MODULE 1M – INTRODUCTION TO PHARMACOLOGY

Pharmacokinetic Phase

What the body does to the drug. Describes the movement of the drug through the body.

Pharmacodynamic Phase

What the drug does to the body, involves receptor binding, postreceptor effects, and chemical reactions. A biologic or physiologic response results from the pharmacodynamic phase.

1\. Absorption

2\. Distribution

3\. Metabolism

4\. Excretion

4 process of pharmacokinetics

Absorption

Refers to the movement of drug into the blood stream after administration

Bioavailability

Percentage of administered drug available for activity

Excipients

Are used in drug preparation to allow the drugs to take on a particular size and shape and to enhance drug dissolution

Dissolution

Drugs in liquid form already in solution, to be absorbed from the gastrointestinal tract into the blood stream.

Disintegration

Breakdown of an oral drug into smaller particles. The rate of dissolution is the time it takes the drug to disintegrate and dissolve to become available for the body to absorb it. Drugs in liquid form are more rapidly available for the GI absorption than are solids.

Enteric-coated (EC) Drugs

Resist disintegration in the gastric acid of the stomach, so disintegration does not occur until the drug reaches the alkaline environment of the small intestine

Passive transport

Occurs through two processes, diffusion and facilitated diffusion

Diffusion

Drugs move across the cell membrane from an area of higher concentration to one of lower concentration

Facilitated Diffusion

Relies on a carrier protein to move the drug from an area of higher concentration

Active transport

Requires a carrier, such as an enzyme or protein, to move the drug against a concentration gradient. Energy is required for active absorption.

Pinocytosis

Is a process by which cells carry a drug across their membranes by engulfing the drug particles in a vesicle.

Distribution

Refers to the movement of the drug from the circulation to body tissues

Free Drugs

Are able to exit blood vessels and reach their site of action, causing a pharmacologic response.

Metabolism

The body chemically changes drugs into a form that can be excreted.

Liver

Primary site of metabolism

Steady state

Occurs when the amount of drug being administered is the same as the amount of drug being eliminated

Loading dose

A large initial dose of a medication.

Prodrug

Is a compound that is metabolized into an active pharmacologic substance

Excretion

Main route is through the kidneys.

Pharmacodynamics

the study of the effects of drugs on the body. Drugs act within the body to mimic the actions of the body’s own chemical messengers

Dose-Response Relationship

It is the body’s physiologic response to changes in drug concentration at the site of action.

Potency

Amount of drug needed to elicit a specific physiologic response to a drug.

Maximal Efficacy

The point at which increasing the drug’s dosage no longer increases the desired therapeutic response.

Therapeutic Index

Describes the relationship between the therapeutic dose of the drug (ED50) and the toxic dose of the drug (TD50).

Therapeutic Dose (ED50)

Is the dose of a drug that produces a therapeutic response in 50% of the population.

Toxic Dose (TD50)

Is the dose of a drug that produces a toxic response in 50% of the population.

Onset

The time it takes for a drug to reach the minimum effective concentration after administration.

Peak

Drug reaches its highest concentration in blood.

Duration of Action

Length of time the drug exerts a therapeutic effect.

Cell membrane-embedded enzymes

The ligand-binding domain for drug binding is on the cell surface. The drug activates the enzyme inside the cell, and a response is initiated

Ligand-gated ion channels

The channel crosses the cell membrane. When the channel opens, ions flow into and out of the cells. This primarily affects sodium and calcium ions.

G protein-coupled receptor systems

The three components to this receptor response are:

▪ The Receptor

▪ The G protein that binds with guanosine triphosphate (GTP), and

▪ The Effector – Which is either an enzyme or an ion channel.

Transcription factors

Found in the cell nucleus on DNA, not on the surface. Activation of receptors through transcription factors regulates protein synthesis and is prolonged. With the first three receptor groups, activation of the receptors is rapid.

