Bevantolol is a beta blocker and calcium channel blocker. It is an oral drug used for the treatment of angina pectoris and hypertension. It targets the myocytes in heart where it acts mainly as a beta-1 adrenergic receptor antagonist, but also an L-type calcium channel blocker. It exerts it’s effects by inhibiting beta-1 adrenergic receptors, which is coupled to the G-protein signaling cascade. Inhibition of this receptor prevents activation of the signaling cascade which activates protein kinase. Protein kinase is required to activate calcium channels in the cell membrane, causing them to open and allow Ca2+ to enter the cell. Ca2+ activates the ryanodine receptor on the sarcoplasmic reticulum, which transports Ca2+ from the sarcoplasmic reticulum into the cytosol. Ca2+ in the cytosol binds to troponin to cause muscle contraction. Since protein kinase activation does not occur, there is a low concentration of Ca2+ in the cell. The low concentration of Ca2+ means that less Ca2+ binds to troponin, reducing inotropy/muscle contraction. In cardiac pacemaker cells a decrease in intracellular Ca2+ decreases the slope of phase 4 of the action potential. The time taken to reach threshold is longer, therefore, the heart rate is decreased. Due to the decreased force of contraction and heart rate, the blood pumped of the heart exerts less force on the blood vessels, thus the blood pressure decreases. This is also effective for treating angina because lowering the heart rate and force of contraction reduces the oxygen demand and how hard the heart has to work. Possible side effects from taking bevantolol include fatigue, headache, dizziness, edema and gastrointestinal upset.

Bevantolol Beta Blocker Cardiac Pathway References