|Instructor:||Dr. Peter Loewen|
|Important Course Pages|
- Be able to describe the physiology of thyroid function.
- Be able to explain the biochemical parameters used to evaluate thyroid function.
- Be able to describe the pathophysiology of the most common causes of hyper- and hypothyroidism.
- Be able to name the signs and symptoms of hyper- and hypo-thyroidism.
By the end of the the session and upon further study and reflection, students should be able to
- rationalize a diagnosis of hypothyroidism on the basis of signs and symptoms combined with biochemical tests.
- design, implement and monitor (efficacy/toxicity) an effective pharmacotherapeutic plan for managing primary hypothyroidism.
- dentify and manage common drug related-causes of hypothyroidism.
- Obtain Peter Loewen's Thyroid Physiology, Pharmacology, & Pharmacotherapy PLOP.
- Read McDermott MT. Hypothyroidism. Ann Intern Med. 2009; ITC6 (1DEC09)
- Complete the self-assessment questions below
- Obtain and review the session slides
Preparatory self-assessment questions
1. The predominant hormone secreted by the thyroid gland is
- a. Triiodothyronine
- b. Tetraiodothyronine
- c. Liothyronine
- d. Parathyroid hormone
2. The metabolically active thyroid hormone, (________), is produced mainly (_________)
- a. T3, in peripheral tissues
- b. T4, in peripheral tissues
- c. T3, in the thyroid
- d. T4, in the thyroid
3. The most common cause of hypothyroidism in North America is
- a. Iodine deficiency
- b. Graves’ disease
- c. Amiodarone
- d. Autoimmune thyroiditis
4. The most common cause of hyperthyroidism in North America is
- a. Iodine excess
- b. Graves’ disease
- c. Autoimmune thyroiditis
- d. Toxic multinodular goitre
5. Which constellation of symptoms is most consistent with hyperthyroidism
- a. Depression, constipation, ascites, bradycardia
- b. Normocytic anemia, pleural effusion, menorrhagia, myalgia
- c. Bradyphasia, eczema, proptosis, paresthesia
- d. Thinning of hair, amenorrhea, osteoporosis, muscle weakness
References & Additional Reading
- ASCE / ATA Clinical Practice Guidelines for Hypothyroidism in Adults Endocrine Practice 2012;18(6):989-1027.
- Levy M. ￼How to interpret thyroid function tests. Clin Med 2013;13:282–6.
- Nygaard B. Hypothyroidism (Primary). ClinicalEvidence 2010;01:605.
- Effects of evening vs morning levothyroxine intake: a randomized double-blind crossover trial. Arch Intern Med. 2010 Dec 13;170(22):1996-2003.
- Pham & Shaugnessy. Should we treat subclinical hypothyroidism? BMJ 2008;337:a834 doi:10.1136/bmj.a834
Pregnancy & Hypothyroidism
- Yassa L, et al. J Clin Endocrinol Metab 2010;95: 3234–3241.
- Alexander EK et al. NEJM 2004;351:241-9
- Bungard & Hurlburt CMAJ 2007;176: 1077-8