DR. LEAL - THYROID & ANTITHYROID DRIGS Flashcards
(119 cards)
1
Q
Function: normalize growth and development, body
temperature, and energy levels.
A
THYROID HORMONES
○ Triiodothyronine (T3)
○ Tetraiodothyronine (T4, Thyroxine)
2
Q
second type of thyroid hormone, is
important in the regulation of calcium metabolism.
A
CALCITONIN
3
Q
Recommended Daily Adult Iodide (I−) Intake:
A
○ 150 mcg
○ 200 mcg during pregnancy and lactation
○ 250 mcg for children
4
Q
absorbed best in the duodenum and ileum.
A
THYROXINE
5
Q
THYROXINE ABSORPTION MODIFIED BY
A
food, drugs, gastric
acidity, and intestinal flora.
6
Q
_ & _
IMPAIRED IN SEVERE MYXEDEMA WITH ILEUS
A
T3 AND T4 ABSORPTION
7
Q
METABOLIC CLEARANCES OF T3 & T4 ARE INCREASED
A
HYPERTHYROIDISM
8
Q
Drugs that induce hepatic microsomal enzymes increase the metabolism of both T4 and T3
A
Rifampin
phenobarbital
Carbamazepine
Phenytoin
Tyrosine kinase inhibitors
HIV protease inhibitors.
9
Q
responsible for optimal growth, development, function, and maintenance of all body tissues.
A
T3 AND T4
10
Q
EXCESS T3 AND T4 (THYROID HORMONES)
A
HYPERTHYROIDISM
11
Q
INADEQUATE T3AND T4
A
HYPOTHYROIDISM
12
Q
T OR F
Thyroid hormones are not effective and can be detrimental in the management of obesity, abnormal vaginal bleeding, or depression if thyroid hormone levels are normal.
A
TRUE
13
Q
SYNTHETIC THYROID HORMONES
A
Levothyroxine
Liothyronine
Liotrix
14
Q
CHOICE FOR THYROID REPLACEMENT & SUPPRESSION THERAPY
A
LEVOTHYROXINE (T4)
15
Q
Long half-life (7 days), which permits once-daily to weekly administration
A
LEVOTHYROXINE (T4)
16
Q
● 3-4x more potent than Levothyroxine
● Best reserved for short-term TSH suppression.
● Not recommended for routine replacement therapy
A
LIOTHYRONINE
17
Q
AVOIDED IN PTS WITH CARDIAC DSE
GREATER RISK OF CARDIOTOXICITY
A
LIOTHYRONINE
18
Q
○ Agents that interfere with the production
of thyroid hormones
○ Agents that modify the tissue response to
thyroid hormones
○ Glandular destruction with radiation or
surgery
A
ANTITHYROID AGENTS
Reduction of thyroid activity and hormone effects
19
Q
Agents that suppress secretion of T3 and T4 to subnormal levels and thereby increase TSH, which in turn produces glandular enlargement (goiter).
A
GOITROGENS
20
Q
Antithyroid compounds:
A
○ Thioamides
○ Iodides
○ Radioactive iodine
21
Q
TXFOR THYROTOXICOSIS
A
THIOAMIDES
Methimazole, Carbimazole and Propylthiouracil
(PTU)
22
Q
PREVENT PROTEIN SYNTHESIS
A
THIOAMIDES
Methimazole, Carbimazole and Propylthiouracil
(PTU)
23
Q
ADVERSE EFFECT OF THIOAMIDES
Methimazole, Carbimazole and Propylthiouracil
(PTU)
A
MACULOPAPULAR RASH
24
Q
MOST DANGEROUS COMPLICATION
THIOAMIDES
Methimazole, Carbimazole and Propylthiouracil
(PTU)
A
AGRANULOCYTOSIS
25
CROSS THE PLACENTAL BARRIER
Secreted in low concentrations in breast milk but are
considered safe for the nursing infant.
THIOAMIDES
(MCP)
26
● 10x more potent than Propylthiouracil.
● Drug of choice in adults and children.
● Readily accumulated by the thyroid gland.
METHIMAZOLE
27
● Single daily dose is effective in the management of
mild to severe hyperthyroidism.
● Associated with congenital malformations
● Cholestatic jaundice is more common.
METHIMAZOLE
28
USED FOR
1ST TRIMESTER OF PREGNANCY
THYROID STORM
ADVERSE RXNS TO METHIMAZOLE
PROPYLTHIOURACIL (PTU)
29
more strongly protein-bound and crosses the
placenta less readily.
PROPYLTHIOURACIL (PTU)
30
Black box warning:
severe hepatitis,
resulting in death.
