Cardio drugs Flashcards
1
Q
Digoxin
- MoA
- Clinical Indications:
- Prescription dose:
- Adverse effects:
- Interactions:
A
- MoA: Na+K+ATPase inhibitor - causes Na+ to be retained in myocytes –> Ca2+ is also retained –> Phases 4 and 0 of cardiac action potential are prolonged ==> increased end-diastolic volume + increased time between contractions
- Clinical Indications: ventricular rate control, esp for supraventricular arrhythmias (A.fib and A.flutetr), HF
- Prescription dose:
> 0.75-1.5mg divided doses over 24h for RAPID CONTROL of a.fib/a/flutter
> 125 - 250 micrograms for daily maintenance
> 62.5 - 125 micrograms daily for HF
> dose reduced in elderly/renal impairment - Adverse effects: DIGOXIN TOXICITY: nausea, vomiting, visual disturbance, confusion, dizziness –> withdraw drug + correct e- disturbance + give digoxin-specific antibody fragments
- Interactions: amiodarone (HALVE digoxin dose, as amiodarone causes increase in digoxin conc), CCB, hypoK drugs (like diuretics), hypomagnesaemia drugs (like PPIs)
2
Q
What do intotropic and chronotropic mean? How would you classify different cardio drugs into inotropic and chronotropic?
A
Inotropic: increases strength of contraction - digoxin, dobutamine, milrinone
Chronotropic: increases heartbeat rate - epinephrine, dopamine
3
Q
When should you AVOID digoxin?
A
heartblock, WPW syndrome, ventricular tachycardia, myocarditis, constrictive pericarditis
4
Q
Thiazide diuretics
- MoA
- Clinical Indications:
- Prescription dose:
- Adverse effects:
- Interactions:
A
- MoA: Inhibits Na+Cl- symporter in distal convoluted tuble –> Na+ and Cl- are not reabsrobed ==> Na+ and water are expelled, blood volume and pressure go down
- Clinical Indications: HTN, oedema in HF (but loop diuetric is preferred in HF)
- Prescription dose:
> 5-10mg mane [morning] for oedema
> 2.5mg mane for HTN - Adverse effects:
> Hypos: hypoK, hypoNa, hypoMg
> Hypers: HyperCa, hyperuricaema (both can cause gout!), hyperglycaemia (avoid in pts w hx of dm) - Interactions: increases plasma conc. of lithium and NSAIDs, avoid using with other drugs that cause HypoNA (diuretics, antideprssants, carbamazepine)
5
Q
Name some thiazide diuretics and thiazide-like diuretics
A
thiazide: bendroflumethiazide, hydrochlorothiazide
thiazide-like: indapamide, chlortalidone, metolazone
6
Q
Thiazide diuretics should NOT be used to treat ________ HTN
A
gestational
7
Q
Thiazide diuetrics are ineffective if eGFR is ________
A
<30mLs/min
8
Q
Loop Diuretics (furosemide)
- MoA
- Clinical Indications:
- Prescription dose:
- Adverse effects:
- Interactions:
A
- MoA: inhibits Na+ resaborption in loop of henle
- Clinical Indications: Chronic HF, pulmonary oedeoma**, resistant HTN
- Prescription dose:
> 20-40mg mane for oedema (can go up to 120mg)
> 40-80mg for HTN - Adverse effects: GI disturbance, postural hypotension, hyperglycaemia, hyperuricaemia, hypocalcaemia, renal and hepatic toxicity, ototoxiity**
- Interactions: lithium, other antihypertensives, NSAIDs (nephrotoxity), aminoglycoside abx and vancomycin (ototoxicity), other diuretics, digoxin (cardiotoxicity)
9
Q
Main difference b/w thiazide and loop diuretics?
A
Thiazide causes HyperCa, loop causes HypoCa
10
Q
STRONG loop diuretic that you only need 1mg of
A
Bumetanide
11
Q
Are loop diuetrics first line for anything?
A
No
12
Q
What must you establish before giving loop diuretic?
