Propranolol

Propranolol (Inderal®) is a non-selective beta blocker drug that is used in treating restlessness and tremors. It was also often used in hypertension and heart disease, but nowadays selective beta blockers are preferred for these indications. Propranolol is the drug of choice in controlling some symptoms of hyperthyroidism (tachycardia, tremor), and it is used to lower portal pressure in portal hypertension when this has led to esophageal varices.

Propranolol, acting as a beta-blocker, has also been shown to have an effect on the formation of memories with strong emotional content. During very emotional or traumatic times, adrenaline and noradrenaline are released from the adrenal medulla which activate beta receptors in the brain. The effect is to give the associated memories more "force" due to the strong emotional content and subsequent beta-receptor activation. Propranolol blocks beta-receptor action, and thereby reduces or eliminated the emotional component of the memory. The effect is to make the memories more mundane, like trying to remember what you had for lunch three weeks ago, rather than emotionally vivid, like where you were when you heard that JFK was assassinated.

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