anti-arrhythmic drugs, amiodarone Flashcards
Can be classified clinically based on where they act. E.g. this one acts on SV arrhythmias
verapamil
Can be classified clinically based on where they act. E.g. this one acts on SV and V arrhythmias
amiodarone
Can be classified clinically based on where they act. E.g. this one acts on V arrhythmias
lidocaine
Vaughan Williams classification is based on their effects on electrical behaviour of myocardial cells during activity
Class 1,2,3,4:
○ Class 1: membrane stabilising drugs (e.g. lidocaine, flecainide)
○ Class 2: BB
○ Class 3: amiodarone, stalaol (also class 2)
○ Class 4: CCBs (incl verapamil but not dihydropyrodines)
What is usually the treatment of choice for terminating paroxysmal SVT
adenosine
very short duration of action, so most SE are short lived. but prolonged in people taking dipyridamole
this drug is preferable to adenosine in people who have SV arrhythmia but have asthma
verapamil
Cardiac glycosides are contraindicated in SV arrhythmias associated with…
accessory conducting pathways (e..g Wolff-Parkinson-White syndrome)
IV administration of BB (e.g. …(2)) can achieve rapid control of ventricular rate
esmolol
propranolol
what can be given in cardiopulmonary resuscitation for ventricular fibrillation or pulseless tachycardia refractory to defibrillation
IV amiodarone
Amiodarone - MHRA
It can cause serious adverse reactions affecting the …..7…. that may persist for a month or longer after treatment discontinuation.
eyes, heart, lung, liver, thyroid gland, skin, and peripheral nervous system
MHRA amiodarone - Patients to seek medical advice if they experience these symptoms with amiodarone. what should HCP do?
new or worsening respiratory symptoms develop
HCP should consider using computerised tomography (CT) scans if pulmonary toxicity is suspected.
4 important SE with amiodarone
Corneal microdeposits
Thyroid function
Hepatotoxicity
Pulmonary toxicity
amiodarone - corneal microdeposits
Reversible on withdrawal of treatment.
However, if vision is impaired or if optic neuritis or optic neuropathy occur, amiodarone must be stopped to prevent blindness and expert advice sought.
Patient on amiodarone has corneal microdeposits. Do they need to stop
Corneal microdeposits associated with amiodarone are a common side effect of this medication, and they typically do not require discontinuation of therapy unless there are other significant ocular symptoms or complications.
Corneal microdeposits can lead to visual symptoms such as blurriness, halos, or glare, especially in bright light conditions. Microdeposits can particularly impact night driving, leading to difficulties with glare and seeing at night, which could pose safety risks.
amiodarone - thyroid disorders
Amiodarone contains iodine and can cause disorders of thyroid function; both hypothyroidism and hyperthyroidism can occur. Hypothyroidism can be treated with replacement therapy without withdrawing amiodarone if it is essential; careful supervision is required.
Pt has hypothyroidism which is amiodarone induced. Should you stop amiodarone
Hypothyroidism can be treated with replacement therapy without withdrawing amiodarone if it is essential; careful supervision is required.
Amiodarone - hepatotoxic or nephrotoxic?
Amiodarone is associated with hepatotoxicity and treatment should be discontinued if severe liver function abnormalities or clinical signs of liver disease develop.
amiodarone - pulmonary toxicity
If new or progressive shortness of breath or cough develops in patients taking amiodarone (or recently stopped), pulmonary toxicity should always be suspected. Pulmonary toxicity is usually reversible following early withdrawal of amiodarone.
amiodarone - phototoxicity
Shield the skin from light during treatment and for several months after discontinuing amiodarone; a wide-spectrum sunscreen to protect against both long-wave ultraviolet and visible light should be used.
amiodarone monitoring
LFTs tests before treatment and then every 6 months.
Serum potassium concentration should be measured before treatment.
Thyroid function tests should be performed before treatment, then at 6-monthly intervals, and for several months after stopping treatment (particularly in the elderly).
Chest x-ray required before treatment.
