I had a patient on Escitalopram for years with no problem and they got the med from Walgreens. This was before the days of less than $10 generics. When those days started most large pharmacies would have the pharmaceutical companies engage in bidding wars which is why the medication prices went down.
So Walgreens had the same companies provide the same meds for years straight. With this new era of bidding wars these generic meds would change every few months.
So this patient told me they were having a bad reaction on Escitalopram and their prior psychiatrist told them "It's all in your head." So this patient started with me. I called the pharmacy and it turned out the very day that patient had new side effects was the same day they picked up Escitalopram from a new manufacturer and Walgreens had used the same one before consistently for years.
"It's all in your head?" The patient had no demographics, history, etc suggesting a psychosomatic illness, the different generic manufacturers both made their pills look the same, the patient had no knowledge this was a different manufacturer, but "it's all in your head."
Again, and I know this of training outside my MD. Lots of the courses we take in medical school are abbreviated versions of the real thing. E.g. MD Physiology is nowhere near as complex as a Master's Degree course in physiology. Our physiology is trimmed for clinical purposes and because the MD curriculum is too much all at once. Same with pharmacology that doesn't teach about excipients at all. How do I know this? I was in a master's program for a few months where I took these courses.
Adding to the equation above, several physicians are narcissists. The patient told me he didn't think the problem was "all in his head" but the more he protested the more the doctor told him he was wrong and he was right without looking into the problem. This isn't the first nor the last time I'll see a physician who doesn't know the answer so they cut-corners and tell the patient the symptoms are fake.
We were able to locate a different pharmacy that used the prior manufacturer for the above patient and the medication was fine. He even tested the older med again in a blind manner having his wife not telling him what was what and 100% of the time he tried the new med he was sick, and 100% of the time he tried the older med he was fine.
Just a few days ago, a patient of mine, a renown professor of anesthesiology from a top-tier program, was diagnosed with Conversion Disorder and I have strong reason to believe the neurologist cut corners and didn't do the due diligence. Quite bold and presumptuous especially since the patient is a renown physician whose usual neurologist (not the one who diagnosed her with Conversion Disorder) is one of the best in the country.