Discontinue a single prescription by right-clicking on the applicable entry in a patient's Medications (Rxs) block or Rx History pop-out and selecting "Discontinue." Discontinue multiple prescriptions by checking the box to the left of each one in a patient's Medications (Rxs) block or Rx History pop-out, clicking on the "Manage Checked Rxs" drop-down menu in the upper right corner of the block (or pop-out) and selecting "Discontinue Checked Rxs".
You will be prompted to indicate whether the patient had an adverse reaction to the medication, or is discontinuing use for some other reason. If you select Adverse Reaction, the medication will be added to the patient's list of allergies and intolerances, along with any explanatory text that you add in the Discontinue pop-up. You will also be prompted to indicate whether the patient has an adverse reaction to any of the medication's parent drug classes, which are listed from most specific to most general. It is unusual, though not impossible, for a patient to have an adverse reaction to a high-level drug class, so you will most likely be indicating a reaction to one or more specific drug classes at or near the top of the list, or just to the specific drug.
The discontinued prescription will continue to appear in the patient's medication list, but will be crossed out and marked as discontinued.