*Beta blockers are drugs which act against the beta adrenergic receptors. There are three kinds of adrenergic receptors namely beta1, beta2 and beta3.
*First generation beta blockers (non-selective beta blockers) :
*Second generatin beta blockers ( Beta1 selective beta blockers = Cardioselective beta blockers ):
- Nebivolol (most cardioselective beta blocker)
*Third generation beta blockers ( These are beta blockers which have additional vasodilator property ):
- Labetalol and Carvedilol ( act as vasodilators by antagonising alpha1 receptors on blood vessels)
- Tilosolol ( act as vasodilator by opening up potassium channels)
- Nebivolol and Nipradilol ( generate Nitric oxide )
- Bevantolol, Betaxolol, Carvedilol ( inhibit calcium channels )
- Bopindolol, Carteolol, Celiprolol ( agonists of beta2 receptors )
* Beta blockers with Membrane stabilising activity (local anaesthetic activity) :
- Propranolol (most effective)
* Beta blockers with intrinsic sympathomimetic activity :
* Beta blockers which are lipid insoluble ( so they are excreted by kidney and hence contraindicated in renal failure - LONG ACTING AGENTS ) :
* Longest acting beta blocker is Nadolol
* Shortest acting beta blocker is esmolol.