6: Endocrine System

Needles for Pre-filled and Reusable Pen Injectors

• The dose of metformin should be built up slowly by 500mg increments per week to minimise GI side effects.
• NICE recommends that the dose should be reviewed if eGFR less than 45 mL/minute/1.73 m2 and to avoid if eGFR less than 30 mL/minute/1.73 m2. Withdraw or interrupt treatment in those at risk of tissue hypoxia or sudden deterioration in renal function, such as those with dehydration, severe infection, shock, sepsis, acute heart failure, respiratory failure or hepatic impairment, or those who have recently had a myocardial infarction.
• Surgery:
  • Contrast media - As the intravascular administration of iodinated contrast materials in radiologic studies can lead to renal failure, metformin should be omitted on the day of surgery.
  • No Contrast media - Metformin can be continued on the morning of surgery.
  • Post-operative advice - Check renal function post-operatively; once eating and drinking normally and variable rate intravenous insulin infusion (where applicable) has been stopped follow the advice below-
    • eGFR > 60ml/min (with or without use of contrast media) – restart metformin
    • eGFR 30 – 60ml/min and no use of contrast media – restart metformin
    • eGFR 30 – 60ml/min and use of contrast media – do not restart metformin until 48 hours post-operatively.
    • eGFR < 30ml/min (with or without use of contrast media) – do not restart metformin until renal function is stabilised.
• Coronary Angiography: withhold metformin for 48 hours post procedure and check renal function prior to re-initiating.

Pioglitazone risk of bladder cancer

MHRA Advice for healthcare professionals:

• Patients with active bladder cancer or with a history of bladder cancer, and those with uninvestigated haematuria, should not receive pioglitazone
• Prescribers should review the safety and efficacy of pioglitazone in individuals after 3–6 months of treatment to ensure that only patients who are deriving benefit continue to be treated. Pioglitazone should be stopped in patients who do not respond adequately to treatment (eg, reduction in glycosylated haemoglobin, HbA1c)
• Before starting pioglitazone, the following known risk factors for development of bladder cancer should be assessed in individuals: age; current or past history of smoking; exposure to some occupational or chemotherapy agents such as cyclophosphamide; or previous irradiation of the pelvic region
• Use in elderly patients should be considered carefully before and during treatment because the risk of bladder cancer increases with age. Elderly patients should start on the lowest possible dose and be regularly monitored because of the risks of bladder cancer and heart failure associated with pioglitazone