A
Adequate urine output from pt
Sufficient eGFR - if too low, may need higher dose
13
Q
Aldosterone-dependent, K-sparing diuretics (Spironolactone)
RMBR: spironolaKtone - k sparing!
- MoA
- Clinical Indications:
- Prescription dose:
- Adverse effects:
- Interactions:
A
- MoA: competitive antagonist for aldosterone receptor in renal tubules, –> reduces aldosterone-induced proteins ==> K+ retained, NA+ and water lost
- Clinical Indications: oedema in congestive HF, ascites, hyperaldosteronism, nephrotic syndrome
- Prescription dose:
> ascites: 50mg twice a day (can be increased to up to 200mg)
> HF: 25mg once a day - Adverse effects: cross-reacts with intracellular androgen receptorms –> gynaecomastia, hypogonadism, impotence, menstrual irregularities. ACUTE renal failure.
- Interactions: other K-retaining drugs (ACE-I, ARBs), NSAIDs, lithium, antihypertensives
14
Q
What is the drug monitering regimen for K+ sparing diuretics
A
- baseline U&Es and LFTs
- re-check after 1 week
- check every 4 weeks for 12 weeks
- check every 3 months for a year
- check every 6 months after that
15
Q
What pt advice do you give for spironolactone
A
Take with/after food. Do NOT take NSAIDs OTC.
16
Q
When to use which diuretic
A
High BP: thiazide is first-line. Act within 1-2 hours, effects last for up to 24h. Milder effect and less dramatic water loss than loop.
Pulmonary oedema: loop diuretics. Very fast acting and cause rapid water loss. Frequent visits to toilet.
HF oedema: K-sparing. Weaker diuretic, prevents too much K+ loss.
17
Q
Amiodarone
- MoA
- Clinical Indications:
- Prescription dose:
- Adverse effects:
- Interactions:
A
- MoA: class lll anti-arrhythmic with MoA unclear lol, but typically non-selective inhibitor of Na, Ca channels and a-adrenoceptor –> prolongs cardiac action potential –> increased QT interval
- Clinical Indications: rhythm control in A.fib and A.flutter, ventricullar tachycardias, WPW
- Prescription dose:
> 200mg 3x daily for 1 week, 2x daily for following week
> 200mg once daily after (maintenance dose) - Adverse effects: bradycardia, hypo/hyperthyroidism, jaundice, grey skin discolouration, pulmonary fibrosis, hepatotoxity, taste disturbance, peripheral neuropathy, optic neuritis (can lead to blindness)
- Interactions: increases digoxin conc, increases anticoagulant effect of warfarin, increased risk of bradycardia when combined with BB/CCB, increased risk of myopathy when combined with statin, increases risk of ventricular arrhythmias when combined with tricyclic antidepressants/lithium, increases plasma conc. of phenytoin
18
Q
drug monitoring for amiodarone
A
LFTs and TFTs when starting tx, repeat every 6 months, CXR before starting tx
19
Q
Pt advice for amiodarone
A
Avoid exposure to direct sunlight and sun lamps (increases photosensitivity), can causes changes to eyes
20
Q
What must IV infusions of amiodarone be diluted with?
