Cardiovascular Drugs Flashcards
Name 7 classes of cardiovascular drugs
- Drugs for heart failure
- Drugs for angina
- Antihypertensives
- Drugs for arrhythmias
- Drugs for dyslipidaemia
- Drugs for pulmonary hypertension
- Drugs for other cardiovascular disorders
Name 4 classes of drugs for heart failure
- Aldosterone antagonists
- Loop diuretics
- Sympathomimetics (cardiovascular)
- Other drugs for heart failure
Name 2 aldosterone antagonists
- Eplerenone
- Spironolactone
Name 2 loop diuretics
- buMETANide
- Furosemide
Name 5 cardiovascular sympathomimetics
- Adrenaline (epinephrine)
- Dobutamine
- Dopamine
- Isoprenaline
- Noradrenaline
Name 4 miscellaneous drugs for heart failure
- digoxin
- ivabradine
- milrinone
- sacubitril with valsartan
Name 2 classes of drugs for angina
- nitrates
- other antianginal drugs
Name 3 nitrates
- glyceryl trinitrate
- isosorbide dinitrate
- isosorbide mononitrate
Name 3 miscellaneous antianginal drugs
- ivabradine
- nicorandil
- perhexiline
Name 7 classes of antihistamines
- thiazide and related diuretics
- other diuretics
- ACE inhibitors
- Angiotensin-II receptor blockers
- Calcium channel blockers
- Beta blockers
- Other antihypertensives
Name one thiazide diuretic
hydrOCHLOROTHIAZIDe
Name 2 thiazide-related diuretics
- Chlortalidone
- Indapamide
Name one miscellaneous diuretic
amiloride
Name 8 ACE inhibitors
- caPTOPRil
- enalapril
- fosinopril
- lisinopril
- perindopril
- quinapril
- ramipril
- trandolapril
Name 7 angiotensin-II receptor blockers
- candesartan
- eprosartan
- irbesartan
- losartan
- olmesartan
- telmisartan
- valsartan
Name 2 classes of calcium channel blockers
- dihydropyridines
- non-dihydropyridines
Name 6 dihydropyridine calcium channel blockers
- amLODIPine
- clevidipine
- felodipine
- lercanidipine
- niFEDIPine
- niMODIPine
Name 2 non-dihydropyridine calcium channel blockers
- diltiazem
- verapamil
Name 9 beta blockers
- atenolol
- bisOPROLOl
- caRVEDILOl
- esmolol
- labetalol
- metoprolol
- nebivolol
- propRANOLol
- sotalol
Name 8 miscellaneous antihypertensives
- clonidine
- diazoxide
- hydrALAZINe
- methyldopa
- minoxidil
- moxonidine
- prazosin
- sodium nitroprusside
Name 11 antiarrhythmics
- adenosine
- amiODAROne
- atropine
- digoxin
- diSOPYRAMIDe
- esmolol
- flecainide
- isoprenaline
- lidocaine
- sotalol
- verapamil
Name 4 classes of drugs for dyslipidaemia
- statins
- fibrates
- PCSK9 inhibitors
- other drugs for dyslipidaemia
Name 5 statins
- atorvastatin
- fluvastatin
- pravastatin
- rosuvastatin
- simvastatin
Name 2 fibrates
- fenofibrate
- gemfibrozil
Name 2 PCSK9 inhibitors
- alirocumab
- evolocumab
Name 3 miscellaneous drugs for dyslipidaemia
- colestyramine
- ezetimibe
- nicotinic acid
Name 4 classes of drugs for pulmonary hypertension
- prostacyclins
- endothelin antagonists
- PDE5 inhibitors
- Other drugs for pulmonary hypertension
Name 2 classes of prostacyclins
- Prostacyclin analogues
- Prostacyclin agonists
Name 2 prostacyclin analogues
- Epoprostenol
- Iloprost
Name 1 prostacyclin agonist
Selexipag
Name 2 endothelin agonists
- ambrisentan
- bosentan
- macitentan
Name 2 phosphodiesterase 5 inhibitors
- sildenafil
- tadalafil
Name 1 miscellaneous drug for pulmonary hypertension
Riociguat
Name 2 classes of drugs for cardiovascular disorders
- drugs for peripheral vascular disease
- drugs for orthostatic hypotension
Name 2 drugs for peripheral vascular disease
- oxerutins
- pentoxifylline
Name 2 drugs for orthostatic hypotension
- fludrocortisone
- midodrine
What is the drug class of digoxin?
