Pharmacology - renal and cardiac Flashcards
Types of diuretics
Loop diuretics
Thiazide and thiazide-like diuretics
Potassium sparing diuretics
Osmotic.
Loop diuretics - examples
Furosemide, bumetanide.
Loop diuretics - mechanism
Inhibit the Na+/K+/2Cl- co-transporter. Excretion of 15-20% of filtered Na+.
Other effects of loop diuretics
venodilatory
Counterindications for loop diuretics
renal impairment,
cardiac glycosides, aminoglycosides.
Thiazide diuretic example
Bendroflumethiazide.
Mechanism of thiazide diuretics.
Inhibit Na+/Cl- co-transporter resulting in the excretion of 5-10% of the filtered Na+.
Indications for thiazide diuretics
Hypertension, with loop diuretic for profound oedema secondary to chronic heart failure.
Potassium sparing diuretics - types
Sodium channel blockers
Aldosterone antagonists.
Sodium channel blockers - examples. (Potassium sparing diuretics).
Amiloride, triampterene.
Aldosterone antagonists - example. (Potassium sparing diuretics).
Spironolactone
Contraindications for aldosterone antagonists
Being on ACEIs.
Treatment of urinary retention
a-blockers e.g. Doxazosin to relax smooth muscle at the urethra.
Parasympathomimetics to increase detrusor contraction.
Anti-androgens for benign prostatic hyperplasia.
Treatment of urinary incontinence
Antimuscarinics.
Aims of treatment of heart failure
Relieve symptoms, improve exercise tolerance, reduce exacerbations, reduce mortality.
Basic treatment for heart failure.
ACE inhibitor (or angiotensin II receptor antagonis if poorly tolerated). B-blocker e.g. bisoprolol, carvedilol.
Heart failure treatment after ACEI and B-blockers, if still symptomatic.
Aldosterone antagonist e.g. spironolactone
Digoxin improves symptoms and exercise tolerance but not mortality.
Heart failure treatment if after basic treatment, still has fluid overload
Thiazide diuretic if good renal function
Loop diuretic if renal impairment.
Treatments for high blood pressure
ACE Inhibitors
Ca++ channel blockers
Diuretics
Treatments for anyone over 55 with high blood pressure
Ca++ channel blocker - amlodipine
Diuretic - indapemide
Treatments for anyone under 55 or of African origin with high blood pressure.
An ACE inhibitor
IF ACD treatment for high blood pressure fails then use…
an alpha blocker e.g. doxazosin
How to treat brady-dysrhythmias.
Stop rate controlling drugs Check TSH and electolytes Atropine Temporary pacing Permanent pacing.
Management of supraventricula tachycardias.
Treat symptoms Carotid sinus massage Adenosine Verapamil DCC
Action of adenosine
Purine nucleotide slowing AV nodal conduction.
Action of verapamil
Calcium channel blocker prolonging conduction and refractoriness in AV node
Digoxin is used for which arrhythmia
atrial fibrillation or flutter.
Flecanide action
Blocks Na+ channels, slows conduction in cardiac channels.
Management of ventricular fibrillation and tachycardia
DCCV
Amiodarone
K+ and Mg++
Lidocaine.
Management of angina
ASA Lipid lowering agent Nitrates B-blockers Calcium channel blockers Potassium channel activators Funny current channel inhibitors.
Action of nitrates
Reduce preload by venodilation, dilates coronaries, reduces afterload by systemic vasodilatation.
What do nitrates interact with?
PDE5 inhibitors LETHALLY by causing profound hypotension.
Role of B-blockers in angina
Reduce HR and contractility leading to less cardiac demand for O2.
What diseases do B-blockers worsen?
Heart blocks
Acute cardiac failure
COPD and asthma
Peripheral vascular disease.
Calcium channel blockers used in angina
Di-hydropyridines and non-dihydropyridines.
Di-hydropyridines action and examples
Nifedipine, amlodipine.
Reduce afterload by arteriolar dilatation. Dilate coronaries.
