United States of America. The ISMP has received numerous reports of mix-ups between OxyContin (Purdue Pharma) oxycodone controlled-release tablets and oxycodone immediate- release tablets. Some of these mix-ups occurred when staff confused the brand name, OxyContin, with “oxycodone”. In other cases, the generic name, oxycodone, was used when ordering the controlled-release product without specifying “controlled-release”. Consequently, patients are accidentally receiving the immediate-release product and may not be able to tolerate the substantial increase in peak blood levels of oxycodone.

The following measures may help to distinguish between these two products:

Immediate-release oxycodone 5 mg tablets are available for example as Roxicodone (Roxane), Percolone (Dupont) and M-Oxy (Mallinckrodt), and in 5 mg capsules as Oxy-I (Purdue Pharma). The dosage form (controlled or immediate-release) must be specified.

Immediate-release and controlled-release products should not be stored near one another or appear as choices on the same computer screen. Indicate “controlled- release” or “immediate-release” with product names on pharmacy computer and automated dispensing module monitors.

If possible, have the pharmacy dispense oral oxycodone products directly for individual patient use, rather than relying on nursing unit stock or automated dispensing modules.

Carefully assess narcotic analgesic sign-out sheets to assure that errors are not being made.

When possible, use colour to help distinguish (not identify) the products. Controlled-release oxycodone (OxyContin) is available in 10 mg, 20 mg, 40 mg and 80 mg tablet strengths. Unlike the immediate-release oxycodone table product, OxyContin tablets are coated with different colours to help differentiate varying strengths and distinguish it from other products.

Educate staff about the potential for confusion between these two products. Consider applying auxiliary labels to the products. Develop posters and post charts to help staff differentiate formulary narcotic analgesics.(1)

Note: These reports highlight the problem of trade names being selected that are confusingly similar to the existing international nonproprietary name(INN), or generic name. This problem was discussed in the Forty-sixth World Health Assembly which noted in Resolution WHA46.19⁽²⁾ the concern expressed by the Sixth International Conference of Drug Regulatory Authorities (1991) about the increasing use of pharmaceutical brandnames that are very similar to or derived from international nonproprietary names and requested, inter alia, Member States to “develop policy guidelines on the use and protection of international nonproprietary names, and to discourage the use of names derived from them, and particularly names including established stems, as trade-marks”.

References:

1) ISMP Medication Safety Alert! Vol. 3, Issue 17, 26 August 1998.
2) World Health Assembly Resolution WHA46.19. Nonproprietary names for pharmaceutical substances. Forty-sixth World Health Assembly, 1993.