Prazosin side effect

[Purple-Bike]

I use Prazosin for possible anti-PCa effects.

Alas, all is not gold that glitters. Prazosin is prescribed for LUTS and high blood pressure, with an effect that tends to lower diastolic more than systolic ( upper number) blood pressure. In my own case it can lower diastolic to below 60, which tends to be bad for heart health in particular if systolic is above 120 i.e. a pulse pressure (difference between systolic and diastolic) of more than 60.

ncbi.nlm.nih.gov/pmc/articl...

sciencedirect.com/science/a...

As noted in the latter, the average age in the study (the first link) was 57 years."One might anticipate that in an older population, the side effects from lower BPs due to drug therapy..... would be greater, and the potential for adverse cardiovascular events due to a J-curve would be substantially increased compared with what was seen in the present study".

Being on the boundary of 120/60, I am having to fine-tune my doseage, and it is barely at the lower end of the dosage in the retrospective study indicating dramatic positive anti-PCa effects for Prazosin with just 1-2 mg daily. nature.com/articles/s41598-...

Eventually I should have a test for high-sensitivity cardiac troponin-T [hs-cTnT]) to see if something is going on.

[Seasid]

I believe if you drive down more your diastolic pressure you could get a stroke. I don't really know but it came to my mind.

[Purple-Bike in reply to Seasid]

Actually stroke incidence was not increased with lower diastolic pressure, according to the study. But other CVD events increased.

[Seasid in reply to Purple-Bike]

I believe that I read somewhere if you drive down the diastolic pressure you are increasing the stroke risk. Are you dehydrated?

[Purple-Bike in reply to Seasid]

I´m not sure about dehydration I don´t drink much water, mainly get my water from a lot of veggies plus some berries and fruits around 1.5 litres hopefully it´s enough.

Don´t know about stroke risk from diastolic pressure more than what that study said: that the increased CVD events from diastolic less than 60 did not include higher stroke risk. Actually the risks - higher hazard ratio - start increasing already when diastolic gets below 70... I disregard that or I could not be taking Prazosin at all.....which is not a good option since I believe Prazosin just might be a game changer.

Things ain´t easy with these complicated trade-offs!

[Seasid in reply to Purple-Bike]

Under 60 is too low. Better if you talk to your doctor. I would not push it too low. You could fall and that could be dangerous for you. I am not a doctor but the limit should be 60 all the time.

People with low blood pressure can fall. If you brake your hip you have about 30% chance to die from complications. Better to be safe than sorry.

[Seasid in reply to Seasid]

You are right under 70 you should not go. 60 is way to low.

[Purple-Bike in reply to Seasid]

I agree it´s important not to go below 60. I will let it go down to 60, or I would have to quit Prazosin. Cancer vs heart. Will monitor high-sensitivity cardiac troponin-T [hs-cTnT]) and if it shows any danger I may reconsider Prazosin.

[Seasid in reply to Purple-Bike]

I believe you could crank up your blood pressure easily. When I am well hydrated (drink lot of fluid) and as a result my blood volume goes up, than my blood pressure also goes up.

I believe that instead of quitting your anticancer drug you should just crank up your blood volume by drinking water and eating soups etc.

Do it slowly, change your habits slowly and you can rest assured that your blood pressure will go to the normal range.

I believe you are dehydrated. Experiment but change slowly. Talk to your doctor as I am not a doctor just realised that when I drink lots of water and eat salty food I have a problem with the high blood pressure what no amount of your medication would push it to under 60 diastolic pressure.

My situation is even more complex than yours as I have a CPAP machine and a CPAP is contraindicated when a blood pressure is low as the air is pressing the major vessels and the heart during the whole night resulting in an even lower blood pressure.

Therefore drink more fluid and salt can crank up any low blood pressure. Be careful what you are doing.

[Purple-Bike in reply to Seasid]

Thanks a lot Seasid, I appreciate this advice. I recall a nurse once saying I was dehydrated it could well be so. I get 1,5 liters from my only meal in the evening and drink almost nothing in between. Now mid-day I gulped down three glasses of water. If you think there is any merit to introducing my new habit gradually rather than in one go please let me know. I think I will start with water rather than salt and hope diastolic is upped more than systolic.

I understand that with a CPAP machine you have all the reason to kow this issue well.....

[Seasid in reply to Purple-Bike]

Every change should be introduced gradually to avoid overshoot of the system. I may be wrong, but it is definitely safer for you.

What is your glomerular filtration rate? If you are dehydrated it is usually lower than when you are well hydrated. I hope that you don't have any aneurysm of your aorta etc. In this case it is better to have a normal blood pressure rather than a higher one.

Most important is that you stay safe. I wish you luck and try to visit a doctors regularly if you can I myself have enough of them but unfortunately we have to visit a medical system if we want to achieve something. The doctors could order all that blood test etc. Hope you find someone who is communicative and caring.

[Purple-Bike in reply to Seasid]

My GFR has held steady 70-72 over the last year, ref range over 60. Will gradually ease into a water regimen, monitor BP, fine-tune my Prazosin even if it means just 0.6 mg a day. Thanks again!

[Scout4answers]

Interesting find

[Purple-Bike]

If I recall correctly your systolic is way below 120 so these findings should not be of concern to you

[Gearhead]

Yes, interesting. My average D is a little more than 60, but my S has been running high lately*, so my average delta is well over 60. Does this mean that if the high S is a given, it would be better if my D was higher?

* I've been working on the high S. I think this is due mainly to abiraterone, and I don't want to discontinue that. Have brought S down somewhat with increased prednisone, and more recently with prednisone + eplerenone. Plus, I've been taking benazepril & amlodipine besylate for many years.

[Purple-Bike in reply to Gearhead]

Right, with a given S, it is better to have a higher D, if the delta/pulse pressure is approaching 60, at least when the numbers are in the 120+/and 60- range. From the text above Table 4 in the study:

After stratifying the study sample by SBP categories, both myocardial damage and clinical event outcomes varied according to baseline DBP levels (Table 4). The association of low DBP (specifically DBP 60 mm Hg). These results were consistent in a number of sensitivity analyses, demonstrating that: 1) low DBP, modeled continuously, is a risk factor for elevated hs-cTnT and incident CHD (particularly after adjusting for SBP) (Online Figure 1); 2) despite the adverse associations with low DBP, high SBP is also a risk factor for elevated hs-cTnT and incident CHD (Online Figure 2); 3) as such, pulse pressure >60 mm Hg appears to be an important driver of these results (Online Figure 3); and 4) consistent with this, the association of low DBP with hs-cTnT and incident CHD is most evident among those with an SBP ≥120 mm Hg (Online Figure 4).

Do you know if any of the other three BP meds you are taking by any chance mainly lower S and hardly lower D?

Eplerenone, sold under the brand name Inspra, is an aldosterone antagonist type of potassium-sparing diuretic that is used to treat chronic heart failure and high blood pressure, particularly for patients with resistant hypertension due to elevated aldosterone.

Benazepril, sold under the brand name Lotensin among others, is a medication used to treat high blood pressure, heart failure, and diabetic kidney disease. It is a reasonable initial treatment for high blood pressure.

Amlodipine is used with or without other medications to treat high blood pressure. Amlodipine belongs to a class of drugs known as calcium channel blockers. It works by relaxing blood vessels so blood can flow more easily.