Thyroid Disorders NAPLEX

full levothyroxine replacement dose

1.6 mcg/kg/day use IBW

what is the most common cause of hypothyroidism? a. grave's dx b. lithium c. amiodarone d. radiation tx e. hashimoto's dx

e. hashimoto's dx an autoimmune condition in which antibodies attack a pt own thyroid gland

(select all that apply) which of the following statements concerning treatment of hyperthyroidism is/are correct? a. Grave's dx can be treated w radioactive iodine, thyroidectomy, or medications b. methimazole is preferred in thyroid storm c. pt receiving methimazole or PTU must be monitored for hepatitis d. beta blockers are often used initially to control sx such as palpitations and racing heart beat e. initially, higher doses of drugs are used to control sx; afterwards, doses are typically decreased to prevent over treatment

a. Grave's dx can be treated w radioactive iodine, thyroidectomy, or medications c. pt receiving methimazole or PTU must be monitored for hepatitis d. beta blockers are often used initially to control sx such as palpitations and racing heart beat e. initially, higher doses of drugs are used to control sx; afterwards, doses are typically decreased to prevent over treatment PTU is preferred in thyroid storm

(select all that apply) choose the correct statement(s) regarding levothyroxine: a. it contains T4 b. it contains T3 c. it is derived from dessicated porcine gland d. it is the preferred agent for treating hypothyroidism e. it will lower TSH

a. it contains T4 d. it is the preferred agent for treating hypothyroidism e. it will lower TSH levothyroxine is synthetic T4, which gets converted in the body to T3. it is the preferred agent and matches human T4

choose the correct statement regarding levothyroxine use in pregnancy: a. it is safe to use in pregnancy b. it is a known animal teratogen. risk vs benefit must be evaluated prior to treating a pregnant patient c. thyroid disorders resolve during pregnancy and do not require treatment until after the baby is delivered d. it is a known human teratogen and should not be used in pregnancy e. it is safe to use only in the 3rd trimester

a. it is safe to use in pregnancy hypothyroidism that goes uncorrected in pregnancy will cause the child to suffer neurological damage. if a woman becomes pregnant while taking levothyroxine, she must continue to use it at an increased dose of 30-50%.

(select all that apply) treatment for thyroid storm includes which of the following: a. PTU b. SSKI c. Lugol's solution d. beta blocker e. corticosteroid f. acetaminophen

a. PTU b. SSKI c. Lugol's solution d. beta blocker e. corticosteroid f. acetaminophen

which of the following is correct regarding drug interactions with PTU? a. PTU can decrease the anticoagulant effect of warfarin. b. there are no drug interactions between PTU, melatonin, warfarin, Zyvox, and a MVI c. PTU is contraindicated with Zyvox d. PTU should be separated from melatonin e. PTU can increase the anticoagulant effect of warfarin

a. PTU can decrease the anticoagulant effect of warfarin. increase risk of clotting

(select all that apply) which of the following is correct regarding thyroid function? a. T4 elevations inhibit TSH secretion and a negative feedback loop is created b. normally, TSH stimulates T4 secretion and, minimally, T3 c. T3 is 3-4x more potent than T4 d. T4 is 3-4x more potent than T3 e. total daily T3 production results from the peripheral conversion of T4 to T3 (~ 80%)

a. T4 elevations inhibit TSH secretion and a negative feedback loop is created b. normally, TSH stimulates T4 secretion and, minimally, T3 c. *T3 is 3-4x more potent* than T4 e. total daily T3 production results from the peripheral conversion of T4 to T3 (~ 80%)

select the correct pathway that describes thyroid function: a. TSH stimulates T4 secretion b. T3 is converted to T4 c. TSH accounts for the majority of T3 production d. in pt w hypothyroidism, T4 cannot be converted into T3 e. TSH is stimulated by T4 elevations

a. TSH stimulates T4 secretion normally, *TSH stimulates T4 secretion* and, minimally, T3. Total daily T3 production results predominantly from *peripheral conversion of T4 to T3*

pt with heartburn has been using OTC anti-gas and antacid products for many years. she's been recently diagnosed with hypothyroidism. which of the following OTC meds will not interact with her thyroid medication? a. famotidine b. aluminum hydroxide c. magnesium hydroxide d. pepcid complete e. calcium carbonate

a. famotidine medications that can decrease absorption of thyroid hormone products: - antacids (AlOH, MgOH, CaCO3) - bile acid sequestrants (cholestyramine, colestipol) - cation exchange resins (sodium polystyrene sulfonate (Kayexalate)) - ferrous sulfate - orlistat (Xenical) - sucralfate - MVI (with ADEK, folate, Fe) ** separate doses by 4 hrs pepcid complete contains famotidine + antacids (MgOH and CaCO3)

