BASIC - CARDIOVASCULAR + DERMATOLOGY Flashcards
Names of loop diuretics?
Furosemide, bumetanide
Indications of loop diuretics?
Acute pulmonary oedema (with O2 and nitrates)
Chronic heart failure
Other oedematous states (renal and liver disease)
Mechanism of action of loop diuretics?
- Act on ascending limb of loop of Henle – inhibit Na/K/2Cl co-transporter (from lumen to epithelial cell)
- Stops water following by osmosis
- Dilatation of capacitance veins – reduces preload and improves contractile function of heart failure
Side effects of loop diuretics?
- Dehydration
- Hypotension
- Low electrolytes (Na, K, Cl, Ca, Mg)
- Tinnitus and hearing loss
Contraindications of loop diuretics?
- Dehydration/Hypovolaemia
- Hepatic encephalopathy (hypokalaemia cause/worsen coma)
Cautions of loop diuretics?
- Electrolyte disturbances (low K, Na)
- Worsens gout – inhibit uric acid excretion
Interactions of loop diuretics?
- Affect drugs excreted by kidneys
o E.g. lithium levels increase and digoxin toxicity by hypokalaemia - Increase ototoxicity and nephrotoxicity of aminoglycosides
Dose of loop diuretics?
o Oral/IV furosemide 40g
o Oral 1mg bumetanide (500mg if elderly)
o Oral doses taken in morning (second dose in early afternoon when BDS) to avoid nocturia
Communication to patient of loop diuretics?
o Medicine will cause urine to be passed more
o Aim for weight loss of no more than 1kg/day
Monitoring of loop diuretics?
o U&Es during treatment
Names of thiazide diuretics?
Bendroflumethiazide, indapamide, chlortalidone, metolazone
Indications of thiazide diuretics?
- Hypertension add-on (step 3)
- Alternative first-line hypertension when CCB cannot be used (HF, oedema)
Mechanism of action of thiazide diuretics?
- Inhibit Na/Cl co-transporter in distal convoluted tubule
- Prevents sodium and water reabsorption
Side Effects of thiazide diuretics?
- Hyponatraemia
- Hypokalaemia
- Cardiac arrhythmias
- Increase glucose, HDLs and triglycerides
- Impotence in men
Contraindications of thiazide diuretics?
- Hypokalaemia
- Hyponatraemia
- Gout
- Hypercalcaemia
- Addison’s Disease
- History of allergy to sulphonamides
Changes in renal failure of thiazide diuretics?
- Ineffective in eGFR<30
- Metolazone effective if eGFR<30
Changes in liver failure of thiazide diuretics?
- Caution mild-to-moderate
- Avoid in severe liver disease
Interactions of thiazide diuretics?
- NSAIDs reduce effectiveness
- Combination of loop and thiazide diuretics lower serum K
Dose of thiazide diuretics?
- Taken orally, regularly
- Indapamide 2.5mg OD used for hypertension
- Take in morning
Monitoring of thiazide diuretics?
U&Es before starting, 2-4 weeks into therapy and after change in dose
Names of K-sparing diuretics?
Amiloride (as co-amilofruse/co-amilozide), spironolactone, eplerenone
Indications of amiloride and spironolactone?
Amiloride - Hypokalaemia (arising from diuretic therapy)
Spironolactone - Ascites and oedema from liver cirrhosis, CHF, Hypertension (resistant), Nephrotic syndrome
Primary hyperaldosteronism
Mechanism of amiloride and spironolactone?
- Amiloride
o Weak diuretic but can counter-act potassium loss
o Inhibits Na and water reabsorption by ENaC in distal convoluted tubule - Spironolactone
o Competitively bind to aldosterone receptors affecting ENaC in distal convoluted tubule
o Increases potassium retention and increases water and Na excretion
Side effects of K-sparing diuretics?
- GI upset
- Dizziness, hypotension and urinary symptoms
- Hyperkalaemia
- Spironolactone only – gynaecomastia, jaundice, liver impairment, SJS (bullous skin eruption)
Contraindications of K-sparing diuretics?
- Severe renal impairment
- Hyperkalaemia
- Anuria
- Spironolactone – Addison’s disease
- Pregnancy and breast-feeding
Interactions of K-sparing diuretics?
