I M Ar 2 Flashcards
Amiodarone mechanism
Blocks sodium, calcium, potassium channels
Antagonism of a/b adrenergic receptors
Amiodarone adverse effects during IV infusion
Hypotension
Amiodarone adverse effects when taken chronically
Pneumonitis, bradycardia, hepatitis, photo sensitivity, thyroid abnormalities
Who shouldn’t take amiodarone
Severe hypotension
Heart block
Thyroid disease
Amiodarone interactions
Increase plasma conc of digoxin, diltiazem, verapamil
Prescription of amiodarone needs
Senior involvement (f1 not on own)
Amiodarone for cardiac arrest
300mg followed by flush
If repeated IV of amiodarone indicated how is it administered? Why?
Central line
Peripheral can cause phlebitis
Why should you not copy the preceding dose on prescription of amiodarone
May be a loading dose
ACEi egs
Ramipril, lisinopril, perindopril
ACEi uses
Hypertension
Chronic heart failure / ischemic heart disease
Diabetic nephropathy / CKD with pronteinuria
Mechanism of ACEi
Presents conversion of angiotensin I -> II
ACEi adverse effects
Hypotension (can be profound after first dose)
Dry cough
Hyperkalaemia
Cause / worsen renal failure (especially with renal artery stenosis)
Rarely - angiodema , anaphylaxis
Wh should not get ACEi
Renal artery stenosis
Acute kidney injury
Pregnant / breastfeeding
Chronic kidney disease (use lower dose)
ACEi interactions
Avoid potassium elevating drugs
NSAIDs -> increas risk of renal failure
How are ACEi prescribed - dose
Usually around 2.5mg daily titrated up to 10mg over few weeks
Dose of ramipril for heart failure / neohropathy
1.25mg daily
What to tell patients getting ACEi
Dizzy - especially after first dose Dry cough Tell someone if allergic signs Avoids NSAIDs eg ibuprofen Will need blood test monitoring
What should be checked before starting ACEi
Electrolytes and renal functions
Angiotensin receptor blockers egs
Losartan, candesartan, irbesartan
ARBs uses
Hypertension
Chronic heart failure / ischemic heart disease
Diabetic nephropathy / CKD with pronteinuria
ARBs mechanism
Block action of angiotensin II on AT1 receptor
ARBs adverse effects
Hypertension (especially first dose)
Hyperkalaemia
Renal failure
Why do ARBs not cause a dry cough
Do not affect ACEi (involved in bradykinin metabolism )
-> also less likely to cause angiodema
Who should not get ARBs
Renal artery stenosis
Acute kidney injury
Pregnant / breastfeeding
CKD - use lower doses
ARBs interactions
Don’t use with potassium elevating drugs
Risk of renal failure with NSAIDs
Prescription on ARBs
50mg orally daily titrated up
Losartan in heart failure
Start on 12.5mg daily
What to tell patients getting ARBs
Dizziness
Will need blood test monitoring
Avoid taking NSAIDs
What should be checked before starting ARBs
Electrolytes and renal function
In what ethnic group are ARBs preferable to ACEi
Black African / Caribbean as risk of angiodema is 5x higher then general population with ACEi
SSRIs egs
Citalopram
Fluoxetine
Sertraline
Escitalopram
SSRIs uses
Moderate - severe depression (mild if other treatments fail)
Panic disorder
OCD
SSRIs mechanism
Inhibit neuronal reputable of serotonin
Why are SSRIs generally preferred to tricyclics
Fewer adverse effects and less dangerous in overdose
SSRIs adverse effects
GI upset, weight / appetite disturbance Hypersensitivity Suicidal thoughts Lower seizure threshold Can prolong QT interval -> arrythmias Increase risk of bleeding Serotonin syndrome
What is serotonin syndrome
Autonomic hyperactivity
Altered mental state
Neuromuscular excitation
When should you be cautious of precribing SSRIs
Epileptics
Peptic ulcer disease
Young people
Hepatic impairment (as metabolised)
Which drugs should not be given with SSRIs ? Why?
Monoamine oxidase inhibitors (also increase serotonin -> serotonin syndrome risk)
Drugs that prolong QT interval eg. Antipsychotics
Carful with aspirin / NSAIDs (due to bleeding risk)
Prescribing SSRIs (citalopram)
20mg orally daily increased as needed
What to tell patient getting SSRIs
May need psychological therapy for longer term benefits
Carry on with SSRIs for 6 months after feel better
Not to stop suddenly -> tummy upset, flu like symptoms
Which SSRIs have fewer interactions
Citalopram and escitalopram
Tricyclics egs
Amitriptyline
Lofepramine
Tricyclics indications
Moderate - sever depression when SSRIs don’t work
Neuropathic pain
Tricyclics mechanism
Inhibit neuronal reuptake of serotonin and noradrenaline
Tricyclics mechanism which causes adverse effects
Block muscarinic, H1, A1/2, D2 receptors
Triclyclics adverse effects ? (Receptor blocked)
Dry mouth, constipation, urinary retention, blurred vision (antimuscarinic).
Sedation, hypotension (a1/H1).
Arrythmias, ECG changes.
Convulsions, hallucinations, mania.
Breast changes sexual dysfunction, extra pyramidal eg tremor / dyskinesia (dopamine)
Sudden withdrawal of tricyclics causes
GI upset, flu like
Who should tricyclics be used with caution
Elderly, CV disease, epilepsy, constipation, prostatic hyper trophy, raised intraoccular pressure
Which drugs should not be given with tricyclics
Mono amine oxidase inhibitors
Amytriptyline dose for neuropathic pain? Depression?
10mg at night
75mg daily
What needs to be thought about when prescribing tricyclics
Very dangerous in overdose -> prescribe small quantity at a time
What to tell patients getting tricyclics
Takes a few weeks for symptom improvement
May need psychological therapy
Keep taking for 6 months after better
Don’t stop suddenly
Amiodarone uses
Tachyarrythmias (usually when other treatments none suitable)
What to tell patients getting tricyclics
Will improve symptoms over a few weeks.
May need psychological therapy for long term benefits.
Keep taking for 6months after symtoms improve
Don’t stop treatment suddenly -> flu like withdrawal
Venlafaxine and mirtazepine uses
Major depression (SSRIs not effective) generalised anxiety disorder (venlafaxine only)
Mechanisms of venlafaxine and mirtazapine
Increase availability of monoamines for neurotransmisson
Venlafaxine and mirtazapine adverse effects
GI upset
CNS effects - headache, abnormal dreams, convulsions….
Less common - hyponatraemia, serotonin syndrome
Venlafaxine and mirtazapine sudden withdrawal ->
GI upset and flu like symptoms