5 Clinical Pearls on Alpha Blockers

Alpha blockers are indicated for both hypertension and BPH.  Here’s a few clinical pearls on alpha blockers that you need to know!

  1. Alpha blockers in females:  I remember a urologist getting frustrated with pharmacists who would always question why he was using Flomax (tamsulosin) in female patients.  You will see alpha blockers used off label in females with bladder outlet obstruction/ureteral stones.
  2. Dosed at night: Why?  Because of the risk of first dose syncope, it is recommended that these medications are dosed at night, right before bed.
  3. Tamsulosin 0.8 mg daily dose.  Patient adherence is one of the greatest challenges facing the healthcare system in relation to medications.  I’ve seen this dose restarted a couple times when the patient had not been taking it for a while.  If patients are on tamsulosin 0.8 mg daily, and therapy gets interrupted for several days, it is recommended to start over at the lower dose (per Lexicomp).
  4. Alpha blockers drop blood pressure (duh…used for hypertension).  What this leads to clinically, and especially in the elderly is the risk for falls.  The highest risk time for orthostatic hypotension is when the medication is first started or increased.  Another situation to keep a close eye on is when another antihypertensive is added.
  5. Alpha blockers work quickly: In a patient with worsening retention due to BPH, alpha blockers provide relief quickly compared to the 5 alpha reductase inhibitors (finasteride, dutasteride) which can take up to months to start providing relief.

Enjoy the blog? Be sure to get more pearls for free! 30 medication mistakes is a free 6 page PDF I created based upon my practice as a clinical pharmacist!


  1. Grant C

    As a LTC consult I will occasionally see patients taking the combination of peripheral alpha blocker (terazosin, doxazosin, prazosin) with Flomax. Usually physicians will agree to stop one but not always. They do have different receptor affinities (why Flomax is not for hypertension) so maybe a benefit to the combo? Definitely something to flag in my opinion.

    • Eric Christianson

      Definitely something I like to try to tackle…depending upon a bunch of different factors, can possibly reduce other BP meds (if necessary) and increase non-selective alpha blocker and DC flomax if concerned about retention risk when flomax trial DC’d – hopefully that makes sense 🙂

  2. Ernest I

    Also just want to add if you don’t mind to the list: (please correct me if I’m wrong)
    1) “New” alpha blockers (flomax, uroxatral, rapaflo) are more selective to prostate and have less side effect than the “old” ones (prazosin, terazosin, doxazosin) but work the same when it comes to HTN.
    2) 5-Alpha reductase inhibitors shrink the prostate but takes about 6 months to work while alpha blockers don’t shrink the prostate thus if patients prostate really big > 40 cc they are placed on both drugs but you can stop alpha blocker after 6 months when 5-alpha reductase inhibitor kicks in.

    Thank you for the posts Eric! Please continue doing so.

  3. Bonnie Hammond

    I’ve seen Prazosin for post traumatic nightmares. What do you think the fall risk is for Tamulosin is in a frail elder?

  4. Ernest I

    Hey Eric!
    Thanks again for the posts! very useful. Can you post Clinical Pearls on Statins? from your clinical experience. And it would be GREAT if you can do the same for other classes of drug as part of you blog, just a thought and something I would really love to see. Will greatly appreciate it.

    • Eric Christianson

      Thanks for the comment Ernest! Will keep writing and creating! 🙂


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Written By Eric Christianson

November 11, 2015

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