"been using zolpidem several years now,  1/2 of a 10mg tablet when required. stayed at that dose for a couple years, until began waking up after 4-5 hours. began taking just a small pinch more to get back to sleep. recently i found myself taking 2/3s pill at bedtime, and though i&#039;ve never had any bizarre behavior on it, have been noting memory and mood changes as i&#039;ve aged past 70 which i was attributing to normal aging and/or my thyroid disorder.  however, after carelessly downing an entire 10 mg pill last night, i woke this morning feeling very groggy, foggy headed, and my vision was blurry. sweet dreams."