What to do if thyroid dysfunction suspected with amiodarone
Thyroid stimulating hormone levels should be measured if thyroid dysfunction is suspected. Consult specialist if thyroid function is abnormal.
Avoid concomitant use of amiodarone and Hep C sofosbuvir regimens unless other antiarrhythmics cannot be given. If not, what do you need to monitor
patients should be closely monitored, particularly during the first weeks of treatment. Patients at high risk of bradycardia should be monitored continuously for 48 hours in an appropriate clinical setting after starting concomitant treatment.
monitoring amiodarone IV use
ECG monitoring and resuscitation facilities must be available.
Monitor liver transaminases closely.
Which drug can cause slate grey skin
amiodarone can cause slate-gray skin discoloration, also known as blue-gray hyperpigmentation. The discoloration appears on areas of the body exposed to sunlight
amiodarone driving and skilled tasks
Patients and carers should be cautioned on the effects on driving and performance of skilled tasks—corneal microdeposits may be associated with blurred vision
what must you provide to pt taking amiodarone
A patient alert card should be provided.
Amiodarone + BB interactions
Amiodarone is predicted to increase the risk of cardiovascular adverse effects when given with BB. Manufacturer advises use with caution or avoid.
Also increased risk of hypotension.
For sotalol: also QT interval porlongation, avoid
Amiodarone + CCs, B2 agonists, loop and thiazides, theophylline interactions
They are predicted to cause hypokalaemia (potentially increasing the risk of torsade de pointes) when given with Amiodarone.
Amiodarone causes…
Qt interval prolongation
avoid other drugs e.g. citalopram, erythromycin, anti-arrhtymics, antipsychotics, hydrozyzine, methadone etc
amiodarone + RLCCB
Amiodarone is predicted to increase the risk of cardiodepression when given with Verapamil. Manufacturer advises avoid. Also bradycardia
flecainide + amiodarone dose adjustment
Manufacturer advises reduce dose by half with concurrent use of amiodarone.
digoxin dose adjustment with concurrent use of amiodarone, dronedarone and quinine.
reduce digoxin dose by half
Important info re sotalol
- Can prolong the QT interval, and it occasionally causes life threatening ventricular arrhythmias
- Manufacturer advises particular care is required to avoid hypokalaemia in patients taking sotalol—electrolyte disturbances, particularly hypokalaemia and hypomagnesaemia should be corrected before sotalol started and during use
What effect can IV admin of sotalol have, and how can you counteract this
With administration by intravenous injection, excessive bradycardia can occur and may be countered with intravenous injection of atropine sulfate.
Therapeutic OD with BB can cause….
Therapeutic overdosages with beta-blockers may cause lightheadedness, dizziness, and possibly syncope as a result of bradycardia and hypotension; heart failure may be precipitated or exacerbated. With administration by intravenous injection, excessive bradycardia can occur and may be countered with intravenous injection of atropine sulfate.
which type of BB are present in breast milk more than others
water soluble - CANS celiprolol, atenolol, nadolol, sotalol
sotalol - monitoring of pt parameters
Measurement of corrected QT interval, and monitoring of ECG and electrolytes required; correct hypokalaemia, hypomagnesaemia, or other electrolyte disturbances.
What should you correct before starting sotalol
hypoK
hypoMg
MOA amiodarone
Class 3 antiarrhythmic (like sotalol)
Mechanism: Primarily potassium channel blockade.
Dose amiodarone
Treatment of arrhythmias, particularly when other drugs are ineffective or contra-indicated (including paroxysmal supraventricular, nodal and ventricular tachycardias, atrial fibrillation and flutter, ventricular fibrillation, and tachyarrhythmias associated with Wolff-Parkinson-White syndrome) (initiated in hospital or under specialist supervision)
200 mg 3 times a day for 1 week, then reduced to 200 mg twice daily for a further week, followed by maintenance dose, usually 200 mg daily or the minimum dose required to control arrhythmia.
label for amiodarone
Protect your skin from sunlight—even on a bright but cloudy day. Do not use sunbeds
amiodarone and statins
increases exposure to statins and also hepatotoxicity
simvastatin max dose 20mg
