Effects of antiepileptic drugs on thyroid hormone function in epilepsy patients
Patient’s demographic data including age, sex, diagnosis, duration of treatment, other medications, and serum fT3, fT4, and TSH levels were monitored. Fasting venous blood sample of 5 ml was collected from the patients and control subjects. Then, the blood was centrifuged and serum obtained was subjected to chemiluminescence autoanalyzer for assessing serum fT3, fT4, and TSH levels (Immulite-Siemens). The normal range of serum fT3 is 1.5–4.1 pg/ml, serum fT4 is 0.8–2.0 ng/dl, and serum TSH is 0.4–4 mIU/ml. The timing of meals relative to your oral levothyroxine dose can affect the absorption of the medication.
Keppra alcohol/food interactions
A hospital-based, analytical cross-sectional study was conducted among the adult epileptic patients receiving conventional AEDs (Group 2) or newer AEDs (Group 3) for more than 6 months. Serum thyroid hormone levels including free triiodothyronine (fT3), free thyroxine (fT4), and thyroid stimulating hormone (TSH) were analyzed and the hormonal status was compared with healthy control subjects (Group 1). A systematic search of databases, PubMed, EMBASE, Web of Science, and the Cochrane Library, was conducted and all observational studies reporting thyroid hormone levels in epilepsy patients receiving monotherapy and controls were included. It is noteworthy that in two studies37,38 patients were switched from the tablet formulation to the liquid one while maintaining the co-ingestion of PPI and the daily dose of LT4, with a significant decrease in serum TSH levels (Table 1). Sometimes drug interactions cannot be avoided because both medicines may be very important to your treatment.
How to take levothyroxine
Automatically receive FDA alerts, drug interaction warnings, plus data on food, allergy & condition interactions. However, this does not necessarily mean no interactions exist. This section collects any data citations, data availability statements, or supplementary materials included in this article. Usually it should be taken at least 30 to 60 minutes before eating breakfast, or at bedtime (3 or more hours after the evening meal).
Your saved search
- Levothyroxine is usually started at a low dose and slowly increased over time.
- These findings are consistent with drug—drug interactions that reduce levothyroxine serum concentrations, leading to a compensatory increase in TSH level and the need to increase levothyroxine dosage.
- A detailed assessment of the systematic error risk of all included studies is presented in Supplementary Tables S2 and S3, and Supplementary Figures S1 and S2.
However, given the small number of studies, further research is needed to clarify the interfering role of PPI on LT4 intestinal absorption. All data analyzed during the study are included in this published version. Levothyroxine is a man-made form of the human thyroid hormone called T4. It is given to people who do not produce enough of their own thyroid hormone (hypothyroidism). Add your drug list to My Med List to view medical information in a simple, easy-to-read, personalized format.
Save Interactions List
- However, given the small number of studies, further research is needed to clarify the interfering role of PPI on LT4 intestinal absorption.
- After another drug has been added to or removed from your regimen, you should report worsening of any disease symptoms or medication side effects to your doctor.
- Do not use more than the recommended dose of levETIRAcetam, and avoid activities requiring mental alertness such as driving or operating hazardous machinery until you know how the medication affects you.
- Following assessment and application of eligibility criteria, seven studies were included.
- Fasting venous blood sample of 5 ml was collected from the patients and control subjects.
In the case of levothyroxine, you may need more frequent testing of thyroid stimulating hormone and T4 levels when other medications are added or removed from your treatment regimen. After another drug has been added to or removed from your regimen, you should report worsening of any disease symptoms or medication side effects to your doctor. The objective of the study was to evaluate and compare the effect of conventional and newer antiepileptic drugs (AEDs) on thyroid hormone levels in adult epileptic patients. The contradictory findings mentioned may result from the limited size of the cohorts analyzed as well as differences in subjects enrolled (patients vs. healthy volunteers). To clarify the effect of the concomitant ingestion of PPI and tablet LT4, we conducted a systematic review of interventional and observational studies in the literature aiming at determining serum TSH changes before and after the concomitant use of these two drugs.
Similar articles
Serum levels of TSH were lower under the oral solution compared with the tablet both in the replacement group (1.63 ± 0.66 mU/l vs. 2.77 ± 2.05 mU/l) and in the suppressive group (0.12 ± 0.12 mU/l vs.1.15 ± 1.85 mU/l). The aim of this study was to assess the effect of concomitant use of levothyroxine (LT4) and proton pump inhibitors (PPIs) on thyroid-stimulating hormone (TSH) levels in patients with primary hypothyroidism. Using multivitamin with minerals together with levothyroxine may decrease the effects of levothyroxine. You should separate the administration of levothyroxine and multivitamin with minerals by at least 4 hours. If your doctor does prescribe these medications together, you may need a dose adjustment or special test to safely use both medications. Mangaiarkkarasi Adhimoolam contributed in the idea of research, study design, data collection, data analysis and manuscript preparation with literature analysis.
Following assessment and application of eligibility criteria, seven studies were included. There was a considerable heterogeneity among the included studies in design, sample size, inclusion and exclusion criteria, treatment regimen, and baseline demographics. Each of the included studies showed an increase in TSH levels following LT4 and PPI consumption, and in the majority of these, the increase was statistically significant. In the preliminary search, 5012 studies were identified through the literature search, and 2004 remained after the duplicates were removed. A title and abstract review was performed on the remaining 2004 studies, with 1983 excluded at this first stage for not meeting the PICOS criteria. A PRISMA flow diagram of the screening and selection process can be found in Figure 1.
Taking it on an empty stomach results in the best absorption of the drug from the intestine. You may be able to take other medications with levothyroxine, but some of them will have to be taken at a different time from when you take your levothyroxine. Horn and Hansten are both professors of pharmacy at the University of Washington School of Pharmacy. For an electronic version of this article, including references, if any, visit
- All data analyzed during the study are included in this published version.
- A PRISMA flow diagram of the screening and selection process can be found in Figure 1.
- Well-designed large studies are needed in order to further better clarify the interfering role of PPI on LT4 intestinal absorption.
- Automatically receive FDA alerts, drug interaction warnings, plus data on food, allergy & condition interactions.
- Make sure to always give all of your healthcare providers a full list of your medications (prescription and nonprescription) and any supplements you take.
In fact, it is recommended to separate the administration of these medicines from levothyroxine by 4 hours. Each of the included studies showed an increase in TSH levels following LT4 and PPI consumption and in the majority of these, the increase was statistically significant. This effect could be much evident in subjects synthroid vegan in whom LT4 absorption is already impaired for other reasons.
Lamotrigine has not been shown to result in endocrine side effects. The newer AEDs have not yet been thoroughly studied, but case reports indicate that some of these drugs could also be suspected to cause such effects if endocrine changes commence after treatment initiation. It is important to be aware of possible endocrine side effects of AEDs as they can have a major impact on quality of life, and are, at least partly, reversible after AED discontinuation.
