MHRA Highlights Risk of Medication Error Associated with Paclitaxel Formulations

Pavankumar Kamat

January 19, 2022

The Medicines and Healthcare products Regulatory Agency (MHRA) has issued a drug safety update for paclitaxel formulations, highlighting the risk of medication error arising from a potential mix-up of conventional paclitaxel and nanoparticle albumin-bound paclitaxel (nab-paclitaxel).

Conventional paclitaxel has been available as an oncology drug since 1993 for the treatment of certain ovarian, breast, and lung cancers, as well as advanced AIDS-related Kaposi’s sarcoma. A nab-paclitaxel formulation was authorised in 2008 under the brand name Abraxane. In 2019, another nab-paclitaxel formulation Pazenir was approved as bioequivalent to Abraxane.

Not Interchangeable

The MHRA has clarified that conventional paclitaxel and nab-paclitaxel formulations are not interchangeable, owing to their significantly different properties. The recommended dosages and infusion times for the formulations are notably different. Nab-paclitaxel formulations need to be infused intravenously over a shorter period of time (30 minutes) compared with a much longer infusion time (3 hours) for conventional paclitaxel. They also differ in terms of other pharmacokinetic parameters such as plasma clearance and volume of distribution.

Inadvertent substitution of paclitaxel formulations could lead a higher than intended dose with the risk of toxicity, or a suboptimal dose with diminished therapeutic effects. Furthermore, nab-paclitaxel is sometimes prescribed to patients who have developed hypersensitivity to conventional paclitaxel. A mix-up of the formulations could increase the risk of hypersensitivity reactions.

No Reports Yet but Caution Advised

As of September 2021, the MHRA had not received any reports of patient harm from medication errors associated with paclitaxel formulations; however, healthcare professionals (HCPs) should remain vigilant when prescribing them.

It is crucial for HCPs to explicitly differentiate between paclitaxel formulations when prescribing, dispensing, administering, and communicating about these drugs. It is advisable to use the brand names when referring to nab-paclitaxel formulations. HCPs are advised to verify the product name and dose prior to administration and ensure adherence to specific instructions mentioned in the Summaries of Product Characteristics.

Any suspected adverse drug reaction, including medication error should be promptly reported to the Yellow Card Scheme.


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