Administration of Medications

Prepared by

Dr. Hoda Abdel Azim

Learning Outcomes (part one)

After completing this lectures the student will be able to: Define key terms. List of drug’s names. Describe legal aspects of drug’s administration. Discuss different drug’s effects. Explain the process of the drug’s actions. Discuss pharmacokinetics of drug. State factors that affects the absorption of drugs. List factors that can affect drug’s action. Convert and calculate drug’s dosage. Describe various routes of drug’s administration.

Learning Outcomes (part two) After completing this lectures the student will be able to: List types of medication orders. State essential parts of a medication order. Discuss physiological changes associated with aging. List six essential steps to follow when administering

medication. Discuss practice guideline for drug administration. State the rights to accurate medication administration. Explain action are required if order medication

inappropriate.

Terminology:Medication:

Is a substance administered for the diagnosis, cure, treatment or relief of a symptom or for prevention of disease.

Prescription: The written direction for the preparation and administration of a drug.

Pharmacology : Is the study of the effect of drugs on living organisms.

Pharmacy : Is the place where drugs preparing, compounding and dispending.

Pharmacist : A person licensed to prepare and dispense drugs and to make up prescriptions.

Pharmacopoeia :

Is a book containing a list of products used in medicine, with descriptions of the product, chemical tests for determining identity and purity, and formula and prescriptions.

Drug Names Generic name : is given before a drug becomes officially an

approved medication.

Official name : is the name under which it is listed in one of the official publications.

Chemical name : is the name by which a chemist know it this name describes the constituents of the drug precisely (chemical formula).

Trade name : is the name given by the drug manufacturer the

name is usually selected to be short and easy to be remember (one generic drug may have several trade names depending on how many companies market the drug).

Legal aspects of drug administration A nurse who administer the written incorrect

dosage is responsible for the error as well as the physician.

Nurses should question any order that appears unreasonable and refuse to give the medication until the order is clarified.

Legal aspects of drug administration cont.

The nurse must use of controlled substances recording.

Controlled substances are kept in a

locked drawer, cupboard, medication cart or computer controlled dispensing system.

Controlled substances recording includes the required information as:

(Inventory Forms)

Name of the drug. Dosage and the signature of the person

who prepared and give the drug.

Name of physician who orders the drugs.

Signature of another registered nurse for administration of a controlled substance.

Record the controlled substances are wasted during preparation.

Two nurse must sign the control inventory form if a portion or all of a controlled substance dose is discarded.

Counts of controlled substance are taken the end of the last shift.

If the number is not the same, the nurse must investigate and correct the discrepancy.

Medications dispensing systems

1. Medication cart

2. Medication cabinet

3. Medication room

4. Automated dispensing

cabinet

Effect of drugs Therapeutic effect (desired effect ) of drug

is the primary effect intended that is the reasons the drug prescribed.

A side effect or secondary effect of a drug is one that is unintended. usually predictable and may be either harmless or harmful.

Adverse effects or reactions may justify the discontinuation of a drug.

Drug toxicity ( harmful effects of a drug on an organism or tissue) results from over dosage, ingestion of a drug intended for external use . most drug toxicity is avoidable if careful attention is paid to dosage .

Drug allergy is an immunological reaction to a drugs. When a client is first exposed to a foreign substance (antigen) the body may react by producing antibodies.

Anaphylactic reaction: severe allergic reaction (responses) usually occur immediately after administration of drugs.

This response can be fatal if the symptoms are not noticed immediately and treatment is not obtained promptly.,

Symptoms include: feeling of swelling in the mouth, tongue , acute shortness of breath, acute hypotension and tachycardia.

Drug tolerance: exist in a persons who has unusually physiological response to drugs and who requires increase in the dosage to maintain a given therapeutic effects.

Drug interaction: occur when the administration

of one drug before, at the same time, or after another drug alters the effect of one or both drugs (beneficial or harmful).

Action of drug in the body Its half life, the time interval required for the body’s elimination processes to reduce the concentration of the drug in the body by one half.

e.g., if drug half life is 8 hours the amount of drug in the

body is:

Initially 100% After 8 hours 50% After 16 hours 25% After 24 hours 12.5% After 32 hours 6.25%

Other terms describing drug actions Onset of action the time after administration when the

body initially responds to the drug.

