It happens in eClinicalworks, I saw it in Intergy, and I now have to maneuver around it in Epic. Those EMRs, and I suspect many others, insert a stop date on what their programmers think (or have been told) are scary drugs.
In my current system all opioid drug prescriptions fall into this category. For a short term prescription that might perhaps be a good idea but for a longer-term or occasionally needed prescription it creates the risk of medical errors.
In Epic there is a box for duration, which is very practical for a ten day course of antibiotics. If I fill in the number 10 in the duration box, the medication falls off the list after 10 days. This saves me the trouble of periodically cleaning up the list.
But if I prescribe three oxycodone tablets a day for a patient with inoperable back pain and follow the convention of saying for 30 days or 28 days, that creates a problem: If my patient is careful not to take more pain pills than absolutely needed and the prescription indicates 28 or 30 days duration, the text on the prescription will read for up to 28 days or for up to 30 days. That language actually suggests they’d better hurry up and finish it and not have any pills left over. The other consequence is that if my patient doesn’t call for a refill until day 32, the medication has already disappeared from their medication list and cannot easily be “restarted”. I have occasionally restarted/re-issued a medication from memory and gotten the dosage wrong. Of course, I can check the state prescription monitoring program display for the pill strength and dosage frequency, but I still have to memorize it and then switch to the prescription screen. And the slightest distraction or interruption creates the potential for errors.
Across the EMRs I have used I have also seen the diuretic spironolactone get a stop date even if I leave the “duration” box empty. I don’t think that’s necessary: I went to medical school and already know this drug can raise serum potassium levels and precipitate kidney failure.
Back to the opiates: I think the plain English printout should say “X tablets daily for no less than 30 days” so nobody gets the idea to take more than the absolutely need because the doctor wants them to.
A Country Doctor Writes: 
I disagree. I think the wording “for no less than 30 days” would make a patient think they have to take it for 30 days.
In this version of the electronic health record is it possible just to write the prescription to say take one pill every six hours as needed for pain and not mention the duration on the prescription bottle? Do the automatically generated instructions clearly tell the patient to call several days ahead of time if they need a refill?
I am just in the process of learning a new EMR called Genesis. I have no idea how this is going to work out for me. I have not talked to one colleague who likes it.
I am now skipping over the duration box.