What is the Cause of Frequent Urination on Certain Drugs?

[SpunkySkunk347]

I've always believed that frequent urination was caused by a drug's effect on constricting/dilating blood vessels,
but why do both amphetamine and alcohol cause frequent urination when amphetamine constricts blood vessels and alcohol dilates them?
The same contradiction exists with other drugs, like caffeine for instance (which I believe dilates blood vessels if I'm not mistaken)

I'm sure a more detailed physiological explanation exists, which is what I am looking for.

When I think about it and try to imagine in my mind what's going on in my body causing frequent urination, both vascular constriction and dilation make sense to me as contributing to frequent urination. With vascular constriction, I imagine my body "tightening up" and water being pushed out like a wet sponge being squeezed. With vascular dilation, I imagine my body inflating and soaking up as much moisture as it possibly can, but eventually getting so filled with water that the excess "spills out" in the form of urination.

Are both of these somewhat accurate ways of looking at it? Or is my intuitive knowledge of physiology not quite on cue?

Even if I'm not too far from the truth, it is still confusing and counter-intuitive that two opposing phenomenon (vascular constriction and vascular dilation) both have a shared effect (frequent urination).

Yet, there still would be unanswered questions: Why do opiates cause the body to retain water and cause urinary retention if they dilate blood vessels? Is the manner in which an opiate dilates blood vessels different from ethanol?

Any reply is appreciated! The rest of the post might be going a little bit off-topic, so just ignore the rest and don't feel discouraged from replying if you notice a wall of text below!

Trying to grasp the mechanics of blood vessel constriction/dilation has lead to more than a few bad amphetamine experiences for me; I wonder "what is causing my body to ache? Is it vascular constriction? Well then I should probably take a hot shower to open up my blood vessels... but wait, blood vessel dilation might dehydrate me! Oh dear." This has also resulted in me realizing that a portion of my drug-experiences is placebo -- because before I ever questioned matters such as vascular constriction, a hot bath while coming down on amphetamine felt almost euphoric - but after I began over-analyzing things (especially physiological and psychological matters), I spend my time in a hot bath worrying whether or not it is helping or worsening my situation, and afterward I don't feel at all better like I used to. Then again, there are too many variables involved to know what exactly is happening -- it could all be placebo, but then again it could be that a hot bath only helped me when I first started using amphetamine, but now my blood vessels are damaged from amphetamine use to an extent that a hot bath no longer helps. It could be that the anxiety I have while in the tub is causing adrenaline to be released, and therefore constricting my blood vessels even more. It could be that a hot bath is causing me to over-heat, etc.. There are just so many variables that confuse me, and a lot have to do with things that are individual to me and are difficult to find answers too (for example, when I first started using amphetamine regularly, I was prescribed 200mg of zoloft which I later discontinued a few months later - but this by itself presents so many questions including questions which relate to the metabolism of amphetamine since zoloft/sertraline inhibit one of the main enzymes metabolizing amphetamine, as well as whether or not sertraline played some roll in vascular constriction/dilation.

I've noticed I'm starting to stray a little off-topic, so I'll stop typing about it anymore unless I get any relevant replies

 

[Smokey McPot]

Speed speeds up metabolism making you process fluids quicker and dehydrated you so you tend to drink more and pee alot even if you don't drink more just barely pee anything because of it's stimulation of metabolism. Alcohol dehydrated you as you drink a lot hence the peeing more, I never really I've those little barely anything pees with alcohol unlike with amphetamines. Booze tends to make me take big long pees. They are also both diuretics I believe, as is coffee (as well as being stimulating)

I don't think this has anything to do with constricting or dilating blood vessels.

 

[JBrandon]

It's a lot more complex than vasoconstriction/dilation. You have to account for drug effects on osmotic balance as well. Where the salts go the water follows. It's multifactorial, I'm sure hormone levels are fluctuating all over the place, etc.

 

[MattPsy]

Look toward effects on vasopressin.

 

[nuke]

I'm trying to find a clear cut article on AVP release from stimulants and I haven't found one yet... I did find this:

Pharmacol Biochem Behav. 1997 Oct;58(2):415-9.
Effects of methylphenidate on oxytocin and vasopressin levels in pinealectomized rats during light-dark cycle.
Appenrodt E, Bojanowska E, Janus J, Stempniak B, Guzek JW, Schwarzberg H.