PROPYLTHIOURACIL (PTU)
31
Perchlorate (ClO4)
Pertechnetate (TcO4−)
Thiocyanate (SCN-)
ANION INHIBITORS
32
Inhibits the first step of iodine synthesis; block uptake of iodide by the gland through competitive inhibition of the iodide transport mechanism.
ANION INHIBITORS
33
Block thyroidal reuptake of I− in patients with iodine-induced hyperthyroidism
POTASSIUM PERCHLORATE
34
ASSOCIATED WITH APLASTIC ANEMIA
POTASSIUM PERCHLORATE
35
● Major antithyroid agents prior to the introduction of the Thioamides in the 1940s.
● Rarely used as sole therapy today.
IODIDES
36
In susceptible individuals, ____ can induce hyperthyroidism (Jod-Basedow Phenomenon) or
precipitate hypothyroidism.
IODIDES
37
Disadvantages of iodide therapy
INITIATED AFTER ONSET OF THIOAMIDE THERAPY
AVOIDED IF TX WITH RADIOACTIVE IODINE SEEMS LIKELY
NOT SHOULD BE USED ALONE
CHRONIC USE IN PREGNANCY SHOULD BE AVOIDED
38
uncommon and in most cases reversible upon discontinuance.
IODISM
39
● The only isotope used for treatment of thyrotoxicosis.
● Administered orally in solution as sodium 1311.
RADIOACTIVEIODINE131
40
Advantages: easy administration, effectiveness, low
expense, and absence of pain.
RADIOACTIVEIODINE131
41
should not be administered to pregnant women or nursing mothers, since it crosses the placenta to destroy the fetal thyroid gland and it is excreted in breast milk.
RADIOACTIVE IODINE
42
● Beta blockers without intrinsic sympathomimetic activity are effective therapeutic adjuncts in the management of thyrotoxicosis since many of these symptoms mimic those associated with sympathetic stimulation.
● Beta blockers cause clinical improvement of hyperthyroid symptoms but do not typically alter thyroid hormone levels.
ADRENOCEPTOR-BLOCKINGAGENTS
PROPANOLOL
43
● Most widely studied and used in the therapy of
thyrotoxicosis.
● by inhibiting the peripheral conversion of T4 to T3.
PROPRANOLOL
44
DECREASE T3 AND T4
INCREASE TSH
HYPOTHYROIDISM
45
DEVELOP DWARFISM AND IRREVERSIBLE MENTAL RETARDATION
CAN OCCUR WITH OR WITHOUT THYROID ENLARGEMENT
HYPOTHYROIDISM
46
AUTOMIMUNE DESTRUCTION OF THYROID
HASHIMOTOS THYROIDITIS
47
IMPAIRED SYNTHESIS OF T4 DUE TO ENZYME DEFICIENCY
DYSHORMONOGENESIS
48
MANAGEMENT OF HYPOTHYROIDISM
MOST SATISFACTORY PREP
LEVOTHYROXINE
49
T OR F
Higher thyroxine requirements in patients with Celiac Disease and H. pylori gastritis
TRUE
50
CAN TYROSINE BE ADMINISTERED IN AN EMPTY STOMACH?
YES
51
THYROXINE DOSAGE
YOUNG
OLD
YOUNG- FULL REPLACEMENT THERAPY
OLD - 50mcg/d
52
in thyroxine usage
in cardiac patients
stop if?
THERE IS ANGINA PECTORIS OR CARDIAC ARRYTHMIA
53
● End state of untreated hypothyroidism, a medical
emergency.
MYXEDEMA COMA
54
TREATMENT FOR MYXEDEMA COMA
LEVOTHYROXINE
55
IN MYXEDEMA COMA
____ IS indicated if the patient has associated adrenal or pituitary insufficiency.
IV HYDROCORTISONE
56
HIGH OR LOW
____levels of circulating thyroid hormone actually protect the heart against increasing demands that could result in angina pectoris, atrial fibrillation, or
myocardial infarction.
LOW
57
T OR F
CORRECTION OF MYXEDEMA
coronary artery surgery is indicated, it should be
done first, prior to correction of the myxedema by thyroxine administration.
TRUE
58
HYPOTHYROID WOMEN
OVULATORY OR ANOVULATORY
ANOVULATORY
59
HYPOTHYROID PTS
INCREASE OF ____ REQUIRED TO NORMALIZE SERUM TSH LEVEL IN PREGNANCY
25-30%
60
Thyroxine should also be administered apart from prenatal vitamins and calcium by at least ____ HRS
FOUR HRS
61
MAINTENANCE OF TSH FOR PREGNANT
○ First trimester: 0.1–2.5 mIU/L
○ Second trimester, 0.2–3.0 mIU/L
○ Third trimester: 0.3–3.0 mIU/L
62
● An elevated TSH level and normal thyroid
hormone levels.
