Generic Levothyroxine Research Articles

Safe for patients to switch generic levothyroxine products, study says

Despite continued debate, practice guidelines state that adult patients with hypothyroidism should consistently use the same levothyroxine product. But a new study published in JAMA Internal Medicine could make the case for a revision.

Dosing study of brand vs. generic levothyroxine in well-controlled primary hypothyroidism

Searchable abstracts of presentations at key conferences in endocrinology ISSN 1470-3947 (print) | ISSN 1479-6848 (online)

Association Between Generic-to-Generic Levothyroxine Switching and Thyrotropin Levels Among US Adults

Switching among generic levothyroxine sodium products made by different manufacturers typically occurs at the pharmacy and may affect serum thyrotropin (TSH) levels. To compare TSH levels between patients who continued taking the same sourced generic levothyroxine product and those who switched. This comparative effectiveness research study with 1:1 propensity matching used data from OptumLabs Data Warehouse, a national administrative claims database linked to laboratory test results. Adults aged 18 years or older were included if they filled a generic levothyroxine prescription between January 1, 2008, and June 30, 2019, and had a stable drug dose, the same drug manufacturer, and a normal TSH level (0.3-4.4 mIU/L) for at least 3 months before either continuing to take the same product or switching among generic levothyroxine products (index date). Patients were excluded if they were pregnant, had diagnosed hypopituitarism or hyperthyroidism, or had a medical condition or used medications that could affect thyrotropin levels. They were also excluded if they filled a prescription for other forms of thyroid replacement therapy between 6 months before the index date and when the first TSH level was obtained 6 weeks to 12 months after the index date. Data were analyzed from December 1, 2019, to November 24, 2021. Proportion of individuals with a normal (0.3-4.4 mIU/L) or markedly abnormal (<0.1 or >10.0 mIU/L) TSH level using the first available laboratory result 6 weeks to 12 months after the index date. A propensity score model was developed to minimize confounding using logistic regression with the binary outcome of continuing the same sourced levothyroxine product vs switching generic levothyroxine. Covariates were demographics, comorbidities, and baseline TSH level. The balance among the treatment groups was evaluated by comparing standardized mean differences of baseline covariates between the groups. A total of 15 829 patients filled generic levothyroxine (mean [SD] age, 58.9 [14.6] years; 73.4% [11 624] were women; 4.5% [705] were Asian, 10.2% [1617] were Black, 11.4% [1801] were Hispanic, and 71.4% [11 295] were White individuals); of these patients, 56.3% [8905] received a daily levothyroxine dose of 50 μg or less. A total of 13 049 patients (82.4%) continued taking the same sourced preparation, and 2780 (17.6%) switched among generic levothyroxine preparations. Among 2780 propensity-matched patient pairs, the proportion of patients with a normal TSH level after the index date was 82.7% (2298) among nonswitchers and 84.5% (2348) among switchers (risk difference, -0.018; 95% CI, -0.038 to 0.002; P = .07). The proportion of patients with a markedly abnormal TSH level after the index date was 3.1% (87) among nonswitchers and 2.5% (69) among switchers (risk difference, 0.007; 95% CI, -0.002 to 0.015; P = .14). The mean (SD) TSH levels after the index date were 2.7 (2.3) mIU/L among nonswitchers and 2.7 (3.3) mIU/L among switchers (P = .94). Results of this comparative effectiveness research study suggest that switching among different generic levothyroxine products was not associated with clinically significant changes in TSH level. These findings conflict with the current guideline recommendation that warns clinicians about potential changes in TSH level associated with switching among levothyroxine products sourced from different manufacturers.

Rates of, and factors associated with, switching among generic levothyroxine preparations in commercially insured American adults.

