Can Ach cross BBB?

Discussion in 'Step I' started by path800, May 20, 2014.

  1. SDN is made possible through member donations, sponsorships, and our volunteers. Learn about SDN's nonprofit mission.
  1. path800

    path800

    6
    0
    May 15, 2014
    Met an UW q asking what cannot be relived after organophosphate poisoning pt treated with atropine. And the answer is N Ach R's effect. But I am wondering some CNS effect caused by M1 R, eg seizure, can be relived by atropine?

    Sorry the title is actually asking can atropine cross BBB?
     
  2. SDN Members don't see this ad. About the ads.
  3. Diggidy

    Diggidy 7+ Year Member

    1,165
    85
    Jan 20, 2009
    https://en.wikipedia.org/wiki/Atropine

    Look at its chemical structure -- do you think it can cross? I would tell you, but I think it's an important thing to understand for boards and beyond, what qualities of compounds allow or don't allow it to cross the BBB.
     
  4. path800

    path800

    6
    0
    May 15, 2014
    thank you
    forget to check the structure
     
  5. tantacles

    tantacles Lifetime Donor SDN Moderator 7+ Year Member

    7,440
    2,260
    Sep 28, 2009
    Physician
    How would it possibly have an effect on pupillary function if it couldn't cross?
     
    periaqueductal likes this.
  6. Diggidy

    Diggidy 7+ Year Member

    1,165
    85
    Jan 20, 2009
    If you're talking about an eye dilation at the ophthalmologist, that's because it's applied topically.
     
  7. tantacles

    tantacles Lifetime Donor SDN Moderator 7+ Year Member

    7,440
    2,260
    Sep 28, 2009
    Physician
    Nope, I'm talking about overdose. Overdose causes mydriasis.
     
  8. path800

    path800

    6
    0
    May 15, 2014
    I checked again. Seem atropine can cross BBB.
    I am not that chemical person but the atropine chemical structure contains a double bond (=O) which may change the polarity of the molecule.
     
  9. Ismet

    Ismet PGY-fun! SDN Administrator 5+ Year Member

    9,699
    9,224
    May 15, 2011
    Physician
    Yeah atropine can cross the BBB.
     
  10. tantacles

    tantacles Lifetime Donor SDN Moderator 7+ Year Member

    7,440
    2,260
    Sep 28, 2009
    Physician
    Or we can just chalk it up to the fact that it's small.

    Honestly, what specific hypothetical molecules will and won't cross the BBB is not within the scope of what we need to know. Generally, the ones that can are small and nonpolar. However, think about the side effects of drugs - if a drug has neuro side effects, that often means it's crossing.
     

Share This Page