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INTRODUCTION TO PHARMACOLOGYN402 Pharmacology

Los Angeles Pierce College

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“PHARMACOLOGY” IS COMPLEX….

Purpose

Site of Action

Precautions

Intended outcome

Delivery methods

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MASTERING PHARMACOLOGY REQUIRES APPLICATION OF KNOWLEDGE FROM OTHER FIELDS

Pharma-cologyAnatomy

Physiology

Chemistry

Micro-biology

Psycho-Social

Nursing

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CLASSIFICATION OF THERAPEUTIC AGENTS

Drug

Chemical agent able to produce biologic responses; “medication” after administration

Biologic

Naturally produced by animal cells, microorganisms, or by the body

“CAM”

Complementary and alternative medicine therapies

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ADVANTAGES OF PRESCRIPTION MEDICATIONS

Patient is examined before medication initiated Diagnosis is obtained Proper amount is recommended Dosing instructions provided Description of correct use and potential side

effects

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FUNCTIONS OF THE FDA(U.S. FOOD AND DRUG ADMINISTRATION)

Assure that foods are safe, wholesome, sanitary, properly labeled Ensuring that human and veterinary drugs,

vaccines, biological products, and medical devices are safe and effective

Protect the public from electronic product radiation

Assure cosmetics, dietary supplements are safe and properly labeled

Regulate tobacco products Facilitate product innovation to advance public

health

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BLACK BOX WARNING

Identification of extreme adverse reactions Potential to cause death or serious injury

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WHAT IS A “PROTOTYPE DRUG?”

A well-understood drug within a specific classification

Other drugs within the class are compared to the prototype drug Knowing the prototype will allow you to predict actions and adverse effects of other drugs in the class

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CLASSIFICATIONS OF DRUGS

The number of drugs available grows every day

Impossible to know everything about every one

Drugs are classified to facilitate understanding of individual drugs

Therapeutic Classification determined by the drug’s intended use in treating disease

Pharmacologic Classification determined by the drug’s effects at the molecular, tissue, and body system level

Pharmacologic Classification provides the student and practitioner with greater ability to understand individual drugs within the class

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DRUG NAMES

Chemical name is unique to that compound Generic name assigned by the US Adopted

Name Council, used by a variety of entities Trade name is assigned by the company

marketing the drug A drug company has exclusive rights to a

new drug for 17 years After 17 years, other companies may market

the drug A generic drug may have several trade

names

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TRADE NAME VS GENERIC DRUGS

Generic generally less expensive May be slight differences in drug formulation Inert ingredients may affect bioavailability Some drugs may take longer than others to

become effective

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DRUGS WITH POTENTIAL FOR ABUSE OR ADDICTION

Such drugs are identified by one of 5 classes:

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WHAT THE REGISTERED NURSE MUST KNOW BEFORE GIVING DRUGS…

What drug is ordered Drug classification Intended use Effects on body Contraindications Patient anthropomorphics Side effects Indications How supplied Administration considerations Assessment strategies

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YOUR GOAL IS TO CARE FOR AND PROTECT YOUR PATIENT

The purpose of understanding Pharmacology is to limit adverse drug events

You CANNOT know if the drug or dose is appropriate unless you know your patient

Therefore…. You CANNOT give a medication until you have performed your physical assessment!

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THE EXPECTED DRUG EFFECT IS INTENDED;OTHER EFFECTS CAN OCCUR

Drug effect

Allergic

Side effect

Adverse

event (exp)

Adverse

event (unexp

)

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ADVERSE DRUG EVENTS/EFFECTS AND THE ELDERLY PATIENT

Can be influenced by non-drug factors: Cognitive impairment Depression Motor dysfunction Complex drug regimen Polypharmacy Fear of adverse drug reaction

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SIX RIGHTS (OR 10, OR 11, OR MORE!)

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CHECK DRUG 3 TIMES

Check with MAR

Check when pouring, preparing, or connecting

Check before administering

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CAUSES OF MEDICATION ADMINISTRATION

Inadequate patient information Inadequate drug information/knowledge Miscommunication of drug orders Improper labeling Distraction by outside influences

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ENTERAL DRUG ADMINISTRATION—ORAL

Use only if patient is fully alert Patient must have ability to swallow Hand patient the cup with drug and provide

water Stay with patient until drug is swallowed May require asking patient to open his mouth

the verify drug has been swallowed

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ENTERAL DRUG ADMINISTRATION--SUBLINGUAL

Make sure patient is fully alert and able to follow your directions

Place tablet under the tongue Instruct the patient to allow drug to dissolve

and not to swallow Remain with patient until fully dissolved Offer water afterward

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ENTERAL DRUG ADMINISTRATION—BUCCAL

Make sure patient is fully alert and able to follow your directions

Place tablet between gum line and the cheek Instruct the patient to allow drug to dissolve

and not to swallow or move the table with his tongue

Remain with patient until fully dissolved Offer water afterward

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ENTERAL DRUG ADMINISTRATION—NASOGASTRIC AND GASTROSTOMY

Give liquid forms or crushed and mixed with at least 30 ml warm water

Enteric coated or extended release cannot be crushed

Verify tube placement Turn off feeding Aspirate stomach contents to see that there is less than 100 mL Return residual, flush with water Pour drug into syringe and allow to flow by gravity Keep HOB elevated Flush with at least 30 mL water

