Pharmacology Flashcards
Alendronate
BiphosphONATE
Osteoporosis
SE: oesophagitis
Atracurium
Muscle relaxant for surgery
Competitive nicotinic antagonist (neuromuscular block)
Neostigmine
Acetylcholinesterase inhibitor
Myasthenia gravis
Reverses the effects of neuromuscular block medication e.g. atracurium
Thiazide diuretics
BendroflumeTHIAZIDE, hydrochloroTHIAZIDE
Inhibit reabsorption of sodium and chloride ions at the distal convoluted tubule (water follows sodium so water is excreted)
Indication: hypertension, heart failure, nephrogenic DI
Cefuroxime
CEPHalosporin antibiotic (Beta lactam)
Indications: infections such as pneumonia, meningitis, sepsis
Celecoxib
NSAID: selective COX-2 inhibitor
Indications: OA pain, RA, ankylosing spondylitis
Ciclosporin
Calcineurin inhibitor (calcineurin activates T-cells)
Immunosuppressant medication
Indications: RA, Crohns, nephrotic syndrome
Ciprofloxacin
Broad spectrum antibiotic
Fluroquinolones suffix -oxacin
Indications: pneumonia, shigellosis, salmonella
Co-amoxiclav
Amoxicillin with clavulanic acid (beta lactamase inhibitor)
Diamorphine
Strong opioid
Heparin
Anti-coagulant
Activation of anti-thrombin III which inactivates thrombin and factor Xa (INDIRECT)
Types:
- Unfractioned heparin
- LMWH (Dalteparin, Enoxaparin) - longer half life
Apixaban, Rivaroxaban
Anti-coagulants
Factor Xa inhibitors (DIRECT/DOAC)
Warfarin
Anti-coagulant
Anti-Vitamin K: II (prothrombin), VII, IX, X (1972)
Alteplase
Thrombolytic
Activates plasminogen which forms plasmin (forms fibrin degradation products)
Furosemide
Loop diuretic -ide
Ascending limb of the loop of Henle
Reversibly inhibit the Na/K/Cl cotransporter
Spironolactone
Competitively antagonises aldosterone receptor
Promotes sodium and water excretion and potassium retention (opposite of aldosterone)
Indications: hypertension, heart failure, hyperaldosteronism
NSAIDs
COX converts arachidonic acid into thromboxanes (platelet adhesion), prostaglandins (vasodilation) and prostacyclins
COX1 key in protecting gastric mucosal lining (SE)
Non-selective: aspirin, ibuprofen (inhibitors of COX1 and COX2) - aspirin is irreversible, ibuprofen is reversible
Selective: celecoxib (COX2 inhibitor)
Dobutamine
IV Beta 1 agonist used in the treatment of cardiogenic shock to increase contractility
INOTROPE
Catecholamine (think DOpAMINE)
Doxazosin, Tamsulosin
Alpha1 blocker (alpha 1 = vasoconstriction so blocking leads to vasodilation) -osin Indications: hypertension, benign prostatic hyperplasia (relaxes bladder muscles)
Ephredine
Alpha and beta adrenergic agonist (increases adrenaline release)
Indications: asthma, reversal of hypotension in anaesthesia
Ethinylestradiol
Oestrogen in contraceptive pill
Direct acting cholinergic agonist
Mimic ACh
Carbachol (pupil constriction)
Indirect acting cholinergic agonists
Inhibit AChE enzyme, increasing ACh
Neostigmine, Rivastigmine (used in AD)
Muscarinic antagonists
Compete with ACh for muscarinic receptor
Atropine (pupil dilation)
- Ipratropium is a derivative of atropine that doesn’t cross the blood-brain barrier preventing CNS SE
Inotrope
Alter contractility of the heart
Positive inotrope (strengthen):
- Catecholamines: Adrenaline, Dopamine, Dobutamine
- Calcium
Negative inotrope (weaken):
- Amiodarone
- Amlodipine
- Ramipril
- Propanolol
Alpha 1 adrenergic receptor action
Smooth muscle contraction (VASOCONSTRICTION) in the skin, GI, kidney and brain (fight or flight: REDUCED blood flow to these organs)
Alpha 2 adrenergic receptor
Located on vascular terminals where it inhibits the release of adrenaline and ACh in a form of negative feedback
Beta 1 adrenergic receptor
Increases cardiac output
Increases heart rate (chronotropic)
Increases atrial contractibility (inotropic)
Renin release
Beta 2 adrenergic receptor
Smooth muscle RELAXATION in bronchi (fight or flight: facilitates respiration) and detrusor muscle of bladder (fight or flight: inhibits micturition), increased muscle and liver glycogenolysis
Loperamide
