Discontinuing Denosumab: Can It Be Done Safely? A Review of the Literature

Denosumab, which has been approved for the treatment of osteoporosis since 2010, is a fully humanised monoclonal antibody against a cytokine, receptor activator of nuclear factor kappa B ligand (RANKL), involved in bone resorption. Continued use of denosumab results in a potent and sustained decrease in bone turnover, an increase in bone mineral density (BMD), and a reduction in vertebral and hip fractures. The anti-resorptive effects of denosumab are reversible upon cessation, and this reversal is accompanied by a transient marked increase in bone turnover that is associated with bone loss, and of concern, an increased risk of multiple vertebral fractures. In this review, we outline the effects of denosumab withdrawal on bone turnover markers, BMD, histomorphometry, and fracture risk. We provide an update on recent clinical trials that sought to answer how clinicians can transition away from denosumab safely with follow-on therapy to mitigate bone loss and summarise the recommendations of various international guidelines.

The Application of ThyPRO Questionnaire in Patients With Graves’ Disease Treated With Antithyroid Medications

Background: The ThyPRO-39 questionnaire assesses health-related QoL (HRQoL) in patients with benign thyroid disease and has been validated for use in the local setting. The aim of the study is to investigate disease specific health-related quality of life using ThyPRO-39 in patients with newly diagnosed Graves’ disease treated with antithyroid medications over one year. Methods: Patients with newly diagnosed Graves’ disease were recruited in the outpatient setting. The ThyPRO-39 questionnaire was administered at baseline, 6 and 12 months of antithyroid medication treatment. Relevant demographic and clinical information was collected at the three time points of the study. Results of clinical parameters and various ThyPRO scales were compared between baseline, 6 months and 12 months of treatment. Results: There were 32 patients with newly diagnosed Graves’ disease recruited between April 2018 and May 2019. All except 2 patients completed all 3 time points of the study. Two patients missed their 6 months questionnaire. There were 24 females (75%) and 8 males (25%) in the study. Analysis of the clinical parameters showed significant changes in weight from baseline (59.7 + 17.7kg) to 6 months (59.4 + 9.9kg) to 12 months (63.4 + 17.4Kg), all p<0.001, TSH receptor antibody level from baseline (17.3 + 12.9IU/L) to 12 months (7.1 + 10.8IU/L), NR <1.76IU/L, p<0.001, fT4 levels from baseline (49.9 + 18.1pmol/L) to 6 months (14.3 + 6.9pmol/L) and from baseline to 12 months (11.8 + 2.3pmol/L), NR 8.8-14.4pmol/L, all p<0.001 and TSH levels from baseline (0.011 + 0.009mU/L) to 6 months (1.38 + 1.74mU/L, p=0.001) and from baseline to 12 months (1.80 + 1.72mU/L, p<0.001), NR 0.65-3.70mU/L. After 6 months of treatment, 7 out of 13 ThyPRO scales improved and 9 out of 13 ThyPRO scales improved after 12 months of treatment. Large treatment effects were observed on 2 ThyPRO scales (Hyperthyroid symptoms and Anxiety) while moderate effects were seen in 5 ThyPRO scales (Tiredness, Cognitive complaints, Depressivity, Impaired daily Life and overall QoL) from baseline to 6 months. Large treatment effects were observed on 2 ThyPRO scales (Hyperthyroid symptoms and Anxiety) while moderate effects were seen in 5 ThyPRO scales (Tiredness, Depressivity, Emotional susceptibility, Impaired daily Life and overall QoL) from baseline to 12 months. Small treatment effects were observed in 2 ThyPRO scales (Goiter symptoms and Tiredness) from 6 to 12 months. Conclusion: There are significant improvements in many aspects HRQL during the first 6 months of antithyroid drug treatment, with hyperthyroid symptoms and anxiety showing the most improvements throughout the 12 month treatment period. Our results complement clinical monitoring of patients with Graves’ disease and provide realistic outcome measures of disease impact and treatment outcomes from the patient’s perspective.

Severe radiation thyroiditis after radioactive iodine for treatment of Graves' disease

Radiation thyroiditis resulting from radioactive iodine-131 treatment for Graves' disease is an uncommon complication. Although a majority of patients are asymptomatic or manifest mild symptoms that can be managed conservatively, published literature describing severe radiation thyroiditis resulting in significant morbidity is lacking. We herein report on six patients with severe radiation thyroiditis that resulted in hospitalisation, including an unusual complication of myopericarditis.

High Thyroid Stimulating Receptor Antibody Titre and Large Goitre Size at First-Time Radioactive Iodine Treatment are Associated with Treatment Failure in Graves' Disease

INTRODUCTION

Our study aimed to identify the factors associated with successful first-time radioactive iodine (RAI) treatment in patients with Graves' disease (GD).

MATERIALS AND METHODS

This is a restrospective study of patients with GD who were treated with RAI. Treatment success was defined as onset of permanent hypothyroidism or euthyroidism after 1 dose of RAI at 1-year follow-up.

