NMS Q&A Family Medicine

208 NMS Q&A Family Medicine16. The answer is C. Start propranolol at 20 mg daily. Insubacute thyroiditis, the thyrotoxic phase usually is mildand lasts about 2 months. Therefore, thiourea drugs (e.g.,methimazole and propylthiouracil) are not necessary andwould not be effective because their action depends onactive hormone production by the gland. The same statementsare true for I 131 . From the foregoing, it is clear thatthyroidectomy is not warranted.17. The answer is B. Typical of subacute or de Quervainthyroiditis is not only a brief thyrotoxic phase but also6 to 9 months of hypothyroidism that follows virtually onthe heels of the toxic phase. Thus, treatment of this conditionwill rarely remain in place for life. The complicationoccurs in nearly one-half of patients, although the vastmajority revert to a euthyroid state without elevated antithyroidantibodies. Approximately 5% of patients will notremit from the hypothyroid phase; a few will have recurrentsubacute phases, and uncommonly some will undergochange to Graves disease. About one-third of subacutethyroiditis patients will have persistent elevations of antithyroidperoxidase antibodies and a persistent goiter.18. The answer is D. Coronary atherosclerosis is not aparticularly strong risk in Graves disease, the most commoncause of hyperthyroid disease, illustrated in thevignette presented. As an autoimmune disease, Graves isassociated statistically with all the other diseases mentionedamong the choices and as well with coeliac disease,myasthenia gravis, cardiomyopathy, and hypokalemicperiodic paralysis. The female-to-male ratio among thoseafflicted with Graves disease is approximately 8:1. Lifetimeincidence (sometime prevalence of this disease) isthus 2.2% for female individuals and about 0.3% for maleindividuals. Indeed, the vast majority of all thyroid problemsoccur more in female than in male individuals.19. The answer is D. Thyroidectomy is the least likelychoice, with the patient having the final vote, assumingshe is well informed of all side effects and contraindications.In the short term, when the patient is uncomfortableor seriously in jeopardy because of the severity of thethyrotoxicosis, nonselective beta-adrenergic blockingdrugs such as propranolol are used while the definitivetherapy takes effect. I 131 therapy is well tolerated but isusually followed ultimately by hypothyroidism and theneed for replacement therapy. The thiourea drugs havethe advantage of often succeeding after finite periods of1 to 2 years. Between the two most often utilized, propylthiouracilis safe even in pregnancy, if kept below 200 mg/day to avoid fetal hypothyroidism. Thyroidectomy is lessand less frequently elected because of its obvious invasivenessand the fact that it too must generally be followed bypermanent hypothyroidism and the need for replacementtherapy.20. The answer is D. This patient has toxic nodular goiter,preceded as happens in a certain proportion of cases,by nontoxic nodular goiter. This disorder is not characterizedby exophthalmos, unlike Graves disease, although theeyes may manifest the stare and the lid lag of thyrotoxicosis.It occurs most frequently in older individuals (i.e., 55 years) and begins as a grouping of nodules, apparentlyunder the influence of an elevated TSH caused byincipient hypothyroidism. In a certain proportion ofcases, the nodules become autonomous and hyperfunctional.This form of thyrotoxicosis is a less severe form ofhyperthyroidism, whether measured in terms of clinicalsymptoms and signs or laboratory measurement of FT 4 ,T 3 , or I 123 uptake.21. The answer is B. Therapy with I 131 is ideal in this diseasebecause it occurs most frequently in older people(but would be the best choice in any adult with toxic multinodulargoiter, as will be clear from subsequent commentary).Surgery is eschewed for the same reasons asdiscussed elsewhere, unless there is reason to expect acancerous nodule or nodules. Thiourea agents are noteffective over the long term, as they are followed by a 95%chance of recurrent multinodular disease. Beta-blockingagents are not needed during the early treatment phase inmost cases because in the vast majority the degree of thyrotoxicosisis mild.ReferencesFitzpatrick PA . Endocrinology . In: Tierney LM , McPhee SJ ,Papadakis MA , eds. Medical Diagnosis and Treatment . 45th ed.New York/Chicago: Lange ; 2006 .Larsen PR , Davies TF , Hay ID . The thyroid gland . In: WilsonJD , Foster DW , Kronenberg HM, Larsen PR , eds. William’sTextbook of Endocrinology . 9th ed. Philadelphia : WB Saunders; 1998 :389–515.Reid JR , Wheeler SF . Hyperthyroidism: Diagnosis and treatment. Am Fam Physician . 2005 ; 72 : 623 – 630 , 635 – 636.Rudy DR , Tzagournis M . Thyroid problems in primary care . In:Rudy DR, Kurowski K , eds. Family Medicine: House OfficerSeries . Baltimore : Williams & Wilkins ; 1997 : 543 – 566 .