Safety alert: Levothyroxine – Potential adverse reactions when switching brands

The Health Products Regulatory Authority (HPRA) Ireland, has announced that SmPC and PL for levothyroxine preparations (Eltroxin®, Levothyroxine Teva®, Oroxine® and other generic products) will be updated to include advice for patients switching brands or formulation due to the increased risk of adverse drug reactions following a potential imbalance of thyroid hormones. This follows recommendations issued by PRAC.

Levothyroxine is a thyroid hormone used to treat thyroid hormone deficiency.

Levothyroxine has a narrow therapeutic index. If a switch to a different brand or formulation is necessary, there is a need to closely monitor patients clinically and to perform thyroid function tests during the transition period.

Patients should be made aware of the symptoms that occur due to an imbalance of thyroid hormones and should be encouraged to consult their physician in the event that they experience any of these symptoms.

Reference: Drug Safety Newsletter, HPRA