- Do not combine with potassium supplements, aldosterone antagonists, ACEi, ARBs – risk of hyperkalaemia
- Dose adjustment of lithium and digoxin needed
Dose of K-sparing diuretics?
o Co-amilofruse tablet at strength 1:8 so state strength and dose as number of tablets taken daily
o Spironolactone = 100-200mg, increased up to 400mg
o Regular OD dose - take with food
o Take in morning to minimise nocturia
Communication to patients of K-sparing diuretics?
o Warn men possibility of growth and tenderness of tissue under the nipples and impotence - spironolactone
o Reversible
Monitoring of K-sparing diuretics?
o Serum potassium, U&Es
1 week after initiation/dose increase
Monthly for 3 months and then 3 monthly for a year
Then every 6 months
Names of ACE inhibitors?
Ramipril, Lisinopril, Perindopril
Indications of ACE inhibitors?
Hypertension (1st or 2nd line Rx)
Heart Failure (1st line)
Ischaemic Heart Disease
CKD
Mechanism of ACE inhibitors?
- Block action of ACE to prevent conversion of angiotensin 1 to angiotensin 2 (Angiotensin 2 is vasoconstriction and stimulates aldosterone secretion)
- Reduces peripheral vascular resistance (BP), dilates efferent glomerular arteriole (reduces intraglomerular pressure – slows CKD)
- Reduces aldosterone level – promotes sodium and water excretion (beneficial in HF)
Side effects of ACE inhibitors?
- Dry cough (1 in 10) – due to increased bradykinin
- Hypotension (especially with 1st dose – take in night)
- Hyperkalaemia
- Worsen renal failure
- Angioedema
Contraindications of ACE inhibitors?
- Renal artery stenosis
- AKI
- Pregnant and breastfeeding women
Dose changes in hepatic and renal impairment of ACE inhibitors?
Hepatic Impairment
- Caution
Renal Impairment
- Start with lower dose, adjust according to response
Interactions of ACE inhibitors?
- Avoid in potassium-elevating drugs (K+ supplements, potassium sparing diuretics)
- NSAIDs and ACEi – increased risk of renal failure
Dose of ACE inhibitors? (ramipril)
- Orally
- Starting dose 1.25-2.5mg ‘titrated up’ to a maximum 10 mg daily dose over a period of weeks
- First dose before bed to reduce symptomatic hypotension
Communication to patient of ACE inhibitors?
- Treatment to improve blood pressure and reduce strain on their heart
- Advise patients about common side effects
- Avoid taking over-the-counter anti-inflammatories (e.g. ibuprofen) due to the risk of kidney damage.
Monitoring of ACE inhibitors?
o Blood test monitoring as can interfere with their kidney function and upset potassium balance
o Check electrolytes and renal function before starting treatment
o Repeat these 1–2 weeks into treatment and after increasing the dose
If eGFR<25% increase and creatinine <30% increase - continue and recheck levels in 1-2 weeks
If eGFR>25% increase or creatinine >30% increase - stop drug or reduce dose to tolerated dose
If K>6 - stop ACEi
Names of beta-blockers?
Bisoprolol, Atenolol, Propranolol, Metoprolol
Indications of beta-blockers?
- 1st line in Angina, ACS
- CHF
- AF
- SVT
- Hypertension (Step 4)
Mechanism of beta-blockers?
- Beta1-adrenoreceptors found in heart mainly and Beta2-adrenoreceptors found in smooth muscle of airways and blood vessel
- Beta-blockers non-specific
o Atenolol, bisoprolol and metoprolol more B1 specific
o Propranolol non-selective - Mechanism:
o Reduce force of contraction and speed of conduction in the heart
o Prolong refractory period in AV node
o Reduce renin secretion
Side effects of beta-blockers?
- Fatigue, cold extremities, headache and GI upset
- Sleep disturbance
- Impotence in men
Contraindications of beta-blockers?
- Asthma (bronchospasm)
- Cardiogenic shock
- Hypotension
- Metabolic acidosis
- Prinzmetal angina
- 2nd degree Heart block
- Pregnancy
Cautions of beta-blockers?
- 1st degree heart block
- Hx of obstructive airway disease
- Myasthenia gravis
Dose changes in hepatic and renal impairment of beta-blockers??