Non-dihydropyridines
Diltiazem, verapamil.
Reduce afterload and have negative chronotropic effect due to affect on action on SA and AV nodes.
Potassium channel activators
Vasodilatory. Nicorandil.
Action of aspirin
COX inhibitor
Action and examples of thienopyridines
Thienopyriines include clopidogrel and ticlopidine. Irreversibly inhibit ADP binding in platelet activation.
Examples of glycoprotein 2b3a antagonists
abciximab, eptifibatide, tirofiban.
Action of glycoprotein 2b3a antagonists
Potent inhibitors of platelet aggregation.
Heart failure treatment
(Diuretics for symptomatic relief) ACEI B-blocker Spironolactone (isosorbide dinitrate with hydralazine, digoxin)
Treatment of unstable angina/NSTEMI: MONA BTC
Morphine
Oxygen
Nitrates
Aspirin
B-blockers
Thrombolysis
Clopidogrel
Thrombolytic drug used in ACS
glycoprotein IIb/IIIa inhibitors such as eptifibatide, tirofiban.
Treatment for STEMI: MOC thought nitrates assuages (the) burning.
Morphine Oxygen Clopidogrel Thrombolysis ACEI B-blockers.
What antibiotic should you absolutely not give with methotrexate?
Trimethoprim
Which antibiotic has 10% allergy crossover with paracetamol
Cephalosporins
How would you give someone furosemide for heart failure?
Starting dose: 40 mg OD, sometimes BD, not in evening. First few doses often given IV to have quicker effect.
What is ramipril?
An ACEI
Why is ramipril used in heart failure?
Because it reduces hospitalisation, slows disease progression and improves mortality of patients with heart failure.
How do you give ramipril to someone with heart failure?
Starting dose: 1.25 mg OD at night due to first dose hypotension. Titrate up; maximum dose is 5 mg BD.
What increases the risk of first dose hypertension with ramipril?
If the patient is elderly, taking a diuretic, or volume depleted.
When can you start B-blockers in a heart failure patient?
TAKE CARE
If they are already taking an ACEI and diuretic, in a patient with a stable, controlled heart rate and at a low dose e.g. 1.25 mg bisoprolol. Gradually titrate up,
DO NOT START IN PULMONARY EDEMA.
What do you cover patients with when starting them on warfarin for a mechanical heart valve?
LMW heparin
For rapid anticoagulation, what should the starting dose of warfarin be?
5-10 mg then adjust according to INR, covered by LMW heparin until INR in correct threshold.
Why would a patient require a lower loading dose of warfarin?
If they have a prolonged prothrombin time, abnormal liver function, cardiac failure.
Also if they are on parenteral feeding, are elderly, are on potent anti-coagulants already or if they have a low body weight.
List some side effects of thiazide diuretics.
postural hypotension,
hypokalaemia, hyponatraemia, hypomagnesaemia, hypercalcaemia.
Gout
Impaired glucose tolerance
List some side effects of Ca++ channel blockers
Abdo pain, nausea, flushing, oedema non-responsive to diuretic therapy, headache.
Drugs that predispose patients to pre-renal acute renal impairment.
Anti-hypertensives, diuretics, ACEI, ARBs, NSAIDs.
Drugs that predispose patients to intrarenal acute renal impairment.
Aminoglycoside antimicrobials Glycopeptide antimicrobials NSAIDs Contrast media Methotrexate Chemotherapy
Drugs that predispose patients to post-renal acute renal impairment.
Anticholinergics.
Which of the following drugs are safe to give with acute kidney injury? Atorvastatin Diclofenac Furosemide Paracetamol Perindopril Metformin Tazocin
ATORVASTATIN
Use cautiously in renal impairment as theoretically increased risk of rhabdomyelosis but rare with atorvastatin
PARACETAMOL
Already metabolised by the time it is renally excreted so no issues with renal impairment.
