Oral cytotoxics: iatrogenic risks?

The last 10 years have seen a considerable boom in oral cytotoxics (chemotherapy and targeted therapies). The iatrogenic risk associated with these products is different from the injectable forms the administration and dispensation of which are no doubt better controlled (clinical units and Clinical Research Units). The iatrogenic risks can be classified into 3 categories depending on their origin:

• iatrogenic risks linked to the molecule itself: these are secondary effects in the true sense of the term. The often narrow therapeutic window and the variation in bio-availability are the source of unforeseeable toxicities or, on the contrary, losses of efficacy.
• patient-related risks: this is a question of compliance. The overall rate in the majority of studies on compliance with cytotoxics is between 40% and 50%. There are many factors in compliance such as the complexity involved in the taking of certain drugs, changes of habit, faulty communication with the health professionals, whether or not the patient believes in the treatment, social conditions or finally prior history of mental illness.
• risks related to the prescription or delivery of the drug. This may involve dose errors or at the very least an imprecise prescriptions, the faith of the prescriber in the efficacy of oral chemotherapies, errors in delivery or in the verification of the doses prescribed at the time of delivery.

Knowledge of these iatrogenic risks means that thought must be given to the management of oral cytotoxics that must be handled as part of an anticipatory approach to the therapeutic education and training of all the professionals concerned, including general practitioners, community nurses and pharmacists. Our modest personal experience of 6 years in oral cytotoxics has also enabled us to appreciate the importance of nursing consultation dedicated to these molecules as part of our announcement system. Optimal supervision of the initial treatment appears to guarantee better compliance and less iatrogenicity. A properly “informed” patient is better able to cope with a toxic effect. Finally, the use of detailed “typical prescriptions” and the notion of prescribers “specialised in chemotherapy” tends to improve the quality and safety of management.

In conclusion, stringent management according to the example of intravenous chemotherapies deserves to be implemented for these oral cytotoxics.