Yes, it is possible for amitriptyline to have side effects like memory problems. This is because the dose of amitriptyline for pain is lower than the dose for depression. The common side effects tend to be milder and they go away within a few days.
Keep taking the medicine but talk to your doctor or pharmacist if these side effects bother you or don't go away:
constipation
dizziness
dry mouth
feeling sleepy
difficulty peeing
headache
Amitriptyline has anticholinergic side effects as it acts on the cholinergic receptors in the brain. These receptors are important for our memory. So it is possible for the patient to complain of memory issues. Some patients complain that the medicine makes them feel weak and sleepy in the daytime. If they rest too much in the daytime, they cannot sleep well at night.
Do let your doctor know about the side effects that you experience. There are alternative medicines that can be prescribed to you, be it to treat chronic pain, insomnia or depression.