Ian Stewart, B.Sc.Phm., R.Ph.
Under the NAPRA Model Standards of Practice, pharmacists must assess all prescriptions for therapeutic appropriateness before the medication is dispensed. This assessment must take place for both new and refill prescriptions.
The following case highlights the importance of this assessment.
Drug: Valacyclovir 500mg
Sig: Two tablets twice daily for one day
Mitte: Four tablets
The above prescription was presented to a pharmacy assistant for processing. The prescription was processed and dispensed as written.
While counselling the patient, the pharmacist enquired about the indication for use and learned that the Valacyclovir was being taken to treat a cold sore (herpes labialis).
Following an assessment, and ensuring that there was no valid reason for a dose reduction (including renal impairment), the pharmacist confirmed that the dose should be 2000mg twice daily and not 1000mg twice daily as prescribed. The pharmacist adapted the prescription by altering the dosage to four tablets (2000mg) twice daily and dispensed eight tablets. The pharmacist informed the patient of the prescribing error and the change in dosage.
If the prescription had been dispensed as written, the patient would have received a sub-therapeutic dose, which is a dosage less than the amount required for the desired therapeutic effect. By adapting the prescription, the pharmacist used the full scope of practice to ensure that the patient received the appropriate dose of the medication without delay.
This is an example of a near miss that should be recorded in the Assurance and Improvement in Medication Safety (AIMS) Pharmapod platform. Near misses provide a great learning opportunity for pharmacy teams to discuss why events occured and any potential process changes that can be implemented to prevent similar events from reccurring.
- Always gather key information required to complete the therapeutic assessment as early as possible including indication for use, allergies, patient’s parameters (including weight for pediatric patients), etc. to streamline workflow processes.
- Always review the patient’s profile including medication history when processing both new and refill prescriptions to identify potential errors including therapeutic duplication, discontinued therapy, drug interactions, contraindications, etc.
- Always screen for changes to health and medications (including Rx, OTC and natural health products). Without a process in place to screen for changes, there is significant risk of missing important information such as a new medical condition or drug interaction with medications that were obtained elsewhere.
- Develop a process to ensure the indication for use is always collected (ideally before the prescription is processed) as it would be difficult to complete the therapeutic assessment without this key piece of information.
- Ensure easy access to therapeutic references to ensure the drug, dose, dosage form, dosing interval and duration of therapy is appropriate based on the indication for use and patient’s parameters.
- Adapt the prescription when appropriate to prevent a delay in therapy.
- With new prescriptions, have a system in place to ensure counselling takes place and a monitoring plan is developed.
- With refill prescriptions, have a system in place to confirm ongoing therapeutic appropriateness and to monitor for adverse effects.
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, etc.) are removed before submitting.