nurs 116 lecture 1

what is pharmacology?

the study of medicines

what medicine is made from the bark of the willow tree?

aspirin

what originally made penicillin?

molds

what drug does the digitalis plant make?

digoxin

what drug does the bark of the pacific yew tree make?

cancer drug taxol

what does poppy milk make?

morphine

what is pharmacotherapeutics?

the use of medicines (drugs) to heal of manage pt care

how many drugs are prescribed per year?

500, 000 (10/person, 18% of healthcare spending)

T or F: all drugs are medication

F. drugs are chemical agents. medications are drugs which have a therapeutic purpose

what does biologic mean

naturally produced by animal cells

examples of biologics

hormones, antibodies (vaccines), blood products, genetic treatment modalities

natural health products (NPH)

naturally occurring, used as an adjunct (supplement)

examples of NPH

vitamins, minerals, dietary supplements

what does health canada do?

evaluates and monitors pharm products for safety, efficacy, quality and advertising

what did the canadian pharmaceutical association publish?

compendium of pharmaceuticals and specialties: compilation of drug information and all adverse affects

hierarchy for pharm regulation

1. health canada

2. health products and food branch (hpfb)

3. therapeutic products directorate, biologics & genetic therapies directorate, natural health products directorate

what are preclinical trials?

laboratory testing on non-humans for 3-5 years

what are the 3 clinical trial phases

1. 100 healthy people

2. 300 people with disease

3. 3000 people

what % of drugs makes it to phase 3 of clinical trials?

10%

new drug submissions (NDS)

-80 per year

-only 10% approved

if a drug is approved after the NDS, what happens?

an NOC (notice of compliance) and DIN (drug ID) are assigned

T or F: after a drug is approved by health canada, it is no longer monitored

F. the drug is continuously monitored by 2 MHDP (marketed health product directorate) databases for adverse reporrts

what is the special access program?

allows for not yet approved drugs to be used in special cases

what is a placebo?

substance that may have an affect because of subjective belief

therapeutic nonemclature

name specifies treatment of specific disease

pharmacological nomenclature

molecular and tissue activity: how it works

antihypertensive

lowers blood pressure

antiemetic

decreases vomiting

if non-active ingredients are not exactly the same, is the amount of drug absorbed into circulation affected?

yes, the inert/added ingredients may interfere

what is prototype drug?

a single drug from a drug class that serves as a reference to predict actions, adverse affects of other drugs in its class

T or F: the prototype is not the most utilized drug

F

schedule 1

available only by prescription and provided by a pharmacist

-all prescription drugs

-drugs with no potential for abuse

-controlled drugs: narcs

how are narcotics prescribed?

with 2 prescriptions by a physician

schedule 2

available only from a pharmacist, must be retained in an area with no public access

schedule 3

available via open access in a pharmacy or pharmacy area (OTC)

unscheduled drugs

can be sold in any store without professional supervision

considerations for evaluating medication admin

• therapeutic outcomes

• side effects

• medication self-admin teaching

• understanding of medication

• necessary monitoring req’d

factors affecting choice of admin route

1. target tissue

2. clinical setting

3. medical situation (urgency)

4. drug dynamic

contradindication

situation where drug should not be used/is harmful to pt

endogenous

naturally found in body (ex. antibodies, hormones, ions)

exogenous

not naturally found in body (ex. most synthetic drug)

how long does it take po meds to have an affect?

20 min

types of liquid drugs

suspension, syrup, elixir, tincture

what does enteral mean?

passes through the GI tract

what is enteral feed

feeding a patient via a tube into the GI tract

what is special about enteric coated tablets?

you cannot crush them because they will irritate the stomach/become inactivatede

what is challenging about taking po drugs?

-acidic environment of stomach

-gastric motility + secretions

-first pass metabolism: a lot of the drug is broken down

is po or sl faster?

sl is faster

T or F: sl med admin goes through the GI system?