RESULTS

There were 388 GD patients who underwent RAI treatment between January 2014 and December 2015. Of these, 74% achieved treatment success. Median time to achieve permanent hypothyroidism was 2 months. Male gender, smoking, higher antithyroid drug dosage, lower thyroid stimulating hormone (TSH) level, large goitre size and TSH receptor antibody (TRAb) titre at time of RAI were significantly associated with treatment failure. Multivariate analysis showed that larger goitre size and higher TRAb titre were associated with lower first-time RAI success.

CONCLUSION

Larger goitre size and higher TRAb titre predict lower success of RAI therapy in GD patients. Treatment decisions and strategies should be customised for patients who present with these characteristics.

Beyond HbA1c: Comparing Glycemic Variability and Glycemic Indices in Predicting Hypoglycemia in Type 1 and Type 2 Diabetes

BACKGROUND

Hypoglycemia is the major impediment to therapy intensification in diabetes. Although higher individualized HbA1c targets are perceived to reduce the risk of hypoglycemia in those at risk of hypoglycemia, HbA1c itself is a poor predictor of hypoglycemia. We assessed the use of glycemic variability (GV) and glycemic indices as independent predictors of hypoglycemia.

METHODS

A retrospective observational study of 60 type 1 and 100 type 2 diabetes subjects. All underwent professional continuous glucose monitoring (CGM) for 3-6 days and recorded self-monitored blood glucose (SMBG). Indices were calculated from both CGM and SMBG. Statistical analyses included regression and area under receiver operator curve (AUC) analyses.

RESULTS

Hypoglycemia frequency (53.3% vs. 24%, P < 0.05) and %CV (40.1% ± 10% vs. 29.4% ± 7.8%, P < 0.001) were significantly higher in type 1 diabetes compared with type 2 diabetes. HbA1c was, at best, a weak predictor of hypoglycemia. %CV_CGM, Low Blood Glucose Index (LBGI)_CGM, Glycemic Risk Assessment Diabetes Equation (GRADE)Hypoglycemia_CGM, and Hypoglycemia Index_CGM predicted hypoglycemia well. %CV_CGM and %CV_SMBG consistently remained a robust discriminator of hypoglycemia in type 1 diabetes (AUC 0.88). In type 2 diabetes, a combination of HbA1c and %CV_SMBG or LBGI_SMBG could help discriminate hypoglycemia.

CONCLUSION

Assessment of glycemia should go beyond HbA1c and incorporate measures of GV and glycemic indices. %CV_SMBG in type 1 diabetes and LBGI_SMBG or a combination of HbA1c and %CV_SMBG in type 2 diabetes discriminated hypoglycemia well. In defining hypoglycemia risk using GV and glycemic indices, diabetes subtypes and data source (CGM vs. SMBG) must be considered.

Radioiodine associated de novo Graves' opthalmopathy in an Asian cohort

Radioactive iodine in the treatment of Graves' disease has been associated with the development of de novo Graves' ophthalmopathy (GO). In this report, we describe five individuals who required extensive ophthalmic treatment for post-RAI de novo GO.

Persistent hyperthyroidism and de novo Graves' ophthalmopathy after total thyroidectomy

We report a patient with Graves' disease who remained persistently hyperthyroid after a total thyroidectomy and also developed de novo Graves' ophthalmopathy 5 months after surgery. She was subsequently found to have a mature cystic teratoma containing struma ovarii after undergoing a total hysterectomy and salpingo-oophorectomy for an incidental ovarian lesion.

LEARNING POINTS

It is important to investigate for other causes of primary hyperthyroidism when thyrotoxicosis persists after total thyroidectomy.TSH receptor antibody may persist after total thyroidectomy and may potentially contribute to the development of de novo Graves' ophthalmopathy.

Clinically relevant drug interactions between anticancer drugs and psychotropic agents

Drug interactions are commonly seen in the treatment of cancer patients. Psychotropics are often indicated for these patients since they may also suffer from pre-existing psychological disorders or experience insomnia and anxiety associated with cancer therapy. Thus, the risk of anticancer drug (ACD)-psychotropic drug-drug interactions (DDIs) is high. Drug interactions were compiled from the British National Formulary (53rd edn), Lexi-Comp's Drug Information Handbook (15th edn), Micromedex (v5.1), Hansten & Horn's Drug Interactions (2000) and Drug Interaction Facts (2008 edn). Product information of the individual drugs, as well as documented literature on ACD-psychotropic interactions from PubMed and other databases was also incorporated. This paper identifies clinically important ACD-psychotropic DDIs that are frequently observed. Pharmacokinetic DDIs were observed for tyrosine kinase inhibitors, corticosteroids and antimicrotubule agents due to their inhibitory or inductive effects on cytochrome P450 isoenzymes. Pharmacodynamic DDIs were identified for thalidomide with central nervous system depressants, procarbazine with antidepressants, myelosuppressive ACDs with clozapine and anthracyclines with QT-prolonging psychotropics. Clinicians should be vigilant when psychotropics are prescribed concurrently with ACDs. Close monitoring of plasma drug levels should be carried out to avoid toxicity in the patient, as well as to ensure adequate chemotherapeutic and psychotropic coverage.