Pharm Exam 1

Pharmokinetics

drug actions as it moves through body and what body does to drug

ADME

A-Absorption

D- Distribution

M-Metabolism

E- Excretion

Factors that effect absorption

Route ( how fast)

GI Motility( how slow GI tract moves)

Food (high fat meals slow the rate at which contents leave the stomach and enter intestines)

Gastric pH

Other medications ( Increase or decrease depending on drug interactions)

Formulation (enteric coatings take longer/ extended release tablets capsules and liquids)

What is the first pass affect?

when a drug is taken orally and absorbed from GI tract before going to the rest of the body’s bloodstream.

Distribution

Drug is delivered to tissues and fluids of the body

Factors affecting distribution

Blood Flow ( larger supply of blood= faster)

Body Comp

Protein Binding

Age

body weight

tissue permeability

blood brain barrier

barriers—> lipid soluble cross easier while water soluble cannot

protein binding ( distribution)

as drug travels drug can remain free or bind to protein portion bound has no therapeutic affect if two drugs are highly protein bound they will compete—> low albumin too much free drug —> higher toxicity levels

metabolism—> Bodies ability to change drug from its dosage form to more water soluble form

several ways of metabolisim

—> drugs can be turned into inactive metabolites

—> some drugs can be converted into active metabolites undergo further metabolisim

—> some drugs dont become active until they are metabolizedf

factors affecting metabolisim

AST and ALT are enzymes released when liver is damaged

-Liver can produce toxic metabolites

Genetics→ some enzymes less common

Age— liver slows down

Excretion —

elimination of drug from the body

half life of a drug

Time it takes for concentration of drug to fall to half its original value this lets us know how often drug needs to be takenacf

factors affecting excretion

Renal Fxn

2 things to monitor

Glomerular Filtration Rate ( GFR)

Creatinine—> if kidneys aren’t working muscles will bdown to clear drug

GFR and Creatine relatiotionship is interchangable

other methods sweat /saliva /breast milk

Onset

how long it takes for drug to work

Peak

when drug reaches max effectT

Trough

Lowest concentration D

Duration

How long it lastsheT

Therapeutic Index

drug safety margin dose that causes and dose that causes effect

Loading dose

taking higher amounts to achieve acquired dose

do this when

drug has long half life and large distribution volume

Pharmokinetics in children

A→higher pH affects drug absorption

slow gastric emptying

D—> babies have higher water concentration and blood brain barrier is weaker

Metabolisim—> liver is immature longer half life

Excretion—> slower

Pharmokinetics in older adults

A—> everything slows down

Distribution—> liver heart kidney slows down

Beers list—> meds to be careful of

Antihistamines

Common ending ( -ine)

action: blocks histamine

Route: oral/ ophatmaolgic

Indications: allergies antiseptic motion sickness

Side effects: dizziness, anticholergenic ,sedation

Interactions: CNS depressants

Nursing consideration: fall risk

Corticosterroids (gluccocorticoids)

Common ending (one)

Route: po, IM, IV, inhalation, topical, ophthalmic, otic, nasal

Action suppress immune rxn

indications: inflammation, desire immunosuppression

Side effects: insomnia, salt retention (edema, weight gain, HTN)

hypokalemia, osteoporosis, GI upset/bleeding/ulcers, impaired

wound healing, personality changes, infections, hyperglycemia

Nursing considerations: with food in am, decrease infection risk,

gargle with water after inhaled use, taper if taken long term

Disease-Modifying Antirheumatic Drug

(DMARDS)

Disease-Modifying Antirheumatic Drug

(DMARDS)

Used primarily for inflammatory autoimmune diseases

DMARDs relieve pain and inflammation and slow the underlying disease process

Example:

Example of PO DMARD: Methotrexate

Side Effects:

Hepatotoxicity, bone marrow suppression, GI effects, oral ulcers, pneumonitis

Nursing Implications:

Avoid pregnancy; limit/avoid alcohol; report infection, Monitor CBC, LFTs

Injectable DMARDS

Examples:

adalimumab (Humira)

etanercept (Enbrel)

Side Effects:

infection

Nursing Implications:

TB screening before starting

No live vaccines when on medication

Watch for infection

Depending on the medication, monitor CBC, liver function, and other drug-specific labs

Anti-Gout Medications

allopurinol reduces uric acid formation

◦ Side effects: rash

◦ Nursing Implications: Monitor uric acid levels

Acute Treatment

◦ NSAIDS

◦ Steroids