If you are trying a new medication, ask your doctor for a sample or ask to see a picture of the drug in the Physician's Desk Reference. You can also go to the Physician's Desk Reference Web site at www.pdr.net.
Many doctors now write prescriptions on a computer. If not, be sure your doctor writes neatly and ask him to identify the drug by both the generic and the brand name.
Also ask your doctor what the medication is most commonly used for, how to take it and what the side effects are.
Then ask the pharmacist those same questions and make sure the explanations match.
Finally, note the strength and instructions your doctor had in mind and make sure the pharmacist fills the order as intended.
If you are the victim of a medication mix-up, file a formal complaint with your state's board of pharmacy.