High Risk Flashcards
What is the common indication for amiodarone?
What else could it be used for in emergency?
- Arrhythmias - esp when other drugs ineffective/contra-indicated
AF, atrial flutter, supraventricular tachycardia
- Cardiac arrest
Oral dose schedule of amiodarone?
200mg TDS for 1 week
200mg BD for 1 week then
200mg daily as maintenance dose
Why load?
Long half life (50 days) means it would take ages to reach therapeutic levels. Also means interactions can still occur months after stopping.
Contra-indications with amiodarone? (5)
Avoid in:
1. Severe conduction disturbances (unless pacemaker fitted)
- Sinus node disease
- Iodine sensitivity
- Sino-atrial heart block (except in cardiac arrest)
- Thyroid dysfunction
Warnings signs with Amiodarone? (6)
- Signs & symptoms of hypo- or hyperthyroidism - because of the iodine in amIODarone.
- Corneal microdeposits. rarely interfere with vision - drivers may be dazzled by headlights at night. IF vision impaired/optic neuritis/optic neuropathy - STOP amiodarone
- Progressive SOB or cough - Pneumonitis
- Clinical signs of liver disease e.g. jaundice, dark urine
- Neurological effect of tremor, peripheral neuropathy (numbness/tingling of hands and feet)
- Phototoxic skin reactions - GREY skin
Monitoring requirements of amiodarone?
IV use?
Thyroid function
Liver function
Serum potassium
Chest X-RAY
IV use:
ECG + resuscitation facilities
Liver transaminases
Thyroid and Liver - repeated every 6 months
Side effects of Amiodarone? (12)
What can occur with parenteral use - following rapid injection?
- Arrhythmias
- Hepatic disorders
- Hyper/hypothyroidism
- Skin reactions - GREY
- Nausea
- Resp disorders - cough, SOB
- Corneal deposits
- Constipation
- Sleep disorders
- Taste altered
- Vomiting
- Photosensitivity
- Hypotension
Due to Amiodarone
long half life (___ days) potential for drug interactions to occur weeks/months after treatment has stopped.
Amiodarone increases the plasma concentrations of which drugs: (6)
50 days
- Coumarins
- Dabigatran (Direct thrombin inhibitor)
- Digoxin (Cardiac glycoside)
- Flecainide (Antiarrhythmics)
- Phenindione (Vit K antagonist - like warfarin)
- Phenytoin (antiepileptics)
Which patients should amiodarone be AVOIDED in?
- Heart block
- Active thyroid disease
- Severe hypotension
If a person develops hyPOthyroidism can they continue with amiodarone?
Yes if it’s essential - then can be treated with replacement therapy
What are some of the RARE/Freq not known side effects of amiodarone?
Oral use:
- Alopecia
- Erectile dysfunction
- Anaemia
- Thrombocytopenia
- Pulmonary haemorrhage
- Vertigo
- Altered smell
- Decreased appetite
- Parkinsonism
- Vasculitis
Parenteral:
- Hot flushes
- Hyperhidrosis
- Neutropenia
- Libido decreased
- Agranulocytosis
Counselling points of Amiodarone? (4)
- Taken by mouth - can be crushed and dispersed in water
- Shield skin from light& use wide-spectrum sunscreen - during and several months after stopping treatment
- Avoid grapefruit juice
- Drivers may be dazzled by headlights at night
How is amiodarone given for cardiac shock? Can it be given before it is prescribed?
300mg followed by 20ml of glucose 5%
yes in this case
Amiodarone increases the plasma concentration of digoxin, diltiazem and verapamil.
What can this increase the risk of … (3)
So what should happen with the dose of these medications?
