I recently stopped taking nightly 300 mg gabapentin because I was having sudden dizziness. On one hand, a neurologist told me that the dizziness COULDN'T be related to the gabapentin, bc I took it at a higher dosage and had no problem. (Of course, at that time I was on muscle relaxants, tramadol and something else as I recovered from a traumatic fall.) On the other hand, my PCP told me that gabapentin ABSOLUTELY could cause dizziness, and recommended I stop taking it, which I did. Long story short, gabapentin has all kinds of side effects, and it differs from person to person whether they experience them. If you are experiencing grogginess during the day, it is something to talk to your doc about. We seniors have to be aware of all the things that contribute to the possibility of falls. I have been managing pain for about 20 years now, and a dr. recommended that a combination of naproxen sodium and acetaminophen was as effective as opioids without the side effects. I have found that to be true, BUT...both medications at high doses can cause liver and kidney problems. Talk to your doctor about using that combo, if it is right for you.