Hey Mister,
Amitriptyline (Elavil) is a tricyclic anti-depressant. It is prescribed for the obvious (Depression) but also for nerve pain and sleep disorders.
Amitriptyline is a pretty old drug and has been around for some time. Your dose is rather small, however, if you've never taken it then it will probably work ok for you at first.
Amitriptyline has some pretty decent sedation qualities. Many people take this drug for sleeping. The problem is, many people report feeling drowsy the next day. It has a longer half-life than other sedative meds. Like Ambien which is in a different drug class all together, but it has a shorter half-life so the next day is usually ok for most people.
The only other thing that I can think about that is negative about this drug is weight gain. Many people report gaining weight while taking Amitriptyline.
You didn't mention what the med was prescribed for. Normal dosages are usually 25-50 mg for anti-d and sleep. I know some people that take 150 mg as well. The longer you take it, the more tolerance you will build to it.
Hope this answered some of your questions.
Take Care