Oncology and supportive care
Practice questions with explanations

C. Rehydrate first, then use a bisphosphonate or denosumab, avoiding thiazides and calcium supplements

Hypercalcaemia causes an osmotic diuresis and volume depletion, which itself raises calcium further, so saline rehydration comes first and often achieves substantial reduction alone. Thiazides reduce urinary calcium excretion and worsen it. The bisphosphonate takes two to four days to act, so it supplements rather than replaces hydration.

A. A bisphosphonate such as zoledronic acid, or denosumab, with attention to dental health before starting

Antiresorptive therapy reduces fractures, cord compression, the need for radiotherapy and hypercalcaemia. Osteonecrosis of the jaw is uncommon but more frequent at oncology doses than at osteoporosis doses, so a dental assessment beforehand and good oral hygiene matter. Calcium and vitamin D adequacy prevents hypocalcaemia, which is otherwise a real risk.

A. Regular prophylactic stimulant laxative with an osmotic agent, titrated to effect and continued as long as the opioid is used

Opioid constipation does not resolve with tolerance and is a leading reason patients reduce or abandon effective analgesia. Prophylaxis from the first dose is standard, and bulk-forming agents are unsuitable because propulsion is impaired. Where laxatives fail, a peripherally acting mu antagonist or methylnaltrexone can be used, and bowel obstruction must be excluded.