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29 Cards in this Set
- Front
- Back
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Beta blockers
- Drugs in class by (a) B1 selective (b) non-selective (c) non-selective AND partial agonists (d) B1, B2 and alpha blockers |
(a) atenolol, metoprolol, bisoprolol
(b) propranolol, SOTALOL (c) pindolol, oxprenolol (d) carvedilol, labetalol |
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Beta blockers
- MOA |
Competetive antagonists at
- heart and vasculature (reduce cardiac output without reflex increase in peripheral vascular resistence) - brain and kidney (may contribute to hypotensive effect; reduce renin) - lungs (commonly causes bronchospasm and dyspnoea) Antianginal (reduces cardiac HR and stroke volume) Antiarhythmic: antisympathetic effect. Sotalol also prolongs action potentials Carvedilol and labetalol provide extra arteriolar dilation |
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Beta blockers
- Indications |
HTN
Angina HF MI Arrhythmias Glaucoma (topical) |
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Beta blockers
- CI? (2) - May worsen which conditions? (at least 6) |
CI in reversible airway disease (i.e. asthma)
CI in cardiogenic shock, bradycardia (<45-50bpm), heart block, severe hypotension, uncontrolled HF Caution when - may worsen PVD, Raynaud's disease, vasospastic angina, and with drugs reducing HR such as verapamil - diabetes (mask signs and increase severity of hypoglycaemia; B1 selective drugs have been shown to be safe in T2DM) - Hx of anaphylaxis (reduced response to adrenalin) - Hyperthyroidism (masks clinical signs; sometimes used for this effect) - Myasthenia gravis: may worsen - Phaeochromocytoma: may worsen HTN; use alpha blockers first |
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Beta blockers
- in LF - in RF - in Preg/BF - in surgery |
- use drugs with predominantly renal elimination (atenolol)
- use drugs with predominantly hepatic elimination (N.B. bisoprolol and oxprenolol have both renal and hepatic clearance) - Cat C: may cause bradycardia in the fetus and newborn - Metoprolol, propranolol, and labetalol are preferred as they are more protein bound and less likely to be excreted in milk - Increased risk of bradycardia and hypotension; but weigh this carefully against the neccessity of withdrawing the drugs, especially in IHD (controversial) |
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Adverse effects
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Common:
- fatigue, decreased concentration - insomnia, nightmares, depression - alteration of glucose and lipid metabolism - bronchospasm, dyspnoea - cold extremeties, exacerbation of Reynaud's disese - hypotension (more with labetal/carvidol), bradycardia, heart block Infrequent: impotence, exacerbation of psoriasis |
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Which has more intrinsic sympathomimetic activity: oxprenolol or pindolol?
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Pindolol
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Which BB have once daily dosing and which 2+
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Once: atenolol, metoprolol (if CR, otherwise bd), bisoprolol, carvedilol
Two: IR metoprolol, labetalol Two-Three: Oxprenolol, pindolol, propranolol |
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Which BB reduce mortality in HF?
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Bisoprolol
Carvedilol CR metopolol |
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What indications do esmolol and sotalol have
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Arythmia only
Esmolol has a short duration of action and is used IV AF and hypertension perioperatively |
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Which BB are used in open angle glaucoma?
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Timolol
Levobunolol Betaxolol |
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Use of pindolol and oxprenolol?
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May cause less bradycardia and less coldness of extremeties
Do NOT benefit patients after a MI and may be less effective for angina and tachyarrhythmias |
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Which BB are NOT lipid soluble; and what is the clinical relevance of this?
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Atenolol and bisoprolol.
Carvedilol and propranolol are MORE lipid soluble Lipid solubility -->CNS --> insomnia, nightmares |
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BBs
Counselling points |
1. Do not stop suddenly, unless your doctor tells you to.
2. May cause dizziness or tierdness, especially at the start of treatment or when doses are increased. Avoid machinery and driving 3. Take care to avoid "explosive sports", especially initially. May cause dyspnoea, fatigue |
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Withdrawal of BBs?
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Abrupt withdrawal can precipitate angina, MI, arythmia and hypertension.
Reduce over 2 weeks. If taken for "many years", reduce over 4-6 weeks. If taken for HF, halve the dose each week. |
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Other random indications for some BBs?