Peak plasma level the highest plasma level achieved by the single dose when the elimination rate of a drug equals the absorption rate.

Drug half life (elimination half life) the time required for the elimination process to reduce the concentration of the drug to one half what it was at initial administration.

Plateau A maintained concentration of a drug in the

plasma during a series of scheduled doses.

Pharmacokinetics Is the study of the absorption, distribution, biotransformation and excretion of drugs.

1. Absorption Is the process by which the drug passes from

administration site into the blood stream, depend on several factors.

absorption is the first step in the movement of the drug through the body.

Factors that affects the absorption of drugs

1. Food can delay the dissolution and absorption of drugs as well as their passage into small intestine.

2. Acid medium in the stomach.

3. Route of administration.

4. Application of heat.

5. Application of cold.

6. Drugs has low solubility medium such as oil.

2. Distribution

Movement of a drug from its site of

absorption to its site of action.

3. Biotransformation (metabolism)

Is a process by which a drug is converted to a less active form (in the liver).

4. Excretion

Is the process by which metabolites and drugs are eliminated from the body.

Factors affecting medication action 1. Developmental factors

Infants usually require small dosages because of their body size and the immaturity of their organs (liver, kidneys).

Adolescence allergic reaction may occur to drugs.

Older adults have different responses to

medications due to physiological changes as: Decrease liver and kidney function Decrease gastric motility, acid production and

blood flow which can impair drug absorption

2.Gender

3.Genetic factorsSome clients may have slow liver metabolism and not achieve an adequate response to medication.

2.Diet

3.Environment (hot or cold)

4.Route of administration

5.Time of administrationTwo hours before meals act faster than those taken

after meals.

Routes of drug’s administration 1. Oral administration

Inappropriate for client with

nausea or vomiting Inappropriate if client cannot

swallow or is unconscious Unpleasant taste of drugs Irritation of the gastric mucosa Irregular absorption from the GIT Slow absorption In some cases harm to the client’s

teeth

Most common Least expensive Convenient route for most

client Drug swallowed and the

skin not broken Safe method

Disadvantages Advantages

2. Sublingual

If swallowed drug may be

inactivated by gastric juice Drug must remain under

tongue until dissolved and

absorbed May cause irritation of the

mucous membranes Rapidly absorbed into the

bloodstream

quickly absorbedA drug is placed under

the tongue where it

dissolves quickly Largely absorbed into

the blood vessels on

the underside of the

tongue

Disadvantages Advantages

3. Buccal and Rectal In buccal administration a medication is held in the mouth against the mucous membranes of the cheek until the drug dissolves

Same as for sublingual Provide a local effect

4. Topical route Applied on the skin or eye, nose, ear Drugs applied on the skin are absorbed into the

dermis where they have a local effect.

Other topical drugs (eye, nose, ear, rectal, vaginal ) applied directly to the mucus membrane are absorbed quickly, may cause systemic effects.

Respiratory route Inhalants such as oxygen,

5. Transdermal

Prolonged systemic effect Few side effects Avoid gastrointestinal absorption problems Onset of drug action faster than oral

Disadvantage Leaves residue on the skin that may soil clothes

6. ParenteralThe Parenteral route is defined as other than through the alimentary or respiratory tract , that is by needle.

More common routes: Subcutaneous : into the subcutaneous tissue,

just below the skin Intramuscular : into a muscle Intradermal : under the epidermis (into the

dermis) Intravenous : into a vein

Advantage of subcutaneous: Onset of drug action faster than oral Avoids gastrointestinal absorption problems.

Disadvantage of subcutaneous: Must involve sterile technique because breaks skin

barrier. More expensive than oral. Can administer only small volume. Slower than intramuscular administration. Some drugs can irritate tissues and cause pain.

Advantage of intramuscular Can administer large volume than

subcutaneous Drug is rapidly absorbed

Disadvantage breaks skin barrier. Anxiety

Intradermal Absorption is low ( this is an advantage in testing for allergies).

