is written Name of drug to be administered Dosage of the drug Route of drug administration Frequency of drug administration Signature of the person writing the order

Subsequent legislation has continued to set standards related to medications, including

Safety Potency Sales Distribution Efficacy

skin preparation

Skin preparations include ointments (spreadable, greasy preparations), creams (not greasy but used on skin only), and lotions (solutions or suspensions used on skin, and not as sticky as creams or ointments). Transdermal patches contain medication absorbed through the skin over an extended period.

Local

Some medications, via some routes, affect only limited body areas. An example of a local response is the localized effect that results when an antipruritic lotion is applied to an insect bite.

Systemic

Some medications, via some routes, affect the whole body and effects are seen in multiple body systems. An example of a systemic response is the biologic response seen in the administration of narcotic pain medication. Effects are noted in the nervous system (sedation), respiratory system (change in respiratory rate), and gastrointestinal system (constipation).

Echinacea

Stimulates the immune system; facilitates wound healing; fights flu and colds Possible liver inflammation and damage if used with anabolic steroids or methotrexate

Suppository

Suppositories are bullet-shaped gelatin tablets commonly administered rectally or vaginally, depending on the medication. Urethral preparations are used for erectile dysfunction.

Powder

Ultrafine drug particles in a dry form is medication powder; depending on the medication, may be inhaled, mixed with food, or dissolved in liquids immediately before administration.

In the United States, official medication lists have been reported in the

United States Pharmacopeia (USP) since 1820 and the National Formulary (NF) since 1898. These sources help protect public safety by identifying medication properties that show an appropriate range of quality and purity.

Now

Used when a medication is needed quickly but not as immediately as a stat medication; given one time. Vancomycin 1 g IV now, on admission

A medication

a drug specifically administered for its therapeutic effect on physiologic function.

Many nonprescription and prescription drug formulations include

a plant or plant extract. Common examples are aspirin (willow tree bark), morphine (opium poppy), and digitalis (foxglove)

Medication orders can change on the basis of the status of the patient. For example

a sudden change in condition, an adverse response to a medication, or a patient transfer to a different care unit can necessitate a change in medication orders. Medications may need to be reordered after surgical procedures or on discharge

A drug

any substance that positively or negatively alters physiologic function.

Troches or lozenges

are medications prepared to dissolve in the mouth.

solution

are medications that are dissolved in liquid. Syrups are mixed with sugar and water. Suspensions are finely crushed medications in liquid. Elixirs are medications dissolved in alcohol and water with glycerin or other sweeteners. Drops are a sterile solution or suspension administered directly into the eye, outer ear canal, or nose, or sublingually. Injectable solutions are sterile suspensions supplied in ampules, vials, prefilled syringes, bags, or bottles.

Side effects:

are predictable, but unwanted, and sometimes unavoidable, reactions to medications. Side effects may be minor and harmless, or they may cause patient injury. Side effects may result in the patient refusing to continue a medication. Patient education regarding how to handle expected side effects can offset these reactions. For example, if nausea is a frequent side effect of a medication, the drug can be taken with a light meal to reduce this sensation. Nurses must be particularly alert for side effects when a new medication is started or the dose is increased.

Adverse effects

are severe, unintended, unwanted, and often unpredictable drug reactions. An adverse effect may occur after one dose, such as a severe allergic response, or it may develop over time, such as the development of anemia associated with a medication. When an adverse reaction occurs, the medication must be immediately stopped. Adverse reactions are reported by health care providers to the FDA by using the MedWatch program

Allergic reactions

are unpredictable immune responses to medications. Minor allergic reactions include: rash; itching of the skin; inflammation of the nasal passages, causing swelling and a clear discharge; and raised skin eruptions (hives). A severe allergic reaction is called an anaphylactic reaction and is a medical emergency. An identification bracelet or tag identifying the allergy should be worn by patients who have experienced a severe allergic reaction. This alerts medical staff to the allergy if the patient is unable to communicate.

Idiosyncratic reactions

are unpredictable patient responses to medication. These responses can be: Over response Under response Abnormal reaction to the medication For example, a patient receiving an antihistamine may become overly alert and be unable to sleep, rather than being drowsy, as expected.

Sublingual and buccal routes

are used for absorbing small amounts of medications quickly through the oral mucosa, preventing its destruction by gastric or intestinal secretions. For the sublingual route, medications are placed under the tongue to dissolve. Nitroglycerin for chest pain is administered by this route. For the buccal route, medications are placed against the mucous membrane of the cheek until dissolved. Antiemetics and opiate pain medications use this route. Sublingual and buccal medications are more potent because the drug bypasses the liver and enters the blood stream directly. They may be inactivated by gastric juices if swallowed.

