Drug withdrawal

Patient: Hi, My mother who is 72 started to take Nortriptyline (10 mg tablet – 1/day) and Haloperidol (0.5 mg – 1/day) about 15 years ago to combat menopause-related symptoms, mainly anxiety. About 4 months ago she decided that she no longer needed the pills so with her doctor’s supervision, the dosage was gradually reduced over 2 months and then stopped. However, she seems to suffer from withdrawal symptoms (fatigue, body ache, nausea, lack of appetite.) I would like to know if this is normal and if her symptoms will gradually disappear. How long can this take? Thank you in advance for your response.