Which of the following drugs are safe to give at a reduced dose with acute kidney injury? Atorvastatin Diclofenac Furosemide Paracetamol Perindopril Metformin Tazocin
TAZOCIN
Given at a reduced frequency of BD when GFR
falls below 20 ml/min
Which of the following drugs are unsafe to give at a reduced dose with acute kidney injury? Atorvastatin Diclofenac Furosemide Paracetamol Perindopril Metformin Tazocin
METFORMIN
Renally cleared. Accumulation increases risk of lactic acidosis
PERINDOPRIL
Reduces filtration pressure at glomerulus by dilating the efferent arteriole
FUROSEMIDE
Worsen renal function by reducing circulating blood volume
DICLOFENAC
If someone has diabetes with renal impairment, what should you be aware of?
The kidney is important in glucose homeostasis: in a prolonged fast it can provide up to 45% of endogenous glucose, and it metabolises 30-40% of insulin.
Insulin doses need to be adjusted in renal impairment.
How does uraemia affect protein binding?
It decreases it, meaning there is more free drug in the plasma.
Indications for loop diuretics.
Heart failure (acute or chronic)
Pulmonary oedema
Hypertension
Cautions with loop diuretics
Electrolyte imbalance
Volume depletion
Tiinitus and ototoxicity
What is the MAJOR risk in giving potassium sparing diuretics like amiloride or spironolactone?
Increased risk of hyperkalaemia.
How do NSAIDs cause AKI?
Disrupts regulation of renal blood flow and can cause acute tubulointerstitial nephritis.
What are the main problems with gentamicin and amikacin?
They are nephrotoxic, ototoxic and have a narrow therapeutic range.
How to treat sinus bradycardia
0.6-1.2 atropine IV
Temporary pacing
How to treat 1st degree heart block
Stop Ca++ channel blockers and B-blockers.
Pace if Mobitz type II or III
How to treat sinus tachycardia
Correct low K+, hypoxia or acidosis.
Give O2 and analgesia if necessary.
How to treat acute AF or flutter
DC cardioversion if necessary (preferred over amiodarone or flecainamide)
Otherwise, control with digoxin +/- B blocker
Amiodarone if intermittent.
Post MI, when should you consider an implantable cardiac defibrillator?
If there is VT and ejection fraction is less than 35%.
Treatment for pericarditis post MI
NSAIDs.
Consider colchicine before immunosuppressants if relapse or continuing symptoms.
Treatment for Dressler’s syndrome
NSAIDs
Why would you give adenosine for a narrow complex tachy-arrhythmia?
Because it transiently slows the ventricular rhythm to show the underlying atrial rhythm, and because it can cardiovert a junctional tachycardia to sinus rhythm
Treatment for stable VT
High flow O2 IV access and bloods 12 lead ECG ABG Amiodarone (central line) Implantation of automatic defibrillators
Treatment for torsades de pointes
Magnesium sulphate
How to treat chronic AF
Rate control: B-blocker or Ca++ channel blocker. If this fails add digoxin or amiodarone.
Anticoagulation: warfarin (target INR 2-3).
Do not give B-blockers in conjunction with …
Verapamil or diltiazem as bradycardia risk (unless advised to by expert) in arrhythmia.
What can block AV node long enough to uncover atrial pathology?
Carotid sinus massage or adenosine.
|ndications for temporary pacing
Symptomatic bradycardia if resistant to atropine.
After anterior MI if Mobitz type I or II, complete AV block.
After inferior MI only if AV block unstable.
Suppression of drug resistant tachyarrhythmias
Indications for permanent pacing
Complete AV block, or persistent AV block after anterior MI.
Mobitz type II.
Symptomatic bradycardias, or drug resistant tachyarrhythmias
Heart failure post MI.
Pharmacological management of heart failure
Diuretics (loop, add K+ sparing if indicated)
ACEI
B-blockers (start low and go slow. Start carvedilol at 3.125 mg/12 h)
Spironolactone
Digoxin
When does BNP rule out/diagnose heart failure?