Cardiac glycoside (arrhythmic agent)
What is the schedule of digoxin?
Schedule 4
Describe the availability of digoxin on the PBS.
Digoxin is available as a general schedule item on the PBS, and can be prescribed by a medical practitioner or a nurse practitioner.
What 5 formulations of digoxin are on the SA Formulary?
- 62.5 µg tablets
- 250 µg tablets
- 50 µg/mL oral solution
- 500 µg/2 mL injection
- 40 mg injection
What are 2 available brands of digoxin?
- Lanoxin
- Sigmaxin
What is the mechanism of action of digoxin in heart failure?
Inhibition of the sodium/potassium ATPase pump in myocardial cells causes a transient increase in intracellular sodium, which in turn promotes calcium influx via the sodium-calcium exchange pump, leading to increased contractility. This may also improve baroreflex sensitivity.
What is the mechanism of action of digoxin in supraventricular arrhythmias?
Direct suppression of the atrioventricular node conduction to increase effective refractory period and decrease in conduction velocity – positive inotropic effect, enhanced vagal tone, and decreased ventricular rate to fast atrial arrhythmias. Atrial fibrillation may decrease sensitivity and increase tolerance to higher serum digoxin concentrations.
Name 2 indications of digoxin
- AF and atrial flutter
- Heart failure
What is the 1 recommended Cautionary Advisory Label for digoxin?
5: ask your doctor or pharmacist before using any other medicine including over-the-counter medicines or health products.
Name 7 common side effects of digoxin
- Nausea
- Vomiting
- Diarrhoea
- Loss of appetite.
- Visual disturbances (such as blurred vision)
- Dizziness
- Headaches
What should be done if acute digoxin toxicity is suspected?
Urgently contact a clinical toxicologist or poisons information centre if acute digoxin poisoning is suspected.
Describe the time to onset daily acute digoxin poisoning.
Effects of acute digoxin poisoning can take up to 6 hours to occur after ingestion because the drug is being distributed into the myocardium and other tissues.
Describe the mechanism of acute digoxin toxicity
Acute digoxin toxicity is dose-related, and directly related to its pharmacological action. It is mediated by an increased intracellular calcium and increased activation of the parasympathetic nervous system due to significant inhibition of the sodium/potassium ATPase pump and atrioventricular nodal blockade. This in turn leads to increased automaticity and decreased conduction respectively.
Describe the time to onset of chronic digoxin toxicity.
Chronic toxicity generally takes much longer to present (months) compared to acute toxicity (hours).
Describe the time to onset of cardiac complications in digoxin overdose.
Cardiac complications tend to appear 8 to 12 hours after initial overdose.
What are 5 classes of effects in acute digoxin toxicity?
- Cardiovascular effects
- CNS effects
- Gastrointestinal effects
- Metabolic effects
- Visual effects
Which class symptoms of digoxin toxicity are the most common symptoms for children to experience?
Cardiovascular effects
What are 2 classes of symptoms of digoxin toxicity which are not commonly seen in children?
- CNS effects
- Gastrointestinal effects
Name 6 cardiovascular effects associated with digoxin toxicity
- Bradyarrhythmias: slow atrial fibrillation, second- and third-degree AV block
- Cardiac arrest
- ECG changes: ST depression (characteristic ‘reverse tick’ appearance), ectopic beats, first-degree atrioventricular (AV) nodal block (usually occur early)
- Hypotension
- Junctional, ventricular and atrial tachycardia
- Loss of consciousness
Name 3 central nervous system effects associated with digoxin toxicity
- Lethargy
- Confusion
- Delirium
Name 4 gastrointestinal effects associated with digoxin toxicity
- Nausea
- Vomiting
- Abdominal pain
- Diarrhoea
Describe the metabolic effects of digoxin toxicity.
Severe poisoning causes hyperkalaemia and associated ECG changes. Hypokalaemia and hypomagnesaemia can exacerbate this.
Name 3 visual effects of digoxin toxicity
- Halos
- Yellow or blurred vision
What should be done if acute digoxin poisoning is suspected?
Urgently contact a clinical toxicologist or poisons information centre (13 11 26).
Name 4 steps in the management of acute digoxin poisoning:
- Early activated charcoal if possible
- Closely monitor for (and treat) cardiovascular complications (life-threatening arrhythmias and myocardial depression)
- Give titrated digoxin-specific immune antibody fragments (digoxin immune Fab) if indicated
- Treat hyperkalaemia.
Which precaution of digoxin has a boxed warning in the AMH?
