PHARMACOKINETICS

 Study of how medications; enter the bod, reach site of action, metabolization, and excrection

Four processes:

Absorption

Distribution

Metabolism

Excretion

How does liver disease affect drug metabolism?

May slow metabolism and alter the dosage of the drug needed to reach a therapeutic level.

How does elevated creatnine levels affect excretion?

Elevated creatnine levels may indicate kidney failure which can lead to toxicity.

How does coughing and deep breathing affect excretion?

The lungs are the primary route for the excretion of gaseous substances, ie. inhalation anesthetics. 

How do fluctuations in blood levels affect onset of Rx?

Plasma protein levels can affect protein binding meds and affect ditribution.

Pharmacodynamics

The study of the physiological effects of Rx and thier mechanisms of action.

Onset

Serum drug level at it's minimum

Peak

Rx at it's highest concentration.

Tate of absoption = rate of elimination

Trough

Rx at it's lowest concentration.

30min- 1hr. before next dose is due.

Half life

Amount of time it takes for excretion to lower the serum drug concetration by half.

Ibuprophen half life

1-2 hours

Diazepam half life

20-50 hours (even longer in elderly)

Digoxin half life

1.5 days

Primary effects

therapeutic effects

predicted, intended, desired

Secondary effects

Unintended or nontherapeutic effects.

 *usually predictable and well tolerated.

Directly related to dose.

Increasing dose increases effect.

Adverse reaction

Harmful and Unpredicted

"Now" Orders

Need to be given within 90 minutes.

3 MEDICATION CHECKS

1.) Before preparing medication

2.) Check medication lable against MAR

3.) At bedside

Administering meds with feeding tubes

• Only some pills may be crushed
• Do not mix with feedings
• Administer seperately w/ 5ml of water between meds
• Follow last med with 15-30ml of warm water
• Elevate HOB for at least 30min to pevent reflux

Transdermal

Nicotine patches, pain meds, angina, motion sickness, estrogen

DO NOT REPLACE PATCH IN SAME SITE

Proetz's Postion

For nasal meds/irrigations/instillations.

Head is hyperextended off the edge of bed.

MDI

Metered dose Inhaler

1.) shake

2.) exhale

3.) slowly inhale and depress trigger simultaneously

4.) Hold breath for 10 seconds

5.) Exhale through nose

6.) Wait one minute before repeating

7.) Rinse mouth

***BRONCHODILATORS 1ST

CORTICOSTEROIDS 2ND

TB syringe

calibrated in 1/10's and 1/100's of a mm

Dose= < 0.5ml

1/4"-1/2" long

26-27ga.

Insulin Syringe

5/16"- 1/2" long

28-30ga.

Never use an insulin syringe for anthing else.

Lovenox

• Less molecular weight than Heparin
• Pinch tissue
• Inset needle @ 90degrees into fat pad on either side of abdomen
• Comes with pre-filled syringe w/ air bubble
• DO NOT EXPELL AIR BUBBLE

Drawing procedure for ampule

• Invert or tip ampule
• Withdraw ALL of the med
• Remove filter needle
• Attach 'saved' needle for injection

Reconstituting Drugs

• Sterile water or Saline
• Instrctions listed on lable
• Solute mustbe thoroughly mixed
• DO NOT SHAKE

Deltoid Intramuscular Injection

Aspirate to make sure you are not in an artery or vein.

No more than 1ml

Needle gauge= 20-23

Needle lenght= 1-3"

3ml or larger syringe

Ventrogluteal or Vast Lateralis

Intramuscular Injections

Aspirate

No more than 3ml

Needle gauge= 20-23

Needle lenght= 1-3"

3ml or larger syringe

Z-Track

• Seals needle track
• Reduces pain
• Prevents med from leaking out
• Required for Vistaril and Iron
• Recommended for ALL IM injections
• Use larger muscles

S/S of Anaphylactic Shock

Uticaria~(raised, often itchy, red welts on the surface of the skin)~Wheals

Bronchiolar constriction- wheezing-dypsnea

Edema

Circulatory collapse

Cummlative Effect

Body cannot metabolize a drug before the next dose is given

Incompatable Meds

Adminstered 15 minutes apart at different sites

Insulin's appearance

Short Acting= Clear

Intermediate/Long= Cloudy

*Except Lantus is clear

Actovials

Diluent and Powder in same vial

separated by a rubber stopper

IM injections

Antibiotics

Vaccines

Hormones

Deconoate

Meds in aqueous solutions

(needle gauge)

20-25ga needle

Oil based meds

(needle gauge)

18-25ga.

Reasons meds can be ommitted

Interferres with diagnostic test

Problem no longer requires med

Allergic reaction

Reconcilliation Lists

Maintains current and accurate list of pt's meds