Disadvantage Amount of drug administered must be

small Breaks skin barrier

Intramuscular injection

Intravenous Rapid effect

Disadvantage. Limited to highly soluble drugs. Drug distribution inhibited by poor circulation

Inhalation Introduce drug throughout respiratory tract Rapid localized relief Drug can be administered to unconscious

client Disadvantage.

Use only for respiratory system May have systemic effect

Lecture

Part two

Medication orders (Types): A stat order : the medication is to be given immediately

and only once (emergency situation). Single order or one time order is for medication to be

given once at a specific time e.g., (before surgery).

Standing order: may or may not have a termination date, May be carried out indefinitely until an order is written to cancel it. Or it may be carried out for specified number of days.

PRN order or ( as needed order), permits the nurse to

give a medication when in the nurse’s judgment , the client require it.

Essential parts of a drug order

The client’s name, room and bed number. Date and time the order is written. Drug name. Dosage of drug Time and frequency of administration Route of administration Signature of the person writing the order.

System of weight and measure Metric system (decimal system ) is a simple

system based on units of 10.

Move the decimal point to the right to change from a larger unit to a smaller unit, and move the decimal point to the left to change from a smaller unit to a larger unit.

Basic measurement units are:

Meter (linear) Liter (volume) Gram (mass or weight)Abbreviations and equivalents:Volume1 milliliter (ml) = 1 cubic centimeter (cc)1,000 milliliters = 1 litter (L)

Weight 1,000 micrograms (mcg) = 1 milligram (mg)1,000 milligrams = 1 gram (g)1,000 grams = 1 kilogram (kg)

Conversion within the metric system

To change milligrams to grams or milliliters to liters divide the number by 1,000.

e.g.,250 mg = X g

X = 0.25 g

0.005 g = X mgX = 5 mg

Dose calculations One formula uses ratios based on the desired dose and the dose on

hand. desired dose quantity desired

__________ X __________ dose on hand quantity on hand

Cross multiply e.g.,

Cephalosporin 500mg (dose desired) is order by the physician: the dose on hand is 250 mg / 5ml. The formula is:

500mg (quantity desired ) ______ X ______________

250 mg 5ml

250 X = 500 X5X = 10 ml

Physiological changes associated with aging that

influence medication administration and effectiveness Altered memory Decrease visual acuity Decrease renal function Less complete and slower absorption from the

GIT Decrease liver function Decrease organ sensitivity Decrease in manual dexterity due to arthritis

Administering medication safety

1. Assess a client’s health status and obtained a medication history prior to giving any medication.

For example: If client has dyspnea, the nurse assesses

respiration A client who is nauseated may not be able to keep

down a drug taken orally.

2. Obtain baseline data by which to evaluate the effectiveness of the medication.

Medication history includes information about :

Drugs the client is taking currently or recently. Drug allergies Eating habits Identify any problems the client may have in self

administration Poor eyesight Unsteady hands Difficulty opening certain containers

Process of administering medications

1. Identify the client

2. Inform the client

3. Administer the drug

4. Provide adjunctive interventions as indicated (client help).

5. Record the drug administered

6. Evaluate the client response to the drug

Practice guideline for administering medications

1. Nurse who administer medications are responsible for their own actions.

2. Be knowledgeable about the medications you administer.

3. Use only medications that are in a clearly labeled container.

4. Do not use liquid medications that are cloudy or have change color.

5. Calculate drug doses accurately.

6. Administer only medications personally prepared.

7. Before administering a medication, identify the client correctly.

8. If a client vomits after taking an oral medication, report this to responsible.

9. Take special precautions when administering certain medications. When a medication is omitted for any reason record the fact together with the reason.

10. When a medication error is made, report it immediately to the nurse in charge.

Ten rights of medication administration

1. Right medication 2. Right dose3. Right time 4. Right route 5. Right client6. Right client education 7. Right documentation8. Right to refuse 9. Right assessment 10. Right evaluation

The following action are required if order medication inappropriate :

1. Contact the primary care provider and discuss the

rationale for believing the medication

inappropriate

2. Document in notes the following When the primary care provided was notified

What was conveyed to the primary care provider

How the primary care provider response

3. If primary care provider cannot be reached,

document all attempts to contact and the reason

for withholding the medication

4. If same one give the medication document data

about the client’s condition before and after the

medication

5. If an incident report is indicated clearly document

factual information