Opioids This might be a stupid question but....

[poppyplanet]

Why do opiates cause constriction of the pupils? I tried researching this online, but couldn't find any relevant answers. Thanks in advance.

 

[sekio]

I thought it was decreased norepinephrine release due to the mu opioid-receptor's inhibitory effect.

 

[lorne667]

^^^Really??? The first time I do suboxone after going into dt's from full agonists, it always constricts my pupils noticeably, even if my tolerance is sky-high.

 

[sekio]

That would make sense, Suboxone still has activity at the MOR and if you are detoxing off full agonists then the receptoer will be understimulated anyway.

 

[ErgicMergic]

I've wondered this, too. Most drugs that increase dopamine (adderall, LSD, meth, ephedrine) make your pupils into giant saucers. Opiates release a lot of dopamine, but the opiate activity must overpower the pupil dilation, making them pinned.

 

[DariaAnne]

if i remember correctly, isn't it just as simple as the blood vessels relaxing???? or something like that

 

[Pegasus]

It's complex. Here's a bit of discussion on it if you want to read a bit about it...

http://books.google.com/books?id=yb...e&q="the pupillary effect of opioids"&f=false