Decreases the frequency of diarrhoea
Metformin
Reduces hyperglycaemia
Biguanide: Inhibits gluconeogenesis in the liver, Decreases intestinal glucose absorption, Improves cellular insulin sensitivity (via AMPK)
Metformin in the only available biguanide
Methotrexate
Immunosuppressant
Indications: RA (DMARD), Crohns
Oxybutynin
Antimuscarinic
Treatment for an overactive bladder
Paracetamol toxicity
Phase II metabolic pathway becomes saturated so more paracetamol is shunted to the CYP system to produce NAPQI (usually only 5%) causing hepatoxicity
Antidote: IV Acetylcysteine
Ramipril
-ipril = ACE inhibitor
Rifampicin
Antibiotic: RNA polymerase
Used to treat TB alongside isoniazid (6 month course)
Salmeterol
Long acting beta 2 adrenergic receptor agonist
(LABA)
Meter = long
Sildenafil
Viagra
PDE5 inhibitor: increases cGMP to vasodilate penile vessels
Suxamethonium
ACh mimetic (hydrolysis is slower than ACh so depolarisation is prolonged) Neuromuscular blockade: used in general anaesthetic
Tramadol
-adol
Opioid analgesic
Enteral route of administration
Systemic
Via the GI tract
Oral (PO), Rectal (PR), Sublingual
Parenteral route of administration
Systemic Not via GI tract IV, IM, SC Inhalation Transdermal
Local route of administration
Topical Intranasal Eye drops Inhalation Transdermal
Pharmacodynamics
Action of the DRUG on the BODY
Drug dancing dynamically around the body
Pharmacokinetics
How the BODY breaks down the DRUG
ADME
First pass metabolism
Gut and liver metabolise drugs before they reach the circulation i.e. absorbed and go straight to the liver via hepatic portal vein
E.g. only around 40-50% of morphine reaches the CNS due to this
IV bioavailability
100%
Process of lipid soluble drug elimination
Kidney can’t eliminate lipid soluble drugs
Liver:
Phase 1 - cytochrome p450 catalyses make drug HYDROPHILIC
Phase 2 - (for some drugs, phase 1 is enough) conjugation: add polarity e.g. acetylation
= water soluble metabolites
CYP inducers
Speed up metabolism of other drugs
E.g. phenytoin
CYP inhibitors
Reduce metabolism of other drugs
E.g. amiodarone
Elimination rate constant (K)
First order (majority of drugs): elimination is proportional to the amount of drug in the body i.e. a high dose will be eliminated at a faster rate
Zero order: rate of elimination is constant e.g. ethanol, phenytoin
Enzyme that metabolises morphine
CYP 2D6
Most important CYP enzyme
CYP 3A4
Bodily fluids to EXCRETE drugs
Urine
Bile > Faeces
Partial agonist
Cannot achieve Emax even with full receptor occupancy
Which classic drug is avoided due to its narrow therapeutic window
Digoxin
Cardiac glycoside (inhibits sodium potassium ATPase)
Indications: AF, atrial flutter, heart failure
When might spironolactone be used?
Hypokalaemic patients
Spironolactone is an aldosterone antagonist so promotes potassium retention
Also used in conns syndrome (hyperaldosteronism)
Drug targets
Receptors, enzymes, transporters, ion channels
Tolerance
Reduction in response to a drug after repeated administration
Desensitisation
Receptors become degraded/uncoupled/internalised
Candesartan
Angiotensin II receptor blocker
Three ways drugs move between fluid compartments
Simple diffusion
Facilitated diffusion
Non-ionic diffusion
Active transport
Treatment of acute hyperkaelaemia
Cardiac risk: calcium gluconate (to protect cardiomyocytes) THEN insulin + dextrose
No cardiac risk: insulin + dextrose (K+ into cells)
ECG will show Tall-Tented T waves and Flattened P-Waves
Clotrimazole
AZOLE = anti-fungal
Anticholinergic side effects
Which antidepressant has anticholinergic effects?
Decrease parasympathetic nervous system: Blurred vision Confusion Dry mouth Urinary retention
Amitriptaline (TCA) has anti-cholinergic properties
Methadone
Medication prescribed for heroin addiction
Drug prescribed to prepare patient for pheochromacytoma surgery
tumour removal can cause large release of chatecholamines causing refractory hypertension
= Phenoxybenzamine - alpha receptor blocker (can add beta blockers AFTER)