The Facts About Dose Splitting

  • Posted on January 30, 2021

By Gayathri Sridhar, R.Ph., BCNP , Staff Pharmacist and Radiation Safety Officer

Dose splitting is the term used to describe the practice of ordering one unit dose of a radiopharmaceutical agent from a nuclear pharmacy and breaking the dose into two or more separate units within the nuclear medicine department or other receiving facility; for example splitting one sestamibi 40 mCi dose for use in both the rest and stress cardiac studies as two injections.


Section 3 U.S. Pharmacopeia (USP) <825>


Receiving a unit-dose preparation and splitting it into two separate doses may only be performed in an ISO Class 5 Primary Engineering Controls (PEC) within a Segregated Radiopharmaceutical Preparation Area (SRPA) or an ISO Class 8 or better buffer area, under USP <825>. 

Patient care area is considered immediate use under USP <825>.  This implies that:

  • Preparation and dispensing is limited to a single patient
  • Administration must begin within 1 hour of the initial needle puncture or exposure of any critical sites (e.g., syringe tip, needle hub, or needle) to ambient air, whichever is first
  • All components – Tc-99m sodium pertechnetate syringe/vial, final prepared kit, vial, diluent must be discarded either within 1 hour of first exposure to ambient air or after use for a single patient administration, whichever is first

In short, a facility should possess a separate ISO Class 5 unit located within a SRPA or an ISO Class 8 (or better) buffer room located outside of the patient care area to perform dose splitting.


Board of Pharmacy Requirements


  • Some states require the patient name be added to the prescription within 72 hours.  Dose splitting would not be an option in such states.1

Pennsylvania State Requirements are given as an example.


RAM License Conditions/ALARA


  • Manipulation of unit dose syringe results in increased radiation exposure
  • Some Radioactive Material (RAM) licenses require receipt of unit doses only and splitting the doses would then be a violation of your license conditions


Safe Injection Practices


  • Dose splitting is a contradiction to  Center for Disease Control’s (CDC) Safe Injection Practices2




1. Pennsylvania Code 27.101. Radiopharmaceutical prescriptions—statement of policy.

 (a)  Definition. The term ‘‘radiopharmaceutical’’ means a pharmaceutical, biological or drug which contains a radioactive entity.
 (b)  Unavailable name. When a pharmacist receives a prescription for a radiopharmaceutical for a patient whose name is unavailable at the time the prescription is received and the pharmacist dispenses the radiopharmaceutical, the pharmacist and pharmacy will be considered to have complied with the provisions of §  27.18(b) and (d) (relating to standards of practice) which require the name of the patient if the pharmacist obtains the name of the patient within 72 hours after dispensing the radiopharmaceutical or, if the radiopharmaceutical is not administered to a patient, marks the prescription ‘‘not used.’’

The provisions of this § 27.101 adopted April 23, 1993, effective April 24, 1993, 23 Pa.B. 1963.

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