From what you say, the discharge started before the medication that your wife used for her injury. So it may not be related. There could be a number of causes for this discharge and given your wife’s age, it’s a good idea that she has a mammogram once a year anyway. Your wife could be approaching menopause and the hormone changes that may be occurring can cause a breast discharge. Since it is affecting both breasts, it is likely that the cause is more hormonal rather than being isolated to pathology within the breast itself. Stimulation is known to also induce a milky discharge but this would have to be long term. You do not mention when last your wife was pregnant etc but it is advisable for her to see a doctor/gynecologist. The relevant tests would have to be conducted. There are other causes which may not be relevant to your wife’s case so it is best to see a doctor and take it from there.