Hey just wondering how do I know if I need to increase my dosage of vistiril? And to tell you if I miss a dose i feel very dizzy well hear lately after I take my morning dose of 37.5mg at 8:00am by 4-5 in the evening I feel dizzy as if I hadn't took it all I feel dizzy again like I missed a dose just wondering why something is changing about the way my meds are responding to my body I have took it for about 8months now and have never had dizzy spells while taking it