Pharmacology Flashcards
Name the routes of administration
Enteral - through GIT
Oral (PO), rectal (PR)
Parenteral - non GIT
SC
IM
IV
Sublingual
Inhalers (INH)
Local effect
Transdermal e.g. patches
Topical cream e.g. steroid
Define agonist
Full affinity and full efficacy
∴ ↑ activation of receptor
Define antagonist
Full affinity and zero efficacy
∴ ↓ activation of receptor
Define affinity
How well ligand bind to receptor
Define efficacy
How well a ligand successfully activates its receptor
Define potency
The relative strength of drug
i.e. lower dose needed for response = more potent
Describe the mechanism of a competitive inhibitor
Binds at the active site
∴ ↓ Efficacy
Reversible, affinity is unchanged
∴ Less potent
Describe the mechanism of a non-competitive inhibitor
Binds away from active site, changing its shape
∴ ↓ Efficacy
Irreversible, affinity is reduced
∴ Less potent
Define bioavailability
How much drug is uptaken systemically for effect
IV route = always 100%
Other routes = suboptimal
What is a therapeutic range?
Upper and lower of safe doses of a drug
Narrowe range = reqs more care in dispensing
Name some drug targets and examples of each
Receptor action - ARBs, BBs, salbutamol, tamoxifen, alpha blockers
Enzymes - ACEi, 5-alpha reductase inhibitors
Ion channels - CCB
Transporters - PPI
Define pharmocodynamics
Effect of drug on the body
Define pharmacokinetics
Effect of body on the drug
(when it’s being broken down)
State the 4 aspects of Pharmacokinetics
ADME
Administration (route)
Distribution
Metabolism! (IV skips this!)
Excretion (hepatically or renally)
Describe GIT metabolism
Mechanical and chemical digestion
Describe renal metabolism
Simple, already soluble molecules. Easy to pee out directly
Describe hepatic metabolism
More complex, hydrophobic molecules. Undergo phase 1 and/or phase 2 reacns
Describe Phase 1 reactions
NON-conjugation. Aims to slightly increase hydrophilicity.
By microsomal enzymes e.g. CYP450
Descrive Phase 2 reactions
Conjugation. Adds functional groups
e.g. glucuronidation to massively increase hydrophilicity
Name the 2 main receptors of cholinergic pharm
Nicotinic and muscarinic
Describe Nicotinic receptors
Usually pre-synpatic
Describe Muscarinic receptors
Usually post-synaptic
M1 = BRAIN
M2 = HEART
M3 = LUNGS
What condition is related to disrupted Ach Transmission at NMJ?
Myasthenia Gravis
Side/Effects of XS acetylcholine stimulation
SLUDGE
Salivation
Lacrimation
Urination
Defecation
GI distress
Emesis
Name the receptors of adrenergic pharm
alpha 1 & 2
beta 1
beta 2
Where are alpha 1 & 2 found?
On vessels and sphincters (e.g. bladder neck)
Example of alpha 1 block and its use + mechanism
Tamsulosin
1st line med for BPH
Relaxes bladder neck ∴ easier urine flow
Where is beta 1 found?
On heart