Yes, the sedating effect is likely to continue, it's used for insomnia, amongst other things. The grogginess the next morning may continue. For many people, it needs to be taken at least 12 hours before you need to function. I've been taking it for 20 years for insomnia. I wake up feeling terrible/drugged, but I have M.E., and most people with it feel awful for a long time after waking. I've recently discovered that it can cause heart problems, and dementia. It seems that all "psychiatric" drugs can cause dementia, due to brain shrinkage. Don't shoot the messenger! I'm now considering gradually coming off it as both my parents have dementia - vascular and Alzheimer's - though I imagine I'm very likely to get it anyway, with or without amitriptyline. 😔
If I were you, I'd think carefully about taking it, and do plenty of research. Some people also have a terrible time coming off it, even done very gradually. I belong to a Facebook group for those taking and withdrawing from it and there are some awful stories on there. It's not a drug to be taken without serious thought, many regret starting it.