YEAR 1 - All dem drugs Flashcards
What is the class, mechanism, main therapeutic effects and side effects of acetazolamide?
Class: Carbonic anhydrase inhibitor
Mechanism: Inhibiting carbonic anhydrase enzyme, so prevents production of carbonic acid, which limits bicarbonate reabsorption in the proximal tubule. Self-limited diuresis as secretion of bicarbonate results in acidaemia, which will reduce the amount of bicarbonate being filtered. Also indirectly influences chloride absorption, meaning that diuresis is caused by both sodium bicarbonate and sodium chloride.
Main therapeutic effects: Could be but not traditionally used as a diuretic (RH: instead used to treat glaucoma and as a prophylactic against altitude sickness).
Side effects: Hypokalaemia and acidosis (and ironically, diuresis - not the intention of this drug).
What is the class, mechanism, main therapeutic effects and side effects of adenosine?
Class: Anti-dysrhythmic
Mechanism: A1 receptors, activation of IKACh, (note channel binds Ach) slow AVN conduction + SAN/AVN hyperpolarisation, ↓dromotropy and chronotropy.
A2 receptors, leads to relaxation of vascular smooth muscle via an intracellular increase in cAMP, decreasing MLCK action and leading to vasodilation. Vasodilation of the coronary arteries may allow matching of metabolic demand with blood flow, correcting the dysrhythmia.
Formed from breakdown of ATP (action also seen in macula densa signalling).
Main therapeutic effects: Rapid treatment of supraventricular tachycardias or other dysrhythmias.
Side effects: Over-vasodilation, can result in flushing and headaches, potential for arterial hypotension and AV block, both of which can be easily reversed through stopping the administration of adenosine. Also nausea.
What is the class, mechanism, main therapeutic effects and side effects of adrenaline?
Class: Catecholamine (hormone)
Mechanism: Acts on adrenoreceptors with varying potency (alpha-1, smooth muscle contraction Gq, alpha-2, pre-synaptic + inhib of NT release Gi, beta-1, increases heart rate Gs, beta-2, smooth muscle relaxation Gs).
Also one of the main hormones affecting metabolism, acting on nearly all tissues to initiate the fight or flight response/divert everything into the synthesis of ATP via cAMP signalling.
In the heart, increased cAMP signalling causes phospholamban and L-type calcium channels to be phosphorylated, increasing their activity and the force of contraction (incr intracellular calcium).
Main therapeutic effects: Used to relieve anaphylactic shock and to reverse cardiac arrest.
Side effects: Tachycardia, sweating, dizziness, nausea, weakness, headaches, anxiety (all symptoms seen in an adrenal tumour/phaeochromocytoma).
What is the class, mechanism, main therapeutic effects and side effects of amiloride?
Class: Potassium-sparing diuretic
Mechanism: Inhibitor of the epithelial Na+ channel in the collecting duct, preventing sodium reuptake, meaning that it is not substituted for K+
Main therapeutic effects: Accompanies administration of other diuretics to limit their side effects
Side effects: Hyperkalaemia
What is the class, mechanism, main therapeutic effects and side effects of amiodarone?
Class: Anti-dysrhythmic (most commonly used)
Mechanism: Potassium channel antagonist, prolonging the action potential through affecting both Kr and Ks currents. Also blocks calcium channels and the metabolites of this drug block sodium channels.
Main therapeutic effects: Given in ventricular tachyarrhythmia and when implanted defibrillators fire too often.
Side effects: Has GI, corneal and respiratory consequences - not the best drug to take.
What is the class, mechanism, main therapeutic effects and side effects of amphetamines?
Class: Catecholaminergic reuptake inhibitor
Mechanism: Inhibits the metabolism and reuptake of neurotransmitters (such as noradrenaline and dopamine), also stimulates the mass release of neurotransmitter.
Main therapeutic effects: Used to treat ADHD
Side effects: Addiction, tachycardia, high blood pressure, restlessness, psychosis
What is the class, mechanism, main therapeutic effects and side effects of aspirin?
Class: Prostaglandin synthesis inhibitor
Mechanism: Inhibits the cyclooxygenase enzyme involved in prostaglandin synthesis, therefore preventing it.
Main therapeutic effects: Pain relief, inhibiting prostaglandin synthesis reduces inflammation, fever and pain.
Side effects: Requires an enteric coating if taken orally, or else will inhibit prostaglandin synthesis in the stomach, effecting the mucus lining of the stomach and increasing the risk of peptic ulcer.
What is the class, mechanism, main therapeutic effects and side effects of atenolol?
Class: Beta(-1) blocker
Mechanism: Beta-1 adrenoreceptor antagonist
Main therapeutic effects: Used to treat heart failure, hypertension and angina, as drug is beta-1 selective.
