Adverse Metabolic Effects of Prescribed Drugs (e.g. Hypokalaemia with Diuretics)

Many commonly prescribed medications in primary care can cause metabolic disturbances. These effects may be subtle, delayed, or masked by other conditions, but they can lead to significant morbidity if missed.

Common metabolic side effects include:

• Electrolyte imbalances (e.g. ↓K⁺, ↓Na⁺)

• Glucose abnormalities (e.g. ↑glucose with corticosteroids)

• Lipid changes (e.g. ↑cholesterol with antipsychotics)

• Acid-base disturbances (e.g. metabolic acidosis with metformin)

Early recognition is essential, especially in older adults, polypharmacy, or renal impairment.

GPs must be vigilant—particularly in patients with polypharmacy, renal impairment, elderly age, or multimorbidity—to detect these early through baseline testing, ongoing monitoring, and patient education.

The RCGP Core Curriculum explicitly highlights this area—stating that GPs should be familiar with adverse metabolic effects of prescribed drugs, such as hypokalaemia induced by diuretics.

Key metabolic adverse effects of common drugs

The following table organises the drug classes listed by the RCGP curriculum and includes additional key examples.