Term
| T/F: Thyroid hormone affects function of only a few organ systems. |
|
Definition
| False; it affects virtually all organ systems |
|
|
Term
| What controls the Thyroid hormone? |
|
Definition
| Hypothalamus Pituitary Thyroid Axis |
|
|
Term
| What are the 2 main hormones produced by the thyroid? |
|
Definition
T4 = Thyroxine
T3= Triiodothyronine |
|
|
Term
| Of the 2 hormones, which one is the more potent? Which one is the major circulating hormone? |
|
Definition
More potent = T3
Major circulating = T4 (98%) |
|
|
Term
| Drugs that increase protein binding will ______________ the effects of thyroid hormone. |
|
Definition
Decrease
(only free hormone can work) |
|
|
Term
| Describe the Hypothalamus Pituitary Thyroid Axis. |
|
Definition
| Hypothalamus stimulates TRH, this signals the pituitary to stimulate TSH. TSH stimulates the Thyroid Gland to release T4/T3. If there is high # of T4/T3 then it will inhibit the pituitar to inhibit TSH, to stop making T4/T3. |
|
|
Term
| If you have Hypothyroidism your TSH levels will be ______________. |
|
Definition
Higher than normal
(thyroid gland isnt working right) |
|
|
Term
| If you have Hyperthyroidism then your TSH levels are _____________. |
|
Definition
Lower than normal
(thryoid gland doing too much) |
|
|
Term
| Because it is the first thing affected w/ thyroid function, what is the most sensitive index for diagnosis? |
|
Definition
|
|
Term
| What is the normal range of TSH? |
|
Definition
|
|
Term
| What are some things that can alter TSH and does not necessarily mean its a thyroid problem? |
|
Definition
1. Non-thyroidal illness
2. Certain Rx like DA, High dose glucocorti.
3. Presence of Hypothalamic/pituitary disease |
|
|
Term
| Describe the levels of TSH, FT4, and FT3 in a patient with Hypothyroidism. |
|
Definition
TSH = High
FT4 = Low
FT3= Low |
|
|
Term
| Describe the levels of TSH, FT4, and FT3 in a patient with Subclinical Hypothyroidism. |
|
Definition
TSH = High
FT4 = No change
FT3 = No change |
|
|
Term
| Describe the levels of TSH, FT4, and FT3 in a patient with Hyperthyroidism. |
|
Definition
TSH = Low
T4 = High
T3 = High |
|
|
Term
| Describe the levels of TSH, FT4, and FT3 in a patient with Subclinical Hyperthyroidism. |
|
Definition
TSH = Low
FT4 = No change
FT3= No change |
|
|
Term
| What is the normal range for FT4 ? |
|
Definition
|
|
Term
| What is the difference between Primary and secondary Hypothyroidism? |
|
Definition
Both have a high TRH and low T4/T3 but in:
Primary = High TSH
Secondary = Low TSH |
|
|
Term
| What is the most common cause of Hypothyroidism? |
|
Definition
|
|
Term
| List some clinical features of Hypothyroidism. |
|
Definition
1. Tired/Lethargy (91%)
2. Dry, patchy skin (97%)
3. Cold intolerance/ decrease sweating (89%)
4. Puffy Eyes (90%)
5. Muscle weakness/cramps (99%)
6. Constipation
7. Inability to Concentrate
8. Moody
9. Forgetful |
|
|
Term
| What are some risks associated with Hypthyroidism? |
|
Definition
1. Increased risk for functional CV changes
2. Increased risk for atherosclerosis |
|
|
Term
| Why is there an increase risk of Atherosclerosis with Hypothyroidism? |
|
Definition
There is a proportionate increase of TC and LDL with increase TSH.
