Unique Eyedrop Calculation Challenges

Pharmacy social media platforms host passionate discussions on the correct way to bill days’ supply for eyedrops almost every week. Do you use 15 drops/mL, 20 drops/mL, or something else? As it turns out, the “right answer”  depends on the PBM you are billing and if the eyedrop is a solution or a suspension. Sound complicated? PAAS National® has a one-page chart and an app for that!

To make matters worse, there are some unique situations where using the PBM guidance is not relevant.

Become an audit assistance member today to continue reading this article. As a member, you’ll have access to hundreds of articles and receive our monthly proactive newsletter!

Join today!

For example, some manufacturers have specific guidance for drops/mL due to a viscosity and drop size difference (e.g., Miebo® [272 drops/3 mL], Vevye® [200 drops/2 mL], and Vyzulta® [81 drops/2.5 mL]), and you should calculate the days’ supply based on the manufacturers’ guidance.

Additionally, some eyedrops have a specific beyond use date in Section 16 Storage and Handling of the product labeling (e.g., AzaSite® [14 days], Rocklatan® [42 days], Rhopressa® [42 days], Vyzulta® [56 days], Xalatan® [42 days]) and cannot have a days’ supply greater than the beyond use date. Do not assume that all eyedrops have a beyond use date of 28 days. This is NOT true in most cases.

If a prescriber indicates that patient should discard the eyedrop after using it for ’X’ number of days, this must be explicitly spelled out in the directions to the patient. For example, eye drops that are to be used in the right eye for two weeks after surgery then discarded for a new bottle to be used for the left eye should clearly indicate this in the directions before billing a 14-day supply. If multiple package sizes of the product exist, use the smallest bottle closest to the treatment duration as possible. The PBM will not pay for a patient to discard the remainder of a 15 mL bottle when a 5 mL bottle would have sufficed.

PAAS Tips:

  • There is no industry accepted conversion for Gel or Ointment products
  • Follow the individual PBM published guidelines when billing days’ supply
  • OptumRx is the only PBM the explicitly states you may use treatment duration (e.g., “Use for ten days”) as the days’ supply
  • The quantity prescribed should contain a unit of measure that corresponds to the billing unit; however, if written for a quantity of “1 bottle”, it should be interpreted as the smallest package size
  • Login to the Member Portal under “Days’ Supply Charts” to find the most current version of PAAS’ Eye Drop Chart with major PBM drops per mL ratios
  • Download the PAAS National® Rx Days’ Supply Calculator from the App Store or Google Play
  • Review the November 2024 article, 2024 Self-Audit Series #9: Eye Drop Days’ Supply for additional guidance

Jenevra Azzopardi, CPhT
Latest posts by Jenevra Azzopardi, CPhT (see all)