Inderetic combines two medicines that have different ways of working (modes of action) and leads to a greater lowering of blood pressure in more people than with either medicine used alone:

• Propranolol (see Inderal) belongs to a group of medicines called beta-blockers.
  
  
  • It works by blocking the action of a chemical called noradrenaline that is released from nerves in the heart, which control its rate.
    
    
  • It also blocks another chemical called adrenaline, which is a hormone (chemical signal carried in the blood) that has similar effects to noradrenaline.
    
    
  • Propranolol stops these chemicals from attaching (binding) to sites called beta-receptors in the heart, so they can’t produce their effects.
    
    
  • Propranolol has effects on many parts of the body, including the heart and circulation.
    
    
  • It also reduces the heart rate and the force of heart muscle contraction and thereby lowers blood pressure.
    
    
• Bendrofluazide is a medicine called a diuretic:
  
  
  • It works by stopping the re-absorption of sodium (salt) and water from the kidneys back into the bloodstream.
    
    
  • This results in increased urine output (diuresis) and increased sodium loss in the urine. These effects lower the blood pressure.