Some practice guidelines warn against generic L-thyroxine preparation switching. To examine the rates of generic L-thyroxine preparation switching within one year of initiating L-thyroxine, and to examine factors associated with switching. Retrospective study using national data from a large administrative claims database from January 2008 through November 2018. Medicare or commercially insured adults (≥18 years) who filled a generic L-thyroxine preparation. At least one switch from one generic L-thyroxine preparation to another within 1 year of L-thyroxine initiation defined by prescription fills. From January 2008 to November 2018, we included 483,390 patients who initiated generic L-thyroxine: mean (SD) age was 61.4 years (15.2), 75.2% were female, 72.6% were white. Within 1 year of initiating therapy, 98,013 (20%) switched to another L-thyroxine generic preparation at least once. In a multivariate logistic regression analysis, factors associated with switching included the number of pharmacies visited to fill L-thyroxine (>2 vs 1 adjusted OR [aOR] 7.15, 95% confidence interval [CI] 6.97-7.34), age ≥75 vs. <45 years (aOR 1.29, 95% CI 1.26-1.33), history of thyroid surgery (aOR 1.22, 95% CI 1.13-1.31), and first L-thyroxine fill date in 2018 vs. 2008 (aOR 3.32, 95% CI 3.14-3.51). One in five patients switched among generic L-thyroxine manufacturers within one year of treatment initiation. Generic L-thyroxine switching occurred more often when more pharmacies were used to fill L-thyroxine. Given existing guideline recommendations, additional studies should clarify the impact of generic L-thyroxine switching on thyroid hormone values.

Real world evidence in effectiveness, safety, and cost savings of generic levothyroxine: a systematic review.

Generic levothyroxine, approved through Abbreviated New Drug Application (ANDA), is available for generic substitution. But ANDA does not require nonclinical or clinical data to establish safety and efficacy. Post-marketing evidence in generic equivalence for marketed levothyroxine products is limited. We conducted a systematic review to synthesize evidence in effectiveness, safety, and cost savings between patients using generic and branded levothyroxine. We systematically searched published literature from Medline, International Pharmaceutical Abstracts, APA PsycInfo, and CINAHL from inception through 04/18/2021. Included studies were limited to post-marketing empirical studies including patients who used levothyroxine products, with direct comparison between generic and brand levothyroxine, and published in English. Risk of bias was assessed using the National Institute of Health Study Quality Assessment Tools. Two reviewers independently extracted data and conducted quality assessment for included studies. Given that the nine studies are so diverse, a meta-analysis was not possible. Therefore we provided a narrative review of the included studies. Of 349 studies identified, nine met the inclusion criteria. Six studies compared thyrotropin levels and adverse events between generic and brand users and provided mixed findings. In addition, generic users may generate prescription cost savings for payers but had suboptimal medication adherence than brand users. Findings from this systematic review highlighted the limited and mixed evidence in real-world clinical and economic outcomes for generic levothyroxine. Continuous post-marketing monitoring and assessment of generic drugs are warranted to ensure treatment effectiveness, patient safety, and achieve financial savings in prescription costs.

Generic and Brand-Name Levothyroxine Formulations Are Equally Effective for Initial Treatment of Mild Hypothyroidism

Generic and Brand-Name Levothyroxine Formulations Are Equally Effective for Initial Treatment of Mild Hypothyroidism

Comparative Effectiveness of Generic vs Brand-Name Levothyroxine in Achieving Normal Thyrotropin Levels

Whether the use of generic vs brand levothyroxine affects thyrotropin levels remains unclear. To compare the effectiveness of generic vs brand levothyroxine in achieving and maintaining normal thyrotropin levels among new users. This retrospective, 1:1 propensity score-matched longitudinal cohort study used the OptumLabs Data Warehouse administrative claims database linked to laboratory results from commercially insured and Medicare Advantage enrollees throughout the United States. Eligible patients were adults (aged ≥18 years) with thyrotropin levels ranging from 4.5 to 19.9 mIU/L who initiated use of generic or brand-name levothyroxine from January 1, 2008, to October 1, 2017. Data were analyzed from August 13, 2018, to October 25, 2019. Patients received generic or brand-name levothyroxine. Proportion of patients with normal vs markedly abnormal thyrotropin levels (<0.1 or >10 mIU/L) within 3 months and with stable thyrotropin levels within 3 months after the thyrotropin value fell into the normal range. A total of 17 598 patients were included (69.0% female; 74.0% White; mean [SD] age, 55.1 [16.0] years), of whom 15 299 filled generic and 2299 filled brand-name levothyroxine prescriptions during the study period. Among 4570 propensity score-matched patients (mean [SD] age, 50.3 [13.8] years; 3457 [75.6%] female; 3510 [76.8%] White), the proportion with normal thyrotropin levels within 3 months of filling levothyroxine prescriptions was similar for patients who received generic vs brand-name levothyroxine (1722 [75.4%; 95% CI, 71.9%-79.0%] vs 1757 [76.9%; 95% CI, 73.4%-80.6%]; P = .23), as was the proportion with markedly abnormal levels (94 [4.1%; 95% CI, 3.4%-5.0%] vs 88 [3.9%; 95% CI, 3.1%-4.7%]; P = .65). Among 1034 propensity score-matched patients who achieved a normal thyrotropin value within 3 months of initiation of levothyroxine, the proportion maintaining subsequent normal thyrotropin levels during the next 3 months was similar for patients receiving generic vs brand-name levothyroxine (427 [82.6%] vs 433 [83.8%]; P = .62). Initiation of generic vs brand-name levothyroxine formulations was associated with similar rates of normal and stable thyrotropin levels. These results suggest that generic levothyroxine as initial therapy for mild thyroid dysfunction is as effective as brand-name levothyroxine.