Hepatic Impairment
- Caution – maximum 10mg in severe
Renal Impairment
- Reduce dose (max 10mg) if eGFR<20
Interactions of beta-blockers?
- Do not combine Beta-blockers and Non-DHP CCB – cause HF and bradycardia
Dose of beta-blockers?
- Oral, start low dose
- Bisoprolol in hypertension = 5-10mg
- Bisoprolol in HF = 1.25mg increased by 1.25mg weekly up to 10mg
- Take at same time each day OD
- Aim for HR of 55-60bpm
Monitoring of beta-blockers?
o Lung function (in patients with Hx of obstructive airway disease)
Cessation of beta-blockers?
Avoid abrupt withdrawal, especially in IHD
Causes rebound worsening of myocardial ischaemia
Names of nitrates?
Isosorbide mononitrate
Glyceryl trinitrate
Indications of nitrates?
- Acute angina, ACS
- Prophylaxis of angina (where BB, CCB not tolerated)
- IV nitrates in pulmonary oedema (with furosemide and oxygen)
Mechanism of nitrates?
- Nitrates converted into NO
- NO increases cGMP and reduces intracellular Ca in vascular smooth muscle cells
- Relaxation of venous capacitance vessels reduces preload
- Reduce cardiac work and myocardial oxygen demand
- Relaxation of systemic arteries, reducing arterial resistance and afterload
Side effects of nitrates?
- Flushing, headaches, light-headedness, hypotension, nausea and vomiting
- Sustained use – tolerance
o Nitrate free period important for 4-12 hours a day
Contraindications of nitrates?
- Severe aortic stenosis
- Cardiac Tamponade
- Constrictive pericarditis
- Cardiogenic shock
- Hypotension
Cautions of nitrates?
- HF due to obstruction
- Hypothermia
- Hypothyroidism
Dose changes in hepatic and renal impairment of nitrates?
Hepatic Impairment
- Caution in severe impairment
Renal Impairment
- Caution in severe impairment
Interactions of nitrates?
- Avoid phosphodiesterase inhibitors (Sildenafil) – hypotension
- Caution in antihypertensives – hypotension
Prescription of nitrates?
o GTN taken sublingually tablets or spray for immediate relief (half-life <5 mins)
o ISMN prescribed BDS/TDS for prevention of recurrent angina
o Available IR, MR, patches
o In ACS GTN given IVI:
Usually given 1mg/mL (50mg in 50mL), express starting dose as rate 1mL/hr
Increase GTN rate by 0.5mL/hr every 15-30 minutes until relieved
Communication to patients on nitrates?
o Take GTN before tasks to prevent angina
o Sit down and rest before and for 5 mins after taking GTN – hypotension
o GTN tablets need to be discarded after 8 weeks, so spray better for infrequent angina
o Ensure nitrate free period – usually overnight to prevent tolerance
Monitoring of nitrates?
o IV nitrates – measure BP and HR - >90mmHg systolic
Cessation of nitrates?
o Avoid abrupt withdrawal
Names of calcium channel blockers?
Dihydropyridines - Amlodipine, Nifedipine (vascular selective)
Non-dihydropyridines – Verapamil, Diltiazem (cardio-selective)
Indications of calcium channel blockers?
- Hypertension – Amlodipine
- Stable angina – amlodipine/Nifedipine
- Supraventricular arrhythmias (diltiazem and verapamil) – SVT, Atrial flutter and fibrillation
Mechanism of action of calcium channel blockers?
- Decrease Ca entry into vascular and cardiac cells
- Causes
o Relaxation and vasodilation in arterial smooth muscle (lowered blood pressure)
o Reduced myocardial contractility
o Reduce cardiac conduction (particularly AV node)
o Reduce myocardial oxygen demand
Side effects of calcium channel blockers?
- DHP
o Ankle swelling, flushing, headache and palpitations (caused by vasodilatation and compensatory tachycardia)
o Abdominal pain, nausea, vomiting - Verapamil
o Constipation, bradycardia, hypotension, heart block, cardiac failure - Diltiazem – any of the above
Contraindications of calcium channel blockers?
- Non-DHP – bradycardia, 2nd/3rd degree heart block, Wolf-Parkinson-White syndrome, hypotension, cardiogenic shock
- DHP - unstable angina, cardiogenic shock and severe aortic stenosis
Dose change in hepatic impairment of calcium channel blockers?