The peak and trough levels of a medication are measured with

blood tests, and results are used to adjust dose amounts and monitor for toxicity. Blood samples for peak serum levels are drawn at specified times after administration on the basis of the drug half-life; samples for trough levels are drawn just before the administration of a scheduled dose.

Nonprescription

can be obtained without a health care provider's authorization. Nurses need to assess patient use of nonprescription and prescription substances and provide teaching on possible interactions among the substances.

The desired drug action is produced when a

certain drug level is reached in the body

Medications can have up to four designations

chemical name, official name, generic name, and trade name.

A specific aspect of nursing practice governed by law is the handling and distribution of

controlled substances.

The chemical name

describes the elements of the medication's molecular structure. Example: 2-(4-isobutylphenyl) propionic acid

The Pure Food and Drug Act of 1906

designated the USP and the NF as the only official authorities to establish drug standards, including the requirement that medications be free of impurities.

Medication interactions occur when a

drug's action is modified by the presence of a certain food, herb, or another medication. The interaction can alter the way the medication is absorbed, metabolized, or eliminated.

A drug's half-life is the

expected time it takes for the blood concentration to measure one half of the original drug dose due to drug elimination. For example, if a drug has a half-life of 12 hours, 50% of the drug's original dose remains in the bloodstream 12 hours after administration. After another 12 hours, only 25% of the drug's original dose remains in the bloodstream. Correct spacing of doses to maintain consistent drug levels and obtain therapeutic effects is based on the drug's half-life and is an important consideration when medications are prescribed.

The body uses Vitamins

for the biologic processes of growth, digestion, and nerve function. Water-soluble vitamins (B and C) are excreted by the body through the kidneys. Fat-soluble vitamins (A, D, E, and K) are stored by the body for use as needed; however, excess can build up in the liver, so they must be used with caution

The CSA mandates regulations

for the handling and distributing of controlled substances by manufacturers, distributors, pharmacists, nurses, and care providers.

Peak and trough levels refer to the

highest and lowest concentration of a drug in the bloodstream over time.

Peak plasma level indicates the

highest serum (blood) concentration of a drug. After the peak is reached, serum levels decrease until another dose is administered.

there is potential for misuse of OTC, including

inappropriate dosing, delay in seeking professional care, and lack of knowledge about interactions with prescription medications. It is important for the nurse to educate patients about following the package directions and notifying the health care provider that OTC meds are being used

Routes of med administration

include oral (by mouth), sublingual (under the tongue), buccal (against the cheek), through a medical tube (e.g., a nasogastric tube, percutaneous endoscopic gastrostomy [PEG] tube), topical (on skin or through mucous membranes), transdermal, parenteral (by injection or infusion), and by inhalation. Each route has advantages and disadvantages.

The quickest rate of absorption is achieved through administration of a medication

intravenously or directly into a blood vessel, followed in descending order by intramuscularly, subcutaneously, and orally administered medications.

The official name

is assigned by the U.S. Adopted Names Council, and it is usually the generic name, which is simpler than the chemical name. Example: Ibuprofen

The generic name

is not capitalized and often contains a prefix or suffix that helps to identify the drug class. For example, beta blockers are drugs prescribed for cardiac conditions; their generic names frequently end in -olol: propranolol, metoprolol. Example: ibuprofen

Therapeutic effect, or intended effect

is the desired result or action of a medication. To achieve a therapeutic effect, the medication must be taken into the body, be absorbed and distributed in cells and tissues, and alter physiologic functioning. Therapeutic effect is influenced by factors such as: Medication dose Route of administration Frequency of administration Function of metabolizing organs, such as the liver or kidneys Age Gender Genetics

Absorption

is the passage of a drug from the administration site into the bloodstream. Several factors affect absorption: Route of administration Ability of the drug to dissolve or become soluble Blood flow to the administration site Body surface area Patient age

Metabolism

is the process by which a drug is altered to a less active form to prepare for excretion. The products of this process are called metabolites. Most metabolisms take place in the liver. In older individuals or anyone with impaired liver function, this process may be slowed

Pharmacodynamics

is the process in which a medication interacts with the body's cells to produce a biologic response. A biologic response can be systemic or local.