Department of Neurophysiology, Otto-von-Guericke University, Magdeburg, Germany.

Although previous reports have shown that methylphenidate (MPH), in addition to its known behavioral effect, can influence the hypothalamo-pituitary-adrenal axis by increasing the plasma ACTH, the pineal gland seems to be involved in neuroendocrinological processes too, e.g., in hypothalamic synthesis and release of oxytocin (OXY) and vasopressin (AVP). Therefore, a study was performed to measure the OXY and AVP content of the hypothalamus, neurohypophysis, and plasma after application of MPH in the morning and evening in pinealectomized (PE) as well as sham-operated control (SO) rats. Pinealectomy influenced both the daily pattern (reversed in the neurohypophysis) and the levels of OXY and AVP. Starting from this different situation, application of MPH produced diverse effects. Hypothalamus: PE, increase in both hormones in the morning and evening; SO, decrease in morning OXY level. Neurohypophysis: PE, increase in morning OXY level; SO, decrease in both hormones even though in the morning only. Plasma: PE, decrease in morning OXY concentration; SO, increase in both hormones in the morning and decrease in the evening. The present results indicate that MPH application influences the hypothalamo-neurohypophysial system. Furthermore, the hypothesis has been supported that this influence may be dependent on the circadian activity of the pineal gland as well.

Which suggested that MPH causes diminished amounts of AVP in the morning but decreased amounts in the evening, which is rather confusing. But, with decreased AVP one would expect more frequent urination.

 

[Epsilon Alpha]

MOAR sympathetic stimulation!

 

[tyrael]

I've always believed that frequent urination was caused by a drug's effect on constricting/dilating blood vessels,
but why do both amphetamine and alcohol cause frequent urination when amphetamine constricts blood vessels and alcohol dilates them?
The same contradiction exists with other drugs, like caffeine for instance (which I believe dilates blood vessels if I'm not mistaken)

As others have stated, there's no one cause.

Alcohol for instance, often in itself contains a large percentage of water. One may drink 8 pints of beers in a night which maybe essentially 7 pints of water (don't quote me here! random numbers just pulled outta no where) and hence increase the frequency of urination.


A number of drugs can effect the (posterior) hypothalamus and hence particularly the release/production of AVP/ADH.

If the substance is sympathomimetic, then a number of resulting effects could (indirectly) effect the frequency of urination/defecation due to actions ranging from the redistribution of your blood supply, to smooth muscle changes, to receptor agonisation/antagonisation, etc. etc.

....
Trying to grasp the mechanics of blood vessel constriction/dilation has lead to more than a few bad amphetamine experiences for me; I wonder "what is causing my body to ache? Is it vascular constriction? Well then I should probably take a hot shower to open up my blood vessels... but wait, blood vessel dilation might dehydrate me! Oh dear." This has also resulted in me realizing that a portion of my drug-experiences is placebo -- because before I ever questioned matters such as vascular constriction, a hot bath while coming down on amphetamine felt almost euphoric - but after I began over-analyzing things (especially physiological and psychological matters), I spend my time in a hot bath worrying whether or not it is helping or worsening my situation, and afterward I don't feel at all better like I used to. Then again, there are too many variables involved to know what exactly is happening -- it could all be placebo, but then again it could be that a hot bath only helped me when I first started using amphetamine, but now my blood vessels are damaged from amphetamine use to an extent that a hot bath no longer helps. It could be that the anxiety I have while in the tub is causing adrenaline to be released, and therefore constricting my blood vessels even more. It could be that a hot bath is causing me to over-heat, etc.. There are just so many variables that confuse me, and a lot have to do with things that are individual to me and are difficult to find answers too (for example, when I first started using amphetamine regularly, I was prescribed 200mg of zoloft which I later discontinued a few months later - but this by itself presents so many questions including questions which relate to the metabolism of amphetamine since zoloft/sertraline inhibit one of the main enzymes metabolizing amphetamine, as well as whether or not sertraline played some roll in vascular constriction/dilation.
....

To a degree you are correct, however I wouldn't say it's as influential as (it sounds like) you're referring. There are still many other variables (both pharmacological and anatomical) to consider.

As Epsilon Alpha has stated, it's (when talking about [meth]amphetamines) predominately due to the sympathetic stimulation.