A
5% dextrose (NOT saline)
21
Q
Selective vs. non-selective betablockers
A
Heart is the most impt organ = 1st organ
Therefore B1 receptor = cardio receptor
Bisoprolol starts with B = cardio-selective
Propanolol starts with P, so does ‘pulmonary’, therefore propanolol acts on B1 and B2
22
Q
Bisoprolol
- MoA
- Clinical Indications:
- Prescription dose:
- Adverse effects:
- Interactions:
A
- MoA: Competitively binds to B1 adrenoceptors instead of ligang noradrenaline produced by sympathetic adrenergc neurones –> adenylyl cyclase inhibited –> cyclic AMP reduced –> low Ca levels in myocytes –> negatively inotropic + negatively chronotropic (contractility AND rate reduced)
- Clinical Indications: resistant HTN, angina, MI, HF, thyrotoxicosis (propanolol), anxiety, migraine
- Prescription dose: 5-10mg daily, max 20mg
- Adverse effects: dizziness, fatigue, cold hands, headache, hypotension, bronchospasms** (asthma, copd), hypogyclaemia** (can mask hypo signs in DM pts), peripheral vasoconstriction (Raynauds, intermittent claudication)
- Interactions: alcohol (increases hypotensiveness), other antihypertensives, antuarrhythmics
23
Q
A
24
Q
Selective vs. non-selective betablockers
A
Heart is the most impt organ = 1st organ
Therefore B1 receptor = cardio receptor
Bisoprolol starts with B = cardio-selective
Propanolol starts with P, so does ‘pulmonary’, therefore propanolol acts on B1 and B2
25
Doxazosin (a1-specific a-blockers)
- MoA
- Clinical Indications:
- Prescription dose:
- Adverse effects:
- Interactions:
- MoA: inhibits binding of normal ligand noradrenaline --> inhibits activation of phospholipase-C enzyme --> reduced inositol triphosphate --> phosphorylation cascade blocked ==> vascular smooth muscle relaxation, vasodilation, reduced aBP
- Clinical Indications: HTN, BPH. Raynaud's (prazosin)
- Prescription dose: varies widely
- Adverse effects: postural hypotension**, give dose at bed-time
- Interactions: other hypotensives, MAOIs
26
If someone's undergoing ______, they should not receive a1-receptor antagonist
cataract surgery, risk of floppy iris syndrome intraoperatively
27
ACE-I (ramipril)
- MoA
- Clinical Indications:
- Prescription dose:
- Adverse effects:
- Interactions:
- MoA: inhibits ACEI --> angiotensin ll (potent vasoconstrictor) is not synthesised --> vascular smooth muscle relaxation + vasodilation
- Clinical Indications: HTN (1st line in caucasian pts <55/diabetcics), HF, type l diabetic nephropathy, after acute MI
- Prescription dose:
>HTN: 2.5mg daily
> HF: 1.25mg daily
>maintenance dose: 10mg daily
- Adverse effects: persistent dry cough**, hyperK, increased serum creatinine
AVOID in pregnancy/women of childbearing age if they're trying to conceive
- Interactions: diuretic, k-sparing diuretics, ciclosporin (hyperK)
28
ARB (irbeSARTAN)
- MoA
- Clinical Indications:
- Prescription dose:
- Adverse effects:
- Interactions:
- MoA: same as ace-i pretty much
- Clinical Indications: HTN esp if pt develops cough on ace-i, hf, post-MI, type ll diabetic nephropathy**
- Prescription dose: varies based on type, use half normal dose in renal impairment
- Adverse effects: hypotension (less marked than ace-i), acute renal failure, angioedema, use with caution in aortic/mitral stenosis and renal artery stensosis
- Interactions: other antihypertensives
29
how do acei/arb help diabetic nephropathy?
They decrease glomerular capillary pressure and retard progress od diabetic nephropathy
30
GTN
- MoA
- Clinical Indications:
- Prescription dose:
- Adverse effects:
- Interactions:
GTN
- MoA: causes there to be less intracellular ca2+ --> vascular smooth muscle relaxation and vasodilation
short-acting preparation that has effect in 1-2 min and works for up to an hour. ISMN and ISDN take effect more slowly, but last for up to 8h.