Digoxin may worsen arrhythmia (proarrhythmic effect), CNS disturbances, rashes (usually all related to plasma concentration)
Certain plants and animals produce digoxin-like compounds which cause similar toxicity to digoxin. How are these managed?
These are managed the same as acute digoxin poisoning.
What are 10 risk factors for digoxin toxicity?
- Digoxin concentration >2ng/mL
- Increased age
- COPD
- Hypotension
- Renal impairment
- Electrolyte disturbances
- Dehydration/over diuresis
- Amyloidosis
- Low body weight
- Concurrent use with drugs which increase digoxin concentration
What are 10 drugs which may increase digoxin concentration
- amiODAROne
- Dronedarone
- ERYthromycin
- Itraconazole
- Lapatinib
- Propafenone
- Quinidine
- Ranolazine
- Ritonavir
- Verapamil
What should you always consider about drug interactions with digoxin?
Digoxin has many potential interactions which are often clinically significant due to its narrow therapeutic window.
What is the interaction between amiODAROne and digoxin?
amiODAROne increases the concentration of digoxin (halve digoxin dose).
What is the interaction between amphotericin B and digoxin?
Increased digoxin toxicity may occur if hypokalaemia occurs with amphotericin
What is the interaction between chloroquine and digoxin?
Chloroquine possibly increases the concentration of digoxin
What is the interaction between ciclosPORIN and digoxin?
ciclosPORIN increases the concentration of digoxin
What is the interaction between colchicine and digoxin?
There is a possibly increased risk of myopathy
What is the most relevant CYP450 enzyme with digoxin?
Digoxin is a minor CPY3A4 substrate
What is the interaction between daclatasvir and digoxin?
Daclatasvir increases the concentration of digoxin
What is the interaction between diltiazem and digoxin?
Diltiazem increases the concentration of digoxin
What is the interaction between diuretics and digoxin?
Diuretics can potentiate digoxin toxicity by inducing hypokalaemia
What is the interaction between dronedarone and digoxin?
Dronedarone increases the concentration of digoxin (halve digoxin dose)
What is the interaction between food and digoxin?
Digoxin peak serum concentrations may be decreased if taken with food. Meals containing increased fibre or foods high in pectin may decrease oral absorption of digoxin.
What is the interaction between hydroxychloroquine and digoxin?
Hydroxychloroquine potentially increases the concentration of digoxin
What is the interaction between itraconazole and digoxin?
Itraconazole increases the concentration of digoxin.
What is the interaction between lasmiditan and digoxin?
Lasmiditan is predicted to increase digoxin exposure (contraindicated)
What is the interaction between lercanidipine and digoxin?
Lercanidipine increases the concentration of digoxin
What is the interaction between digoxin and medicines that affect heart rate/rhythm?
Drugs that slow cardiac conduction, cause bradycardia or cause arrhythmias may potentiate the cardiac adverse effects of digoxin; use combinations carefully and monitor cardiac function.
What is the interaction between mefloquine and digoxin?
Mefloquine increases the risk of bradycardia
What is the interaction between niFEDIPine and digoxin?
niFEDIPine increases the concentration of digoxin
What is the interaction between nircardipine and digoxin?
Nircardipine increases the concentration of digoxin
What is the interaction between phosphate binders and digoxin?
Concomitant administration reduces gastrointestinal absorption of digoxin by up to 25%
What is it important to remember digoxin is a substrate of?
P-glycoprotein
What is the interaction between propafenone and digoxin?
Propafenone increases the concentration of digoxin (halve digoxin dose)
What is the interaction between quinine and digoxin?
Quinine possibly increases the concentration of digoxin
What is the interaction between siponimod and digoxin?
Both digoxin and siponimod can lower heart rate, and these effects could be additive (contraindicated)
What is the interaction between spironolactone and digoxin?
Spironolactone increases the concentration of digoxin
What is the interaction between St John’s Wort and digoxin?
St John’s Wort decreases concentration of digoxin (contraindicated)
What is the interaction between telmisartan and digoxin?
Telmisartan increases digoxin toxicity
What is the interaction between tepontinib and digoxin?
Tepotinib is predicted to increase the concentration of digoxin (contraindicated)
What is the interaction between ticagrelor and digoxin?
Ticagrelor increases the concentration of digoxin
What is the interaction between verapamil and digoxin?
Verapamil increases the concentration of digoxin and increases the risk of atrioventricular block and bradycardia.
What is the elimination half-life of digoxin in premature neonates?
