is half of a 0.25 dose a common dose , or is it not much of theraputic dose
Honestly, no it's not a common dose. Of course it depends on the person, but depending on circumstances and reasons for use anything less than 0.25mg is probably not very therapeutic in my opinion.
Xanax is what's called a benzodiazepine. It works pretty much just to treat stress, anxiety, panic disorders, sleep disorders, etc. You can think of it kind of as a sedative to calm you down. It's meant to be used only on an "as needed" basis, as it is short acting and doesn't really work to change much in your brain function. Lexapro on the other hand is an antidepressant in the category of SSRIs. Main function is to treat depression, but it also treats generalized anxiety disorder. SSRIs must be taken daily for awhile to be effective, but they do indeed work. Their mechanism of action is more unknown, but daily use is thought to cause a whole cascade of functional changes in receptors and pathways in the brain mainly related to serotonin. This is why they take awhile to work. Anti-anxiety effects usually after the first 2 weeks, and antidepressive effects around 4-6 weeks. Taken daily, they do well to prevent generalized anxiety, but do not treat acute attacks. Treatment of acute anxiety is better managed with a benzodiazepine, such as Xanax.
In regards XXXXX XXXXX second question, Ativan is also a benzodiazepine like Xanax. All benzodiazepines work the same exact way. Their main difference is their onset of action (how quickly they work) and their durations of action (how long they last). As I stated previously, Xanax peaks at 1-2 hours, and can last anywhere from 6-12 hours. Ativan 2-4 hours, but can last anywhere from 10-20 hours.
what does it mean when you say it peaks, does that mean its on its way from working and has already been the strongest it could be. what is better for sleep, xanax or ativan.
Also if i take half of a 0.25 xanax every 10 hours or so does that mean it is accumulating in my body and i am getting a higher dose because i have taken it more often. as you can hear, iam afraid of getting addicted to it
Above is a simple, generic picture representation of how much drug is in your bloodstream relative to time, courtesy of ScienceBasedMedicine.org. Going up or down on the graph is the drug concentration in your blood. Moving from left to right is time since you took the drug. When the concentration of the drug is in the area between the dotted lines, it is therapeutic and will be having an effect on you. The "T-max" is the time at with the drug reaches it's highest concentration, or "peak" as I described before. The duration of action is how long the blood concentration is in the therapeutic range and is still affecting you. If you compared Xanax to Ativan, Xanax would reach the peak much more to the left, and the curve would come down faster out of the therapeutic range since it's duration of action is less. Ativan would curve up much slower to reach the peak, and then the curve coming back down would be more flat and less steep since it's duration of action is longer. I know this was a long answer, but I really want to make sure you understand. :)
Because Ativan lasts longer, it is usually recommended for insomnia over Xanax. In fact, Ativan is approved by the FDA for sleep, whereas Xanax is not. That doesn't mean it can't be used for sleep, just that it's not recommended the first drug to try.
Don't be afraid of getting addicted to it. It's usually the people who are afraid of addiction and are cognizant of it, that are not prone to experience it.
I've spent quite a bit of time answering this for you, and if I've answered your questions to your liking, I would appreciate clicking accept. Thanks :)
Referenced graph: http://www.sciencebasedmedicine.org/index.php/generic-drugs-are-they-equivalent/