If BNP is less than 50 ng/l then rules out
If BNP is more than 100 ng/l then very likely
Hypertension monotherapy if older than 55 yrs
Ca++ channel blockers
Hypertension monotherapy if black
Ca++ channel blockers
Hypertension monotherapy if under 55 and white
ACEI
Combination therapy for hypertension
ACEI, Ca++ channel blocker and thiazide
When would ACEI be first choice for hypertension?
If co-existing LVF, diabetes or proteinuria.
Aim of treatment in malignant hypertension
Controlled drop over days, not hours.
Treatment of malignant hypertension with encephalopathy.
IV furosemide and labetalol/sodium nitroprusside to reduce BP to 110 mmHg diastolic in 4 hours.
Treatment for rheumatic fever
Abx: penecillin (if allergic erythromycin)
Analgesia for carditis/arthritis
Haloperidol for chorea.
Treatment for sarcoidosis
Acute: bed rest and NSAIDs.
Indications for steroids include parenchymal lung disease, uveitis, hypercalcaemia and neuro/cardiac involvement.
Extrinsic allergic alveolitis treatment
Remove allergen and give O2 then oral prednisolone followed by reducing dose.
Idiopathic pulmonary fibrosis treatment
Oxygen, pulmonary rehab, opiates and palliative. No high dose steroids unless diagnosis in doubt.
Lung transplantation.
Treatment of obstructive sleep apnoea
Weight management, avoidance of tobacco and alcohol.
CPAP for those with moderate or severe disease.
Potentially surgery to relieve pharyngeal obstruction.
Treatment for BPH
alpha-1 antagonists (first line tamsulosin, alfuzosin), 5 alpha-reductase inhibitors.
Surgery
Side effects of alpha-1 antagonists in BPH
dizziness, postural hypotension, dry mouth, depression
5 alpha-reductase inhibitors; examples and mechanism of action in BPH
Finasteride
Block the conversion of testosterone to dihydrotestosterone (DHT), which is known to induce BPH
Unlike alpha-1 antagonists causes a reduction in prostate volume and hence may slow disease progression. This however takes time and symptoms may not improve for 6 months. They may also decrease PSA concentrations by up to 50%
5 alpha-reductase inhibitors; side effects
erectile dysfunction, reduced libido, ejaculation problems, gynaecomastia
Which patients with ischaemic heart disease should take aspirin?
All of them
What drugs are contraindications for viagra?
Nitrates and nicorandil
Agents which are effective at cardioverting AF
amiodarone flecainide (if no structural heart disease)
Agents used to control rate in AF
beta-blockers
calcium channel blockers
digoxin
Agents used to maintain sinus rhythm with history of AF
sotalol
amiodarone
flecainide
Factors favouring rate control in AF
Older than 65 years
History of ischaemic heart disease
Factors favouring
Younger than 65 years Symptomatic First presentation Lone AF or AF secondary to a corrected precipitant (e.g. Alcohol) Congestive heart failure
Side effects of ACEI
- Cough
* Hyperkalaemia
Side effects of B-blockers
- Bronchospasm (especially in asthmatics)
- Fatigue
- Cold peripheries
Side effects of doxazosin
• Postural hypotension
Drugs to avoid in renal failure
antibiotics: tetracycline, nitrofurantoin
NSAIDs
lithium
metformin
Drugs that may build up in renal failure
most antibiotics including penicillins, cephalosporins, vancomycin, gentamicin, streptomycin digoxin, atenolol methotrexate sulphonylureas furosemide opioids
Drugs that are relatively safe in renal failure
antibiotics: erythromycin, rifampicin
diazepam
warfarin
What is streptococcus bovis associated with?
Endocarditis and colorectal cancer
Acute treatment for supraventricular tachycardia
vagal manoeuvres: e.g. Valsalva manoeuvre
intravenous adenosine 6mg → 12mg → 12mg: contraindicated in asthmatics - verapamil is a preferable option
electrical cardioversion
Prevention of supraventricular tachycardia
beta-blockers
radio-frequency ablation
What medications prevent oxalate stones?
cholestyramine reduces urinary oxalate secretion
pyridoxine reduces urinary oxalate secretion
