Published: 6 June 2024
Publications
Potassium in dietary supplements may lead to hyperkalaemia
Published: 6 June 2024
Prescriber Update 45(2): 37–38
June 2024
The Centre for Adverse Reactions Monitoring (CARM)/Medsafe recently
received a report of an elderly person with chronic kidney disease who
experienced hyperkalaemia (report ID 153740). The person was taking
a potassium-containing supplement marketed for joint health. The product
was thought to be a contributing factor to the hyperkalaemia. This is
the fourth CARM report where a dietary or herbal supplement was reported
to have caused hyperkalaemia.
Hyperkalaemia
Hyperkalaemia is defined as a serum potassium level greater than 5.3 mmol/L. It is more common in older people and those with renal impairment.1
Hyperkalaemia is often asymptomatic. When there are signs and symptoms, these may include:1
- nausea and vomiting
- muscle pain and weakness
- paraesthesia
- flaccid paralysis
- ECG changes, palpitations and arrythmias.
Severe hyperkalaemia (≥7.0 mmol/L or ≥5.4 mmol/L with ECG changes or symptoms) is life-threatening.1
Medicines and supplements may contribute to hyperkalaemia
A wide range of medicines can cause hyperkalaemia through a variety of mechanisms, for example, by inhibition of the renin-angiotensin system or interference with potassium renal excretion. Hyperkalaemia-inducing medicines include angiotensin converting enzyme (ACE) inhibitors, angiotensin II receptor blockers (ARBs), non-steroidal anti-inflammatory drugs (NSAIDs), spironolactone, potassium supplements, beta blockers, digoxin and trimethoprim.2
Some herbal ingredients in supplements contain potassium, including (but not limited to) stinging nettle, evening primrose, turmeric, dandelion. Other supplements may contain potassium as an ingredient or excipient, for example, glucosamine sulfate–potassium chloride complex.1,3
New Zealand reports
Between 1986 and 2023, Medsafe and CARM received 84 reports of hyperkalaemia. The most frequently reported suspect medicines include ACE inhibitors (21 reports), trimethoprim or cotrimoxazole (17 reports), NSAIDs (9 reports), spironolactone (6 reports) and ARBs (6 reports).
Prescribing considerations
Remind patients who are at risk of hyperkalaemia to carefully read the ingredients list and seek medical advice before taking potassium-containing supplements.
If hyperkalaemia occurs, consider whether a medicine or supplement could be a contributing factor and discontinue the suspect medicine or supplement if appropriate.1
For information on the management of hyperkalaemia, refer to local clinical guidelines.
Labelling requirements for medicines
New labelling requirements for the potassium content in oral medicines came into effect on 1 March 2024. If the total potassium content of the maximum recommended daily dose is greater than 39 mg (1 mmol) elemental potassium, the medicine packaging must state the quantity of potassium contained in each dosage unit.4 However, this requirement does not apply to dietary supplements, as they are not subject to the Medicines Regulations 1984.
Medicine data sheets and Consumer Medicine Information (CMI) also list excipients.
Further information
- Medsafe patient leaflet on new labelling requirements for excipients
- Prescriber Update September 2015: Medicines and hyperkalaemia
- United States National Kidney Foundation: Herbal supplements and kidney disease
- Search for a data sheet or CMI
References
- bpacnz. 2011. A primary care approach to sodium and potassium imbalance. Best Tests September 2011. URL: bpac.org.nz/bt/2011/september/imbalance.aspx (accessed 17 April 2024).
- Ben Salem C, Badreddine A, Fathallah N, et al. 2014. Drug-induced hyperkalemia. Drug Safety 37(9): 677–92. DOI: 10.1007/s40264-014-0196-1 (accessed 17 April 2024).
- National Kidney Foundation. 2019. Herbal supplements and kidney disease April 2019. URL: www.kidney.org/atoz/content/herbalsupp (accessed 17 April 2024).
- Medsafe. 2023. Label Statements Database Edition 2.02 August 2023: Potassium salts. URL: www.medsafe.govt.nz/regulatory/labelling.asp (accessed 8 April 2024).