F. bypasses GI and 1st pass metabolism

intranasal (insufflation) meds go where?

into the nasal cavity for capillary absorption

direct CNS affect of intranasal admin occurs how?

diffusion across mucosa and distribution along CNS nerve networks

what % of med given intranasally reaches system circulation when it is supposed to be local?

34% reaches systemic circulationw

what effects can intranasal admin have?

local, systemic, direct CNS (preparation dependent, size of molecules)

why does inhalation admin have a rapid affect?

the pulmonary capillary network

when is et admin used?

er/icu situations (ex. epinephrine). ultimately is inhalation

intranasal drug examples

1. local - rhinocort spray

2. systemic - flu vaccine

3. direct CNS - cocaine

inhalation drug examples

1. local - asthma drugs

2. systemic - general anesthesia

top systemic presence

-minimal

-can be contraindicated

top drug example

retinoid creams (wrinkle tx)

• local effect at reticular layer of dermis (collagen fiber repair and synthesis)

• low systemic effect but contraindicated in pregnancy

rank for safety for pregnant women

A (safe), B, C, D, X (not safe)

td capillary absorption

-passive diffusion

-systemic effect desired

td drug examples

nicotine, morphine patch

rectal drugs are given where?

lower GI into the rectum

why does the rectal route have a lower first pass metabolism effect?

the venous return is not transported by the liver

why is the system effect of the rectal admin route unreliable?

peristalsis, the presence of poo

what do parenteral routes require?

injections

why are IV’s risky?

infection risk

what is the fast IM prep?

aqueous. moves into bloodstream more easily

what is the slow IM prep?

depot prep. meds are stored at the injection site

most important im injection site

ventrogluteal

all the main im injection sites

deltoid, ventrogluteal, rectus femoris, vastus lateralis

why is the dorsogluteal site not recommended?

too close to sciatic nerve

where is sc injection made?

into adipose tissue of hypodermis

angle of im vs. sc

im: 90

sc: 45

insulin injection sites

upper outer arms/thighs, tummy, butt

what is intrathecal admin?

epidural + spinal: bypasses BBB

implanted port admin

port with meds that stays in place and is connected to circulation

intraosseous admin

into bone (ex. top of tibia) in emergencies

pharmacokinetics vs dynamics

kinetics: what body does to drug

dynamics: what drug does to body

where does absorption primarily occur?

tummy, *sm int

where does distribution occur

bloodstream

where does metabolism primarily occur

liver

where does excretion primary occur

urinary system, lg int

what happens when a molecule becomes ionized?

not likely to absorb because it can’t cross the plasma membrane

what happens to drugs that aren’t easily permeable?

they can become 2nd messengers

characteristics for easy absorption?

lipophilic, non-ionized, small

characteristics for easy excretion?

hydrophilic, ionized

what is bioavailability?

systemic circulation’s plasma drug concentration

where can you measure bioavailability?

blood (plasma) tests. rarely urine

how can you adjust bioavailability?

titrate (give meds) to patient until desired effect achieved

what is heavy first pass effect?

a very small % of po drugs reach systemic circulation

amount of po dose vs. iv dose?

po dose is 3x bigger than iv dose because of heavy first pass effect

what is hepatic biliary secretion?

drug goes into bile, secreted from duodenum

or is reabsorbed into circulation - prolongs life of drug in body

path of drug in first pass metabolism

mouth —> esophagus —> tummy —> lumen of GI tract —> capillary network —> hepatic portal vein —> liver/gallbladder —> systemic circulation —> hep vein —> inf vena cava —> RA

fast absorption =?

faster onset

drugs with extensive first pass metabolism

My Mom Does My Laundry Perfectly Everytime

morphine - pain

meperidine (demerol) - opiod

diazepam - anxiety

midazolam - sedative

lidocaine - numbing

propanolol - heart

etoh - alc

morphine iv vs. po dose

iv dose 5-10 mg q4h

po up to 30 mg q4h

onset of action

drug reached systemic circulation

drug/route specific

what is the therapeutic range?

amount of drug + time it takes to achieve desired affect

cmax peak highest to lowest (im, po, iv)

iv (15-30 min)

im (30-60 min)

po (60 min)