Side effects: Less likely to cause bronchoconstriction than propranolol, gives cold feet and hands and may unmask vasoconstriction.
What is the class, mechanism, main therapeutic effects and side effects of atropine?
Class: Cholinergic antagonist (anti-muscarinic)
Mechanism: Cholinergic muscarinic antagonist, inhibits M2 muscarinic receptor stimulation, therefore reducing intracellular cAMP levels - constant sympathetic tone therefore increase in heart rate.
Main therapeutic effects: Treats (sinus) bradycardia, decreases saliva secretion during surgery as well as treating some nerve agents.
Side effects: Dry mouth, blurred vision, nausea, lack of sweating.
What is the class, mechanism, main therapeutic effects and side effects of bendroflumethiazide?
Class: Thiazide diuretics
Mechanism: Inhibit action of NaCl transporter in the distal tubule.
Main therapeutic effects: Less potent diuretic than loop diuretics, usually used to treat hypertension and heart failure chronically, sometimes used to treat stone formation in the urinary tract.
Side effects: Hypokalaemia, hypovolaemia, calcium retention (can lead to increased risk of urinary stones).
What is the class, mechanism, main therapeutic effects and side effects of botox (botulinum toxin)?
Class: Vesicular release inhibitor
Mechanism: Proteolytic, cleaves the three main snare proteins at different sites, this prevents the binding of the vesicle to the membrane and its subsequent release of contents into the synapse.
Main therapeutic effects: Used cosmetically to remove wrinkles, to treat hyperhidrosis (excessive sweating), overactive bladder, lazy eye and neck spasms.
Side effects: Droopiness, pain or swelling at the injection site, crooked smile.
What is the class, mechanism, main therapeutic effects and side effects of digoxin?
Class: Cardiac glycoside
Mechanism: Not known, thought to act through the inhibition of the Na+/K+ ATPase, causes Na+ to build up within the cell and therefore the gradient for the Na+/Ca2+ exchanger (NCX) to be depleted, meaning that more calcium will be retained within the cell. This causes positive inotropy without a large increase in O2 demand. May also affect ryanodine receptors directly and have transcriptional effects in the long term.
Main therapeutic effects: Used in heart failure to increase the force of contraction, no longer first line treatment. Also used to treat atrial fibrillation.
Side effects: (/toxicity) Diarrhoea, visual disturbances, abdominal pain, arrhythmias and vomiting. Increased risk of toxicity at low plasma potassium levels.
What is the class, mechanism, main therapeutic effects and side effects of dobutamine?
Class: Beta-1 agonist/sympathomimetics
Mechanism: Act on cardiac beta-1 receptors to increase rate and force of contraction but also increase myocardial oxygen consumption. Similar action to adrenaline.
Main therapeutic effects: Positive inotrope, increases ventricular contractility and cardiac output in heart failure. Used to treat cardiogenic shock and severe heart failure. Should not be used when cardiac ischaemia is a feature of the disease.
Side effects: Better than dobutamine as minimises risk from myocardial ischaemia and doesn’t agonise the dopamine receptors. Increased risk of potentially fatal arrhythmias, also hypertension, angina and tachycardia.
What is the class, mechanism, main therapeutic effects and side effects of furosemide?
Class: Loop diuretic
Mechanism: Inhibition of the NaK2Cl transporter (NKCC) in the thick ascending limb disrupts the osmotic gradient needed for urine concentration.
Main therapeutic effects: Diuretic, treats heart failure and hypertension.
Side effects: K+ loss, hypokalaemia, hypovolaemia, calcium and magnesium loss.
What is the class, mechanism, main therapeutic effects and side effects of insulin?
Class: Protein (hormone)
Mechanism: Hormone of the fed state. Influx of glucose through GLUT-2 channels in the beta cells of the pancreas causes insulin release, which then instructs cells to insert GLUT-4 channels into the membranes of peripheral (muscle and adipose tissue) cells. Activates enzymes (e.g. glucokinase) that favour storage of fuels/synthesis of molecules (also allow organs like the liver to respond to glucose levels), and inactivates enzymes (e.g. PDH phosphatase) of opposing pathways. Inhibits lipolysis.
Main therapeutic effects: Used to treat diabetes mellitus (type 1 and 2) - difficult to administer in a way that mimics natural rhythms, achieved through injections or pumps. Insulin is needed to prevent dominance of the fasted state. Administered after the beta cells of the pancreas lose their ability to secrete insulin.
Incretins can also be used to treat type 2 diabetes to increase insulin secretion. Metformin and sulphonylureas increase insulin sensitivity.
Side effects: Injected insulin remains in the body for long periods of time, which can cause issues with hypoglycaemia - most issues arise with incorrect dosage or difficulty in timely administration.