- Bradycardia
- AV block
- Heart failure
dose should be halved
There is an INCREASED risk of VENTRICULAR ARRHYTHMIAS when amiodarone is given with which medicines… (long list) (20)
- Amisulpride
- Atomoxetine
- Chloroquine
- Citalopram
- Disopyramide
- Escitalopram
- Haloperidol
- Hydroxychloroquine
- Levofloxacin
- Lithium
- Mizolastine
- Mefloquine
- Moxifloxacin
- Phenothiazines
- Pimozide
- Quinine
- Sulpiride
- Telithromycin
- Tolterodine
- Tricyclics
There is increased risk of myopathy when amiodarone is given with _____
Simvastatin
Can Amiodarone be used in:
- Pregnancy
- Breast feeding
- Possible risk of neonatal goitre - use only if no alternative
- Avoid - present in milk in significant amounts - risk of neonatal hypothyroidism from release of iodine
What is the MHRA warning for taking amiodarone with Sofosbuvir & daclatasvir OR Sofosbuvir & ledipasvir OR Sofosbuvir & simeprevir?
AVOID - Risk of severe bradycardia and heart block
If need to use - pts to be closely monitored esp during first few weeks of treatment.
What is Lithium used for? (4)
Prophylaxis and treatment of:
Mania
Bipolar disorder
Recurrent depression
Aggressive or self-harming behaviour
Can you easily switch between different Lithium preparations?
No because they vary in bioavailability - requires same precautions as initiation of treatment.
What are the serum level monitoring requirements of lithium?
-Serum concs: 0.4-1mmol/L
(lower end of the range for maintenance and the elderly)
Blood samples should be taken 12 hours.
0.8-1mmol/L: acute episodes of mania and relapse patients and sub-syndromal symptoms
Monitoring requirements / before starting treatment for Lithium? (6+1)
Before & every 6 months
- Renal eGFR
- Cardiac
- Thyroid function
- BMI
- FBC
- Electrolytes
ECG is recommended in patient with CVD or risk factors.
What are the CI of lithium? (6)
- Addison’s disease
- Cardiac insufficiency
- Dehydration
- Family/Personal history of Brugada syndrome
- Low sodium diets
- Untreated hypothyroidism
What are cautions of lithium? (10)
- Avoid abrupt withdrawal
- Cardiac disease
- QT interval prolongation
- Diuretic treatment (risk of toxicity)
- Concurrent ECT (may lower seizure threshold)
- Elderly (reduce dose)
- Epilepsy (may lower seizure threshold)
- Myasthenia gravis
- Psoriasis (risk of exacerbation)
- Review dose in diarrhoea;
intercurrent infection (especially if sweating profusely);
vomiting;
surgery
What is the association with long term use of lithium? (2)
- Thyroid disorders (monitor thyroid function every 6 months)
- Mild cognitive and memory impairment
What are the signs of overdose of lithium? (10)
Must withdraw treatment
- Increasing gastro disturbance - vomiting/diarrhoea
- Incontinence/polyuria (renal dysfunction)
- Visual disturbance - blurred vision
- CNS disturbance - drowsiness/confusion/unsteadiness
- Muscle weakness/ tremor
Severe:
- Serum conc more than 2mmol/L
- Seizure/Coma
- Renal/Circulatory failure
- Blood pressure changes
- Cardiac arrhythmias
What is the conception, contraception advice and pregnancy & breast feeding advice with lithium?
Effective contraception during treatment for women of child bearing potential.
Pregnancy - AVOID particularly in FIRST trimester - risk of teratogenicity, including cardiac abnormalities.
Dose requirements increased during 2nd and 3rd trimesters BUT on delivery return abruptly to normal.
Breastfeeding - AVOID
present in milk & risk of toxicity in infant
When should serum levels of lithium be measured & how often?
Samples should be taken 12 hours after dose
0.4-1mmol/L - lower end for maintenance/elderly
0.8-1 mmol/L for mania/relapsed
Weekly after initiation and after each dose change until levels are stable.
Every 3 months for the first year then every 6 months
What advice should be given when stopping lithium treatment?
Abrupt withdrawal - increase chance of relapse
Dose should be gradually decreased over at least 4 weeks.
