From the September 2008 issue

In our March 2008 issue, we discussed confusion that was occurring between metoprolol tartrate (LOPRESSOR) and metoprolol succinate (TOPROL XL). Since the introduction of generic forms of metoprolol succinate, pharmacies have been receiving prescriptions that do not clearly indicate which formulation, succinate or tartrate, a prescriber intends for the patient. We also mentioned the possibility for prescribers to select the incorrect product in electronic prescribing systems. The risk of a selection error is increased due to name similarities and overlapping dosage strengths. A pharmacist recently shared with us that his pharmacy has received several e-prescriptions for the wrong formulation. It appears that most of the errors have occurred when requests for refills of metoprolol succinate have been answered with prescriptions for metoprolol tartrate. To reduce the risk of mix-ups, make all staff aware of the possibility of confusing these products and incorporate safeguards in your processes for handling these prescriptions. Prescribers should request e-prescribing vendors to include alerts such as: short-acting or long-acting for the two salts. These same alerts can be incorporated into the pharmacy system. Pharmacy benefit managers (PBMs) should also have a check system in place when adjudicating refill prescriptions. Be sure patients understand that various dosage forms of metoprolol exist and help them understand which one has been prescribed for them. With this information, they will be armed to provide a final verification any time the medication is dispensed. The pharmacy that reported these events now double checks all medication profiles of patients receiving prescriptions for either metoprolol tartrate or metoprolol succinate before doing data processing. A review of the patient’s profile for current and past medications is a key safety strategy when prescribing and dispensing all drugs, not just metoprolol. Total reliance on software checking, even if prescribers are using e-prescribing, may not be adequate to prevent these errors.