Hepatic Impairment
- Caution – start at low dose
Interactions of calcium channel blockers?
- Non-DHP – do not prescribe with Beta-blockers
Dose of amlodipine/diltiazem?
- Oral, OD (amlodipine)
- E.g. amlodipine 5-10mg OD for hypertension, diltiazem MR 90mg 12hr for angina
- MR swallowed whole, not crushed or chewed
Names of angiotensin receptor antagonists (ARBs)?
Losartan, Candesartan, Irbesartan
Indications of angiotensin receptor antagonists (ARBs)?
- When ACEi not tolerated: o Hypertension o HF o IHD o CKD
Mechanism of angiotensin receptor antagonists (ARBs)?
- ARBs block the action of angiotensin II on the AT1 receptor
- Angiotensin II is a vasoconstrictor and stimulates aldosterone secretion
- Blockage - reduces peripheral vascular resistance (Low BP), dilates the efferent glomerular arteriole (reduces intraglomerular pressure and slows the progression of CKD), reducing the aldosterone level promotes sodium and water excretion
- Reduce venous return (preload), which has a beneficial effect in heart failure.
Side effects of angiotensin receptor antagonists (ARBs)?
- Hypotension (particularly first dose)
- Hyperkalaemia
- Renal Failure
Contraindications of angiotensin receptor antagonists (ARBs)?
- Renal artery stenosis
- AKI
- Avoid in pregnant or breast feeding women
Dose changes in hepatic and renal impairment of angiotensin receptor antagonists (ARBs)?
Hepatic Impairment
- Caution in mild to moderate – dose reduction
- Avoid in severe
Renal Impairment
- Start low dose and adjust according to response
Interactions of angiotensin receptor antagonists (ARBs)?
- Avoid in potassium-elevating drugs (K+ supplements, potassium sparing diuretics)
- NSAIDs and ACEi – increased risk of renal failure
Prescription of angiotensin receptor antagonists (ARBs)?
- Orally
- Starting dose ‘titrated up’ to a maximum daily dose over a period of weeks
- First dose before bed to reduce symptomatic hypotension
Monitoring of angiotensin receptor antagonists (ARBs)?
o Check U&E before starting treatment
o Repeat these 1–2 weeks into treatment and after increasing the dose
If eGFR<25% increase and creatinine <30% increase - continue and recheck levels in 1-2 weeks
If eGFR>25% increase or creatinine >30% increase - stop drug or reduce dose to tolerated dose
If K>6 - stop ACEi
Indications of aspirin?
- Acute in ACS/CVA ischaemic
- 2o prevention in CVD, CVA, PAD
- AF (when warfarin or NOAC contraindicated)
- Following coronary by-pass surgery
- Pain (mild-to-moderate)
Mechanism of aspirin?
- Antiplatelets (along with clopidogrel, ticagrelor) – work on platelets in arterial systems
- Irreversibly inhibits cyclooxygenase (COX) to reduce thromboxane production from arachidonic acid – reduces platelet aggregation
- Antiplatelet effect at low doses and lasts lifetime of platelet
Side effects of aspirin?
- GI irritation, ulceration and haemorrhage
- Bronchospasm
- Tinnitus
Overdose symptoms of aspirin?
o Hyperventilation, hearing changes, metabolic acidosis, confusion, collapse
Contraindications of aspirin?
- <16 years old (Reye’s syndrome)
- Active peptic ulcer (and previous)
- Bleeding disorders
- Allergy to NSAIDs
Cautions of aspirin?
- Anaemia
- Uncontrolled hypertension
- Third trimester of pregnancy
- Gout (may trigger acute attack)
Dose changes in hepatic and renal impairment of aspirin?
Hepatic Impairment
- Avoid in severe impairment
Renal Impairment
- Avoid in severe
Interactions of aspirin?
- Synergistic increase risk of bleeding
Doses of aspirin?
o ACS – Once-only loading dose 300mg followed by 75mg regularly
o Ischaemic CVA – 300mg for 2 weeks before switching to 75mg daily
o Long-term prevention – 75mg daily
- Gastroprotection in people at risk
- Take after food
Indications of clopidogrel?
ACS
Coronary artery stents
2o prevention of CVD, CVA and PAD
AF (where warfarin or NOACs CI)
Mechanism of clopidogrel?