What are the patient/career advice for lithium? (8)
Report any signs of:
- Toxicity
- Hypothyroidism
- Renal dysfunction - polyuria/polydipsia
- Benign intracranial hypertension (persistent headache & visual disturbance)
- Maintain adequate fluid intake (to prevent hyponatraemia)
- Avoid dietary changes which reduce or increase sodium intake
- Avoid alcohol
- Risks of driving/operating machinery - sleepy
Give pts Lithium treatment pack
e.g. Priadel, Liskonum, Camcolit
What drugs increase the toxicity of lithium? (10)
- ACE inhibitors
- Angiotensin II receptor antagonists
- Loop diuretics
- Thiazides
- NSAIDs
- Potassium sparing diuretics
- Aldosterone antagonsits
- Metronidazole
- SSRIs
- Tricyclics
What drug increases risk of ventricular arrhythmias For lithium?
Amiodarone
What drugs increase the risk of neurotoxicity of lithium? (5)
- Methyldopa
- Phenytoin
- Carbamazepine
- Diltiazem
- Verapamil
What drugs is there an increased risk of extrapyramidal side effects ( tremor, slurred speech, akathesia, dystonia, anxiety, distress, paranoia) with lithium? (7)
- Clozapine
- Haloperidol
- Sulpiride
- Phenothiazines
- Risperidone
- Flupentixol
- Zuclopenthixol
Side effects of Lithium? (14)
- Abdominal discomfort
- Angioedema
- Electrolyte imbalance
- Hypothyroidism
- Cardiomyopathy & AV block
- Arrythmias
- Weight gain
- Tremor/ movement disorders
- Leukocytosis (WBC increase)
- Polydipsia (excessive thirst), Polyuria
- Memory loss
- Skin reactions/ulcers
- Vision disorders
- Vertigo
What are the indications for Carbamazepine? (3)
Unlicensed uses? (2)
- Focal and secondary generalised tonic-clonic seizures,
Primary generalised tonic-clonic seizures - Trigeminal neuralgia
- Prophylaxis of Bipolar disease unresponsive to lithium.
- Alcohol withdrawal
- Diabetic neuropathy
Mechanism of action of Carbamazepine?
Block sodium channels
Monitoring of carbamazepine? (3)
- Blood count
- Renal function
- Liver function (metabolised by the liver)
Side effects of carbamazepine? (6)
- GI effects - nausea & vomiting (modified release to help)
- Neurological - dizziness, ataxia (drunk like symptoms)
- Hypersensitivity - skin reactions - maculopapular rash
- Hypersensitivity syndrome - Steven - Johnson’s syndrome, skin necrolysis, fever
- Oedema - due to antidiuretic hormone like activity
- Hyponatraemia - due to antidiuretic hormone like activity
Warning signs of carbamazepine? (5)
- Toxicity - blurred vision, ataxia, diplopia (double vision), nystagmus (involuntary, uncontrollable eye movements), drowsiness, diarrhoea, arrhythmias, hyponatraemia
- Blood disorders - leucopoenia, thrombocytopenia (fever, sore throat, unexplained bruising/bleeding)
- Skin disorders - toxic epidermal necrolysis (mouth ulcers, rash)
- Hepatic disorders e.g. hepatitis
- Antiepileptic hypersensitivity syndrome - skin reactions, fever, swollen lymph nodes
Serum levels of carbamazepine? When should they be measured?
4-12 mg/L or 20-50micromol/L
not routine to check but after 1- 2 weeks and after a dose change
Interactions - Carbamazepine decreases the concentration of which drugs? (7)
what increases (5) plasma concentration of carbamazepine?
Carbamazepine is a P450 inducer so will decrease the concentration & efficacy of the following:
- Antipsychotics
- Corticosteroids
- Coumarins
- Eplerenone
- Oestrogens
- Progesterone ** (careful Levonelle/levonorgestrel after morning pill)
- Simvastatin
Plasma conc of carbamazepine will INCREASE with:
P450 enzyme inhibitors as it is metabolised by the enzyme
1. Macrolides (clarithromycin, erythromycin)
2. Cimetidine (histamine H₂ receptor antagonist)
3. Acetazolamide (for glaucoma etc)
4. Fluoxetine (SSRI)
5. Isoniazid (TB Abx)
Interactions - efficacy of antieplipetic drugs reduced by those that lower the seizure threshold …such as (4)
- SSRI
- Tricyclic antidepressants
- Antipsychotics
- Tramadol