61 to 170 hours
What is the elimination half-life of digoxin in full-term neonates?
35 to 45 hours
What is the elimination half-life of digoxin in infants?
18 to 25 hours
What is the elimination half-life of digoxin in children?
18 to 36 hours
What is the elimination half-life of digoxin in adults?
36 to 48 hours
What is the elimination half-life of digoxin in adults with renal failure?
3.5 to 5 days
What is the time to onset of oral digoxin?
0.5 to 2 hours after initial oral dose of 500 to 750 micrograms
What is the time to onset of IV digoxin?
5 to 30 minutes after initial IV dose of 400 to 600 micrograms
What is the time to maximal effect of oral digoxin?
2 to 6 hours
What is the time to maximal effect of IV digoxin?
1 to 4 hours
How does acidosis effect digoxin?
Acidosis increases sensitivity to digoxin
How does acute myocardial infarction effect digoxin?
Acute myocardial infarction increases the risk of arrhythmias and may lead to ischaemia
How does severe aortic stenosis effect digoxin?
Severe Aortic Stenosis may lead to worsened cardiac function due to increased force of myocardial contraction.
How should digoxin be used in atrial fibrillation?
Consider maintaining lower concentrations of 0.5 to 0.8 µg/L (0.6–1 nanomol/L) as there may be improved outcomes or reduced hospitalisations compared with higher concentrations, and higher concentrations may be associated with increased risk of mortality. Balance the clinical benefit against the incidence of adverse effects and reduce dose if appropriate.
How does Beri Beri heart disease effect digoxin?
Patients with Beri Beri heart disease may fail to adequately respond to digoxin, so their underlying thiamine deficiency should be treated concomitantly.
How should digoxin be used in heart failure?
Consider maintaining lower concentrations of 0.5 to 0.8 µg/L (0.6 to 1 nanomol/L) as there may be improved outcomes or reduced hospitalisations compared with higher concentrations, and higher concentrations may be associated with increased risk of mortality. Balance the clinical benefit against the incidence of adverse effects and reduce dose if appropriate.
How does hypercalcaemia effect digoxin?
Hypercalcaemia increases the risk of heart block
How does hyperkalaemia effect digoxin?
Hyperkalaemia increases there risk of heart block
How does hyperthyroidism effect digoxin?
Hyperthyroidism may decrease digoxin concentration and increase sympathetic tone; monitor digoxin concentration and alter dose when required or combine with another agent; dosage adjustment may be required when condition is corrected.
How does hypokalaemia effect digoxin?
Hypokalaemia increases the risk of toxicity
How does hypomagnesemia effect digoxin?
Hypomagnesaemia increases the risk of toxicity
How does hypothyroidism effect digoxin?
Hypothyroidism may increase digoxin concentration; monitor digoxin concentration and alter dose as required; dosage adjustment may be required when condition is corrected.
How does hypoxia effect digoxin?
Hypoxia increases sensitivity to digoxin
How does ischaemic heart disease effect digoxin?
Ischaemic heart disease leads to an increased risk of arrhythmias
How should digoxin be used in patients with malabsorption syndrome or gastrointestinal reconstruction?
Patients may require larger doses
How does myocarditis effect digoxin?
Myocarditis increases the risk of arrhythmias.
Describe the use of digoxin in patients with preserved left ventricular function
Decreased cardiac output may occur in patients with preserved left ventricular systolic function, including restrictive or hypertrophic cardiomyopathy, constrictive pericarditis, amyloid heart disease, and acute coronary pulmonale; in general, the manufacturer recommends to avoid use unless used to control ventricular response with atrial fibrillation
How does respiratory disease effect digoxin?
Patients with severe respiratory disease may have an increased myocardial sensitivity to digitalis glycosides.
How should digoxin be used in sick sinus syndrome?
Use cautiously due to risk of severe bradycardia or sinoatrial block.
Describe the use of digoxin in pregnancy
Digoxin is in pregnancy Category A however dose requirements are unpredictable. May required increased dose
What is a specific use of digoxin in pregnancy?
Digoxin can be used to treat foetal arrhythmias
What is a practice point to consider with digoxin in pregnancy?
Heart failure and atrial fibrillation may worsen during pregnancy.
Describe the use of digoxin in breastfeeding.
It is safe to use
Describe the use of digoxin in the elderly
Elderly patients have a reduced clearance of and increased sensitivity to digoxin. Reduce dose and monitor closely
Name 12 contraindications of digoxin.