Agonist

Drugs that activate receptors and produce a desired response

Partial Agonist

Are drugs that elicit only moderate activity when binding to receptors; partial agonists also prevent receptor activation by other drugs

Antagonist

Drugs that prevent receptor activation and block a response

Nonspecific drug

Drugs that affect multiple receptor sites

Nonselective drug

Drugs that affect multiple receptors.

Side effects

Secondary effects of drug therapy. Can be desirable; can be a reason for a client to stop taking the medication

Adverse reaction

Are unintentional, unexpected reactions to drug therapy that can occur at normal drug dosages. May be mild to severe, always undesirable.

Drug Toxicity

Occurs when drug levels exceed the therapeutic range. Toxicity may occur secondary to overdose or drug accumulation.

Tolerance

A decreased responsiveness to a drug over the course of therapy.

Tachyphylaxis

Acute, rapid decrease in response to a drug.

Drug interaction

Altered or modified action or effect of a drug as a result of interaction with one or multiple drugs

Drug-Nutrient Interactions

Food may increase, decrease or delay the body’s pharmacokinetic response to drugs

Additive Drug Effect

Response is increased beyond what either could produce alone

Synergistic Drug Effect or Potentiation

The clinical effect of the 2 drugs given together is substantially greater than that of either drug alone

Pharmacogenetics

The study of genetic factors that influence an individual’s response to specific drug

Placebo effect

A drug response not attributed to the chemical properties of a drug.

Ethnopharmacology

A subdivision of ethnomedicine and focuses on the use of herbs, powder, teas and animal products as healing remedies

Stimulation

MECHANISM: Enhances intrinsic activity (adrenergic drugs) which increases heart rate, sweating, and respiratory rate. (E.g. Epinephrine)

Depression

MECHANISM: Depressant drugs decrease neural activity and bodily functions. (E.g. Barbiturates) which causes CNS depression

Irritation

MECHANISM: Drugs that irritate have noxious effect. (E.g. Laxatives – Bisacodyl, Senokot) Irritates the sensory nerve endings in the intestinal mucosa.

Replacement

MECHANISM: Such as Insulin, replace essential body compounds. In the case of a person with a Diabetes Mellitus, the problem is there could be an adequate number of insulins in the body that’s why the person needs to receive an exogenous source of insulin

Cytotoxic action

MECHANISM: Selectively kill parasites or cancer. (E.g. Chemotherapeutic Drugs/Antineoplastic Medications)

Antimicrobial actions

MECHANISM: Drugs that prevent, inhibit, or kill infectious organisms. (E.g. Co-amoxiclav) This medication is an antibiotic.

Modification of Immune Status

MECHANISM: Modify, enhance, or depress the immune system. (E.g. Corticosteroids) This medication is taken for a long time, it will make the person immunocompromised

Pregnancy

LABELING: Provides information about dosing and potential risks to the developing fetus and registry information that collects and maintains data on how pregnant women are affected when they used the drug or biological products

Lactation

LABELING: Replace the nursing Mother Subsection of the old label. Information include drugs that should not be used during breast feeding, no human or animal data regarding active metabolites in milk, as well as clinical effects on the infant. Other information may include Pharmacokinetic Data like metabolism or excretion, a risk and benefit section as well as timing of breast feeding to minimize infant exposure.

Females and Males of Reproductive Potential Subsection

LABELING: Relevant info, pregnancy test or birth control, BDA drug therapy and the medications effect on fertility or pregnancy loss will be provided when available

Tablet

Most common form of oral medication

Capsule

Liquid or powder form

Timed-release capsule or Spansule

Medication will be released on small amounts over time

Enteric-coated

Do not crush the medication, the coating is designed to hold the coating together in the stomach and released in the intestine

Elixir

It is a liquid-containing medicinal drug with syrup, glycerin, or alcohol added to mask its unpleasant taste.

Emulsion

Mixture of two or more liquids that are normally immiscible or unmixable.

Suspension

Consists of undissolved particles of one or more medicinal agents mixed with a liquid vehicle. For oral administration, you must shake this before using.

