Posted by IsoM on August 20, 2002, at 15:12:23
In reply to Bizarre sensations during yawns, posted by Eddie Sylvano on August 20, 2002, at 11:56:01
SSRIs seem to increase yawning in some people. I know it has in me but I yawned excessively even before I took ADs. Yawning is NOT a reaction of the body to decreased oxygen levels or increased CO2 levels. Research has shown people yawn even when breathing 100% oxygen. It is known that yawning and stretching increase blood pressure & heart rate & also flexes muscles and joints. Probably adrenaline (epinephrine) is released too.
Even though a lot of research has been done on yawning, the mechanism is still not fully understood. What is known is that it originates in the paraventricular nucleus of the hypothalamus. When yawning occurs, different neurotransmitters are released such as dopamine, glycine, oxytocin, excitatory amino acids, nitric oxide & ACTH, & some neuropeptides.
Yawning will occur when the brain switches attention or focus to another task too. Perhaps the neurotransmitters released facilitate attention & focus. Yawning does serve to "wake up" the brain & shivering can occur with an increase in excitement & focus.
I'm wondering if it's possible that Effexor has made the release of these chemicals more accentuated, causing the degree of shivering you experience. I know that my yawning is deep & frequent, causing my eyes to water & my nose to plug up. I'll often get shivers with it too, but not to your extent. The pathway your shivers take can be explained with the flow of blood out from the central region to the peripheral parts, very similar to the way an addict feels when shooting up their drug.
None of this sounds alarming but more a nuisance than anything. Still, mention it to your doctor when you see him/her next.
poster:IsoM
thread:117101
URL: http://www.dr-bob.org/babble/20020814/msgs/117137.html