Pharmacology M1-M3

Pharmacology

the study of drugs

drugs

substances that alter physiology

pharmacokinetics

what the body does to the drug

kinetics

how the drug gets in, moves through, and is removed from the body

bioavailability

how much intact drug reaches the general circulationand is available for therapeutic effect

pharmacodynamics

what the drug does to the body

dynamics

how the drug changes physiologic activity (what does the med do to the target tissue)

polypharmacy

use of 5 or more medications (increases risk of drug - drug interactions)

administration

how the drug gets into the body

absorption

sometimes skipped based on administration method

distribution

how drugs move through the body, blood flow

metabolism

biotransformation - mostly occurs in the liver

elimination

excretion, mostly occurs in the kidneys, but can also be through skin, urine and respiration

4-5

it takes _____ half lives to reach steady state; when the amount entering the body is the same as the amount leaving the body

repeated dose kinetics

drug accumulation over time

ceiling effect

the most a drug can do; more and more of the drug won’t do anything else once it’s already reached max effect

therapeutic index (TI)

median toxic dose (TD) / median effective dose (ED)

high, low

the therapeutic index is _____ for OTC drugs and _____ for prescription

potency

the amount of a drug required for an effect

efficacy

the maximum effect of a drug

agonist

a drug binds to a receptor facilitating the desired reaction to occur (has affinity and efficacy)

antagonist

a drug that binds to a receptor which “blocks” naturally occurring agonistic compounds from binding to receptor, thus not allowing a reaction to occur (has affinity but not efficacy)

full agonists

can produce the maximal response obtainable in a tissue (maximal efficacy)

partial agonists

can produce only a submaximal response

affinity

the attraction of the drug to its receptor

efficacy

the ability to activate the receptor and produce and physiological reaction

neutral antagonist

sufficient affinity to occupy the agonist receptors and prevent binding of the agonist, without producing an effect by itself

selectivity

the characteristic of acting on only 1 type of cell or tissue and producing a specific physiological response

synergism

2 drugs combining to produce an effect that is greater than either individually

antagonism

2 drugs combining to produce an effect that is less than either individually

antitussives

cough suppressants

classic antitussive

codeine - suppresses cough reflex center

nonopioid antitussive

dextromethorphan (robitussin) - inhibits cough reflex but non-narcotic

adverse effects of antitussives

sedation, dizziness, GI issues, tolerance and dependence

decongestants

treat runny nose and stuffy head with vasoconstriction of blood vessels

alpha-1 adrenergic agonist decongestants

pseudoephedrine (sudafed, pill) and oxymetazoline (afrin, nasal spray)

side effects of decongestants

headache, dizziness, nervousness, nausea, CV irregularities. tolerance

antihistamines

treats the common cold and seasonal allergies by blocking histamine at the H1 receptor

1st gen antihistamine

diphenhydramine (benadryl)

2nd gen antihistamines

loratadine (Claritin) or fexofenadine (allegra)

side effects of antihistamines

sedation, fatigue, dizziness, blurred vision, incoordination, GI distress

mucolytics

treats common cold, pneumonia, emphysema and chronic bronchitis by decreasing viscosity of secretions; inhaled; acetylcysteine (mucomyst)

side effects of mucolytics

nausea and vomiting

expectorants

treats common cold, pneumonia, emphysema, and chronic bronchitis by increasing mucus ejection via oral administration; guaifenesin (mucinex)

side effects of expectorants

GI distress

beta adrenergic agonists

bronchodilators that treat bronchoconstriction; stimulate beta 2 adrenergic receptors to relax bronchiole smooth muscle and cause bronchodilation

albuterol (proventil)

short acting beta 2 adrenergic bronchodilators

salmeterol (serevent)

long acting beta 2 adrenergic bronchodilators

epinepherine

general beta 1 and beta 2 bronchodilators

side effects of beta 2 adrenergic agonists bronchodilators

bronchial constriction with prolonged use, tolerance, cardiac irregularities, CNS symptoms

anticholinergics

bronchodilators that treat bronchoconstriction (COPD/Asthma) by blocking muscarinic receptors in the airway to prevent bronchoconstriction

ipratropium (atrovent)

short acting anticholinergic bronchodilator

tiotropium (spiriva)

long acting anticholinergic bronchodilator

side effects of anticholinergic bronchodilators

dry mouth, constipation, urinary retention, tachycardia, blurred vision, confusion