Other names: Beta-receptor blockers, beta-receptor blockers, β-blockers, beta-adrenoceptor antagonists
1. Function of beta blockers¶
Beta-blockers inhibit the activating effect of adrenaline and noradrenaline on the β-adrenoceptors. This reduces the stimulating effect of the sympathetic nervous system on the target organs, primarily the heart. On other organ systems, beta-blockers counteract the effects of adrenaline.
stimulating β1-adrenoceptors:
- Cardiac output (heart force and rate)
- Blood pressure
- Kidney: increased secretion of the blood pressure-increasing enzyme renin, which has a blood pressure-lowering effect.
β2-Adrenoceptors act on the smooth muscles of
- Bronchi
- Uterus
- Blood vessels.
Blockade has a contracting effect on the smooth muscle, which, among other things, increases the tone of the bronchial muscles, which can lead to their spasm. Therefore, bronchial asthma (unlike COPD) is a contraindication for β2-acting beta blockers.
2. Effect of different beta blockers¶
Beta-blockers have different β-adrenoceptor affinities.
| Active ingredient |
β1-blocker |
β2-blocker |
other effects |
| Acebutolol |
x |
|
ISA |
| Alprenolol |
x |
x |
ISA |
| Atenolol |
x |
|
|
| Betaxolol |
x |
|
|
| Bisoprolol |
x |
|
|
| Bupranolol |
x |
x |
|
| Butoxamine |
|
x |
|
| Carteolol |
x |
x |
Stimulation of NO release in endothelial cells, ISA |
| Carvedilol |
x |
x |
Blockade of α1-receptors |
| Celiprolol |
x |
|
ISA |
| Esmolol |
x |
|
very short acting |
| ICI-118,551 |
|
x |
|
| Labetalol |
x |
x |
Blockade of α1-receptors |
| Landiolol |
x |
|
very short acting |
| Metipranolol |
x |
x |
|
| Metoprolol |
x |
|
|
| Nadolol |
x |
x |
|
| Nebivolol |
x |
|
Stimulation of NO release in endothelial cells |
| Oxprenolol |
x |
x |
ISA |
| Penbutolol |
x |
x |
|
| Pindolol |
x |
x |
ISA |
| Practolol |
x |
|
ISA |
| Propranolol |
x |
x |
|
| Sotalol |
x |
x |
Class III antiarrhythmic agent |
| Talinolol |
x |
|
|
| Timolol |
x |
x |
|
|
|
|
|
|
|
|
|
ISA: intrinsic sympathomimetic activity, also partial agonistic activity (PAA). IdR undesirable.
Acebutolol and pindolol should be avoided due to decreased cardiac efficacy and increase in arterial vascular resistance.
CI-118,551 and butoxamine are currently used for research purposes only.
3. Beta blockers for ADHD¶
Beta blockers are not a common medication for ADHD.
However, one small study reported helpful comedication along with stimulants.
Another small study reported a responder rate of 85% with propanolol monotheraopia.
An open-label study of propranolol in ADHD adults with anger outbursts reported improvements at daily doses up to 640 mg ((Wilens and
Spencer, 1999, cited in Biederman J, Spencer T, Wilens (2004):. Evidence-based pharmacotherapy for attention-deficit hyperactivity disorder. Int J Neuropsychopharmacol. 2004 Mar;7(1):77-97. doi: 10.1017/S1461145703003973. PMID: 14733627.))
A double-blind, placebo-controlled trial compared 2 x 20 mg pindolol and 2 x 10 mg MPH daily in 52 children with ADHD. Pindolol showed paresthesias and more intense nightmares and hallucinations so much more often than MPH or placebo that the trial was terminated after 32 participants. Pindolol improved hyperactivity and behavior problems at home and hyperactivity at school as effectively as MPH. However, pindolol showed inferiority to MPH on psychological tests and in behavior problems at school. Overall, pindolol was moderately effective with respect to ADHD, with significant side effect risks. Pindolol should be avoided anyway due to decreased cardiac efficacy and increase in arterial vascular resistance.
A study of nadolol in 12 children with aggression and developmental delay found clinical improvements in 10 children, but these were not significant with respect to inattention/hyperactivity.
A Swedish cohort study found no association between beta-blockers and ADHD.
In our view, beta-blockers could be a useful adjunct to ADHD treatment in cases of comorbid aggressiveness or comorbid cardiac problems.
It should be noted that quite a few beta-blockers are metabolized via CYP2D6, as are amphetamine drugs. Therefore, taking them together may reduce the effect. However, as long as the dosing is done together under consideration of this effect, this should not be a problem.
