Pharmacology Flashcards
Distinguish between pharmacodynamics and pharmacokinetics
PharmacoDynamics - how the Drug affects the body
Pharmacokinetics - how the body affects the drug (disposition of a compound within an organism)
Pharmacokinetics 4 principles (ADME)
Absorption
Distribution
Metabolism
Excretion
Absorption
Transfer of drug from administration site to the circulation
Distribution
Transfer of drug from general circulation to tissues and back
Metabolism
Transformation of drug molecule into different molecule
Excretion
Molecule expelled either in solid, liquid or gaseous state
Elimination
Removal of a drugs activity from the body
Elimination includes metabolism and excretion
Bioavailability
The fraction of administered drug that reaches the systemic circulation unaltered
IV = 100%
Oral = <100%
Efficacy
How well ligand activates receptor (full or partial agonist)
Potency
Binding affinity
5 Muscarinic receptors and their effects on body
M1 - Brain
M2 - Heart (Slows down)
M3 - Glandular/SM (Bronchoconstriction, sweating, salivary gland secretion)
M4/M5 - CNS
Salbutamol
B2 adrenoreceptor agonist
SABA (Short acting Beta-agonist)
Asthma
Which NS branch does noradrenaline (NAd) work on?
Sympathetic
Effects on body when noradrenaline (NAd) binds to alpha-1 and alpha-2 adrenoreceptors
Alpha-1) Vasoconstriction, mydriasis (pupil dilates), contraction of bladder neck (urinary retention)
Alpha-2) Reduces insulin production from pancreas
Effects on body when noradrenaline (NAd) binds to beta-1, beta-2 and beta-3 adrenoreceptors
Beta-1) Increased HR/BP
Beta-2) Vasodilation, bronchodilation, decreased GI motility
Beta-3) Relaxation of bladder
Opposite to agonists
Blockers (e.g. Beta blockers)
Name a drug which is a B-adrenoreceptor blocker
Atenolol (B1 selective) - Reduces HR/BP
Treats hypertension, angina, arrhythmia
Drugs that end in -olol are classed as
B-adrenoreceptor blockers
In what condition must you not prescribe a beta blocker?
Asthma
4 Side effects of beta blockers
Wheeze
Tiredness
Bradycardia
Hypoglycaemia
COX enzymes produce 2 molecules
COX 1) Thromboxane (Vasoconstriction and platelet aggregation)
COX 2) Prostaglandins (Inflammation and pain)
Name a drug other than paracetamol that is classed as a COX inhibitor
Aspirin
Low dose - inhibits COX1
High dose - Inhibits COX1/2
What is the cellular effect of a paracetamol overdose
Cellular necrosis
Name a drug that is an ACE inhibitor
Enalapril (Hypertension and heart failure)
3 important things to consider with enalapril
Contraindicated in renal artery stenosis
Must not prescribe in patients with eGFR <60
Side effect - Dry cough
Name an addictive opioid
Morphine
What is the bioavailability in % of oral morphine?
50%
How do opioids work?
Inhibit descending pain signals
4 Side effects of opioids
Respiratory depression
Sedation
Nausea/vomiting
Constipation
Name a drug that is classed as an opioid antagonist
Naloxone (used in overdose or respiratory depression)