- Clinical Indications: acute relief for angina (GTN), prophylaxis (ISDN, ISMN)
- Prescription dose:
> GTN: 0.3-1mg sublingually as required
- Adverse effects: headahce, hypotension, tachycardia, flushing
tolerance to gtn can be overvome with nitrate-free interval (nitrate-free for 4-8h every 24h)
AVOID in hypothyroidism, recent MI, HF
- Interactions: CCBs, antihypertensives
31
Amlodpipine
- MoA
- Clinical Indications:
- Prescription dose:
- Adverse effects:
- Interactions:
- MoA: L-type calcium channel antagonists. Prevent influx of calcium ions into vascular smooth muscle cells --> less intracellular calcium ==> decreased arterial smooth muscle contractility + vasodilation
- Clinical Indications: 1st line for HTN in pts >55/afro-caribbean, angina prhlx
- Prescription dose:
>5mg mane
>maintain w 5-10mg mane
- Adverse effects: abdo pain, dizziness, ankle swelling**
avoid in UA, those who have recently had MI, elderly, HF
- Interactions: other hypertensives, statins (increased myopathy risk), antiepileptics (decreased efficacy of ccb), digoxin (increases plasma digoxin conc), theophylline
32
Verapamil (rate-limiting ccb)
- MoA
- Clinical Indications:
- Prescription dose:
- Adverse effects:
- Interactions:
- MoA: same as amlodipine, but favours the hyperpolarised Ca2+ channels in cardiac muscle cells --> no influx of Ca2+ into myocytes --> decreased cardiac contractility
- Clinical Indications: angina, supraventricular arrythmias, HTN
- Prescription dose:
> 40-120mg TID for arrhythmias
> 80-100mg for angina
240-480mg for HTN
- Adverse effects: asthenia (weakness), bradycardia, constipation**, ankle oedema
avoid in 2nd/3rd degree heartblock, WPW
- Interactions: beta-blockers** do not combine
33
Nicorandil
- MoA
- Clinical Indications:
- Prescription dose:
- Adverse effects:
- Interactions:
- MoA: K+ channel activator --> opens channels on smooth muscle cells which causes K+ to leave cell --> cell membrane gets hyperpolarised --> voltage-gated Ca2+ close --> less intracellular Ca2+ --> overall muscle relaxation and dilation in arterial system as afterload and preload are reduced
- Clinical Indications: mx of stable angina in pts with prev MI, prev CABG, CAD, LVH, DM, HTN or PVD --> reduces frequency of angina attacks. Used as last line usually.
- Prescription dose: 10-20mg BD
- Adverse effects: cutaneous vasodilation with flushing, dizziness, headache
**nicorandil can cause skin, mucosal and eye ulceration including GI ulcers
- Interactions: viagra (sildenafil)
34
LMWH (Enoxaparin)
- MoA
- Clinical Indications:
- Prescription dose:
- Adverse effects:
- Interactions:
- MoA: anticoagulant; inhivits factor Xa in clotting cascade --> prothrombin is not converted to thrombin --> coagulation inhibited
- Clinical Indications: VTE prophylaxis, tx for VTE before oral anticoagulation with warfarin is established, tx for acute MI and unstable CAD, PE, DVT
- Prescription dose: subcut injection
>DVT prophylaxis in surgical pts: 20mg 2h before surgery, then 20mg every 24h (40mg if high risk, like orhtopaedic surgery)
>DVT prophylaxis in medical pts: 40mg once daily
>Tx for DVT/PE: 1.5mg/kh once daily
>Tx for acute MI: 30mg loading dose, then 1mg/kg every 12h for 8 days [prevents mural thrombosis after MI]
- Adverse effects**: hameorrhage (usually, it's okay to just withdraw heparin, but if reversal needed, used PROTAMINE SULFATE), heparin-induced thrombocytopenia (HIT) with 30% reduction of platelet count, thrombosis, skin allergy. Replace heparin with alternative anticoag, hyperK
Avoid in haemophilia/bleeding disorders, hepatic impairment
- Interactions: NSAIDs and antiplatelets (increased risk of haemorrhage), ACE-I, ARBs (increased risk of hyperK)
35
Warfarin
- MoA
- Clinical Indications:
- Prescription dose:
- Adverse effects:
- Interactions:
- MoA: anticoagulant; vitamin K antagonist --> less clotting factors 1,9,7 and 2
Warfarin's anticoag effect is delayed for several days until already formed clotting factors have been degraded
- Clinical Indications: prophylaxis of embolisation in A.fib, prophylaxis after prosthetic heart valve replacement, tx for VTE and PE, TIA
- Prescription dose:
>loading dose: 5-10mg
> maintenance: 3-9mg once daily AT THE SAME TIME
> dose depends on pt's prothrombin time (INR)
- Adverse effects: haemorhage, bruising, skin necrosis**, liver dysfunction**
- Interactions:
All pts on warfarin must have INR checked regularly - start with doing every other day, then once every 12 weeks
Do NOT take aspirin without checking with pharmacist
Don't get pregnant, drinking cranberry juice, eating too much leady vegetables, excess alcohol consumption
36
Which drugs enhance anticoagualant effect?