Relevant Issues of Planning Bioequivalence Studies of Drugs with a Narrow Therapeutic Range

In order to be registered, generic drugs with a narrow therapeutic range have to undergo bioequivalence or therapeutic equivalence studies. In most cases, comparative pharmacokinetic studies and demonstration of bioequivalence between the test and the reference products are sufficient for this group of drugs. However, there is no established official definition in Russia for the group of drugs that are regarded as having a narrow therapeutic range. Evaluation of bioequivalence of such drugs has to be performed providing for narrower confidence intervals, which entails certain problems at the stage of bioequivalence study planning. Finding solutions to the problems stated above is of great importance. The aim of the study was to develop approaches to planning bioequivalence studies of drugs with a narrow therapeutic range. Materials and methods: the paper analyses the results of 33 bioequivalence studies of drugs with a narrow therapeutic range, in which Cmax, AUC0-t, and tmax were calculated. Intra-individual variation and weighted mean intra-individual variation of Cmax and AUC0-t were estimated in the study. Statistical processing was performed using IBM SSPS Statistics v.25. and Microsoft Office Excel 2016. Results: the paper summarises criteria for categorising drugs as having a narrow therapeutic range and describes general requirements for assessing their bioequivalence. A number of bioequivalence studies of generic valproic acid, carbamazepine, levothyroxine, tacrolimus, and cyclosporine products which meet the criteria for drugs with a narrow therapeutic range, were analysed retrospectively. The data on their pharmacokinetics and intra-individual variation were calculated. It also summarises requirements for bioequivalence evaluation of drugs with a narrow therapeutic range. The paper gives product-specific recommendations for performing bioequivalence studies. Conclusion: the study helped to formulate approaches to the planning of bioequivalence studies of generic drugs with a narrow therapeutic range using the examples of valproic acid, carbamazepine, levothyroxine, tacrolimus, and cyclosporine.

The etiology and treatment of refractory Hypothyroidism - management issues: A cross sectional observational study

Introduction: Primary hypothyroidism is considered to be refractory to treatment when there is clinical or biochemical evidence of hypothyroidism (level of TSH above the target range, usually 5.5 mIU/L) even after 6 weeks of treatment with Levothyroxine at a dosage of 1.9 mcg/kg/day. This study intended to find out the common factors responsible for the refractory nature of the hypothyroidism. The study also highlights how simple correction measures would improve the outcomes. Materials and Methods: This is a prospective, Cross sectional and observational study conducted in the Department of Endocrinology, Sapthagiri Institute of Medical Sciences and Research center. The study population included 25 patients with treatment refractory hypothyroidism. The patients were identified after screening about 900 patients with primary hypothyroidism, between age group of 15-50 years and BMI of 19-25 kg/m2. Levothyroxine absorption test was performed when deemed necessary. Results: In 10 patients (40%) the reason for refractory nature of the hypothyroidism was found to be due to keeping the levothyroxine containers in the kitchen close to flame or above the refrigerator and due to disposing of the silica pack from the container. In 8 (32%) patients the reason was inappropriate timing of Levothyroxine with food and beverages or due to the usage of concomitant medications. 6 (24%) patients used generic Levothyroxine, which could be less effective. Remaining 1 patient (4%) were subjected to Levothyroxine absorption test, which suggested that malabsorption is the etiological factor. Conclusions: The most common reason for the refractory nature of the hypothyroidism was found to be due to improper storing conditions of the medication. The other reasons included switching over to the generic brands of levothyroxine, and not maintaining the adequate time gap between consumption of Levothyroxine and interfering medications like antacids. Malabsorption was found to be uncommon reason for refractory hypothyroidism.

