I would like to know if the prescription was received electronically from the prescriber or if this was a hand-written prescription turned in to the pharmacy. Also, what was the total volume dispensed by the pharmacy? 2 teaspoons = 10mL so more than likely, the technician that entered the order in the computer system could have just mistakenly typed the shortcode for teaspoons instead of drops. If the prescription was handwritten, prescribers may abbreviate drops as “gtts”. Usually, Potassium Iodide is dispensed in small bottles ( 1 ounce = 30ml glass) with droppers attached. Someone would have had to pour 4 small bottles into a 4-ounce container (10ml 4 times daily=40ml x 30 day supply = 120ml) or label 4 x 1-ounce bottles. I would be surprised if the pharmacy even had 120ml of SSKI in stock. Did the pharmacy have to special order enough to fill the prescription? I would investigate whether the pharmacy computer system has a warning for volume dispensed based on the NDC number of the medication.
Another safeguard usually occurs at the insurance company/payer source level. If the pharmacy submits an electronic claim for such a large volume, usually the insurance may reject the claim for payment due to excessive quantity based on a 30 day supply. So another question should be, did the patient pay cash or run the prescription through their insurance? There are multiple steps in the prescription dispensing process where this error should have been caught. I do not expect the pharmacy technician to have the expertise necessary to identify the error when he/she entered the order in the computer system. The pharmacist checking the order would have had the opportunity to catch the error by checking the accuracy of the entered order against the hard-copy or electronic copy of the prescription. Then again labeling 4 bottles of SSKI might have been a sign something was not correct.
Finally, the pharmacist on duty when the patient came to pick up the prescription had an opportunity to catch the error by educating or counseling the patient about proper use of the medication and asking the patient what the doctor told them about their medication and how to take it.