- Constrictive pericarditis.
- Cor pulmonale (acute and chronic)
- Heart block (second‑ or third-degree) without pacemaker
- Hypertrophic obstructive cardiomyopathy
- Hypersensitivity to digoxin
- Lasmiditan: combination is contraindicated
- Preexcitation associated with an accessory pathway (may lead to ventricular arrhythmias).
- Siponimod: combination is contraindicated
- St John’s Wort: combination is contraindicated
- SVT involving accessory pathway (Wolff-Parkinson-White syndrome)
- Tepotinib: combination is contraindicated
- Ventricular tachycardia and fibrillation
What is the risk associated with DC cardioversion in patients taking digoxin?
Digoxin increases risk of arrhythmias after DC cardioversion. Withhold digoxin for 1 to 2 days before cardioversion or use lowest effective energy.
Describe the risk of rapid IV injection of digoxin.
Rapid intravenous injection can cause vasoconstriction producing hypertension and/or reduced coronary flow. A slow injection rate is vital in hypertensive heart failure and acute myocardial infarction.
What is a practice point to remember with IV digoxin?
Digoxin is vesicant. It can cause blistering if accidentally injected into a tissue surrounding a vein. It is important to ensure correct needle placement in IV administration.
What monitoring should always be performed before starting digoxin?
Check renal function and electrolyte concentrations
Describe the role of loading doses of digoxin.
A loading dose may not be needed, such as in mild heart failure; but it may sometimes be used for more rapid control of ventricular rate in AF and atrial flutter. Digoxin loading can usually be achieved by the oral route. If a loading dose is not given, levels will not be useful until 3 to 5 days of therapy.
What are the 4 key investigations for acute digoxin poisoning are:
- ECG
- Serum concentration: initially 6 hours after ingestion, then every 6 hours until concentration is falling. Concentrations measured before 6 hours may be inaccurate because distribution into the tissues is not complete.
- Electrolyte levels (potassium, sodium, bicarbonate, magnesium, calcium)
- Serum creatinine and urea concentrations
How often should electrolyte levels (potassium, sodium, bicarbonate, magnesium, calcium) be measured in a patient taking digoxin?
At least every 12 months.
How often should serum creatinine and urea concentrations be measured in a patient taking digoxin?
At least every 12 months, but more frequently in renal impairment and the elderly
Describe the therapeutic range of digoxin.
The generally accepted therapeutic range is 0.5 to 2 µg/L (0.6 to 2.6 nanomol/L) as toxicity is more common at digoxin concentrations >2 µg/L. However, toxic effects can occur at lower concentrations, particularly in the elderly or in those with electrolyte disturbance, hypoxia or hypothyroidism.
Describe the progression of symptoms associated with digoxin toxicity
Gastrointestinal symptoms (such as nausea and anorexia) may precede cardiac symptoms (such as arrhythmias).
Describe the role of serum concentration monitoring with digoxin.
Serum concentration monitoring can be used to guide dose adjustment and confirm toxicity. Serum levels do not correlate well with toxicity, but can indicate peak toxicity and recovery. If serum concentration is >15.6 microgram/L (20 nanomol/L), seek advice from a clinical toxicologist.
Describe the role of serum digoxin monitoring after a patient has been given digoxin-specific immune antibody fragments.
Serum concentrations cannot be interpreted after digoxin-specific immune antibody fragments (digoxin immune Fab) have been given. Most assays measure total digoxin concentration in the serum (which increases after giving digoxin immune Fab because antibodies bind digoxin in the circulation). Free serum digoxin concentration can be measured, but the assay is not as readily available, and the result is unlikely to change management; further management is guided by symptoms.
When should serum digoxin levels be taken?
Trough concentrations should be taken just prior to the next dose (at a minimum of 6 to 8 hours after the previous dose)
Describe the routine monitoring for digoxin toxicity.
Regularly monitor for digoxin toxicity (including resting heart rate); routine measurement of pulse rate before giving next dose of digoxin is not necessary
Describe the heart rate monitoring for digoxin patients.
Heart rate: monitor within first week of starting and after every dose change. If heart rate falls below 60, review if digoxin is appropriate.
How should digoxin dose be tailored?
Tailor dose according to renal function, clinical response and concentration monitoring.
What are 7 times when a digoxin serum level should be taken?
- Any changes to relevant diseases (such as thyroid disease)
- Compliance is in question
- Dose is changed
- Initiation or cessation of drugs which may potentially interact with digoxin
- Poor response
- Renal function changes
- Toxicity is suspected
When should thyroid levels be measured in patients taking digoxin?