- Used when platelet-rich thrombus forms in atheromatous arteries
- Prevents platelet aggregation by binding irreversibly to ADP receptors on platelet surface
Side effects of clopidogrel?
- Bleeding
- GI upset – dyspepsia, abdominal pain, diarrhoea
- Thrombocytopenia
Contraindications of clopidogrel?
- Active bleeding
- Stop 7 days before elective surgery
Dose changes in hepatic and renal impairment of clopidogrel?
Hepatic Impairment
- Avoid in severe
Renal Impairment
- Caution
Interactions of clopidogrel?
- Pro-drug requires CYP450 enzymes hepatic to convert to active form
- Efficacy affected by CYP450 inhibitors and inducers
- Increased risk of bleeding – antiplatelets, anticoagulants, NSAIDs
Dose of clopidogrel?
- Doses require week to reach full antiplatelet effect
- Loading dose – oral 300mg, maintenance dose 75mg OD
- PPI used
Names of LMWH?
Tinzaparin, enoxaparin, dalteparin, fondaparinux
Indications of LMWH?
Prophylaxis of VTE (inpatients and initial treatment)
Treatment of DVT/PE
VTE in Pregnancy
ACS
Mechanism of LMWH?
- Unfractioned heparin – activates antithrombin that inactivates Factor 10a and thrombin
- LMWH – similar but preferentially inhibit Factor 10a
- Fondaparinux – synthetic compound inhibits Factor 10a only
Side Effects of LMWH?
- Bleeding
- Injection site reaction
- Heparin-induced thrombocytopenia
Contraindications of LMWH?
- Acute bacterial endocarditis
- Major trauma
- Epidural/Spinal anaesthesia/lumbar puncture (12hs after dose)
- Haemophilia
- Peptic ulcer
Dose reduction in renal impairment of LMWH?
Dose reduction if eGFR <30 (use unfractioned heparin)
Interactions of LMWH?
- Combined antithrombotic drugs increase risk of bleeding
- Protamine can be given in major bleeding to reverse anticoagulation (effective for UFH mostly)
Prescription of LMWH?
- SC injection – dose dependent on patient weight and indication
- Long-term therapy
- Tinzaparin = prophylaxis 50U/kg, treatment 175U/kg
Monitoring of LMWH?
o Baseline FBC and U&Es
o Platelet count monitored in therapy > 4 days
o U&Es regularly checked if >7 days
Indications of warfarin?
Prophylaxis and treatment in DVT and PE
Prophylaxis in AF and heart valve replacement (lifelong after mechanical valve)
Mechanism of warfarin?
- Inhibits vitamin K epoxide reductase, preventing reactivation of vitamin K and coagulation factor synthesis (2, 7, 9, 10)
- Vitamin K must be in reduced form for synthesis of coagulation factors, which it is then oxidised
- Thins the blood
Side effects of warfarin?
- Bleeding (1-2%)
- Diarrhoea, nausea, rash
Contraindications of warfarin?
- Immediate risk of haemorrhage – stroke, bleeding
- Pregnancy - <48 hours postpartum and not conceive (teratogenicity)
- Women in 1st trimester
Caution of warfarin?
- Bacterial endocarditis
- Hx of GI bleeding
- Hyperthyroidism
Dose changes in hepatic and renal impairment of warfarin?
Hepatic Impairment
- Avoid in severe
Renal Impairment
- Monitor INR more frequently
Interactions of warfarin?
- Low therapeutic index
- Altered drug content by CYP450 inhibitors and inducers
- Antibiotics kill gut flora which synthesis Vitamin K so increase anticoagulation
Dose of warfarin?
o Oral OD – usually 6pm, same time
o 5-10mg on day 1
o Subsequent doses guided by INR
- If immediate effect needed – started on LMWH concomitantly
Practicalities of warfarin?
o Patients receive anticoagulant book (yellow book) used to record doses and blood test results
o Always carry anticoagulant alert card with you
Monitoring of warfarin?
o INR between 2-3 measured daily in hospital
Initially be frequent (every 3-4 days until two consecutive readings are within range) then twice weekly for 1-2 weeks (again until two consecutive readings within range)
Thereafter, testing can increase to longer periods (e.g. every 12 weeks)
Missed dose rules of warfarin?
o Never double up on doses: If a dose is accidentally missed, they should continue with the regimen as prescribed, and never take a double dose (unless specifically advised)
Lifestyle changes of warfarin?
o Avoid liver, spinach, cranberry juice, alcohol binges
o No NSAIDs/aspirin
Names of NOACs?