The etiology and treatment of refractory Hypothyroidism - management issues: A cross sectional observational study

Introduction: Primary hypothyroidism is considered to be refractory to treatment when there is clinical or biochemical evidence of hypothyroidism (level of TSH above the target range, usually 5.5 mIU/L) even after 6 weeks of treatment with Levothyroxine at a dosage of 1.9 mcg/kg/day. This study intended to find out the common factors responsible for the refractory nature of the hypothyroidism. The study also highlights how simple correction measures would improve the outcomes. Materials and Methods: This is a prospective, Cross sectional and observational study conducted in the Department of Endocrinology, Sapthagiri Institute of Medical Sciences and Research center. The study population included 25 patients with treatment refractory hypothyroidism. The patients were identified after screening about 900 patients with primary hypothyroidism, between age group of 15-50 years and BMI of 19-25 kg/m2. Levothyroxine absorption test was performed when deemed necessary. Results: In 10 patients (40%) the reason for refractory nature of the hypothyroidism was found to be due to keeping the levothyroxine containers in the kitchen close to flame or above the refrigerator and due to disposing of the silica pack from the container. In 8 (32%) patients the reason was inappropriate timing of Levothyroxine with food and beverages or due to the usage of concomitant medications. 6 (24%) patients used generic Levothyroxine, which could be less effective. Remaining 1 patient (4%) were subjected to Levothyroxine absorption test, which suggested that malabsorption is the etiological factor. Conclusions: The most common reason for the refractory nature of the hypothyroidism was found to be due to improper storing conditions of the medication. The other reasons included switching over to the generic brands of levothyroxine, and not maintaining the adequate time gap between consumption of Levothyroxine and interfering medications like antacids. Malabsorption was found to be uncommon reason for refractory hypothyroidism.

Generic levothyroxine initiation and substitution among Medicare and Medicaid populations: a new user cohort study.

Generic levothyroxine has been approved and available since 2004 but its substitution remains controversial. Therefore, the objective was to examine patterns of and identify factors associated with initiation and substitution of generic levothyroxine treatment. This was a retrospective observational study, including new users of brand and generic levothyroxine in 2013-2015 Medicare (n = 15,877) or 2011-2012 Medicaid (n = 9390) administrative claim databases. The primary outcomes included (1) generic levothyroxine initiation, and (2) among brand-new users, generic levothyroxine substitution in 12 months. The factors associated with generic levothyroxine initiation and substitution were measured. Among all levothyroxine new users, Medicare beneficiaries had a higher proportion of generic levothyroxine initiation than Medicaid beneficiaries (66.40% vs. 44.04%, respectively). Medicare beneficiaries' demographic factors, and health service utilizations were associated with generic levothyroxine initiation. Medicaid beneficiaries who were male and residing in the northeast region and rural areas were more likely to initiate generic levothyroxine. Among brand levothyroxine new users, the generic substitution rate was higher in the Medicare than the Medicaid cohort (18.26 vs. 3.88%). Medicare brand levothyroxine new users' demographic factors and health service utilizations were associated with generic levothyroxine substitution. Medicaid brand levothyroxine new users who were residing in the northeast region, with more prior hospitalization, and initiating a lower dosage of brand levothyroxine, had higher rates of generic substitution. Patient demographic factors and health service utilizations are associated with generic levothyroxine initiation and substitution. Educational outreach programs targeted to increase generic levothyroxine use and prescription savings should be tailored based on different patient populations.

Study addresses dosing concern with brand vs. generic levothyroxine

Study addresses dosing concern with brand vs. generic levothyroxine

Generic and Brand-Name Thyroid Hormone Drug Use Among Commercially Insured and Medicare Beneficiaries, 2007 Through 2016.

