Generally, licensed drug-dosing recommendations for many drugs are based on results from clinical trials where underweight and obese subjects or subjects with cachexia, the wasting syndrome that stops cancer patients from wanting to eat, have been under-represented. In fact they are usually excluded. Such scenarios result in doctors having to estimate or guess the appropriate dose of drug for a patient. Dosing that is inappropriate for the patient’s body composition i.e. mg/kg based on total body weight (TBW) can increase the risk of adverse events; in an underweight population (they also reduce clinical effectiveness in obese patients).
Unfortunately, there are almost no guidelines that can aid the clinician to select the optimal dose in patients outside of the ‘normal weight’ spectrum. Total body weight is the variable that is often used however it will not result in comparable drug exposure across the spectrum of body compositions (fat, water, muscle, for example). To ensure normalised drug exposure, doses of drugs need to be chosen based upon a metric correlated with drug clearance.
The Bioimpedence Scales will provide our researchers with a suitable method to assist dose adjustment. The scales will be used in HMRI’s Clinical Cancer research studies. The Bioimpedence Scales would be ‘housed’ in the Medical Oncology (Chemo Day Suite area of Oncology) at the Newcastle Calvary Mater Hospital as this is where the patients come to their booking appointment but can also be wheeled to the ward for palliative care patients.
The Bioimpedence Scales will be purchased as soon as funds become available as they are urgently needed for a number of research projects.