How To Start Taking Nortriptyline Capsules?

I was taking 10 mg Nortriptyline 4 capsules every night. I quit taking them, but would like to start again, but I am allergic to so many things that I wondered if it would be safe to take the 4 or just take one and then add one after a week, and keep going that way till I was taking 4 again. I am not depressed but they helped me sleep. I am 87. Charlotte