Stijgend gebruik van levothyroxine in België

Abstract

Increasing use of levothyroxine in Belgium In the past decades, increased prescription of levothyroxine (LT4) has been observed in Belgium, different countries in Western Europe and North America. The increased screening for thyroid dysfunction, longer life expectancy and lower threshold for the initiation of LT4 therapy are believed to play a role. The goal of this article is to present a data overview on the prevalence of hypothyroidism, LT4 use and screening for hypothyroidism in Belgium and other countries. The Belgian data are in line with those from other countries, where an increase in LT4 prescriptions has been observed. The threshold for the initiation of LT4 seems to have lowered. Not only the indication to start LT4, but also follow-up of the serum thyroid-stimulating hormone (TSH) are important to avoid complications. The elderly deserve special attention because of an age-related increase of the serum TSH level. This may increase the risk of overdiagnosis of hypothyroidism and overtreatment with LT4, which is associated with iatrogenic thyrotoxicosis, atrial fibrillation and osteoporosis. In the elderly, the decision whether or not to start LT4 needs to be individualized, particularly in cases with mild TSH elevation. If LT4 is initiated, the principle ‘start low, go slow’ should be followed. There is a need for a better knowledge and implementation of guidelines, adopting age-specific reference ranges for TSH in order to optimize the use of LT4.