You are here

Duro-K 600 mg potassium chloride tablets

Advisory – lead content may exceed regulatory guidelines

15 March 2018

Consumers and health professionals are advised that the TGA is aware that one batch of Duro-K 600 mg potassium chloride tablets that has been supplied in Australia has higher levels of lead than permitted under new regulatory guidelines.

Duro-K tablets are prescription medicines used to provide extra potassium:

  • for adults who do not have enough potassium in their regular diet
  • for adults who have lost too much potassium from their bodies because of illness or treatment with certain medicines.

Duro-K is also used in those patients who cannot tolerate or refuse to take liquid or effervescent potassium chloride.

Following testing to comply with a new regulatory guidelines that came into effect in December 2017, the sponsor, Novartis, notified the TGA that Duro-K potassium chloride 600 mg tablets and Slow-K potassium chloride 600 mg tablets may exceed the new maximum oral permitted daily exposure (PDE) for lead, which is 5 micrograms.

The TGA then tested samples from each of the batches of Duro-K and Slow-K tablets that were being supplied in Australia. Of these samples, only one batch of Duro-K exceeded the new PDE for lead. However, that batch was compliant with the limit set by the previous guidelines, which was in effect at the time of manufacture. Novartis has also confirmed they no longer hold supply of this batch.

The TGA also tested two other potassium chloride products, Span-K and Chlorvescent, which are sponsored by a different company. The lead content in these two products was within acceptable limits.

The TGA has determined that the lead content in the affected batch of Duro-K does not present a significant health risk, even for people taking the maximum dose (12 tablets per day).

The PDE for lead in the new regulatory guidelines is based on the paediatric population, who absorb more lead than adults and are more sensitive to the toxic effects of lead. Duro-K tablets are not indicated for use in children.

As of 13 March 2018, there have been no reports of adverse events relating to exposure to lead associated with Duro-K.

Based on these considerations, the TGA has determined that no further action regarding the affected batch is required. However, any future batches of Duro-K and Slow-K tablets must be tested to ensure they comply with the new PDE for lead before they can be supplied in Australia.

Information for consumers

If you or someone you provide care for takes Duro-K 600 mg potassium chloride tablets, please be aware of this issue but do not be alarmed. Even if you are taking tablets from the one affected batch of Duro-K, the risk to your health is considered negligible.

It should be noted that, lead is a known impurity that can occur due to the mining process for potassium chloride.

If you have any questions or concerns about this issue, speak to your health professional.

Information for health professionals

Novartis has sent a letter to health professionals providing further information about this issue.

If you are treating patients who take Duro-K 600 mg potassium chloride tablets, consider informing them of this issue and advise them accordingly.

If you have any questions or concerns about this issue, contact Novartis on 1800 671 203 or email

Reporting problems

Consumers and health professionals are encouraged to report problems with medicines or vaccines. Your report will contribute to the TGA's monitoring of these products.

The TGA cannot give advice about an individual's medical condition. You are strongly encouraged to talk with a health professional if you are concerned about a possible adverse event associated with a medicine or vaccine.