Graves Disease, Hyperthyroidism
Conditions
Keywords
Hyperthyroidism,Graves disease,Cholestyramine,Prednisolone
Brief summary
Hyperthyroidism is the second most common endocrine disorder in the world with Graves' disease being the commonest. Anti thyroid drugs including methimazole, carbimazole, and propylthiouracil are effective treatments but take in most cases between 6 to 8 weeks to achieve euthyroidism. This study aim to assess the efficacy of cholestyramine and prednisolone as adjunctive treatment to standard treatment in patients with overt hyperthyroidism in 4 weeks.
Detailed description
Hyperthyroidism is the second most common endocrine disorder in the world with an estimate prevalence rate of 0.5-1.3% with Graves' disease being the commonest cause. Uncontrolled hyperthyroidism results in increase cardiovascular morbidity and mortality primarily due to heart failure and thromboembolism. Therefore treatment is essential to restore a euthyroid state in order to reverse the cardiovascular complications. Anti thyroid drugs (ATDs) including methimazole, carbimazole, and propylthiouracil are effective treatments that inhibit thyroid hormone synthesis, and have clinically important immunosuppressive effects including reducing serum antithyrotropin receptor antibody (TRAb) concentration with time but take in most cases between 6 to 8 weeks to achieve euthyroidism. Therefore there may be a role for adjunctive treatment added on to ATDs. It may be situations where adjunctive treatment is required to alleviate symptoms and restore euthyroidism rapidly such as before surgery or radioactive iodine treatment or in vulnerable groups such as the elderly or those with serious thyrotoxic complications. This study aim to assess the efficacy of cholestyramine and prednisolone as adjunctive treatment to standard treatment in patients with overt hyperthyroidism in 4 weeks. Cholestyramine is an anion exchange resin that binds thyroxine (T4) in the intestine resulting in fecal excretion of T4 thus reducing the enterohepatic circulation and absorption in hyperthyroidism. Steroids have been shown to be effective in controlling hyperthyroidism by inhibiting the conversion of thyroxine to triiodothyronine peripherally and also blocks the release of thyroxine from the thyroid gland. It may also have the potential to suppress the immune response and hence decrease stimulation of the thyroid gland in Graves. 135 patients with moderate to severe uncontrolled overt hyperthyroid patients secondary to Graves disease will be randomized into 3 groups. Group 1 patients will be treated with cholestyramine 4g twice a day plus carbimazole and propanolol for 4 weeks. Group 2 patients will be treated with prednisolone 30 mg daily for week 1, 20 mg daily for week 2, 10 mg daily for week 3 and 5 mg daily for week 4 plus carbimazole and propanolol for 4 weeks. Group 3 patients will be treated with carbimazole 30 mg daily and propanolol 40 mg bd for 4 weeks. Patients will have their clinical status (weight, blood pressure, pulse rate) measured at baseline along with a TRAb level and Free Triiodotyronine (T3), Free T4 and Thyroid stimulating hormone (TSH) levels. They will be evaluated at week 2 and week 4 of intervention period and have their clinical status (weight, blood pressure, pulse rate) and laboratory (Free T3, Free T4, TSH, Potassium, Fasting/random blood glucose) measured. Adverse events will be monitored at week 2, 4, and 6.
Interventions
DRUGCholestyramine Powder 4g
Cholestyramine powder 4g twice daily, Tablet Carbimazole 30 mg daily, Tablet propanolol 40 mg twice daily for 4 weeks
DRUGPrednisolone
Tablet prednisolone 30 mg daily for week 1, 20 mg daily for week 2, 10 mg daily for week 3 and 5 mg daily for week 4, Tablet carbimazole 30 mg daily, Tablet propanolol 40 mg twice daily for 4 weeks
DRUGStandard treatment
Carbimazole 30 mg daily and propanolol 40 mg twice daily for 4 weeks
Sponsors
Ministry of Health, Malaysia
Clinical Research Centre, Malaysia
Study design
Allocation
RANDOMIZED
Intervention model
PARALLEL
Primary purpose
TREATMENT
Masking
NONE
Intervention model description
Multi-center, open label, randomised, parallel-group
Eligibility
Sex/Gender
ALL
Age
18 Years to No maximum
Healthy volunteers
No
Inclusion criteria
1. Provision of written consent by subject or guardian. 2. Subject of either sex, more than 18 years of age 3. Subjects with moderate to severe overt hyperthyroidism (caused by Graves' disease). * Moderate to severe overt hyperthyroidism is defined as Free T4\> 1.5 times upper limit of normal reference range and TSH below lower limit of reference range, who are either newly diagnosed or previously diagnosed and receiving ATDs currently. * Graves disease is defined as hyperthyroidism coupled with clinical signs of symmetrical diffuse goiter, thyroid orbitopathy, or diffuse and vascular thyroid on ultrasound or positive TRAb antibody 4. Female patients will either be * post-menopausal for \> 2 years * Women of childbearing potential can be included if surgically sterile or using double contraception with at least one method being barrier contraception. Women of childbearing potential must have a negative pregnancy test at screening and at randomisation. Pregnancy tests will be repeated during each visit.
Exclusion criteria
1. Inability or unwillingness to provide written consent. 2. Inability or unwillingness to comply with the requirements of the protocol as determined by the investigator. 3. Pregnancy, breastfeeding or use of non-reliable method of contraception. 4. Subjects with history of chronic liver disease, chronic renal failure, heart failure, diabetes mellitus 5. Subjects with history of peptic ulcer disease, upper gastrointestinal bleeding, diverticulitis or ulcerative colitis. 6. Subjects who have recently had live or attenuated virus vaccines 7. Subjects with current infection (systemic fungal, active tuberculosis, cerebral malaria, viral hepatitis, HIV) 8. Subjects with cataracts and glaucoma 9. Subjects with osteoporosis 10. Subjects with psychiatric disorders 11. Subjects with complete biliary obstruction, bleeding disorders, hypertriglyceridemia (fasting triglyceride levels \> 300mg/dL) 12. Previous history of adverse reactions to cholestyramine or other bile acid sequestrants 13. Previous history of adverse reactions to prednisolone or other steroid compound 14. Current use of cholestyramine or prednisolone or other steroid compound 15. Participation in another clinical trial and/or receipt of cholestyramine or prednisolone within 4 weeks prior to screening visit. 16. Subjects with history of bronchial asthma, bronchospasm, peripheral vascular disease or adverse reactions to propanolol 17. Subjects with adverse reactions to carbimazole 18. Hypokalemia (serum K+ \<3.5 mmol/L) 19. Thyroid storm defined as Burch Wartofsky Score \>45
Design outcomes
Primary
| Measure | Time frame | Description |
|---|---|---|
| Percentage of patients whose Free T4 normalize between the groups | 4 weeks | Normal Free T4 is defined as Free T4 level between 9-25 pmol/L |
| Percentage of patients whose Free T3 normalize between the groups | 4 weeks | Normal free T3 is defined as Free T3 level between 3.5-6.5 pmol/L |
Secondary
| Measure | Time frame | Description |
|---|---|---|
| Adverse events between the groups | 6 weeks | Number of adverse events between the groups |
| Reduction in Free T4 levels | 4 weeks | Reduction in Free T4 levels ( Change from baseline within 4 weeks) |
| Reduction in Free T3 levels | 4 weeks | Reduction in Free T3 levels (Change from baseline within 4 weeks) |
Countries
Malaysia
Contacts
Primary ContactSerena SK Khoo, Dr.
Backup ContactZanariah Hussein, Dr.
Outcome results
None listed