Dr J - fundamentals Flashcards
pharmacokinetics
what the body does to drugs and how fast it does it (e.g. absorption, distribution, metabolism (biotransformation), excretion)
Pharmacodynamics
what drugs do to the body
(receptor binding, signal transduction, physiologic effect)
Drugs are chemical substances used for:
- Preventing, treating or diagnosing disease (1938)
- Preventing pregnancy (1960’s)
- Recreational or other forms of abuse (1970)
Pharmacotherapeutics
and 2 types of these.
Treatment of disease by drugs.
- Palliative (most drugs) - symptomatically
- Curative (some drugs)
drugs that prevent:
- Vaccines
- Anticoagulants
- Antiseptics
drugs that Dx
- Radiographic contrast media (e.g. barium)
- Mydriatics for dilating pupil in ophthalmic exams
drugs that tx
Palliative (most drugs): Nasal Decongestants Antihypertensives Anxiolytics Analgesics Curative: Antibiotics Antineoplastics
Most drugs are _____ compounds with C, O, H, and st N.
organic
most drugs have 3 names
chemical
generic (official)
trade (proprietary)
What are the multiple formulations of drugs?
Formulations: Tablets, Capsules, Pills? (not these as far as MDs wld think), Pearls, Solutions, Suspensions, Ointments, Tinctures, Salves
What are the routes of administration of drugs?
- Enteral (ent-gut): oral, rectal
- Parenteral (parent - other than gut):
Sublingual
Intramuscular
Intravenous
Subcutaneous
Intrathecal (into CSF)
Topical (rub only skin)
Transdermal (applied with patch to expose to skin longer*)
Why are transdermal patches used vs topical application?
*Keratin – boxcar like protein that gives skin rigidity and this binding with AAs creates a insoluble barrier keeping drugs from passing easily. Transdermal holds drug in place and this hydrolyzes the keratin.
drug absorption
passage of drug from site of administration into bloodstream
drug distribution
passage of drug from bloodstream
Drug absorption and distribution are determined by 3 things:
- Drug molecular size.
- Drug solubility (and polarity).
- Conditions (i.e. blood flow, cell junctions, inflammation) at site of tissues to be penetrated by drug.
What increases drug solubility?
lipid or water solubility
lipid solubility (nonpolar/nonionized) molecules can dissolve in the phospholipid layer of cell membrane & filter through protein layer. Highly lipid soluble drugs must often attach to water soluble plasma proteins to be transported in the aqueous blood stream.
What barrier is an example of conditions that limit absorption and distribution of a drug?
BBB - blood brain barrier
Plasma proteins help with what?
Transport of highly lipid soluble (nonpolar/nonionized) drugs in blood plasma. These are temp inactive and cannot be distributed.
What form of drug can be distributed and be physiologically active upon receptors?
“Free drugs” - not bound in plasma proteins
drugs that activate receptors are termed:
agonists
drugs that block receptors are termed:
antagonists
measures of desirable drug actions include:
potency - dose req’d to produce min response
efficacy - max magnitude of response
measures of drug toxicity:
margin of safety - diff bet toxic and effective dose (a neg MoS means there’s neg effects before therapeutic effect. You want a large MoS.)
Therapeutic index - ratio of toxic and effective dose (TI=TD/ED) want a larger TI
measures of drug longevity
duration of action - amt of time the drug acts on system
half-life - time req’d for 1/2 of drug to be eliminated.
most drug/receptor bonds are reversible _____ (_____) bonds.
ionic (weak) bonds
what type of drug/receptors bonds are rare?
Covalent (strong) irreversible bonds
Drug stimulating a receptor and causing change inside a cell is an ____.
agonist
drug inhibiting a receptor from causing change inside a cell is an ____.
antagonist
