Posted by ed_uk on October 30, 2005, at 10:11:11
In reply to Re: Beta blockers for anxiety -- interactions with WB?, posted by SLS on October 29, 2005, at 18:28:28
Hi Scott,
>I don't really know, but doesn't a beta-blocker have to cross the blood-brain barrier to have the desired anti-anxiety effect?
No. Beta blockers are not anti-anxiety as such. They can be effective in relieving *some* of the peripheral manifestations of anxiety - which can in turn reduce psychological distress. Cardioselective beta blockers (eg. atenolol, metoprolol) are only effective in relieving cardiac symptoms..... tachycardia, chest discomfort, palpitations etc. Cardioselective beta blockers do not relieve tremor. Non-cardioselective beta blockers eg. nadolol can relieve tremor as well as cardiac symptoms. Beta blockers do not relieve muscle tension, there is no evidence that they decrease sweating. In fact, tremor and cardiac symptoms are usually the only symptoms which are relieved. My experience of beta blockers suggests that the large majority of peripheral symptoms of anxiety are not affected.
Propranolol (Inderal) crosses the blood brain barrier. Nadolol, an non-cardioselective beta blocker which does not cross the BBB might be equally effective with less side effects. Beta blockers which cross the BBB can cause sleep disturbances, most frequently nightmares.
The term 'cardioselective' implies that the drug is beta-1 selective eg. atenolol. Some 'cardioselective' beta blockers cross the BBB eg. metoprolol, bisoprolol, whereas others do not eg. atenolol.
'Non-cardioselective' implies that the drug acts as an antagonist at beta-1 *and* beta-2 receptors. Some 'non-cardioselective' beta blockers cross the BBB eg. propranolol, whereas others do not eg. nadolol.
Some beta-blockers are lipid soluble and some are water soluble. Atenolol, celiprolol, nadolol, and sotalol are the most water-soluble. Water soluable beta blocker cause less sleep disturbances and nightmares than other beta blockers....... because they penetrate the BBB only to a limited extent.
Water-soluble beta-blockers are excreted by the kidneys.... they accumulate in patients with renal impairment and dosage reduction is necessary.
Which beta blocker to choose????????????
Cardiac symptoms of anxiety: atenolol
Tremor due to anxiety: nadolol, propranolol
Tremor + cardiac symptoms of anxiety: nadolol, propranolol
Hypertension: atenolol, bisoprolol, metoprolol
Angina: atenolol, bisoprolol, metoprolol
Chronic stable heart failure: bisoprolol (in countries where low dose formulations are available), carvedilol
Relief of symptoms of thyrotoxicosis: propranolol
Intravenous use in patients suffering from acute myocardiac infarction or acute coronary syndrome: atenolol, metoprolol, esmolol
Situations in which a short-acting IV beta blocker is necessary: esmolol
Prophylaxis following myocardial infarction: metoprolol, bisoprolol, timolol, propranolol
Hypertensive crisis: labetalol
Hypertension in pregnancy: labetalol
Prophylaxis of recurrent migraine: propranolol
Topical treatment of gluacoma: timolol, betaxolol, carteolol, levobunolol, metipranolol
Situations in which a class III anti-arrhythmic is required: sotalol. Warning - sotalol is *only* indicated for the treatment and prophylaxis of serious cardiac arrhythmias
Patients with stable well-controlled asthma who require a beta blocker for the treatment of angina: bisoprolol, atenolol, metoprolol. All beta blockers are contra-indicated in severe or unstable asthma. Non-cardioselective beta blockers are always contra-indicated in asthma, even mild asthma.
Patients with asthma who require a beta blocker for the treatment of hypertension only: nebivolol
Diabetic patients who require a beta blocker: atenolol, bisoprolol, metoprolol.
Adjunct in the treatment of severe depression: pindolol
Patients who require a beta blocker with intrinsic sympathomimetic activity: oxprenolol, pindolol, acebutolol, celiprolol
~Ed
poster:ed_uk
thread:569702
URL: http://www.dr-bob.org/babble/20051024/msgs/573341.html