Whenever thyroid disease is suspected
Describe the effect of hyperthyroidism on digoxin.
In hyperthyroidism, there is relative digoxin resistance and the dose may have to be increased.
What should be done when changing from oral (tablets or liquid) to IV digoxin therapy?
Reduce dose by 20% to 30% and periodically monitor digoxin concentrations as appropriate for the indication, especially if renal impairment occurs. Toxicity may occur even within therapeutic range in some settings (such as hypokalaemia)
Describe the usual loading dose of digoxin in adults.
Loading (oral or IV): 125 to 500 µg (over several minutes) 4 to 6 hourly. Maximum 1.5 mg (500 µg in the elderly)
Describe the usual maintenance dose of digoxin in adults.
Maintenance (oral): 62.5 to 250 µg ONCE daily. Rarely increased to a maximum of 500 µg daily (125 µg daily in the elderly).
Severe acute digoxin toxicity has been associated with what level of ingestion of digoxin in adults?
More than 6 mg.
What should you always do when determining the dose of digoxin for a child?
Always seek specialist advice
Describe the use of digoxin in newborn infants.
Newborn infants display considerable variability to their tolerance to digoxin; premature and immature infants are particularly sensitive to the effects of insulin.
Describe the usual loading dose of digoxin in children under 2 years.
Loading (oral or IV): 15 to 20 µg/kg (over several minutes), then 7.5 to 10 µg/kg at 6 to 12 hours, then 7.5 to 10 µg/kg again at 12 to 18 hours.
Describe the usual maintenance dose of digoxin in children under 2 years.
Maintenance (oral or IV): 4 to 10 µg/kg daily in one or two doses, maximum dose 250 µg daily
In children, what are the earliest and most frequent indicators that digoxin dosage is too high?
Arrhythmias (including sinus bradycardia)
How should arrhythmias in children takin digoxin be treated?
Assume any arrhythmia in a child taking digoxin is drug-induced until proven otherwise
Severe acute digoxin toxicity has been associated with what level of ingestion of digoxin in children?
Severe acute digoxin toxicity has occurred with dose over 0.3 mg/kg in children.
Describe the usual loading dose of digoxin in children over 2 years.
Loading (oral or IV): 12 to 15 µg/kg (over several minutes), then 6 to 7.5 µg/kg at 6 to 12 hours, then 6 to 7.5 µg/kg again at 12 to 18 hours.
Describe the usual maintenance dose of digoxin in children over 2 years.
Maintenance (oral or IV): 4 to 10 µg/kg daily in one or two doses, maximum dose 250 µg daily
Describe the role of digoxin in dialysis patients.
Digoxin should be avoided in both peritoneal dialysis and haemodialysis if possible. If needed (only if rapid rate control is necessary), use 50% of the recommended dose and monitor closely. Reduce dose according to drug concentration monitoring if necessary.
What is the recommended digoxin dose for a patient weighing 45 kg to 50 kg with a CrCl > 60 mL/min?
125 µg ONCE daily
What is the recommended digoxin dose for a patient weighing 45 kg to 50 kg with a CrCl 15 to 60 mL/min?
62.5 µg ONCE daily
What is the recommended digoxin dose for a patient weighing 50 kg to 60 kg with a CrCl > 110 mL/min?
250 µg ONCE daily
What is the recommended digoxin dose for a patient weighing 50 kg to 60 kg with a CrCl 45 to 100 mL/min?
125 µg ONCE daily
What is the recommended digoxin dose for a patient weighing 50 kg to 60 kg with a CrCl 15 to 45 mL/min?
62.5 µg ONCE daily
What is the recommended digoxin dose for a patient weighing 60 kg to 70 kg with a CrCl > 110 mL/min?
250 µg ONCE daily
What is the recommended digoxin dose for a patient weighing 60 kg to 70 kg with a CrCl 35 to 100 mL/min?
125 µg ONCE daily
What is the recommended digoxin dose for a patient weighing 60 kg to 70 kg with a CrCl 15 to 35 mL/min?
62.5 µg ONCE daily
What is the recommended digoxin dose for a patient weighing 70 kg to 80 kg with a CrCl > 80 mL/min?
250 µg ONCE daily
What is the recommended digoxin dose for a patient weighing 70 kg to 80 kg with a CrCl 20 to 80 mL/min?