Distribution

is the process of delivering the medication to tissues and organs and, ultimately, to the specific site of action. Distribution is affected by the: Chemical properties of the drug Effectiveness of the cardiac system Ability to pass through tissue and organ membranes Extent to which the drug binds to proteins or accumulates in fatty tissue

Excertion

is the process that removes the less active drug or its metabolites. Most metabolites exit the body through the kidneys in urine, but some may be excreted in feces, breath, saliva, sweat, and breast milk. A drug may accumulate to unwanted levels in older individuals and people with impaired kidney function. Prescribing smaller doses with longer durations between doses may be advised.

Pharmacokinetics

is the study of how a medication enters the body, moves through the body, and ultimately leaves the body. describes the absorption, distribution, metabolism, and excretion of medication. These processes affect the action of a medication.

Safe nursing practice includes

knowledge and understanding about the basics of medication use, including medication regulations, actions, side effects, interactions, prescription requirements, and common forms and routes.

It is illegal to dispense prescription medications without a

legal prescription. Prescribing medications is limited to providers with prescriptive privileges, which includes many physicians, dentists, specially qualified nurse practitioners or other advanced practice nurses, and physician assistants.

Herbal Therapy

more than 38 million people in the United States reported using an herb or supplement. Among the top 10 were Echinacea, flaxseed, ginseng, ginkgo, and garlic

Anatagonistic effect

occurs when a drug's effect is decreased by taking it with another substance. For example, antibiotics can lessen the effect of birth control medications, and grapefruit juice alters the absorption of statins, a class of lipid-lowering drugs.

Synergistic effect

occurs when a drug's effect is increased in the presence of another substance in the body. Alcohol, for example, is a central nervous system depressant that has an increased effect when taken with antihistamines, antidepressants, or barbiturates. A synergistic effect may be specifically sought by the health care provider.

The trade name

or brand name, is a registered name assigned by the drug manufacturer. Because one type of medication can be manufactured by several companies, it can have several different trade names while having a common generic and chemical name Example: Motrin, Advil, Nuprin

There are certain conditions in which vitamins should be considered for use

pregnancy, breastfeeding, a vegetarian or vegan diet, an illness or condition that prevents oral consumption of foods, and the need for dietary supplements.

Vitamin products are regulated by the FDA as dietary supplements, with testing for

purity, strength, and composition

Comprehensive Drug Abuse Prevention and Control Act (1970), known informally as the Controlled Substances Act

regulates controlled substances.

Prescription

require a legal prescription from a health care provider.

Toxic effects

result from a medication overdose or the buildup of medication in the blood, due to impaired metabolism and excretion. Toxic levels of a drug can lead to serious physiologic effects that may be deadly. For example, toxic levels of a pain medication, such as morphine sulfate, may cause respiratory depression, leading to respiratory arrest. Organs that can be damaged from drug toxicity include: Kidneys (nephrotoxicity) Liver (hepatotoxicity) Organs of hearing (ototoxicity) Heart (cardiotoxicity) With careful patient care and monitoring, most drug toxicity is avoidable.

Herbs are often taken for

specific symptoms and for a limited period of time. Because many nonprescription herbal preparations have the same properties as prescription medications, the patient taking an herb and prescription medication for the same effect could experience a toxic reaction.

Forms of medication

tablet capsule powder troche or lozenges solutions inhalants skin preparations suppositories

Enforcement of medication legislation in the United States is the responsibility which mandates that all medications undergo safety testing before being released to the public.

the U.S. Food and Drug Administration (FDA)

The drug's half-life, onset of action, and peak and trough levels affect

the amount of a drug in the body. Administering recurring doses at regular intervals is necessary to keep medication levels constant over time.

classified into five (5) distinct categories or schedules depending upon

the drug's acceptable medical use and the drug's abuse or dependency potential.

It is the nurse's responsibility to understand and follow

the nurse practice act and policies of the facility when administering any medication, particularly controlled substances. Violations of regulations can result in fines, imprisonment, and the loss of the nurse's licensure.

Understanding these processes helps the nurse evaluate the

therapeutic, or intended, response and adverse, or unintended, effects caused by the administered medication.

Onset of action is the

time it takes the body to respond to a drug after administration. Onset is affected by the route of administration, the drug formulation, and pharmacokinetic factors. For example, the onset of action for insulin varies greatly, depending on the route (intravenous versus subcutaneous) and on the type of insulin (e.g., Humalog versus Lantus).

One objective of the CSA is

to reduce opportunities for drugs to be diverted from legitimate sources to drug abusers