ArticleDrugs in R&D2016
Comorbidities, Concomitant Medications, and Diet as Factors Affecting Levothyroxine Therapy: Results of the CONTROL Surveillance Project.
Article in Drugs in R&D, 2016. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Cited by 31 papers.
What it found
Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.
The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.
The trial behind it
Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.
Neither the registry nor the abstract names a trial number. If this is a trial report, that itself is worth knowing.
Who cites it
31 citing papers in PubMed, 60 citations in OpenAlex.
- Phase 1 Study Evaluating the Pharmacokinetics, Dose Proportionality, Bioavailability, and Tolerability of Subcutaneous Levothyroxine Sodium (XP-8121).Clinical and translational science · 2025Trial
- A Novel Levothyroxine Solution Results in Similar Bioavailability Whether Taken 30 or Just 15 Minutes Before a High-Fat High-Calorie Meal.Thyroid : official journal of the American Thyroid Association · 2022Trial
- Review
- Thyroid Hormone Replacement Dose Is Not Associated with Anti-TPO and Anti-TG Antibody Titers in Hashimoto's Disease.Journal of clinical medicine · 2026Article
- Italian guidelines for the management of adult individuals with primary hypothyroidism outside pregnancy.Journal of endocrinological investigation · 2025Article
- The Chronobiology of Hormone Administration: "Doctor, What Time Should I Take My Medication?"Endocrine reviews · 2025Review
- Breakfast Habits in Patients Using Levothyroxine: Patient Experiences and Preferences.Journal of the Endocrine Society · 2024Article
- Thyroid function status in patients with hypothyroidism on thyroxine replacement and associated factors: a retrospective cohort study in primary care.BMC primary care · 2024Article
- Association of pharmacogenomic, clinical and behavioural factors with oral levothyroxine (LT-4) dose of hypothyroid patients in Sri Lanka: a matched case control study.BMC medical genomics · 2024Article
- Lactose intolerance and levothyroxine malabsorption: a review of the literature and report of a series of patients treated with liquid L-T4 without lactose.Frontiers in endocrinology · 2024Review
- Demographic, Healthcare Access, and Dietary Factors Associated With Thyroid Hormone Treatments for Hypothyroidism.The Journal of clinical endocrinology and metabolism · 2023Article
- Unusual causes of hyperthyrotropinemia and differential diagnosis of primary hypothyroidism: a revised diagnostic flowchart.European thyroid journal · 2023Review
- Levothyroxine Timing during Ramadan: A Randomized Clinical Trial.International journal of endocrinology · 2023Article
- Pharmacokinetics and Clinical Implications of Two Non-Tablet Oral Formulations of L-Thyroxine in Patients with Hypothyroidism.Journal of clinical medicine · 2022Review
- Factors influencing the levothyroxine dose in the hormone replacement therapy of primary hypothyroidism in adults.Reviews in endocrine & metabolic disorders · 2022Review
- An Overview on Different L-Thyroxine (l-TFrontiers in endocrinology · 2022Review
- Levothyroxine sodium oral solution to control thyroid function in a patient with hypothyroidism and celiac disease.Clinical case reports · 2021Article
- Levothyroxine Interactions with Food and Dietary Supplements-A Systematic Review.Pharmaceuticals (Basel, Switzerland) · 2021Review
- Levothyroxine Sodium Oral Solution Normalizes Thyroid Function in a Patient with Hashimoto's Disease, Gastritis, Diabetic Gastroparesis, and Small Intestinal Bacterial Overgrowth (SIBO).International medical case reports journal · 2021Article
- The activities of drug inactive ingredients on biological targets.Science (New York, N.Y.) · 2020Article
Corrections and comments
PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.
Authors and funding
8 authors at 4 institutions in 3 countries.
Funding
No grant is acknowledged in the PubMed record.
Abstract
backgroundThe CONTROL Surveillance Project was a comprehensive patient-based survey conducted among hypothyroid patients undergoing treatment. The primary objective of the study was to specifically quantify the prevalence of factors adversely affecting levothyroxine therapy.
methodsParticipants were selected from a large proprietary database. Those eligible for the study completed a 21-question survey.
resultsOf the eligible hypothyroid patients, 925 (92.5%) were being treated with levothyroxine monotherapy. The mean age was 60.4 years; 755 (81.6%) were female and 168 (18.2%) were male. Almost half of those receiving levothyroxine (435, 47.0%) had at least one comorbid condition that could adversely affect its absorption: gastroesophageal reflux disease (33.8% of patients), irritable bowel syndrome (9.7%), lactose intolerance (7.8%), or a history of gastric bypass surgery or bowel resection (3.0%). Other factors reported by many patients that could adversely affect levothyroxine absorption included use of prescription medications (20.6%) and over-the-counter medications (34.3%) used to treat comorbid gastrointestinal (GI) conditions; use of dietary supplements (51.8%, primarily calcium and iron); and intake of foods/beverages high in fiber, iodine, or soy (68.0%). Of the 13.4% who reported difficulty controlling their hypothyroid symptoms, significantly more patients with comorbid GI conditions reported such difficulty (7.8 versus 5.6%, P < 0.01). Frequent changes in levothyroxine dosing (two or more dose changes in the past year) were reported by 8.0% of survey participants. Those with GI comorbidities were nearly twice as likely to have such changes (5.0 versus 3.0%, P < 0.01).
conclusionBetter initial workup of patients, including identification of relevant GI comorbidities and allergies, may help in the early detection of factors that may affect the performance of levothyroxine.
Indexed as
Identifiers
What OpenQuestion holds
Registered trials
Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.