125 µg ONCE daily
What is the recommended digoxin dose for a patient weighing 70 kg to 80 kg with a CrCl 15 to 20 mL/min?
62.5 µg ONCE daily
What is the recommended digoxin dose for a patient weighing 80 kg or more with a CrCl > 70 mL/min?
250 µg ONCE daily
What is the recommended digoxin dose for a patient weighing 80 kg or more with a CrCl 15 to 70 mL/min?
125 µg ONCE daily
As a rough guide, what is the recommended dose of digoxin for a patient with CrCl 30–60 mL/min?
Oral 62.5–250 micrograms once daily.
As a rough guide, what is the recommended dose of digoxin for a patient with CrCl 10–30 mL/min?
Oral 62.5–125 micrograms once daily.
As a rough guide, what is the recommended dose of digoxin for a patient with CrCl <10 mL per minute?
Oral 62.5 micrograms once daily or on alternate days.
Describe the effect of haemodialysis on digoxin levels.
5 hours of haemodialysis only reduces dose 3%
Describe the pathway of elimination of digoxin.
Digoxin is predominantly renally cleared (about 70%); reduce dose in renal impairment.
What should you consider with weight-based dosing of digoxin?
Use ideal weight rather than actual weight in obese patients
What should you always remember when giving digoxin IV?
Give IV over at least 5 minutes
Name 3 compatible fluids for digoxin.
- Sodium chloride 0.9%
- Glucose 5%
- Glucose/sodium chloride.
Describe the role of IM digoxin.
Do not give digoxin IM (unpredictable absorption, local irritation).
Describe the effect of digoxin in rapid ventricular rate associated with increased sympathetic tone
Digoxin is relatively ineffective in slowing rapid ventricular rate associated with increased sympathetic tone (such as exercise, hyperthyroidism, fever)
Describe the role of digoxin in converting atrial fibrillation to sinus rhythm?
Digoxin is not effective in converting AF to sinus rhythm or preventing recurrence of AF after cardioversion
Describe the role of digoxin for rate control during high-adrenergic effects?
It is also not effective for rate control during high-adrenergic effects (such as exercise). Beta-blockers are preferred for this.
In ventricular rate control in AF, what should the target ventricular rate be?
<110 beats/minute
Describe the ECG effects of digoxin.
Digoxin usually alters ECG and may result in prolonged PR interval, ST depression or T wave inversion (these changes do not necessarily indicate digoxin toxicity or myocardial ischaemia).
How do some specialists use digoxin?
Some specialists reserve digoxin in patients whose rate has not been adequately controlled with other agents or interventions.
What 3 formulations is digoxin available in?
- Tablet
- Oral Liquid
- Injection
Describe the crushing suitability of digoxin.
Digoxin can be crushed, but first line option is to use the oral liquid.
Should digoxin be taken with food?
It should be taken with consistent regard to food
How should blood samples of digoxin be timed?
Take blood samples at least 6 hours after a dose to allow for distribution.
Does digoxin have linear or non-linear kinetics?
Digoxin has linear kinetics
Describe the distribution of digoxin.
Digoxin is 20% to 30% protein bound (this is consistent in uraemic patients). The initial distribution of digoxin from the central to peripheral compartment generally lasts from 6 to 8 hours. This is followed by a more gradual decline in serum digoxin concentration, which is dependent upon digoxin to be extensively bound to body tissues. The highest concentrations of digoxin are found in the heart, lungs and kidney (30 fold increase in heart compared to plasma)
Describe the therapeutic window of digoxin.
Digoxin has a narrow therapeutic range; adverse effects are related to plasma concentration. Very few occur at <0.8 µg/L (1 nanomol/L).
Describe the time to steady state of digoxin.
Steady state is reached after about 7 days if renal function is normal (half-life is 36 hours); this may be prolonged in renal impairment.
Is dose adjustment of digoxin required in hepatic impairment?
No dose adjustment is required in hepatic impairment.
Describe the use of digoxin around elective electrical cardioversion.
It is not routinely necessary to hold digoxin prior to elective electrical cardioversion for atrial fibrillation; however, exclusion of digoxin toxicity is necessary prior to cardioversion.
What are 5 key words to consider with digoxin?
- µg
- Toxicity
- Concentrations
- Creatinine clearance
- Contraindications
What are the 4 main points to check for when reviewing a patient on Entresto?
- Blood pressure
- Potassium level
- Renal function
- Concurrent ACE Inhibitor use
Describe the risk of angioedema with angiotensin II receptor blockers.
