The effect of antiepileptic drugs on thyroid hormonal function: causes and implications

The effect of antiepileptic drugs on thyroid hormonal function: causes and implications

Study quality was assessed with the Newcastle–Ottawa quality assessment scale for observational studies and the Risk Of Bias In Non-randomized Studies – of Interventions (ROBINS-I) tool was used. Anti-seizure drugs have long been known to affect thyroid hormone levels in epilepsy patients. The current study is a network meta-analysis designed to produce a systematic review and comprehensive evaluation of thyroid hormone changes to inform future research and clinical treatment. Antiepileptic drugs (AEDs) are known to have endocrine side effects in both men and women. These can affect fertility, sexuality, thyroid function, and bone health, all functions of major importance for well-being and quality of life. The liver enzyme inducing antiepileptic drugs (EIAEDs), like phenobarbital, phenytoin, and carbamazepine, and also valproate (VPA), a non-EIAED, are most likely to cause such side effects.

How long after taking levothyroxine can you drink milk?

Thyroid abnormalities were reported in one-third of the patients on AEDs. All reported patients were clinically euthyroid and hormonal changes were reversible after AED withdrawal. The mechanisms for thyroid dysfunction with AEDs include enhanced metabolism and/or altered protein binding or interference of hypothalamic-pituitary-thyroid axis function.

However, this finding should be interpreted with caution due to the limited number of studies with relatively short follow-up period and lack of robust statistical evidence. Well-designed large studies are needed in order to further better clarify the interfering role of PPI on LT4 intestinal absorption. Saraceno et al.37 carried out a crossover study in 15 patients on LT4, 6 of them on replacement therapy and 9 on TSH-suppressive therapy, who were receiving PPI. The patients switched from the tablet to the oral solution of LT4.

  • Patient’s demographic data including age, sex, diagnosis, duration of treatment, other medications, and serum fT3, fT4, and TSH levels were monitored.
  • One factor that probably contributes to the variability of levothyroxine drug—drug interactions is that some individuals are completely dependent on exogenous levothyroxine (eg, following total thyroidectomy) while others have varying degrees of residual thyroid function.
  • This review focuses on the evidence, mechanisms of thyroid abnormalities with AEDs and their clinical implications.
  • Do not stop using any medications without first talking to your doctor.
  • The GRADE quality of evidence suggested that there was moderate quality of evidence in the included studies (Supplementary Table S4).

levothyroxine

This will help you and your doctors to evaluate all possible interactions and come up with a plan to avoid or minimize them. Completed the searching and screening of literature and data extraction. Gave the methodological guidance and writing guidance throughout the process. Each author contributed to the article and approved the submitted version. Alcohol can increase the nervous system side effects of levETIRAcetam such as dizziness, drowsiness, and difficulty concentrating. Some people may also experience impairment in thinking and judgment.

View interaction reports for Keppra (levetiracetam) and the medicines listed below. synthroid gout Enter medications to view a detailed interaction report using our Drug Interaction Checker. To view an interaction report containing 4 (or more) medications, please sign in or create an account.

EIAEDs increase sex hormone binding globulin (SHBG) concentrations in both men and women. Over time, this elevation can lead to lower levels of bioactive testosterone and estradiol, which may cause menstrual disturbances, sexual problems, and eventually reduced fertility. In women, VPA can also lead to androgenization with increased serum testosterone concentrations, menstrual disturbances, and polycystic ovaries.

Therefore, levothyroxine should be taken on a consistent schedule with regard to time of day and relation to meals to avoid large fluctuations in blood levels, which may alter its effects. In addition, absorption of levothyroxine may be decreased and/or delayed by foods such as soybean flour, cotton seed meal, walnuts, dietary fiber, calcium, calcium fortified juices and grapefruit or grapefruit juice. These foods should be avoided within several hours of dosing if possible. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.

  • Regarding the quality assessment, six out of seven studies were considered at low risk of bias,25–28,31,38 while one37 was considered at moderate risk because of measurement of outcomes.
  • The current study is a network meta-analysis designed to produce a systematic review and comprehensive evaluation of thyroid hormone changes to inform future research and clinical treatment.
  • Using multivitamin with minerals together with levothyroxine may decrease the effects of levothyroxine.
  • Therefore, the results of this systematic review were summarized qualitatively.
  • Thyroid abnormalities were reported in one-third of the patients on AEDs.

Keppra alcohol/food interactions

The full effects of levothyroxine may take weeks to months to realize. With hypothyroidism, you will need to take thyroid replacement such as levothyroxine for the rest of your life. Likewise, one coauthor of this paper (RV)38 evaluated the efficacy of a liquid formulation of LT4 in correcting tablet LT4 malabsorption by PPI in 24 patients, switching from the LT4 tablet formulation to the oral solution while maintaining the same dose. Indeed, serum TSH levels were lower under the oral solution compared with the tablet both in the replacement group (1.7mU/l ± 1.0 vs. 5.4 mU/l ± 4.3) and in the TSH-suppressive group (0.1 mU/l ± 0.3 vs. 2.1 mU/l ± 2.7). One factor that probably contributes to the variability of levothyroxine drug—drug interactions is that some individuals are completely dependent on exogenous levothyroxine (eg, following total thyroidectomy) while others have varying degrees of residual thyroid function. Those with some thyroid function may also have varying degrees of feedback stimulation of endogenous thyroid release via thyroidreleasing hormone and TSH.

A recent study assessed thyroidstimulating hormone and levothyroxine dosage in 5426 outpatients who had been prescribed levothyroxine, along with drugs that can impair levothyroxine absorption or affect levothyroxine metabolism. The results were supplemented by a manual search of the bibliographies of the shortlisted review and original study articles. In addition, a number of field experts were approached in order to identify additional viable studies from the gray literature. Two independent investigators (YGP and OS) separately screened the titles and abstracts for eligible studies published up to September 1, 2019. For drug interactions that result in binding of the levothyroxine and therefore decreased absorption of the drug from the intestine, it is very important to avoid taking the interacting medicine at the same time as levothyroxine.

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This review focuses on the evidence, mechanisms of thyroid abnormalities with AEDs and their clinical implications. The associations between subclinical hypothyroidism and metabolic risks due to AEDs are also discussed. Therefore, the results of this systematic review were summarized qualitatively. A systematic review of interventional and observational studies that compared the TSH levels before and after concomitant use of LT4 and PPI was performed. Articles published in English up to September 1, 2019, were included. Gray literature was also searched in repositories, websites OpenGrey and Google Scholar, and abstracts of major international congresses.