(Cholesterol increases with increase in TSH) |
|
|
Term
| List some long term consequences of Hypothyroidism. |
|
Definition
1. Decreased QOL
2. Increased Death
3. Increase risk for CV events
4. Heart Failure
5. Negative metabolic consequences |
|
|
Term
| Do you expect to see weight gain or weight loss in a patient with Hypothyrodism? |
|
Definition
Weight Gain
(lower metabolic function) |
|
|
Term
| What are the goals of therapy for thyroid hormone replacement in treating Hypothyroidism? |
|
Definition
1. Restore thyroid hormone levels
2. Provide symptomatic relief
3. Reverse biochemical abnormalities
4. Prevent long term consequences
5. Prevent neurological deficits in newborns/kids |
|
|
Term
| What is the treatment of choice for Hypothyroidism? |
|
Definition
| Synthetic Levothyroxine (aka Synthroid) |
|
|
Term
| Which synthetic Thyroid hormone replacement product contains both T3 and T4? |
|
Definition
|
|
Term
| Which synthetic Thyroid hormone replacement product contains only T3? |
|
Definition
|
|
Term
| Why are natural thyroid hormone replacement products not recommended? |
|
Definition
| Because there is an increase risk for allergic rxns and the potency varies by product |
|
|
Term
| What is the average dose of Levothyroxine for treating Hypothyroidism? |
|
Definition
100-150 ug/day
or
(1.6-1.7 ug/kg/day) |
|
|
Term
| What is the initial dose for Levothyroxine in younger adults and those w/out CV disease? |
|
Definition
| Start at 50 ug/day and then increase to 100 ug/day after 1 month |
|
|
Term
| What is the initial dose of Levothyroxine in adults > 65yro or patients with heart disease? |
|
Definition
| Start at a lower initial dose of 25ug/day and titrate at 25 ug/month intervals |
|
|
Term
| What things can occur with an excess doses of Levothyroxine? |
|
Definition
1. Tachycardia
2. Atrial Arrhythmias
3. Reduced exercise performance
4. Increased risk of cardiac mortality
5. Impaired Ventricular relaxation |
|
|
Term
| If TSH levels remain high in Hypothyroidism, what should you do to the dose of Levothyroxine? |
|
Definition
| Increase the dose by 25-50 ug/day , but do not over dose! |
|
|
Term
| When should a patient get symptomatic improvement with Levothyroxine? What about max effect? |
|
Definition
See improvement in 2-3 weeks
Max effect in about 6 weeks |
|
|
Term
| When should we monitor a patient on Levothyroxine? |
|
Definition
In 4-6 weeks intervals
(The appropriate dose should normalzie the TSH, FT4 and alleviate symptoms) |
|
|
Term
| Once the TSH and FT4 levels are stable, when should we monitor a patient on Levothyroxine? |
|
Definition
|
|
Term
| T/F: Over replacement with Levothyroxine can lead to excessive bone loss. |
|
Definition
|
|
Term
| What are some practical considerations when taking Levothyroxine? |
|
Definition
Take in the a.m. on an empty stomach with a full glass of water
(has food/drug interactions) |
|
|
Term
| Levothyroxine has many drug interactions. Which drugs reduce the production? |
|
Definition
Lithium
Amiodarone
I2 containing meds |
|
|
Term
| Levothyroxine has many drug interactions. Which drugs reduce the absorption? |
|
Definition
1. Fe++
2. Bile acid sequesterants
3. Fiber
4. Food
5. Ca++
6. Al+++ |
|
|
Term
| Levothyroxine has many drug interactions. Which drugs increase the metabolism? |
|
Definition
1. Barbituates
2. Carbamazepine
3. Phenytoin
4. Rifampin |
|
|
Term
| Amiodarone Induced Hypothyroidism (AIH) resembles native Hypothyroidism. When does it occur? |
|
Definition
| Between 6-12 months of therapy |
|
|
Term
How do you treat AIH?
And when do you monitor? |
|
Definition
Use Levothyroxine 25-50 ug/day and titrate to TSH
At baseline and then every 6 months |
|
|
Term
| How does Lithium cause Hypothyroidism? |
|
Definition
| It inhibits the release of Thyroid hormone from the thyroid gland . The TSH will increase while the hormone levels decrease. |
|
|
Term
| If a patient is pregnant when should Levothryoxine be administered? |
|
Definition
| In the 1st 2 months of gestation |
|
|
Term
| What does Estrogen do to the levels of free T4? |
|
Definition
| Estrogen increases the TBG (binding globulin) so it decreases the amount of free T4. Will need to increase dose to compensate for this. |
|
|
Term
| With Subclinical Hypothyroidism there is no or few signs/symptoms with normal T3/T4 but an elevated TSH. When do you treat? |
|
Definition
1. When the TSH > 10 uIU/mL
2. TSH is 5-10 uIU/mL with a goiter or + Anti-thyroid peroxidase AB
3. Has symptoms
4. Has prior treatment w/ RAI
|
|
|
Term
How do you treat Subclinical Hypothyroidism?
