Levoxyl vs synthroid which is better

In , the manufacturer of the levothyroxine brand Thyrax experienced an interruption in production that required approximately , Dutch patients to change their levothyroxine supplier. The current study examined the effect of the shortage of the levothyroxine brand Thyrax in the Netherlands and subsequent switch to a different brand on thyroid stimulating hormone TSH levels. Epub Mar PMID: Summary of the study. Patients taking at least 25 mcg Thyrax daily for at least one year were included.

Two groups were included: a group of patients who switched from Thyrax to another brand and a group of patients who continued taking Thyrax. In particular, memory problems and depression psychometric problems as well as weight gain are very common symptoms in hypothyroidism but also have multiple other nonthyroidal causes as well. Levothyroxine is the main thyroid hormone produced by the thyroid gland and the synthetic form is the most common form of thyroid hormone replacement therapy.

Prior to the availability of the pure levothyroxine, desiccated animal thyroid extract was the only treatment for hypothyroidism. In addition, some patients who continue to have symptoms of hypothyroidism when taking levothyroxine report improvement in these symptoms when switched to desiccated thyroid extract. This study was performed to compare levothyroxine to desiccated thyroid extract in terms of thyroid blood tests, changes in weight, psychometric test results and patient preference.

J Clin Endo- crinol Metab ; Elsevier Saunders Co; Reducing bias in observational studies using subclassification on the propensity score. Estimation of regression coefficients when some regressors are not always observed. Endocrine Society. Bioequivalence of sodium levothyroxine: an Endocrine Society Position Statement. Published June 1, US Food and Drug Administration. Published October 3, Accessed April 8, The Colorado thyroid disease prevalence study.

Generic and brand-name L-thyroxine are not bioequivalent for children with severe congenital hypothyroidism. Factors affecting gastrointestinal absorption of levothyroxine: a review. Get the latest research based on your areas of interest.

Weekly Email. Monthly Email. Save Preferences. Privacy Policy Terms of Use. Limit characters. Limit 25 characters.

Conflicts of Interest Disclosure Identify all potential conflicts of interest that might be relevant to your comment. Err on the side of full disclosure. Yes, I have potential conflicts of interest. No, I do not have potential conflicts of interest. Limit characters or approximately words. The following information is required and must be completed in order to submit a comment:. Thank You. Your comment submission was successful. Please allow up to 2 business days for review, approval, and posting.

In my anecdotal experience, I've had patients that required dose adjustments after such switches. I'd love to see a crossover study to see if switching brand-generic or generic-generic makes much of a difference in a population of people. I salute the FDA for regulating the levothyroxine LT4 market resulting in effective standards of manufacturing, performance and potency in LT4 products on the US market. I am reassured that both generic and name-brand products seem equally effective in achieving initial and relatively short term longitudinal normalization of TSH in patients with primary hypothyroidism.

I agree with the comment below that this is good news but does not have impact on the clinically important circumstance of retail switching from one product to another as required by most state laws. This occurs when prescriptions for name-brand products are not protected with language such as "Name-Brand Necessary.

The recommendations of the American Thyroid Association, American Association of Clinical Endocrinologists and The Endocrine society as cited in the Brito report seem more valid than ever, start LT4 therapy with one product and stick with it.

As there are several generic LT4s on the US market the source of generic LT4 may be dependent on which pharmacy the patient utilizes. Chain pharmacies tend to carry the same source of generic throughout their network and with few exceptions, maintain the same source prospectively assuring patients of consistent dosing from refill to refill. Similar results may be achieved by using name brand products from refill to refill but leave more flexibility of pharmacy choice for the patient.

Smaller pharmacy operations may be dependent on distributers to supply their generic LT4 and personal experience has lead me to believe that the source of generic LT4 may vary from restocking to restocking while name-brand LT4 remains consistent from refill to refill. In summary we have high quality LT4 products on the US market.

The study of Brito et al. The question of safe switching remains open to further study. This Issue. Views 26, Citations 2.

Comments 2. View Metrics. Twitter Facebook More LinkedIn. Original Investigation. September 30, Juan P. Dutcher, PhD 6 ; David J. Shah, PhD 5,9,11 ; Kasia J. Key Points Question What is the comparative effectiveness of generic vs brand-name levothyroxine in achieving normal thyrotropin levels? Study Design and Data Source. Study Outcomes. Statistical Analysis. Sensitivity Analysis. Normal and Clinically Abnormal Thyrotropin Values. Subgroup Analyses. Sensitivity Analyses. Back to top Article Information.

Access your subscriptions. Access through your institution. Add or change institution. Free access to newly published articles. Purchase access. Rent article Rent this article from DeepDyve. Access to free article PDF downloads. Save your search. Customize your interests. Create a personal account or sign in to:.