Generic drugs account for 9 out of 10 prescriptions dispensed in the United States but for a lower proportion of commonly prescribed thyroid hormone replacement therapies. Characterize temporal patterns of generic and brand-name thyroid hormone drug use, including patient and prescriber characteristics associated with brand-name use. Cross-sectional longitudinal analysis of national data from a large administrative claims database from January 2007 through December 2016. Adults with insurance coverage through commercial, Medicare Advantage, and Medicare Part D health plans. Generic and brand-name thyroid hormone drug use. From 2007 to 2016, the annual number of thyroid hormone treatment pharmacy fills increased from 8,905,836 in 2007 to 11,613,923 in 2016, 73.6% of which were for generic levothyroxine, 23.4% for brand-name levothyroxine, and the remaining for other formulations. Dispensing of generic thyroid hormone drugs increased from 59.8% in 2007 to 84.9% in 2016 and was consistently higher among Medicare Advantage and Medicare Part D when compared with the commercial beneficiary population. For all three beneficiary populations, use of brand-name products was less common among older adults and more common among women and those receiving prescriptions from endocrinologists and was more common among those of white race and with greater household income for the Medicare Advantage and commercial beneficiary populations (P < 0.001). Brand-name thyroid hormone product use declined from 2007 to 2016 among three large, national insurer beneficiary populations. Although certain patient characteristics were associated with brand-name use, prescriber specialty was the strongest predictor.

Identification of Primary Medication Concerns Regarding Thyroid Hormone Replacement Therapy From Online Patient Medication Reviews: Text Mining of Social Network Data

BackgroundPatients with hypothyroidism report poor health-related quality of life despite having undergone thyroid hormone replacement therapy (THRT). Understanding patient concerns regarding levothyroxine can help improve the treatment outcomes of THRT.ObjectiveThis study aimed to (1) identify the distinctive themes in patient concerns regarding THRT, (2) determine whether patients have unique primary medication concerns specific to their demographics, and (3) determine the predictability of primary medication concerns on patient treatment satisfaction.MethodsWe collected patient reviews from WebMD in the United States (1037 reviews about generic levothyroxine and 1075 reviews about the brand version) posted between September 1, 2007, and January 30, 2017. We used natural language processing to identify the themes of medication concerns. Multiple regression analyses were conducted in order to examine the predictability of the primary medication concerns on patient treatment satisfaction.ResultsNatural language processing of the patient reviews of levothyroxine posted on a social networking site produced 6 distinctive themes of patient medication concerns related to levothyroxine treatment: how to take the drug, treatment initiation, dose adjustment, symptoms of pain, generic substitutability, and appearance. Patients had different primary medication concerns unique to their gender, age, and treatment duration. Furthermore, treatment satisfaction on levothyroxine depended on what primary medication concerns the patient had.ConclusionsNatural language processing of text content available on social media could identify different themes of patient medication concerns that can be validated in future studies to inform the design of tailored medication counseling for improved patient treatment satisfaction.

Adherence to thyroid hormone replacement therapy: a retrospective, claims database analysis

Objective: The objective of this analysis was to compare adherence at 6 months and 12 months across levothyroxine formulations for patients with hypothyroidism.Methods: This retrospective analysis utilized insurance claims data from a commercially insured population from January 1, 2000 through March 31, 2016. Patients were included if they were diagnosed with hypothyroidism and initiated treatment with generic levothyroxine, Levoxyl, Synthroid, Unithroid, or Tirosint. Patients were excluded if they were younger than age 18, were diagnosed with thyroid cancer, received a prescription for liothyronine, or did not have continuous insurance coverage over the study period. Adherence, defined by the proportion of days covered (PDC) ≥ 80%, was examined using multivariable analyses for both 6 and 12 months post-initiation on therapyResults: The study identified 580,331 patients who fit the study criteria. At 6 months, 40.3% of patients were found to be non-adherent, while 51.9% were non-adherent at 12 months. Synthroid was associated with significantly higher adherence compared to all other levothyroxine formulations at both 6 and 12 months. Compared to generic levothyroxine, the likelihood of being adherent at 12 months was highest for Synthroid (OR = 1.44; 95% CI = 1.43–1.46), followed by Levoxyl (OR = 1.20 95% CI = 1.17–1.23). Tirosint and Unithroid were associated with significantly lower adherence at 12 months compared to generic levothyroxine (OR = 0.65; 95% CI = 0.57–0.75 and OR = 0.79; 95% CI = 0.71–0.89, respectively).Conclusions: This large, retrospective real-world study demonstrated that adherence to levothyroxine remains a concern among patients with hypothyroidism, and that differences in adherence may exist across levothyroxine formulations.