Erythromycin (broad-spec abx)
NSAIDs
Heart rate: amiodarone
Alcohol
Nazoles (antifungals)
CAD: statins
E: omeprazole
37
Which drugs reduce anticoagulant effect?
Antiepileptics, OCP, Vitamin K, Retinoids (acitretin), antidepressants
38
Rivaroxaban
- MoA
- Clinical Indications:
- Prescription dose:
- Adverse effects:
- Interactions:
- MoA: Factor Xa inhibitor, similar to heparin --> less thrombin produced --> fibrinogen not converted to fibrin --> less thrombus formed
- Clinical Indications: VTE prophylaxis following hip/knee replacement, DVT tx, stroke prophylaxis in pts with A.fib. stroke prophylaxis after pt has had TIA, prophylaxis of atherothrombotic event after ACS (with aspirin/clopidogrel)
- Prescription dose:
>20mg once daily for stroke
> 10mg for most others 2 weeks
> 2.5mg once daily for a year after ACS
- Adverse effects: haemorrhage, abdo pain, caution in elderly/pts who weigh <50kg, pts with recurrent GI ulceration
- Interactions: NSAIDs (bleeding), amioadrone, verapamil, antifungals (avoid)
Main positive: BROAD therepeutic index unlike warfarin, can be used without coagulation monitoring. But no antidote.
39
Aspirin
- MoA
- Clinical Indications:
- Prescription dose:
- Adverse effects:
- Interactions:
- MoA: irreversible inhibitor of cyclo-oxygenase enzymes --> thrombane As and prostacyclin synthesis in platelets inhibited --> reduced platelet aggregation
- Clinical Indications: secondary prevention after MI, ACS, angina, stroke
- Prescription dose: 75mg once daily
- Adverse effects: GI irritation, ulceration, bleeding, bronchospasm
- Interactions: NSAIDs, anticoags, SSRIs
don't give to children under 12
40
Clopidogrel
- MoA
- Clinical Indications:
- Prescription dose:
- Adverse effects:
- Interactions:
- MoA: antiplatelet, ADP receptor inhibitor --> platelet aggregation inhibited
- Clinical Indications: secondary after MI/ischaemic stroke/peripheral arterial disease, use with aspirin for 1 year after ACS/procedures to coronary arteries
- Prescription dose:
>secondary prevention after MI/stroke: 75mg daily
>ACS: loadinf dose 300-600mg, maintenance 75mg daily
- Adverse effects: GI disturbance, bleeding, GI ulcers
Avoid in pregnancy, hepatic/renal impairment. Discontinue 7 days before surgery.
- Interactions: antiplatelets, anticoags, fibronolytics, ulcer-healing drugs (reduced effect), NSAIDs
41
Statins
- MoA
- Clinical Indications:
- Prescription dose:
- Adverse effects:
- Interactions:
- MoA: Increases hepatic removal of LDL from circulation
- Clinical Indications: primary hypercholestraenia, familial hypercholesterolaemia, prevention of cardiac event in those with DM or CAD
- Prescription dose: 20-80mg nocte
- Adverse effects: abnormal LFTs (raised transaminases), GI disturbance, myositis (painful and weak muscles), rhabdomyolysis
Avoid in active liver disease/pregnancy, discontinue if transaminases >3x ULN or creatone kinse >5x ULN
- Interactions: amioadrone, abx, antifungals, colchicine --> myopathy risk
Check LFTs at baseline and every 3 months
