My Husband Began Taking Desipramine Approximately 4 Months Ago. 6

My husband began taking desipramine approximately 4 months ago. 6 weeks ago he was on his full dose of 150 milligrams a day, after being slowly ramped up. At that time he began having difficulty sleeping. Some nights he does not sleep at all. Some nights he sleeps 2 hours. He spoke to his psychiatrist about this at his last appointment. In addition to the ambien that he was already taking, he also prescribed another sleep aid but I can't remember the name of. Its not a common one. In addition to the sleeplessness he also had occasional heart palpitations. He called his primary physician and scheduled an appointment. Is revealed that he had a hyperactive thyroid. I've been doing some reading and I've come across some studies suggest that desipramine can have an effect on the thyroid. Am I correct in thinking that the deseprimine could be affecting his thyroid? He has an appointment with a psychiatrist next week and a psychiatrist stated he would address it then. But his family physician wants to send him to an endocrinologist. I really don't want him being put on a pill for his thyroid if it's simply and effect from a pill he's already taking.