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TOPICAL DRUG ADMINISTRATION—TRANSDERMAL

Use gloves Label patch with initials, date, time Remove previous patch Place on clean, dry hairless skin Rotate sites

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TOPICAL DRUG ADMINISTRATION—OPHTHALMIC

Instruct patient to tilt head back Pull lower lid down with nondominant hand Keep dispenser ¼ to ⅛ inch above

conjunctival sac Instill drops in center of pocket Instill thin line of ointment along inner lid

margin Instruct to blink gently Provide with tissue

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TOPICAL DRUG ADMINISTRATION—OTIC

Instruct patient to lie on opposite side Hold dropper ¼ inch from ear canal Instill drops to side of ear canal Pull pinna up on adult, down on child Once instilled, apply intermittent pressure to

tragus 3 or 4 times Have patient remain side lying for 10

minutes

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TOPIC ADMINISTRATION—NASAL

Ask patient to blow nose first, tilt head back Have patient open mouth and breathe

through mouth Hold dropper just above nostril Direct drops along side or back of nostril so

drug does not go down eustachian tube

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VAGINAL ADMINISTRATION

Have patient lying down after emptying bladder

Provide for privacy Medication should be placed against the

cervix

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RECTAL ADMINISTRATION

Used when patient is comatose or experiencing nausea and vomiting

May require use of lubricant

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INTRADERMAL ADMINISTRATION

Use TB syringe or other 1mL syringe with 26-27 gauge needle

Spread skin taut with nondominant hand; swab antiseptically

Insert with bevel up until entire bevel under skin

Slowly inject to form small wheal Do not massage after removing needle

quickly Draw circle around site

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SUBCUTANEOUS ADMINISTRATION

Use 23 to 25 gauge syringe Chose appropriate site; swab antiseptically;

allow to dry Rotate sites; bunch skin with nondominant

hand Insert at 45º to 90º angle depending on

patient size Inject slowly, remove needle quickly Massage site with antiseptic swab unless

medication is an anticoagulant

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INTRAMUSCULAR ADMINISTRATION

Prepare using a 20-23 gauge needle Clean site antiseptically with swab Form a V with the nondominant hand above

the site Inject into the skin at the angle of the V Aspiration before injection is not required Inject slowly; remove needle quickly Apply pressure and massage gently

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PHARMACOKINETICS VS PHARMACODYNAMICS

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ADME… DETERMINES THE EFFICACY OF THE DRUG

Distribution:Blood flowMolecular sizeBind to serum protein?

Metabolism:Breakdown by liverCompound converted tometabolites

Excretion:Removal of compound and metabolitesKidney, gut, lungsIf incomplete → toxicity

Drug Performance

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PLASMA CONCENTRATION ANDTHERAPEUTIC RANGE

During absorption, time is required for drug to reach minimum effective concentration (MEC)

Drug remains in therapeutic range and reaches peak

Drug continues to be effective during excretion decreases the drug’s concentration

Drug continues to be excreted after passing below minimum effective concentration

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LOADING DOSE AND MAINTENANCE DOSE

A loading dose is larger than usual dose intended to quickly bring the drug to therapeutic range

Maintenance doses follow Maintenance doses are given at regular

intervals to keep the drug in therapeutic range and to prevent complete elimination

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THERAPEUTIC INDEX

A comparison of drug that causes a therapeutic effect to the amount of that drug that causes toxicity or death

Toxic dose is divided by the effective dose The larger the ratio, the larger the therapeutic index The smaller the ratio, the smaller the therapeutic index and the greater the chance for toxic effects

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AGONISTS AND ANTAGONISTS

Agonist—produces the same effect as a natural

chemical at the receptor site Antagonist—binds to receptor site to prevent a sub- stance from binding at that receptor site

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THE NURSING PROCESS AND MEDICATION ADMINISTRATION—ASSESSMENT

Your assessment focuses on the patient, not on the task

Obtain or review health history Physical assessment of the patient’s

condition Assessment of:

Patient’s baseline understanding of the drug Indication and need for specific drug Potential allergies/adverse reactions The patient’s ability to participate in the medication process (compliance)

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NURSING DIAGNOSIS

Major areas of concern:

Promote therapeutic

effects of drug

Maximize patient self-care

Minimize ADE and toxicity

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ESTABLISHING DESIRED OUTCOMES

Describes the intended state of the patient after the care plan is performed

Often focuses on enhanced self-care abilities Self-care is promoted through education by

the nurse Administration skills (e.g., how to give self

insulin) Knowledge of desired effects (what the drug will

do) What to report to provider (nausea, changes in

VS) Special considerations for effective dosing (e.g.,

grapefruit inhibits the metabolism of statins)

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IMPLEMENTATION

In addition to actually giving the medication, includes…

Ongoing assessment Monitoring drug effects Large component is patient education

Use of the drug Monitoring side effects Medication administration

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EVALUATION

Compare the patient’s current status with the desired outcome

Were the therapeutic effects achieved? Requires documentation, continuation, or

revision of plan

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ESTABLISHING PRIORITIES IN MEDICATION ADMINISTRATION

Safety first…safety second…safety always! Consider each encounter as thoroughly as your

first Validate allergies, identity Ask and assess regarding potential side effects or

adverse reactions Whether giving medications or providing any other

care, always identify: “What is my patient’s most immediate need?”