Apixaban, Dabigatran, Rivaroxaban
Indications of NOACs?
Prevention of VTE following knee/hip replacement surgery
DVT/PE – treatment and prophylaxis in recurrent
Prevention in AF
ACS (Rivaroxaban)
Mechanism of NOACs?
- Direct factor 10a inhibitor
Side Effects of NOACs?
- Bleeding
- Abdominal pain, diarrhoea, constipation
- Headache
Contraindication of NOACs?
- Antiphospholipid syndrome
- Active bleeding
Cautions of NOACs?
- Prosthetic heart valve
- Recent surgery (rivaroxaban
Dose changes in hepatic and renal impairment of NOACs?
- Avoid in severe
- Avoid eGFR <15 (apixaban & rivaroxaban)
- Reduce dose to 2.5mg BD if eGFR 15-29 (apixaban & rivaroxaban)
Dose of NOACs?
Apixaban
- Prophylaxis - 2.5mg
- Treatment - 10mg
Dabigatran
- Prophylaxis - 75mg
- Treatment - 150-110mg
Rivaroxaban
- Prophylaxis - 10mg
- Treatment - 15mg
Names & Indications of statins?
Simvastatin, Atorvastatin, Pravastatin, Rosuvastatin
- 10 prevention of CVD (<84 years and with QRISK2 >10%)
- 20 prevention of CVD
- Offer in Type 1 diabetes, CKD, Primary hyperlipidaemia – in primary/familial hypercholesterolaemia, mixed dyslipidaemia
Mechanism of statins?
- Reduce serum cholesterol levels
- Inhibit hydroxy-3-methyl-glutaryl coenzyme A (HMG-CoA) reductase
- Decrease cholesterol production by liver and increase LDL clearance from blood
- Reduce triglycerides and slightly increase HDL levels
Side effects of statins?
- Muscle aches (myopathy/rhabdomyolysis)
- Headache and GI disturbances
- Rise in ALT/CK
- Drug-induced hepatitis
Contraindications of statins?
- Porphyria
- Pregnant or breastfeeding women – adequate contraception during treatment and for 1 month afterwards
Caution of statins?
- Elderly
- High alcohol intake
- Hepatic impairment – avoid in active or persistent elevated serum transaminases
- Dose reduction starting at 20mg in renal impairment (excreted)
Interactions of statins?
Metabolism reduced by CYP450 inhibitors – higher levels and risk of SE
- May have to withhold statin for period
- E.g. amiodarone, diltiazem, itraconazole, macrolides
- Avoid grapefruit juice
Maximum 10mg dose if using ciclosporin
Prescription info of statins?
- If myalgia – check CK
- Oral OD
- Atorvastatin - 20mg (primary prevention), 80mg (secondary prevention)
- Taken in evening, after meal at same time per day
- Avoid grapefruit juice (atorvastatin, simvastatin)
Monitoring of statins?
o Baseline – Lipids profile, CK, LFTs, U&Es, HbA1c, TFTs
o CK – before treatment only measured if muscle aches – if >5x upper limit, repeat in 7 days and if >5x then do not start
o 3 months - Lipids screen (aim >40% reduction in non-HDLs), LFTs at 3 months and 12 months (if serum transaminases >3x upper limit then stop), HbA1c
o 12 months - LFTs
o Review annually
o Efficacy should be monitored in 20 prevention – specific target of total cholesterol <4mmol/L or LDL cholesterol <2mmol/L
Indications of digoxin?
- AF and Atrial flutter (usually after BB, CBB) – sedentary patients
- HF
Mechanism of digoxin?
- Negatively chronotropic (reduced HR)
- Positively ionotropic (increases force of contraction)
- Increases vagal tone
- Inhibits Na/K/ATPase pump, elevation of Na in cells causes Ca to accumulate (cannot be extruded by NaCa exchanger) in cell – increasing contraction
Side effects of digoxin?