What is the target TSH? |
|
Definition
Levothyroxine 25-50 ug/day
0.3-3.0 uIU/mL |
|
|
Term
| What is the peak age in peeps with Hyperthyroidism? |
|
Definition
|
|
Term
| What is the most common cause of Hyperthyroidism? |
|
Definition
|
|
Term
| What are some risks with untreated Hyperthyroidism? |
|
Definition
1. Osteoporosis
2. Anoxeria
3. Congestive HF
4. A. Fib
5. Decreased QOL |
|
|
Term
| List some signs and symptoms of Hyperthyroidism. |
|
Definition
1. Change in appetite
2. Nervousness/irritability
3. Palpitations
4. Heat intolerance/ increased sweating
5. Insomnia
6. EXOPTHALMUS
7. Increased metabolism/aggitation |
|
|
Term
| With Graves Disease there is a _____________ in RAI-U that leads to hyperthyroidism. |
|
Definition
|
|
Term
| What does the Thyroid gland look like in patients with Graves Disease? |
|
Definition
|
|
Term
| Why does exophtalmos occur in patients with Graves? |
|
Definition
| Because the Autoantibodies react with orbital muscle |
|
|
Term
| What is Thyrotoxicosis Factitia? |
|
Definition
| Hyperthyroidism induced by excessive hormone ingestion |
|
|
Term
| What are the goals of therapy for Hyperthyroidism? |
|
Definition
1. Elminate xs hormone
2. Minimize symptoms
3. Avoid long term consequences |
|
|
Term
| What are the 3 different Tx options for Hyperthyroidism? |
|
Definition
1. Surgery
2. Anti-thyroid Rx
3. Radioactive I2 |
|
|
Term
|
Definition
|
|
Term
| Name the 2 Rx used for Anti-thyroid |
|
Definition
Propylthiouracil (PTU)
Methimazole (Tapazole) |
|
|
Term
| Who are the better candidates for Anti-thyroid Rx? |
|
Definition
1. Children/ young adults
2. pregnant
3. Before having surgery
|
|
|
Term
| What are some advantages of Anti-thryoid Rx? |
|
Definition
1. Non invasive
2. No risk of permanent hypothyroidism
|
|
|
Term
| What are some disadvantages of Anti-thyroid Rx? |
|
Definition
1. Low cure rate (30-80%)
2. poor compliance
3. Lifetime therapy
4. Possible drug toxicity |
|
|
Term
| Out of the 2 Anti-thyroid Rx, which is the most potent? |
|
Definition
| METH is 10x more potent then PTU |
|
|
Term
| What is the max dose for PTU? Max dose for METH? |
|
Definition
PTU = 1200 mg/day
METH = 120 mg/day |
|
|
Term
| What is the starting dose for PTU? |
|
Definition
|
|
Term
| When do you follow up on a patient taking Anti-thyroid Rx? |
|
Definition
Every 4-6 wks
After 3-6 months on Rx then follow up every 2-3 mo then every 4-6 months |
|
|
Term
| What can be taken with an Anti-thyroid Rx to help relieve symptoms of hyperthyroidism? |
|
Definition
|
|
Term
| When should a patient see improvement of clinical symptoms when taking an Anti-thyroid Rx? |
|
Definition
|
|
Term
| On average what % of peeps achieve remission with the use of Anti-thryoid Rx? |
|
Definition
Avg 40-50%
Can be seen anywhere btwn 10-98% of peeps |
|
|
Term
| Which treatment option for Hyperthyroidism is a cure, most cost effective but causes permanent hypothyroidism? |
|
Definition
| Radioactive Iodine (I131) |
|
|
Term
| What is the best treatment option for toxic nodules and toxic multinodular goiters in hyperthyroidism? |
|
Definition
|
|
Term
| When should surgery be performed in a person with Hyperthyroidism? |
|
Definition
| When there is a concern of cancer, or when a person refuses RAI. |
|
|
Term
| Which thionamide has dose related ADRs? Describe the relationship btween Dose and ADR. |
|
Definition
METH
The higher the dose the more ADR |
|
|
Term
| What is the most common ADR associated w/ the use of Thionamides? |
|
Definition
Benign transient leukopenia
(12% of adults, 25 % in kids) |
|
|
Term
| What is a very serious ADR of thionamides that has an abrupt onset and occurs withint he 1st 3 months? |
|
Definition
|
|
Term
| How many times a day do you take METH? PTU? |
|
Definition
METH is more potent so only need 1/day
PTU is less potent so 2-3 doses/day |
|
|
Term
| Which Thionamide would you choose if your patient was pregnant or breastfeeding? |
|
Definition
|
|
Term
| Which Thionamide is associated with more severe liver toxicity and vasculitis? |
|
Definition
|
|
Term
| Subclinical Hyperthyroidism has a TSH < ___________ and _______ T3/T4. |
|
Definition
|
|
Term
| What is Thyroid storm? How do you know it is that? |
|
Definition
Life threatening, medical emergency
Severe Thyrotoxicosis
Fever > 103 F
Tachycardia, tachypnea
Dehydration
Nausea/Vomiting
Delirium
Diarrhea |
|
|
Term
| What things can cause a Thyroid Storm? |
|
Definition
1. Infection
2. RAI
3. Anti-thryoid Rx withdrawal
4. Trauma |
|
|
Term
| How do you treat Thyroid Storm? |
|
Definition
1. High dose PTU (before Iodides)
2. Iodides (NaI or KI)
3. B-blocker (propranolol or esmolol)
4. Coritcosteroids
5. Supportive measures |
|
|
Term
| Since RAI is contraindicated in pregnant women and surgery is discouraged, one should use an Anti-thryoid Rx. Which one is preferred over the other? |
|
Definition
|
|
Term
| _________ directly interacts w/ Warfarin, in addition to hormonal effect, increasing the risk for bleeding. |
|
Definition
|
|
Term
| Amiodarone is 37% I2 by weight and can induce Type 1 and 2 Hyperthyroidism. Type 1 is I2 induced whereas Type 2 is Drug induced destructive Thyroditis. How do you treat both types? |
|
Definition
Type 1 = Discontinue amiodarone and administer large doses of Anti-thyroid Rx
Type 2 = Prednisone 40-60 mg/day |
|
|
Term
| T/F: Amiodarone can only cause Hyperthyroidism. |
|
Definition
| False; it can cause Hypothyroidism and Hyperthyroidism |
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