SUBCLINICAL HYPOTHYROIDISM
63
Treating with levothyroxine should be individualized based on the risks and benefits of treatment.
SUBCLINICAL HYPOTHYROIDISM
64
thyroid hormone therapy should be considered for patients with TSH levels greater than 10 mIU/L while close TSH monitoring is appropriate for those with lower TSH elevations.
SUBCLINICAL HYPOTHYROIDISM
65
Also termed as thyrotoxicosis.
● Clinical syndrome that results when tissues are
exposed to high levels of thyroid hormone.
HYPERTHYROIDISM
66
● Also known as diffuse toxic goiter.
● Most common form of hyperthyroidism.
GRAVES DSE
67
● An autoimmune disorder in which a defect in
suppressor T lymphocytes stimulates B lymphocytes to synthesize TSH receptor–stimulating antibody (TSH-R Ab [stim]) to thyroidal antigens.
GRAVES DSE
68
INCREASED T3 AND T4
DECREASE TSH
GRAVES DSE
69
MANAGEMENT OF GRAVES
Antithyroid Drug Therapy
○ Methimazole and Propylthiouracil.
70
○ Most useful in young patients with small
glands and mild disease.
○ The only therapy that leaves an intact
thyroid gland.
○ Require a long period of treatment and
observation (12-18 months).
Antithyroid Drug Therapy
○ Methimazole and Propylthiouracil.
71
○ Preferred than propylthiouracil.
○ Lower risk of serious liver injury.
METHIMAZOLE
72
Mild to moderately severe thyrotoxicosis
METHIMAZOLE
73
PREFERRED IN PREGNANCY AND THYROID STORM
Propylthiouracil (PTU)
74
Inhibits iodine organification, and inhibits the conversion of T4 to T3,
Propylthiouracil (PTU)
75
treatment
of choice for patients with very large glands
or multinodular goiters.
○ Patients are treated with antithyroid drugs
until euthyroid (about 6 weeks).
THYROIDECTOMY
76
preferred treatment for most patients over 21 years of age.
○ Patients without heart disease
RADIOACTIVE IODINE (RAI)
77
IN REGARDS TO RAI
Patients with underlying heart disease or severe thyrotoxicosis and in elderly patients:TREAT WITH
METHIMAZOLE
78
_______ should be avoided to ensure maximal 131I uptake.
IODIDES
79
occurs in about 80% of patients following RAI.
HYPOTHYROIDISM
80
When hypothyroidism develops,
prompt replacement with ________, 50–150 mcg daily, should be instituted.
ORAL LEVOTHYROXINE
81
LARGE GOITER
METHIMAZOLE THEN PTU FOLOWED BY
SUBTOTAK THYROIDECTOMY
TOXIC MULTINODULAR GOITER
82
Destruction of thyroid parenchyma with transient release of stored thyroid hormones during the acute phase of a viral infection of the thyroid gland (similar state may occur in patients with Hashimoto’s thyroiditis).
SUBACUTE THYROIDITIS
83
IN SUBACUTE THYROIDITIS
SUPPORTIVE THERAPY IS GIVEN IF NOT RESOLVED SPONTY
B BLOCKERS (PROPANOLOL)
ASPIRIN OR NSAIDS
CORTICOSTEROIDS
84
KNOWN AS THROTOXIC CRISIS
THYROID STORM
85
● Sudden acute exacerbation of all of the symptoms of
thyrotoxicosis, presenting as a life-threatening
syndrome.
THYROID STORM
86
MEDS FOR THYROID STORM
PROPANOLOL
87
IN THYROID STORM
WHAT MEDS GIVEN IF
control the severe
cardiovascular manifestations.
ESMOLOL
88
IN THYROID STORM
WHAT MEDS GIVEN IF
ASTHMATIC PATIENT
DILTIAZEM
89
Release of thyroid hormones from the gland is retarded by the administration of
POTASIUM IODIDE SATURATED SOLUTION
90
IN THYROID STORM
Hormone synthesis is blocked by the administration OF
PROPYLTHIOURACIL
91
IN THYROID STORM IS THERE RECTAL FORMULATION OF PROPYLTHIOURACIL?
