Benzos are harder to tolerate as we age. Or if your kidney functions are changing.(this happens with the elderly).

Ativan is a moderate acting one. Xanax has the shortest half life,
Ativan is next as moderate, Valium is long, Klonopin the longest.
(this does not include the sleeping types, Temazepam and
Dalmane).

So if you are having some issues with sedation, either cut the ativan in 1/2 or cut out that night time dose entirely.

Xanax has the fastest onset, orally and briefest active time.
Ativan is longer acting and therefore used in institutions and hospitals more often for this reason.

You might mention this to your doctor... as a dosage adjustment may be in order. And perhaps some kidney tests too, to check your clearance rates.

I occasionally take both. I take the Ativan for muscle spasms. However, I only take 1 0.5 mg tablet. That 1 tablet lasts me a good 24 hours. It may be that taking 0.5 mg at night and 0.5 mg in the morning is too much for you and that is what is making you so sleepy. (I know it would me but I'm a light weight. And, it only takes about an hour for the Ativan to kick in and start working for me.).

Next time, maybe try skipping one of the doses (either morning or night) and see if that makes a difference.

And, B2Y does have a good point, always check with a dr. before changing dosages on regular medications and/or talk to the pharmacist about it (many times they are more knowledgeable than the drs. on medications, interactions, side effects, etc.).