Although brain shivers is a less common side effect, we’ve got several members of the Venlafaxine Forum often complain of brain shivers, zaps, and headaches in general.
Steve says:
Been getting what I can only describe as “brain shivers”, a dizzy type sensation which I get on and off through the day? I’m sure that I have heard this discussed - anybody had this?
Byllyc says:
I had them for about 2 and 1/2 weeks after stopping effexor. yes, that dizzy type sensation and the frequent “ZZZZZZZZZZZZZ” going through my head. at times i was afraid to stand in a puddle as i thought i would fry myself from all the static electricity i felt in my head. (just kidding) it did get better and i was completely free from the shivers and zaps after about 3 weeks. did you just stop taking effexor?
If you’ve experienced similar Venlafaxine side effects, please share them here.
More info on how serotonergic medications cause sexual problems (see also previous post on Venlafaxine and orgasms).
It is hypothesized that SSRI’s affect the sexual response system by raising levels of serotonin. Serotonin, a neurotransmitter, appears to have a negative impact on the desire and arousal phases of the sexual response cycle which consists of four phases including: desire, arousal, orgasm, and resolution. This seemingly occurs through its inhibition of dopamine and norepinephrine, which are other neurotransmitters.
Serotonin also appears to exert direct effects on sexual organs by decreasing sensation and by inhibiting nitric oxide. Nitric oxide is thought to be a key player in the sexual pathway as it is thought to relax smooth muscle and blood vessels and therefore allow adequate blood supply to the sexual organs. Overall, it is the interplay of these neurotransmitters that causes antidepressant-induced sexual side effects.
And, to be more specific or scientific (according to a genius I know), these meds are thought to cause sexual dysfunction by acting at the serotonin receptor type 2a, and probably by changing the function of alpha-adrenoceptors. I don’t really know enough about the different receptors and sub receptors to fully comprehend that but I thought I’d post it in case someone else can appreciate it.
Although muscle twitching is a less common side effect, some members of the Venlafaxine Forum often complain of muscle twitching, muscle cramps or spasms, muscle pain or stiffness.
Here’s one account:
I’m a 26 year old male and have recently been diagnosed with Anxiety (GAD)/ Depression. Anxiety is my main issue. I noticed a year ago that I was getting a lot of shoulder pain(with no knowledge of an injury), my trap muscles felt really tight. I went on anti inflam meds, creams and physio, it helped but the discomfort always returned. Last November I started having difficulty falling and staying asleep. My doctor give me Ambiem, which helped for the first few weeks but the effect wore off. I also began to notice that I got worked up over little issues, I became forgetful and irritable,unable to stay focused, felt fatigued and losing interest in things I usually enjoy doing. I saw my doctor a week ago and give her all my symptoms, she said I had Anxiety and Depression and recommended I tried Effexor XL 75. She explained that this drug has had success treating Depression in high doses, but is used to treat Anxiety in lower doses. She also give me Zopiclone 7.5 (x 2 at night) for sleep.
I’ve been on Effexer XL six days now. I batted with nausea and constipation for the first couple of days (and nearly give up!). But I stuck with it and thankfully these awful effects wore off as my body got used to the drug. It has diminshed my libido (doc warned it might). I usually take it between 1pm-2pm with food. I’ve heard some people take it before bed???
If you’ve experienced similar Venlafaxine side effects, please share them here.