YES
92
IN THYROID STORM RECTAL EXAM
METHIMAZOLE
93
IN THYROID STORM
protect the patient against shock and will block the conversion of T4 to T3, rapidly reducing the level of thyroactive material in the blood.
HYDROCORTISONE
94
IN THYROID STORM
essential to control fever, heart failure, and any underlying disease process
SUPORTIVE THERAPY
95
IN THYROID STORM
been used to lower the levels of circulating thyroxine.
oral bile acid sequestrants(eg,cholestyramine), plasmapheresis, or peritoneal dialysis
96
Ideally, women in the childbearing period with severe disease should have definitive therapy with __ AND __ prior to pregnancy in order to avoid an acute exacerbation of the disease during pregnancy or following delivery
IODINE 131
SUBTOTAL THYROIDECTOMY
97
If thyrotoxicosis does develop during pregnancy,
WHAT is contraindicated because it crosses the placenta and may injure the fetal thyroid.
RADIOACTIVE IODINE
98
IN PREGNANCY DURING THYROTOXICOSIS
WHAT IS THE PREFERRED TX
PROPYLTHIOURACIL - FIRST TRIMESTER
METHIMAZOLE - REMAINDER PREGNANCY
99
subtotal thyroidectomy can be safely performed during the
MID TRIMESTER OR
2ND TRIMESTER
100
may occur in the newborn infant, due either to passage of maternal TSH-R Ab [stim] through the placenta, stimulating the thyroid gland of the neonate, or to genetic transmission of the trait to the fetus.
NEONATAL GRAVE’S DISEASE
101
NEONATAL GRAVE’S DISEASE
INCR OR DEC
T3 AND T4
TSH
T3 AND T4 - INCREASED
TSH - DECREASED
——————NORMAL INFANT INCREASED TSH
102
NEONATAL GRAVE’S DISEASE
THERAPTY OR MANAGEMENT
PROPYLTHIOURACIL
LUGOLS SOLUTION
PROPRANOLOL
103
NEONATAL GRAVE’S DISEASE
IF INFANT IS VERY ILL GIVE
ORAL PREDNISONE
104
Defined as a suppressed TSH level (below the normal range) in conjunction with normal thyroid hormone levels.
SUBCLINICAL HYPERTHYROIDISM
105
Approximately 3% of patients receiving Amiodarone will develop hyperthyroidism.
AMIODARONE-INDUCED THYROTOXICOSIS
106
AMIODARONE-INDUCED THYROTOXICOSIS
- Often occurs in persons with underlying thyroid disease (eg, multinodular goiter, Graves’ disease)
- Treatment: therapy with
thioamides (methimazole)
IODINE INDUCED - TYPE 1
107
AMIODARONE-INDUCED THYROTOXICOSIS
- Occurs in patients without thyroid disease due to leakage of thyroid hormone into the circulation.
- Treatment: can give anti-inflammatory drugs, responds best to glucocorticoids.
INFLAMMATORY THYROIDITIS - TYPE 2
108
IN AMIODARONE -INDUCED THYROTOXICOSIS
OFTEN ADMINISTERED TOGETHER
THIOAMIDES
GLUCOCORTICOIDS
109
A syndrome of thyroid enlargement without excessive thyroid hormone production.
NONTOXIC GOITER
110
● Enlargement is often due to TSH stimulation from inadequate thyroid hormone synthesis.
NONTOXIC GOITER
111
Most common cause of nontoxic goiter worldwide is
IODIDE DEFICVIENCY
112
Most common cause of nontoxic goiter IN US
HASHIMOTOS THYROIDITIS
113
Managed by prophylactic administration of iodide.
● The optimal daily iodide intake is 150–200 mcg.
● Iodized salt and iodate used as preservatives in
flour and bread are excellent sources of iodine in the
diet.
GOITER DUE TO IODIDE DEFICIENCY
114
● Managed by elimination of the goitrogen or by adding sufficient thyroxine to shut off TSH stimulation.
GOITER DUE TO INGESTION OF GOITROGENS IN THE DIET
115
Adequate thyroxine therapy—_______—will suppress pituitary TSH and result in slow regression of the goiter as well as correction of hypothyroidism.
150–200 mcg/d orally
116
NOT RECOMMENDED FOR BENIGN LESIONS OR ADENOMAS
LEVOTHYROXINE
117
Requires a total thyroidectomy, postoperative
radioiodine therapy in selected instances
THYROID CARCINOMA
118
lifetime replacement with levothyroxine
THYROID CARCINOMA
119
can produce comparable TSH elevations without discontinuing thyroxine and avoiding hypothyroidism.
recombinant human TSH (Thyrogen) - IM