Levothyroxine for Hypothyroidism: Current Status of Biowaiver and Bioequivalence Studies

Hypothyroidism is a common disease that needs to be closely treated, in order to reduce adverse symptoms and pathophysiological effects. For thyroid hormone replacement is preferred a therapy with a synthetic form of thyroxine (levothyroxine), a drug recognized by its Narrow Therapeutic Index. Generic levothyroxine can be an economic alternative for Hypothyroidism treatment.

Congenital Secondary Hypothyroidism Evidences in a Dog

Background: Deficiency of thyroid hormones thyroxine (T4) and triiodothyronine (T3) results in multisystemic disease described as hypothyroidism (HpoT). Secondary HpoT is defined by TSH decreased production and, therefore, thyroid hormones. This condition is rare in dogs, accounting for less than 5% of cases. The objective of this report is to describe evidence of congenital secondary hypothyroidism in a mongrel dog and therapeutic response obtained.Case: A 3-year-old neutered male mongrel dog was brought to the veterinarian with a history of overweight without polyphagia, associated with discrete alopecia, poor quality skin and hair coat, lethargy and evident exercise intolerance. Physical examination revealed a body condition score of seven (1 to 9 scale), disqueratosis, pyoderma, ventral cervical alopecia, hair thinning on the posterior surface of the pelvic limbs and nonpalpable thyroid. A body conformation characterized by disproportionate dwarfism was observed. Owners provided a former patient´s X-ray (18 months of age), showing growth plate non-closure in vertebral bodies. Results of a complete blood count (CBC) and serum biochemical profile were within normal limits except for elevated fructosamine (459 µmol/L; reference range: 170-338 µmol/L) and total cholesterol (558 mg/dL; reference range: 135-270 mg/dL). Analyses of the hormone profile showed decreased levels of canine thyroid-stimulating hormone (cTSH) 0.03 ng/mL (reference range: 0.05-0.5 ng/mL), free thyroxine by equilibrium dialysis (fdT4) 0.57 ng/dL (reference range: 0.8-3.0 ng/dL), and total thyroxine (tT4) 5.1 ng/mL (reference range: 15-30 ng/mL). A distal forelimb X-ray was performed and showed opened epiphyseal growth plates from radius and ulnar bones. The patient was discharged with sodium levothyroxine (20 µg/kg PO q 24 hr) until re-evaluation. The patient was re-evaluated 2 months later and clinical symptoms observed at the first admission were still persistent. CBC and serum biochemical profile were within normal range. The values of T4t and cTSH were 21.3 ng/mL (reference range for treated dogs 25-45 ng/mL post-thyroxine) and 0.03 ng/mL respectively. Owners were administering a generic levothyroxine, and then a commercial sodium levothyroxine was prescribed at the same dose for treatment. Clinical improvement was reported by the owner 4 weeks later. A new forelimb and vertebral radiographic examination performed 6 months later revealed complete epiphyseal ossification.Discussion: The patient was diagnosed with central hypothyroidism based on the clinical presentation in conjunction with the laboratory tests results. The main hypothesis argues for a congenital pituitary malformation, leading to a defective hypothalamic-pituitary-thyroid axis function. This decreased hormonal TSH secretion culminated in a chronic mild state of hypothyroidism associated with reduction in the thyroid hormones secretion. Metabolic consequences of mild hypothyroidism affect bone development directly and lead to delayed epiphyseal ossification and epiphyseal growth, reduced long bone growth, and disproportionate dwarfism. Studies have suggested a genetic relation with the development of congenital hypothyroidism, although no disease-causing mutations were found in the genes previously investigated. The prognosis for dogs with secondary hypothyroidism due to malformation or destruction of the pituitary ranges from poor to reserved, with shorter life expectancy in dogs with congenital pituitary malformation due to cysts expansion. Although cost is limiting for some owners, advanced imaging such as computed tomography or magnetic resonance may be useful in the macroscopic evaluation of the pituitary gland and are recommended in central hypothyroidism cases.

Provider and Patient Determinants of Generic Levothyroxine Prescribing: An Electronic Health Records-Based Study.