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Migraine prophylaxis
- atenolol - propranolol - metoprolol Control of anxiety and essential tremor: propranolol Control of hyperthyroid symptoms: propranolol, pindolol Phaeochromocytoma: propranolol with an alpha blocker |
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Atenolol
- dose forms, brands - doses |
50mg.30 tab (Tenormin, Noten, Tensig, Atehexal, Anselol)
25-100mg d * reduce dose in RI |
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Bisoprolol
- dose forms, brands - PBS listing, primary use - doses |
1.25, 2.5, 5, 10mg x28 tab (Bicor)
PBS-A for mod-severe HF patients who are "stabilised" Start: 1.25mg for 7/7--> 2.5mg 7/7 --> 3.75mg 7/7 --> 5mg 4/52 --> 7.5mg 4/52 --> 10g d (Increase doses only when previous dose tolerated) |
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Bisoprolol
- before starting, do what? - how do you manage "intolerance"? |
Patients should be stabilised. Sitting systolic BP should be >85mmHg, no peripheral oedema, no recent cardiac surgery, VA, unstable angina
If HR <55bpm: reduce dose If hypotension: reduce diuretics first If transient worsening of HF: increase diuretics, temporarily withhold bisoprolol prn |
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Carvedilol
- dose forms, brands - PBS - doses |
3.125x30, 6.25x60, 12.5x60, 25mgx60 tab (Dilatrend, Kredex, Dilasig)
*PBS-A for mod-severe HF which is "stabilised" HTN: 12.5mg d for 2/7, then 25mg d (max 50mg d) HF: 3.125mg bd--> 6.25 --> 12.5 bd (Go to 25mg bd if >85kg, not severe HF, and tolerated) |
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Carvedilol
- interval for dose increase - other considerations for initiation in HF |
- 2 weeks, even in HTN
- as for bisoprolol: start when stable, increase slowly, reduce dose if low HR. Avoid reducing dose if transient worsening of HF (use diuretics), and reduce other drugs first for low BP |
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Labetalol
- dose forms, brands - PBS - doses |
100mg.100, 200mg.100 (Trandate, Presolol)
General PBS item For hypertension Start on 100mg bd, maintenance 200-400mg bd |
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Metoprolol
- dose forms, brands - PBS |
- 50mg, 100mg.100 tab (Lopresor, Betaloc, Minax, Metohexal)
- 1mg/mL.5mL (Betaloc) - 23.75x15, 47.5x30, 95x30, 190mgx30 CR tab (Toprol-XL) - Toprol-XL titration pack **Toprol-XL is a PBS-A item for mod-severe stable HF |
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Metoprolol (Minax, Toprol-XL)
- dosing |
HTN: 50-100mg d-bd (bd for MI, bd-tds for angina and tachycardia)
MI: 25-50mg qid for first 48hr Migraine: 50-75mg bd HF: 0.5-1x 23.75mg tab d--> increase at 2 weekly intervals Do all the things on initiation as with bisoprolol and carvedilol |
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Can you halve Toprol-XL
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yes
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Oxprenolol
- dose forms, brands - PBS - dosing |
20mg.100, 40mg.100 tab Corbeton
General PBS benefit HTN: 80-160mg bd (start on 40-80mg) Angina & tachyarrythmias: there are doses but prefer to use other beta blockers |
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Pindolol
- dose forms, brands - PBS - dosing |
5mg.100, 15mg.50 (Barbloc, Visken)
General PBS benefit HTN: 10-30mg d in 2-3 doses Angina & Tachyarrhythmias: There are doses but preferred to use other beta blockers |
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Propranolol
- dose forms, brands - dosing |
10mgx100, 40mgx100, 160mgx50(Inderal, Deralin)
1. 40-80mg (c) bd for migraine prevention (a) tds for HTN/tremor/angina (b) 40mg qid for MI --> 80mg bd after 2/52 Tachyarrhythmia: 10-40mg tds-qid Inoperable phaeochromocytoma: 10mg tds |
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Beta blockers
- DIs (a) all (7) (b) metoprolol (c) propranolol (d) hepatically cleared BBs |
1. Hypotension, NSAIDs
2. Mask hypoglycaemia (B1 selectives ok) 3. Reduce heart contractility (avoid verapamil inc eye drops unless under specialist supervision) Specific drugs: pnemonic: BACE 4. Adrenalin less effective in anaphylaxis 5. Antagonise B2 agonists - a B1 selective drug may be appropriate; see a specialist 6. Clonidine - possibility of paradoxical hypertension; stop clonidine slowly over 7 days & after stopping BBs to reduce risk of withdrawal effects 7. Risk of peripheral ischaemia with ergot alkaloids 8. amiodarone increases metoprolol; while metoprolol can reduce lecarnidipine 9. propranolol and CPZ increase each other 10. rifampicin reduces all hepatically cleared BBs |
