Crunching Numbers: How Pharmacy Techs Can Keep It All Straight
Pharmacy technicians are counting machines! OK, not literally counting machines (which some stores are actually lucky enough to have), but they do count a variety of items throughout the day. How many customers were in the drive-through before opening? How many refills in the queue? And perhaps the most important…how many minutes until closing time? Counting counts for so much, and there are certain reminders that are worth revisiting, starting at the beginning…with zero.
Believe it or not, there are many ways to express the number zero! The British use the term "naught" but in the United States other options include aught, cipher, goose egg, nil, nothing, zilch, and zip. However one chooses to describe zero around the world, pharmacy personnel must honor the concept of "leading" and "trailing" zeroes. A leading zero is a zero preceding a decimal point, such as Risperdal 0.5 mg PO daily. Leading zeroes must always be used when writing prescriptions for quantities of drugs that are fractions of a unit to avoid dosing confusion. For example, if the prescription above is written without the leading zero, i.e. Risperdal .5 mg PO daily, the result may be a tenfold dosing error! Pharmacy technicians that encounter a prescription written incorrectly should notify their supervisor of the need to clarify the drug strength.
On the other side of this concept is a "trailing" zero. A trailing zero refers to a zero that follows a decimal point, such as Clonidine 1.0 mg PO TID. Using a zero after a decimal point can also result in a tenfold dosing error if the decimal point is illegible or not noticed. For this reason, the Joint Commission on the Accreditation of Hospitals has included trailing zeroes on their official "Do Not Use" list.
Another topic in pharmacy where confusion may come up are with starter packs. A starter pack refers to a unique manufacturing package size for medication regimens with quantities that may increase during the first few days or weeks of use. Examples of starter packs include the following regimens:
- Chantix (Varenicline): The patient should take one 0.5 mg tablet PO for 3 days, then one 0.5 mg tablet PO BID for 4 days. Continued treatment is 1 mg PO BID. The dose is started slowly to reduce adverse effects with varenicline, including strange dreams and trouble sleeping.
- Namenda (Memantine):
- Week 1 (day 1-7): The patient should take one 5 mg tablet PO daily for 7 days.
- Week 2 (day 8-14): The patient should take one 10 mg tablet per day for 7 days.
- Week 3 (day 15-21): The patient should take one 15 mg tablet per day for 7 days.
- Week 4 (day 22-28): The patient should take one 20 mg tablet per day for 7 days.
- The maintenance dose is 20 mg per day. Each tablet strength is a different color, and starting with lower doses reduces the risk of side effects such as headache and sleepiness.
- Xarelto (Rivaroxaban): This starter pack is designed for the first 30 day supply. The patient should take 15 mg PO BID for 21 days, then the dose is reduced to 20 mg PO daily. Higher doses are given at the start of treatment when the patient is most vulnerable to a clotting event such as deep vein thrombosis (DVT) or pulmonary embolism (PE).
- Lamictal (Lamotrigine): This medication has not one, but THREE different types of starter kits, each based upon other medications taken by the patient. The starter kits help minimize drug interactions, including life-threatening rashes.
- Blue starter kit: for patients taking valproate
- Green starter kit: for patients taking carbamazepine, phenytoin, phenobarbital, or primidone
- Orange starter kit: for patients NOT TAKING carbamazepine, phenytoin, phenobarbital, primidone, or valproate
Take extra precaution when entering prescriptions for starter kits and ensure that you pick the right packaging and kit choice, and confirm the patient has received counseling from the pharmacist on how to use these kits to prevent errors related to patients who do not take these items as prescribed.
A final consideration when entering and filling prescriptions are errors related to the package size itself and how these items are billed to insurance. Stock bottles often come in quantities of 90 or 100, but there are some exceptions. Tizanidine products, for example, often contain 150 tablets per stock bottle (not 100) which can increase the risk of error when pouring an entire bottle into a vial. Other examples include testosterone gel packets supplied in boxes of 30 packets but billed for a quantity of 150 grams, and birth control packets which may have 21, 28, or 91 tablets.
The bottom line is take your time and focus on the details!