Transdermal

A patch is used. Only the Transdermal formulation are designed to penetrate through the skin layer and exert their effects on deeper or more distant tissues

Topical

A cream is used. Only minimally penetrate the skin layer which is its designed intent.

Instillations

Generally, in liquid form either drop by drop or with a catheter into a body space or cavity.

Inhalations

✓ Metered-Dose Inhaler (MDI)

✓ MDI with spacer – “Spacer”, to facilitate the inflow of medicine into the lungs.

✓ Nebulizer

Nasogastric route

a tube is inserted the nose into the stomach.

Gastronomy wall

A tube is inserted through the stomach through the abdominal wall

Suppositories

Solid medical preparation. Made from glycerinated gelatin or high molecular weighted polyethylene glycols and are more common vehicles for a variety of drugs

* Intradermal – 10-15 Degree Angle


* Subcutaneous – 45 Degrees \*\*For Insulin Syringe it has to be inserted at 90 Degrees.


* Intramuscular – 90 Degrees

Degree angles of Parenteral Med

1\. Assessment - information

2\. Diagnosis - analysis, type of care

3\. Planning - set goals

4\. Implementation - interventions

5\. Evaluation - determine if goals are met

Nursing Process

1\. Right Patient

2\. Right Drug

3\. Right Dose

4\. Right Time

5\. Right Route

6\. Right Assessment

7\. Right Documentation

8\. Right to Education

9\. Right Evaluation

10\.Right to Refuse

Five plus Five “Rights of Medication Administration”

Just culture

Does not hold individual practitioners responsible for a failing system, although it does not tolerate disregard for a patient or gross misconduct

Medication Reconciliation

Process of identifying the most accurate list of all medications that the patients is taking at transitions in care

Counterfeit drugs

Look like the desired drug but may have no active ingredient, the wrong active ingredient or the wrong amount of active ingredient.

High alert medications

can cause significant harm to the patients.

Akapulko

HERBAL: Used to treat tinea infections, insect bites, ringworms, eczema, scabies and itchiness

Ampalaya

HERBAL: Found to be effective in the treatment of diabetes (diabetes mellitus), hemorrhoids, coughs, burns and scalds, and being studied for anti-cancer properties.

Garlic

HERBAL: Used to treat infection; with antibacterial, anti-inflammatory, anti-cancer and anti-hypertensive properties. It is widely used to reduce cholesterol level in blood

Guava

Used as antiseptic, anti-inflammatory, anti-spasmodic, antioxidant hepatoprotective, anti-allergy, antimicrobial, anti-plasmodial, anti-cough, antidiabetic, and antigenotoxic in folkloric medicine.

Lagundi

Used to treat cough, cold and fever (Antitussive medicine). It is also used as a relief for asthma and pharyngitis, rheumatism, dyspepsia, boils, and diarrhea.

Niyog-niyogan

HERBAL: Used to eliminate intestinal parasites

Sambong

HERBAL: Used to treat kidney stones, wounds and cuts, rheumatism, anti-diarrhea, anti-spasms, colds and coughs and hypertension

Tsaang Gubat

HERBAL: used to treat skin allergies inc. eczema scabies and itchiness wounds in childbirth

Ulasimang Bato/ Pansit-Pansitan

HERBAL: Used in treating arthritis.

Yerba Buena

HERBAL: as analgesic to relieve body ahces and pain due to rheumatism and gout. It is also used to treat coughs, colds and insect bites.

Astragalus

HERBAL: Used as an adjunct to boost immune system.

Chamomile

HERBAL: For sleeplessness, anxiety, stomach and intestinal ailments.

Cinnamon

HERBAL: Bronchitis, GI problems, anorexia and diabetes.

Echinacea

HERBAL: For colds, flu and infection

Ginger

HERBAL: Nausea, motion sickness and diarrhea

Gingko

HERBAL: Asthma, bronchitis, fatigue and tinnitus.