Angioedema related to angiotensin II receptor blockers is reported to be less severe and occurs earlier compared to angioedema that develops during ACE inhibitor therapy.
Describe the use of GTN Spray post TAVI.
GTN is contraindicated in aortic stenosis due to a risk of excessive hypotension. After TAVI, you should always consider if GTN is appropriate as it is no longer contraindicated (provided there are no other contraindications)
Describe the relationship between age and digoxin effectiveness.
Digoxin is less effective in younger patients as they have stronger compensatory mechanisms.
What is the class abbreviation for Entresto?
ARNI (angiotensin receptor-neprilysin inhibitor)
What are 3 reasons you may wish to start with a low furosemide dose?
- The patient is elderly
- The patient is furosemide naive
- The patient has good renal function
What are the first 3 things you should always consider when a patient is starting perhexiline?
- Blood glucose levels
- Concurrent SSRI use (particularly paroxetine)
- Severe hepatic impairment
What should you always ask yourself when reviewing a decompensated heart failure patient?
Ask why they are decompensated now.
What should you always remember when dosing nitrates?
Patients will always require a nitrate free period.
What should you always remember when dosing nitrates?
Patients will always require a nitrate free period.
Name 6 Classes of antihypertensives
- Thiazide and related diuretics
- Other diuretics
- ACE inhibitors
- Sartans
- Calcium channel blockers
- Beta-blockers
Name 3 thiazide and related diuretics
- hydrOCHLOROTHIAZIDe (Thiazide)
- Chlortalidone (Thiazide-related)
- Indapamide (Thiazide-related)
What is the standard (oral) dosage of hydrOCHLOROTHIAZIDe for hypertension?
12.5 to 50 mg daily (usually in the morning)
What is the standard (oral) dosage of hydrOCHLOROTHIAZIDe for oedema?
25 to 100 mg daily (usually in the morning), or intermittently on 3–5 days each week.
What is the standard (oral) dosage of hydrOCHLOROTHIAZIDe for kidney stones?
25 to 50 mg once or twice daily.
Describe the use of thiazide diuretics in renal impairment.
Thiazide diuretics are less effective as diuretics when CrCl <30 mL/minute; however, they may retain their antihypertensive effects
What is the mechanism by which thiazide diuretics have antihypertensive effects in low doses?
By causing vasodilation.
Name 8 ACE Inhibitors.
- Captopril
- Enalapril
- Fosinopril
- Lisinopril
- Perindopril
- Quinapril
- Ramipril
- Trandolapril
If a patient is allergic to perindopril erbumine, can you give perindopril arginine?
No
If a patient has their ACE inhibitor or angiotensin-II receptor blocker held, what should you always check?
If there is an indication for which they require an ACE Inhibitor or angiotensin-II receptor blocker
Name 7 Sartans (Angiotensin Receptor Blockers)
- Candesartan
- Eprosartan
- Irbesartan
- Losartan
- Olmesartan
- Telmisartan
- Valsartan
What are two common indications of irbesartan?
- Hypertension
- Reduction of renal disease progression
If a patient has their ACE inhibitor or angiotensin-II receptor blocker held, what should you always check?
If there is an indication for which they require an ACE Inhibitor or angiotensin-II receptor blocker
What are the 2 classes of calcium channel blockers?
- Dihydropyridines
- Non-dihydropyridines
Name 6 dihydropyridine calcium channel blockers
- Amlodipine
- Clevidipine
- Felodipine
- Lercanidipine
- Nifedipine
- Nimodipine
Name 2 non-dihydropyridine calcium channel blockers
- Diltiazem
- Verapamil
Name 9 beta-blockers.
- Atenolol
- Bisoprolol
- Carvedilol
- Esmolol
- Labetalol
- Metoprolol
- Nebivolol
- Propranolol
- Sotalol
What is the standard dosage of atenolol (oral)?
Initially 25 to 50 mg once daily; increase if required to 100 mg daily in 1 or 2 doses.
Does atenolol require dose adjustment in renal impairment?
Yes
What are the two indications of nebivolol as per Medication Profiler?
- To slow your heart beat down and help it work better when you have heart failure.
- To help drop and control high blood pressure (hypertension)
What does the “generic subheading” section on MedProfiler say about prednisolone?
Take these tablets with food to prevent stomach upset
How does atenolol compare to metoprolol in stroke prevention?
Metoprolol offers improved protection against stroke compared with atenolol.
What is a common indication of prazosin in the setting of mental health?
Prazosin can reduce the incidence of nightmares.