- Bradycardia
- GI upset
- Rash
- Dizziness
- Blurred vision
- Low therapeutic index so safety is paramount
Contraindications of digoxin?
- Intermittent complete heart block
- 2nd degree heart block
- SV arrhythmias (WPW)
- Constrictive pericarditis
- Hypertrophic Cardiomyopathy
- Myocarditis
- WPW syndrome
- VT/VF
Dose change in renal failure of digoxin??
- Dose reduction in renal failure (eliminated by kidneys) – monitor plasma-digoxin concentration
Interactions of digoxin?
- Hypokalaemia
o Loop and thiazide diuretics increase risk of toxicity - Increase plasma concentration of digoxin
o Amiodarone, CCB, spironolactone, quinine – reduce dose by half
Prescription of digoxin?
- Oral administration common – effect seen after 2 hours
- Loading dose needed if rapid effect
- IV given slowly
Monitoring of digoxin?
o Plasma digoxin concentration 6 hours after dose if toxicity suspected o ECG (ST segment depression – reverse tick - normal) o Electrolytes and U&Es
Indications of amiodarone?
- Tachyarrhythmias (AF, AF, SVT, VT, VF) – when electrical CV not used
- CPR algorithm
Mechanism of amiodarone?
- Blockage of Na, Ca and K channels
- Antagonises of alpha and beta-adrenergic receptors
- Effects
o Reduce spontaneous depolarisation, conduction velocity
o Increases refractoriness, including AV node
Side effects of amiodarone?
- Hypotension if IV
- Pneumonitis
- Bradycardia, AV block
- Hepatitis
- Photosensitivity and grey discolouration
- Thyroid problems
Contraindications of amiodarone?
- Severe conduction disturbances
- Iodine sensitivity
- Heart block
- Active thyroid disease
Interactions of amiodarone?
- Lots of interactions
- Increases plasma concentration of digoxin, diltiazem and verapamil – risk of bradycardia and AV block
- Long half-life – takes weeks to be eliminated
Prescription of amiodarone?
o Senior involvement needed
o Usually needs loading dose and then maintenance dose so CHECK
o In cardiac arrest, given after third shock in ALS (300mg IV, followed by 20mL of 0.9% NaCl as a flush)
o If continuous IV needed – central line (can cause phlebitis)
Communication of amiodarone?
o Advise the patient not to drink grapefruit juice, as this can increase the risk of side effects
o Avoid exposure of their skin to direct sunlight due to the risk of photosensitivity
Monitoring of amiodarone?
o LFTs, TFTs done before and every 6 months
o U&Es done before treatment
o CXR
o IV – continuous ECG monitoring
Definition of creams?
Emulsions of oil and water and well absorbed into skin
May also contain an antimicrobial preservative
Less greasy and easier to apply than ointments
Definition of gels?
Active ingredients in suitable hydrophilic or hydrophobic bases
High water content
Face and scalp suitable
Definition of lotions?
Cooling effect and preferred over hairy areas
Can sting broken skin
Definition of ointment?
Greasy preparations, more occlusive than creams
Suitable for dry, chronic lesions
Commonly used is soft paraffin or combination with hard paraffin
Definition of pastes?
Stiff preparations containing high proportion of finely powdered solids such as zinc oxide
Quantity to prescribe for face?
Usually for an adult for BDS application for 1 week
- Creams and ointments – 15-30g
* Lotions – 100ml
Quantity to prescribe for both hands?
Usually for an adult for BDS application for 1 week
- Creams and ointments – 25-50g
* Lotions – 200ml
Quantity to prescribe for scalp?
Usually for an adult for BDS application for 1 week
- Cream and ointments – 50-100g
* Lotions – 200ml
Quantity to prescribe for both arms or legs?
Usually for an adult for BDS application for 1 week
- Creams and ointments – 100-200g
* Lotions 200ml
Quantity to prescribe for trunk?
Usually for an adult for BDS application for 1 week
- Creams and ointments – 400g
* Lotions – 500ml
Quantity to prescribe for groin/genitalia?
Usually for an adult for BDS application for 1 week
- Creams and ointments – 15-25g
* Lotions – 100ml
Names of emollients?
Aqueous cream, liquid paraffin
Examples - E45, Aveeno (colloidal oatmeal)
Indications of emollients?
