The MHRA has suspended its licence for Teva and Numark levothyroxine 100mcg tablets after manufacturing problems and concerns the tablets are not interchangeable with other brands.

Teva has voluntarily ceased manufacture and distribution of the tablets, which will cease to be available in the UK in the next few weeks as stocks are exhausted. The suspension will remain in place until Teva has completed its investigation and resolved any issues; only Teva and Numark brands are affected.

The move follows a review by the MHRA Commission on Human Medicines, which found "manufacturing issues" and "sporadic reports" of loss of control of hypothyroid symptoms when patients switched between brands.

Pharmacists should advise any patient who feels unwell taking Teva levothyroxine tablets to return to their GP as adjustments to the dose may be required; patients at particular risk of changes to thyroid stimulating hormone (TSH) should be monitored by their GP, including pregnant women, those with heart disease, and patients being treated for thyroid cancer.

Further information is published in a Q&A on the MHRA website: www.mhra.gov.uk