Both my husband and I were given Soma after the accident which was close to 2 years ago. At first I loved them and they were really helpful with the pain meds but then they started making me super tired - as in not being able to stay awake! I stopped taking them and never had a single issue - I had taken them about 4 months and stopped in one day. I later got a stronger one after they operated but again stopped them when I felt no need to take them. I take soma at night sometimes.
My husband has taken them all along and they never make him sleepy - so go figure.