ISMP Medication Safety Alerts

July 17, 2014 (Volume 19, Issue 14)

A recent overdose with oral lomustine was reported to the Institute for Safe Medication Practices (ISMP). The patient inadvertently took an equivalent of three cycles of lomustine at one time after thinking the pharmacy had dispensed a single dose. There have been at least five similar errors with lomustine reported by the ISMP, where more than one dose was dispensed and taken. The ISMP recommends that prescribers, pharmacists, nurses, insurers, manufacturers, and the U.S. Food and Drug Administration follow several safe practices for oral lomustine therapy, including the following:


  1. On the prescription, specify that only a single dose should be dispensed.
  2. Discuss with the patient that a single dose should be taken no sooner than every 6 weeks.
  3. Review and provide written instructions for the patient. Remind the patient that he or she should not assume he or she should be taking all the capsules in the bottle. The patient should compare the pre- scriber’s written instructions with the pharmacy label, and he or she needs to call if there are any questions prior to taking a dose.


  1. Program alerts into order entry systems to prevent errors (e.g., al- lowing only a single dose to be entered).
  2. Dispense only a single dose per filled prescription. Call the pre- scriber if multiple doses have been prescribed.
  3. Ensure patients receive counseling when picking up new prescriptions and refills for lomustine.
  4. Supply written drug education materials to patients that include information about dispensing only a single dose per fill. Verify the written drug education materials are consistent with the labeled instructions.
  5. Enhance labels with bold font or all capital letters.
  6. Avoid filling lomustine prescriptions via mail order or specialty pharmacies unless patient counseling can occur by phone prior to dispensing the drug.


  1. Reinforce education on taking only a single dose for those patients being discharged on lomustine therapy.


  1. Do not approve more than a single-dose supply for outpatient lomustine prescriptions.


  1. Enhance label warnings to dispense only enough capsules for one dose.

FDA and Manufacturer

  1. Require distribution of medication guides to patients receiving lomustine.