Think: Circulation Airway Breathing Then, everything else….

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REPORTING AND DOCUMENTING MEDICATION ERRORS

Each facility has its own procedure Documentation should be objective Statement of events and facts Does not include description of contributing

factors Document exactly what was given or what

was omitted In-house incident or occurrence reports

provide forum for describing contributing factors objectively

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STRATEGIES TO REDUCE MEDICATION ERRORS

Assess and question your patient Act only on clear orders and question unclear ones Eliminate distractions Use at least 2 identifiers each encounter Follow prescribed procedures and techniques Validate patient has taken in the drug Calculate correctly and precisely Record drug administration immediately Recognize that many drugs when crushed are

toxic Guard against easily confused and different drugs Always observe for expected and unexpected

outcomes

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PREGNANCY RISK CATEGORIES

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GUIDELINES FOR DRUGS DURING BREAST FEEDING

Large number of drugs are secreted into breast milk in varying amounts

Infants vary in their ability to metabolize small amounts of drug

Best to postpose pharmacotherapy until after baby is weaned

If drugs are necessary, give immediately after breast feeding

Drugs with shorter half-life are preferred OTC products should also be avoided

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PHARMACOTHERAPY ACROSS THE LIFESPAN—SPECIAL CONSIDERATIONS

Rate of metabolis

m

Understanding and

inquisitiveness

Potential for abuse

or overdose

Dosing variations

Individual physical health

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FACTORS CONTRIBUTING TO POLYPHARMACY

Defined as taking 4 or more drugs Multiple medications for many diseases Elderly purchase 40% of OTC drugs and use

twice as much herbals Going to multiple healthcare providers Using different pharmacies

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EFFECTIVE PHARMACOTHERAPY REQUIRES CONSIDERATION OF MULTIPLE FACTORS

Holistic

model

Cultural influence

s

Environ-mental factors

Genetics Gender

Psycho-socialfactors

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CHALLENGES OF COMPLEMENTARY AND ALTERNATIVE MEDICINE

The use of CAM is increasing among adults and children

More likely when client cannot afford conventional care

Such products are not standardized; therefore, effects cannot be predicted

Manufacturer is not required to demonstrate a product’s effectiveness or to prove its safety

Actual toxicity of certain products may not be known because effects are not reported

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NURSING RESPONSIBILITIES REGARDING CAM

Include OTC, herbal preparations, dietary supplements, and performance (sports) supplements in your questioning during health and medication history

Be alert to documented herb-drug and supplement-drug interactions

Ask the patient why he or she is taking such products to identify potential health risks or concerns

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PATIENT EDUCATION AND CAM

Instruct regarding potential serious side effects

Advise pregnant women to inform physician of CAM use

Older adults at greater risk for drug-herb interaction

Inform patients with allergies that such products have multiple components

Educate regarding unrealistic advertising claims

Caution not to exceed suggested doses

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NOW, A REAL PROBLEM….

Potential for Abuse

Conventional Drug Therapy

OTC ProductsCAM

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SOME TERMS RELATED TO CONTROLLED SUBSTANCES

Substance abuse:  patterned use of a drug in amounts harmful to the user or others Substance dependence: an adaptive state

that develops from repeated drug use Substance addiction: compulsive, out-of-

control drug use despite negative consequences

Withdrawal: symptoms that occur after abruptly stopping a drug upon which one has become dependent

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PHYSICAL VS PSYCHOLOGICAL DEPENDENCE

Physical

Adaptation of the nervous system to repeated

substance use

Withdrawal results when substance is discontinued

Psychological

Overwhelming desire to continue drug seeking behavior, regardless of

consequences

No obvious physical signs of discomfort when substance is

discontinued

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“WITHDRAWAL SYNDROME”

Also known as “discontinuation syndrome” Risk of withdrawal syndrome increases with

dosage and length of time Symptoms are specific to drug withdrawn,

e.g.: Opioids: inner restlessness, chills, cramping,

dizziness, ↑heart rate Cannabinoids: hallucinations, myocardial

infarction SSRIs: Flu-like symptoms, vertigo, dysphoria

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IN SUMMARY…

The Registered Nurse is the coordinator of all patient care The RN has the best access to determining

competency and appropriateness of the patient’s drug therapy

The RN matches the patient discovered on physical assessment to the medication treatment plan ordered

Omissions, duplications, and unnecessary drugs are identified and reconciled

After appropriate drug administration, careful continuous assessment is performed

The patient is assessed uniquely and independently