(select all that apply) which of the following are s/sx of hypothyroidism? a. feeling more tired than usual b. increase in weight c. low TSH d. depression e. diarrhea and oily skin

a. feeling more tired than usual b. increase in weight d. depression fatigue, wt gain, dry skin, constipation are common in hypothyroidism. pt may feel depressed and suffer from memory impairment, may have difficulty tolerating cold weather, menstrual periods may be heavier, voice may be hoarse, hair may be coarse or hair loss may occur. long term hypothyroidism untreated increases the risk of CV dx

what is the most common cause of hyperthyroidism? a. grave's dx b. hashimoto's dx c. lithium d. amiodarone e. radiation tx

a. grave's dx an autoimmune condition in which antibodies stimulate the thyroid to over-produce T4 hormone tends to occur in females in their 30s and 40s

(select all that apply) choose the correct statement(s) regarding generic options for levothyroxine brand formulations: a. levothyroxine has a narrow therapeutic index b. all generics of levothyroxine are A rated to each of the available brand formulations c. patients should be told to use brand name only d. the correct source to check for therapeutic (A rated) equivalents is the Red Book e. if a pt changes manufacturers, it is prudent to monitor for sx of hypo- or hyperthyroidism as the dosage may require adjustment

a. levothyroxine has a narrow therapeutic index e. if a pt changes manufacturers, it is prudent to monitor for sx of hypo- or hyperthyroidism as the dosage may require adjustment - the Orange Book is the correct source to check for therapeutic (A rated) equivalents - levothyroxine comes in many dosages and various brands; dosages across manufacturers may not be A rated - monitor sx if a dosage or mftr is changed - pt should try to stay with the same formulations - RPh should only dispense alternatives that are A rated to the formulation the pt has been using

PTU can have this effect on blood cells: a. low WBCs (leukopenia) b. decreased RBCs c. decreased platelets d. high WBCs (leukocytosis) e. increased platelets (thrombocytosis)

a. low WBCs (leukopenia) PTU and methimazole have a risk of decreasing WBCs, including risk of agranulocytosis. pt should watch for s/sx infection

(select all that apply) AA (F, 33 yo) diagnosed with hyperthyroidism awaits an appointment to see an endocrinologist. in the meantime, she's been given a Rx for PTU and propranolol. choose the correct statement(s): a. propranolol will reduce hyperthyroid sx b. PTU increases T3 production c. PTU inhibits thyroid hormone synthesis d. PTU increases T4 production e. propranolol increases TSH production

a. propranolol will reduce hyperthyroid sx c. PTU inhibits thyroid hormone synthesis beta blockers can block tachycardia and trembling associated with hyperthyroidism PTU and methimazole inhibit thyroid hormone synthesis

pt (F, 40 yo) has been prescribed levothyroxine 50 mcg qday. choose the correct counseling statement: a. take this medication 1 hour before breakfast on an empty stomach b. take this medication at bedtime with a light snack c. take this medication with lunch d. take this medication with dinner e. take this medication with breakfast

a. take this medication 1 hour before breakfast on an empty stomach levothyroxine is taken in the morning, preferably on an empty stomach 1 hr before breakfast to optimize drug absorption. if the pt has been taking it with breakfast, do not change it as their levels may have been adjusted accordingly. it will cause insomnia if taken later in the day.

which of the following statements is correct regarding the treatment of hyperthyroidism during pregnancy? a. radioactive iodine is the treatment of choice b. PTU is used in the 1st trimester c. should not be treated during pregnancy due to risks associated with all available treatments d. methimazole is used in the 1st trimester e. potassium iodide is used in the 1st trimester

b. PTU is used in the 1st trimester methimazole is used in 2nd and 3rd trimesters due to higher risk of liver toxicity from PTU

