You should have a return to work interview each time you record an absence, the idea is that if someone comes back to work on medication and has an accident the company can stop this by finding out how they feel and what meds etc.
some companies do this but not all my wife had a mild heart attack and her boss wanted her to come back full time, no chance she is doing a few hours per day until she feels well enough.
Stand your ground and speak to your doctor, it may be difficult with driving but not impossible