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Levothyroxine generics can cause side effects

The Medicines and Healthcare products Regulatory Agency (MHRA) have published new guidance regarding levothyroxine

The MHRA have just published new prescribing advice for healthcare professionals who prescribe levothyroxine due to reports of some patients experiencing symptoms on switching between different tablet products.

Levothyroxine is usually a generic product i.e. a copy of a previous brand rather than a branded version.  There are several levothyroxine generics nowadays and this means that you may not be given the same generic every time you collect your prescription.

The MHRA state, “This means that patients may receive different levothyroxine tablet products according to what is available at their local pharmacies. The prescriber is generally unaware of the specific product that the patient is taking. This generic prescribing approach is supported by strict UK regulatory requirements for licensing to ensure compatibility (bioequivalence) between products.

The Medicines and Healthcare products Regulatory Agency (MHRA) received a number of reports predominately from patients and some HCP’s via the Yellow Card scheme  who reported adverse events/symptoms on switching between different levothyroxine products. 

We have conducted a review of the available data and sought advice from the Commission on Human Medicines(CHM) who advised that levothyroxine should continue to be prescribed generically for most patients. If a patient reports symptoms after their brand of levothyroxine is changed, healthcare professionals are advised to consider testing of the thyroid function and follow the ‘Advice for healthcare professionals’ section in the new prescribing advice.

The problem is, many patients do not realise that they have been given a different generic. Sometimes they don’t notice that the design of the box is different.  They have no reason to suppose that their medication has been changed.  The name of the medication may be the same but generally, the ingredients are different. 

We are often contacted by people who have been poorly with adverse effects for months and they have no idea why.  When we ask them if their medication has been changed for a different generic, the answer is most often yes.

The patients are very angry about this as the side effects have affected their home, work and social lives.

We know that many people who have contacted us about this have gone on to complete a Yellow Card.  These people are mostly women and, once again, we are not being listened to.

Thyroid UK believes that patients should be left on the generic that makes them feel well and not have the risk that a different one may or may not make them ill with hypothyroid symptoms again or worse, the symptoms people are telling us about – headaches, nausea, joint pain, extreme fatigue, heightened anxiety, the shakes, stomach pain and heightened depression.

The product information and patient information leaflet (PIL) for levothyroxine tablet products is being updated to include this advice for prescribers.  However, we are not sure that doctors actually read this information so make sure you show them the PIL when you visit them. 

So, let’s spread awareness of this issue!  Make sure people are aware that they may be given a different generic so that, should they get symptoms, they can go back to the pharmacy or their clinician and ask for their usual generic.  If this happens to you, your clinician will need to write the exact generic on all future prescriptions.

If your usual pharmacy informs you that they cannot get your usual prescription, try another pharmacy or download our list of Pharmacies and Wholesale Pharmacies and find one that will help you.

Please continue to report suspected adverse drug reactions to the Yellow Card scheme

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