Policy statement
“The use of cytotoxic drugs is justified for the treatment of neoplastic disease in companion animals where there is evidence that such agents have a beneficial effect on quality of life / survival. However, many of these drugs have toxic properties which must be taken into consideration when undertaking chemotherapy."
Summary of recommendations
The following risks should be considered when using cytotoxic drugs:
- Risk to animal receiving chemotherapy
- Risk to owner of animal receiving chemotherapy
- Risk to veterinary staff handling and administering drugs
Guidance notes
Risk to animal receiving chemotherapy
1. Indications
Chemotherapy drugs should only be administered once a definitive diagnosis has been reached. This would usually require histopathological examination of tissue biopsy or cytological examination of an aspirate taken from the lesion. Care should be taken when using tests based on “markers” of neoplastic disease in blood samples and the sensitivity / specificity of such diagnostic tests should be considered when interpreting results.
Except when drugs are being given to maintain druginduced clinical remission or as adjuvant therapy after treatment of the primary tumour by surgery or radiation, chemotherapy drugs should not be administered where there are no overt signs of disease present. The choice of chemotherapy drugs used should be based on published evidence. Unless enrolled on a clinical trial, companion animals should be treated with chemotherapy drugs shown to have a beneficial effect on quality of life / survival in that particular tumour type, using protocols and dosages that are consistent with those in the published literature.
2. Adverse effects
The adverse effects of each chemotherapeutic agent should be noted and explained to the owner. It is advisable to monitor patients regularly to ensure prompt detection of adverse effects, allowing early interventional measures.
Examples include:
a.Monitoring neutrophil counts when using cytotoxic drugs that are myelosuppressive.
b.Monitoring urine for the presence of blood when administering cyclophosphamide.
Risk to owner of animal receiving chemotherapy
Owners should receive written information about the potential hazards associated with the cytotoxic drugs being used. The risks to children and pregnant women should be emphasised.
- Written information detailing the administration of oral cytotoxic drugs should be provided to the owner. Particular care should be taken to ensure that owners are aware of the potential hazards associated with handling these drugs and advised that cytotoxic tablets should not be broken or divided.
- Owners should receive written information describing how to deal with the patients excreta (vomit, faeces, saliva, urine) during therapy.
Risk to veterinary staff handling and administering cytotoxic drugs
- All personnel should be informed of the potential hazards associated with the use of cytotoxic drugs within the practice. Particular care should be taken to avoid exposure of pregnant women to cytotoxic drugs.
- Patients receiving chemotherapy, their kennels, and areas where cytotoxic drugs are being prepared / administered, should be clearly marked as a potential hazard to human health.
- All personnel should be made aware of the potential hazards associated with exposure to the patient’s excreta (vomit, faeces, saliva, urine) during therapy.
- Protective clothing should be provided and procedures put in place for dealing with excreta, disposal of contaminated material and cleaning surfaces likely to have been contaminated.
- Standard operating procedures should be followed for preparation and administration of cytotoxic drugs and staff should be properly trained to implement these.
- Personal protection equipment must be provided to prevent / minimise exposure to cytotoxic drugs when these are being prepared and administered. Where a designated safety cabinet is not available for reconstituting cytotoxic drugs, consider using alternative protective devices, e.g. PhaSeal (http://www.cavereferrals.com/Phaseal.htm)
- There should be a clear procedure for dealing with accidental spillages.
Further information:
Hayes, A. (2005) Safe use of anticancer chemotherapy in small animal practice. In Practice 27; 118127.
http://inpractice.bvapublications.com/cgi/reprint/27/3/118
“Preventing occupational and environmental exposure to cytotoxic drugs in veterinary medicine” [Download]