- Topical treatment for all dry or scaling skin disorders
- Used alone or in combination with topical corticosteroids in the treatment of eczema
Mechanism of emollients?
- Emollients replace water content in dry skin
- Contain oils or paraffin-based products that soften skin and reduce water loss by protecting against evaporation
- Many preparations used as soap substitute (as soap is drying to the skin) and also bath or shower emollients
Side effects of emollients?
- Greasy on skin but this is part of therapeutic effect
- Exacerbate acne and folliculitis by blocking pores and hair follicles
Interactions of emollients?
- Space out topical emollients – usually apply emollient 15 minutes before application of steroid cream
Contraindications of emollients?
- Fire hazard when oil content high
Properties of emollients?
o Emulsions of oil and water to make creams, lotions and ointments o Lotions (less oil, more water) and creams (50% oil and water) spread further o Ointments (80% oil, 20% water) are more occlusive and potent
Directions of emollients?
o Applied BDS/TDS in active disease
o Give sufficient supply for frequent use – 500g
o Continue after improvement to prevent recurrence
o Apply emollients in the direction of hair growth
o If using other topical agents, apply 15 minutes after emollient
Names of oral antihistamines?
Chlorphenamine (Piriton), Cetirizine, loratadine, fexofenadine
Indications of oral antihistamines?
- Symptomatic relief of allergy (hay fever, pruritus, urticaria, food allergy, drug reactions, itch)
- Anaphylaxis emergency treatment
- Relief of itch in chickenpox
Mechanism of oral antihistamines?
- Antagonism of H1 receptor, blocking effects of excess histamine
- Histamine is released by mast cells as a result of IgE binding
o Induces: wheals, flares, itch
o In hay fever – nasal irritation, sneezing, rhinorrhoea, congestion, itch
o Widespread histamine release – vasodilatation, vascular leakage and hypotension
Side effects of oral antihistamines?
- 1st gen (chlorphenamine) – sedation
- 2nd gen (loratadine, cetirizine, fexofenadine) – do not cross blood brain barrier
- General SE
o Concentration impaired, dry mouth, fatigue, vision blurred
Dose reduction of oral antihistamines?
o Avoid cetirizine if eGFR <10
o Half dose in eGFR 30-50
Prescription of oral antihistamines?
o Cetirizine – 10mg tablets OD
o Loratadine – 10mg tablets OD
o Chlorphenamine – 4mg tablets and 2mg/5ml solution every 4-6 hours
o In anaphylaxis – chlorphenamine IV/IM 10mg
o Fexofenadine – 120mg OD
Patient information for oral antihistamines?
o Chlorphenamine may make you sleepy and avoid with alcohol which can increase sedation
Names of topical glucocorticoids?
Mild – Hydrocortisone 0.5-2.5%
Moderate – Eumovate (Clobetasone butyrate 0.05%)
Potent – Betnovate (betamethasone valerate 0.1%)
Very Potent – Dermovate (Clobetasol propionate 0.05%)
Indications of topical glucocorticoids?
- Inflammatory skin conditions, e.g. eczema, psoriasis where emollients are ineffective
Mechanism of topical glucocorticoids?
- Upregulate anti-inflammatory genes and downregulate pro-inflammatory genes (e.g. cytokines, tumour necrosis factor alpha)
- Suppression of circulating monocytes and eosinophils
- Increased gluconeogenesis from increased circulating amino and fatty acids, released by catabolism of muscle and fat
- Mineralocorticoid effects, stimulating Na+ and water retention and K+ excretion in the renal tubule
- Because topical, effects limited to site – need prolonged use of potent topical steroids for systemic effects
Side effects of topical glucocorticoids?
- Skin thinning
- Telangiectasia
- Skin depigmentation
- Contact dermatitis
- When used on face:
o Perioral dermatitis
o Exacerbate acne
Contraindications of topical glucocorticoids?
- Contra-indications o Infection present o Perioral dermatitis - Avoid potent on face and course should be short - Keep away from eyes
Prescription of topical glucocorticoids?
- Use as mild as possible for as short a time
- < 2 weeks (1 week for facial lesions)
- Prescription
o Name, strength, formulation, amount
Application of topical glucocorticoids?
o One fingertip unit can be spread across two adult palms
o BDS applied thinly on affected area
o Wash hands after application
o 5 minutes between different preparations applied to same skin