Despite the availability of generic levothyroxine products for more than a decade, uptake of these products is poor. We sought to evaluate determinants of generic prescribing of levothyroxine. In a cross-sectional analysis of electronic health records data between 2010 and 2013, we identified adult patients with a levothyroxine prescription from a primary-care physician (PCP) or endocrinologist. We used mixed-effect logistic regression models with random intercepts for prescribing provider to examine predictors of generic levothyroxine prescribing. Models include patient, prescription, and provider fixed-effect covariates. Odds ratios (ORs) and 95% CIs were generated. Between-provider random variation was quantified by the intraclass correlation coefficient (ICC). Study patients (n = 63 838) were clustered among 941 prescribing providers within 25 ambulatory care clinics. The overall prevalence of generic prescribing of levothyroxine was 73%. In the multivariable mixed-effect model, patients were significantly less likely to receive generic levothyroxine from an endocrinologist than a PCP (OR = 0.43; 95% CI = 0.33-0.55; P < 0.001). Women were less likely to receive generic levothyroxine than men from endocrinologists (OR = 0.68; 95% CI = 0.59-0.78; P < 0.001) but not from PCPs. Between-provider variation in generic prescribing was 18.3% in the absence of fixed-effect covariates and could be explained marginally by patient, prescription, and provider factors (ICC = 15.9%). Generic levothyroxine prescribing differed by PCPs and endocrinologists. Residual variation in generic prescribing, after accounting for measurable factors, indicates the need for provider interventions or patient education aimed at improving levothyroxine generic uptake.

Evaluation of racial and socioeconomic disparities in medication pricing and pharmacy access and services.

Results of a study to determine if disparities in drug pricing, pharmacy services, and community pharmacy access exist in a Tennessee county with a predominantly minority population are reported. A cross-sectional survey of community pharmacies in Shelby County, a jurisdiction with a total population more than 60% composed of racial and ethnic minority groups, was conducted. Data collection included "out-of-pocket" (i.e., cash purchase) prices for generic levothyroxine, methylphenidate, and hydrocodone-acetaminophen; pharmacy hours of operation; availability of selected pharmacy services; and ZIP code-level data on demographics and crime risk. Analysis of variance, chi-square testing, correlational analysis, and data mapping were performed. Survey data were obtained from 90 pharmacies in 25 of the county's 33 residential ZIP code areas. Areas with fewer pharmacies per 10,000 residents tended to have a higher percentage of minority residents (p = 0.031). Methylphenidate pricing was typically lower in areas with lower employment rates (p = 0.027). Availability of home medication delivery service correlated with income level (p = 0.015), employment rate (p = 0.022), and crime risk (p = 0.014). A survey of community pharmacies in Shelby County, Tennessee, found that areas with a high percentage of minority residents had lower pharmacy density than areas with a high percentage of white residents. Pharmacies located in communities with low average income levels, low employment rates, and high scores for personal crime risk were less likely to offer home medication delivery services.

Services provided by community pharmacies in Wayne County, Michigan: A comparison by ZIP code characteristics

To document the availability of selected pharmacy services and out-of-pocket cost of medication throughout a diverse county in Michigan and to assess possible associations between availability of services and price of medication and characteristics of residents of the ZIP codes in which the pharmacies were located. Cross-sectional telephone survey of pharmacies coupled with ZIP code-level census data. 503 pharmacies throughout the 63 ZIP codes of Wayne County, MI. The out-of-pocket cost for a 30 days' supply of levothyroxine 50 mcg and brand-name atorvastatin (Lipitor-Pfizer) 20 mg, availability of discount generic drug programs, home delivery of medications, hours of pharmacy operation, and availability of pharmacy-based immunization services. Census data aggregated at the ZIP code level included race, annual household income, age, and number of residents per pharmacy. The overall results per ZIP code showed that the average cost for levothyroxine was $10.01 ± $2.29 and $140.45 + $14.70 for Lipitor. Per ZIP code, the mean (± SD) percentages of pharmacies offering discount generic drug programs was 66.9% ± 15.0%; home delivery of medications was 44.5% ± 22.7%; and immunization for influenza was 46.7% ± 24.3% of pharmacies. The mean (± SD) hours of operation per pharmacy per ZIP code was 67.0 ± 25.2. ZIP codes with higher household income as well as higher percentage of residents being white had lower levothyroxine price, greater percentage of pharmacies offering discount generic drug programs, more hours of operation per week, and more pharmacy-based immunization services. The cost of Lipitor was not associated with any ZIP code characteristic. Disparities in the cost of generic levothyroxine, the availability of services such as discount generic drug programs, hours of operation, and pharmacy-based immunization services are evident based on race and household income within this diverse metropolitan county.