Is it OK to use another person's medication if I have the same health condition?
It can't be emphasized too strongly: Do not take prescription medication that was not specifically prescribed for you - even if you have the same health condition. Their medication was prescribed for them based on their health history (including his or her age, weight, other medications, and other health conditions they may have) and their specific diagnosis. The same health condition can have varying types of treatment. You may not need the same type as they do.
Taking prescription medications that are not prescribed for you is illegal, and what is worse is that doing so can result in very serious complications as a result of incorrect dosage, interactions with other medications you may be taking, or an allergy to one of the medication's ingredients.
Ask your pharmacist about using an appropriate over-the-counter medication to treat your condition until you can consult your doctor about prescription therapy.