Ian Stewart, B.Sc.Phm., R.Ph.
Pharmacists must take all necessary steps to ensure that the correct medication is given to the correct patient, in the correct dose, in the correct strength, with the correct instructions for use as intended by the prescriber. This includes instances where a patient may present a prescription to a pharmacy staff member for products that are Schedule II, Schedule III or unscheduled.
These cases highlight the potential for medication errors if unregulated pharmacy staff members misinterpret prescriptions and do not consult with pharmacists to ensure patients are receiving the correct medications. Pharmacist interventions are critical in improving patient care outcomes and reducing the risk of harm.
A physician wrote a prescription for diphenhydramine oral liquid for a two-year-old child with the instructions to give five millilitres every four to six hours.
The parent presented the written prescription to a pharmacy assistant at their local community pharmacy for processing. Upon reading the prescription, the pharmacy assistant incorrectly assumed that diphenhydramine was Gravol.
She therefore informed the parent that Gravol can be purchased without a prescription, and it would be less expensive. The parent was then directed to the appropriate aisle to pick up and purchase Gravol oral liquid instead of Benadryl oral liquid as prescribed.
Upon reading the recommended directions for use on the Gravol package, the parent noted a discrepancy compared to the dosage recommended by the physician. The parent therefore approached the pharmacist for clarification. The error in interpretation was therefore detected. The parent was understandably upset that he was instructed to purchase the incorrect product for his two-year old child.
The above prescription was presented to a pharmacy assistant for processing. In error, the pharmacy assistant interpreted the prescription as Polysporin ophthalmic drops (Polymyxin B Sulphate 10,000 units and Gramicidin 0.025mg/ml) while the prescriber intended Polytrim ophthalmic drops (Polymyxin B Sulphate 10,000 units and Trimethoprim 1mg/ml).
The patient was therefore directed to the appropriate aisle to pick up and purchase Polysporin ophthalmic drops. Fortunately, the Polysporin ophthalmic drops was unavailable at the time. The patient therefore approached the pharmacist for an alternative. The error in interpretation was therefore detected.
Possible Contributing Factors:
- A pharmacy assistant misinterpreted the prescriptions in both cases due to the similarity in drug names.
- The pharmacists working at the time each prescription was presented for processing were not initially involved in the assessment of each written prescription.
- Establish workflow processes to ensure that all prescriptions presented for processing are appropriately assessed by a pharmacist to ensure that the correct medication is given to the correct patient, in the correct dose, in the correct strength, with the correct instructions for use as intended by the prescriber.
- A non-regulated support staff member should never be the only staff member assessing any prescription. Note that if an error does occur and a complaint is filed with the College, it will be the supervising pharmacist and/or Designated Manager who will be held accountable as the College has no jurisdiction over non-regulated personnel. Remember that the Designated Manager is responsible for ensuring that staff are appropriately trained and supervised and assigned tasks that they are competent to perform.
- It is critical that standard operating procedures for processing all prescriptions are established, clearly communicated to all staff, and adherence monitored to ensure compliance.
- Following the appropriate assessment of a prescription, if the decision is made to provide the product over the counter and not process the prescription, details of the new drug therapy should be added to the patient profile for future reference.
- Cost should not be the only factor to consider when deciding whether to process the prescription as written or to provide the product over the counter. Processing the prescription will ensure that the patient receives the directions for use clearly printed on the prescription label. This is especially important for senior patients. The computer’s drug utilization review program will also be utilized to identify possible drug related problems with the new drug therapy.
- Appropriate patient education should also be provided even in cases where the product is provided over the counter.
- Note that Benadryl is available as both Diphenhydramine Hydrochloride 6.25 mg/5 ml and 12.5 mg/5 ml. Use the child’s age and weight to confirm the correct concentration to be provided.
Please continue to send reports of medication errors in confidence to Ian Stewart at: firstname.lastname@example.org . Sharing your experience can prevent similar occurrences at other practice sites. Please ensure that all identifying information (e.g., patient name, pharmacy name, healthcare provider name) are removed before submitting.