POST TRAUMATIC STRESS DISORDER AND PROPRANOLOL
Propranolol is an antihypertensive medication [lowers blood pressure] that works by blocking beta adrenergic receptors in the body and brain. A number of years ago I learned that propranolol can be used to treat performance anxiety such as public speaking fears. It could successfully reduce the anxiety that would be triggered in some people by having to speak in public. Their anxiety could be crippling and even prevent them from speaking at all. This anxiety appeared to be related to a past stressful event that the person recalled when they had to speak in public. A single dose of propranolol could reduce this anxiety significantly so that the person could speak in front of people. I believe that the dose typically was 20 mg tablet but it varied. The reason that propranolol worked was thought to be that when it blocks beta-adrenergic receptors in the body it can lower heart rate and keep the person’s heart from racing when they are feeling anxious doing something like public speaking. It also can reduce the likelihood of the person sweating and having tense muscles. It was thought that all of the above changes reduced the physical symptoms that were associated with feeling anxious and overwhelmed and helped someone feel less anxious like with public speaking.
However, once I learned how propranolol works in the brain by blocking beta-adrenergic receptors that bind to epinephrine and norepinephrine that are directly linked to fight or flight stress responses. This will reduce the brains stress responses that are connected to certain memories. I believe that it was propranolol blocking beta-adrenergic receptors in the brain that reduced anxiety being connected to the memory of public speaking and then the person felt less stressed and anxious about speaking in public. After taking the propranolol, when a person starts anticipating having to speak in public and recalls past memories of how terrifying this was, the memory of it being terrifying is not as strong or not there at all. This made me wonder if propranolol could help people with post traumatic stress disorder [PTSD] not be as anxious when they recall memories from the past as these memories would be less connected to feeling anxious. This reduced anxiety connected to past events seems to be what helps people with PTSD that I have prescribed propranolol for.
For years it was recognized that propranolol can lower performance type anxiety such as public speaking. It was also recognized that propranolol can lower heart rate, reduce muscle tension and lower the breathing rate. All of these changes seemed to occur in the body as propranolol was blocking the the beta-adrenergic receptors and thus lowering heart rate, muscle tension and even breathing rate. Propranolol’s affect on the brain was not considered to be significant. As I was prescribing propranolol I noticed that my patients did not experience body changes like slowed heart rate or lower blood pressure and if they did they would experience lightheaded ness, nausea or tiredness as a consequence of having their blood pressure lowered too much as they were not having high blood pressure symptoms. This lightheadedness was associated with less or no benefit in reducing their anxiety and fear responses. I wondered if stopping the propranolol and restarting it 7-10 days later would allow the propranolol to have it’s affect in the brain and not in the body. For almost everyone doing this successfully stopped the lightheadedness and allowed me to prescribe the propranolol to lower the anxiety symptoms connected to past events. Also, not having side-effects to propranolol allowed me to recommend increasing doses if needed to lower or stop the anxiety my patients were experiencing. This was fortunate as the effective dose of propranolol varies a great deal and a few people require high doses and still did not having any side-effects. I have been able to help a lot of people to significantly lower their post traumatic stress disorder [PTSD] symptoms by prescribing propranolol.
