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While propranolol does not directly treat anxiety, it can help to ease many of the symtoms associated with anxiety. When anxiety is increased, it causes an increase in the amount of adrenaline and similar compounds released in the body, both as part of the involuntary nervous system and in the blood stream. The propranolol blocks the action of adrenaline by blocking beta-receptors, so can help prevent some of the symptoms associated with anxiety.
Different people have different symptoms with anxiety, so the propranolol may work to varying extent in different people. But if it helps to ease symptoms, it would be appropriate to continue the propranolol.
It is true that this is not one of the approved indications for the use of propranolol, but there have been many studies supporting the use for this indication and it has been used for this for many years.
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