(select all that apply) which of the following drugs can cause hyperthyroidism? a. lithium b. amiodarone c. iodine d. thyroid hormone taken in excess e. prednisone

b. amiodarone c. iodine d. thyroid hormone taken in excess - lithium causes hypothyroidism - amiodarone and interferons can cause both hypo- and hyperthyroidism

(select all that apply) which of the following s/sx would be expected to be present in a pt diagnosed w hyperthyroidism? a. high tsh b. diarrhea c. depression d. agitation, irritability, and tachycardia e. low FT4

b. diarrhea d. agitation, irritability, and tachycardia thyroid disorders are diagnosed using TSH, FT4, and clinical sx. hyperthyroidism: high FT4, low TSH hypothyroidism: low FT4, high TSH

which of the following is an appropriate generic substitution for Cytomel? a. propylthiouracil b. liothyronine c. levothyroxine d. thyroid USP e. methimazole

b. liothyronine (Cytomel) propylthiouracil (PTU) levothyroxine (Synthroid) methimazole (Tapazole)

AA has been prescribed propylthiouracil, which should be reserved for patients who cannot use other options due to the risk of this adverse reaction: a. renal failure b. liver damage c. fatal skin rash d. trouble breathing/laryngoedema e. cardiotoxicity

b. liver damage PTU has a boxed warning for severe liver injury, which can come on suddenly, even after long-term use

which of the following is an appropriate generic substitution for Tapazole? a. Thyroid USP b. methimazole c. levothyroxine d. propylthiouracil e. liothyronine

b. methimazole

(select all that apply) pt takes warfarin for AFib and has been d/c from the hospital with the following new meds: levothyroxine, diltiazem, amiodarone. select the correct statement(s) a. levothyroxine will incr pt risk of DVT b. diltiazem can decr levels of levothyroxine and suboptimal control of hypothyroidism c. levothyroxine can lead to supratherapeutic INR d. diltiazem can lead to a subtherapeutic INR e. amiodarone can lead to a supratherapeutic INR

c. levothyroxine can lead to supratherapeutic INR e. amiodarone can lead to a supratherapeutic INR monitor INR in pt on warfarin who take levothyroxine or amiodarone as both may increase INR and bleed risk. amiodarone cause a large INR increase; warfarin dose should be decreased

JH (F, 78 yo, PMHx: HF, MI) has just been diagnosed with hypothyroidism. she is 5'0", 103 lbs, and is going to start levothyroxine. what is an appropriate starting dose for this patient? a. 75-100 mcg/day b. 100-150 mcg/day c. 25-50 mcg/day d. 12.5-25 mcg/day e. 50-75 mcg/day

d. 12.5-25 mcg/day pt with *known CAD* are *start*ed at *12.5-25 mcg/day*, returning in 4-6 wks to dose adjust until TSH is normalized and sx resolved. the average levothyroxine maintenance dose for most adult pt is 100-150 mcg/day. older pt often require less.

pt taking levothyroxine 100 mcg qday at home is hospitalized and is NPO. what is the most appropriate dose for the pharmacist to dispense in order to continue the levothyroxine IV? a. 200 mcg b. 100 mg c. 112 mcg d. 75 mcg e. 50 mcg

d. 75 mcg levothyroxine IV:PO ratio is 0.75:1, which corresponds best to absorption of levothyroxine in the fasting state

what common side effect might a pt taking PTU experience? a. bradycardia b. hypotension c. hyperglycemia d. GI upset e. diarrhea

d. GI upset PTU and methimazole can cause rash and GI ADRs (N/V)

the thyroid gland is the only organ which has the ability to absorb: a. T3 b. T4 c. TSH d. iodine e. levothyroxine

d. iodine

(select all that apply) which of the following is a correct statement(s) regarding Armour Thyroid? a. some patients prefer it b. it will raise TSH c. it is not preferred for hypothyroidism d. it is not synthetic; it is derived from pork thyroid gland e. it contains both T3 and T4

re: Armour Thyroid: a. some patients prefer it c. it is not preferred for hypothyroidism d. it is not synthetic; it is *derived from pork thyroid gland* e. it contains both T3 and T4 the preferred agent for treating hypothyroidism is levothyroxine; some pt feel better using Armour Thyroid although there is no proof that it works better.