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Author 9 Posts
James
Senior Member

Topics: 14
Posts: 127
Posted 12/13/11 - 01:14 AM report   #1
Appropriate therapy for hypothyroidism in a patient who also has angina.

In the beginning, for patients with coronary disease, start with a low dose of thyroxine- either 12.5 or 25 micrograms or else one can precipitate angina. Then gradually advance the dose(every 2 weeks -increase dose by 12.5--25 micrograms).

On the other hand when a patient is in myxedema coma the doses used are high and most importantly for them you should administer steroids prior to the thyroxine- not because their adrenals have failed but because the adrenal becomes underactive because of the low basal metabolic rate and cannot cope with the suddenly increased metabolic rate that occurs due to initiation of thyroxine therapy.
James
Senior Member

Topics: 14
Posts: 127
Posted 12/13/11 - 01:16 AM report   #2
Hypothyroidism is notorious for giving elevated prolactin levels. It is thus important to check the TSH in every case with hyperprolactinemia.

Drugs such as Phenothiazines can also do this because of their anti-dopaminergic effect. This makes it important to take a good drug (medication) history in patients with galactorrhea.
James
Senior Member

Topics: 14
Posts: 127
Posted 12/13/11 - 01:17 AM report   #3
The thyroid radioactive iodine uptake is the test of choice to distinguish this from Graves disease where thyroid scan shows increased uptake in graves but decreased uptake in thyroiditis . Thyroiditis is best treated with Aspirin or steroids and use Beta blockers to control peripheral manifestations of hyperthyroidism.
James
Senior Member

Topics: 14
Posts: 127
Posted 12/13/11 - 01:19 AM report   #4
evaluation of hypothyroidism.

The two most important tests in evaluation of hypothyroidism are TSH and free T4 (total T4 may be almost equally good as free).

If a new patient has high TSH and symptoms of hypothyroidism- treat as hypothyroidism.If no symptoms-then check free T4. If free T4 is normal in such a new patient then the patient has what is called subclinical hypothyroidism and needs to be treated IF patient has goiter or thyroid antibodies or history of Radioactive iodine treatment in the past. These predict the possibility of future development of hypothyroidism.

If the patient has had a pituitary ablation/surgery then use free T4 as the guide. If the patient is known to be on treatment with thyroxin and has an elevated TSH but normal T4 then he has a compliance problem and usually forgets to take meds but popped in his dose just before coming to the doctor who checked the labs.
James
Senior Member

Topics: 14
Posts: 127
Posted 12/13/11 - 01:21 AM report   #5
Lithium induced DI can also be treated with Amiloride (Drug of choice) or by Indomethacin.
James
Senior Member

Topics: 14
Posts: 127
Posted 12/13/11 - 01:22 AM report   #6
High Ca & PO4 = Vitamin D toxicity

High ALP and normal Ca & PO4 = Paget's

High ALP and low Ca & PO4 = Rickets/Osteomalacia
James
Senior Member

Topics: 14
Posts: 127
Posted 12/13/11 - 01:26 AM report   #7
The following conditions cause hypercalcemia by mediators other than PTH thus PTH levels in them will be LOW

Myeloma- Hypercalcemia mediated via OAF(osteoclast activating factor)

SQUAMOUS cell cancer of Lung- Mediated via PTHrp(PTH related peptide) and also because of osteolytic metastases (commoner of the two).

Sarcoidosis- Via excess producion of vit D3(by alpha 1 hydroxylase) in the granulomas which also produce ACE(angiotensin converting enzyme)

Milk alkali syndrome- in a patient who has reflux disease and who thus consumes large amounts of antacids containing calcium or consumes a lot of milk to douse the heartburn.

Vitamin D excess- these patients have an increased absorption af Ca & PO4 from the GIT. They may also have an increased reabsorption from the kidneys. This leads to high Calcium & PO4 - both.
James
Senior Member

Topics: 14
Posts: 127
Posted 12/13/11 - 01:32 AM report   #8
manifestations of polycystic ovary syndrome.

Obesity, hirsutism, secondary amenorrhea, Key feature is LH/FSH ratio > 2--2.5. It can be confirmed by ultrasound of the ovaries/pelvis

The treatment of choice is oral contraceptive agents.

Although it is unlikely to be asked on the test- Insulin resistance is the Chief mechanism for this condition therefore insulin sensitizing agents like Troglitazone(Rezulin) or Metformin may also be used to treat this.
James
Senior Member

Topics: 14
Posts: 127
Posted 12/13/11 - 01:37 AM report   #9
Acromegaly:

Is the excess of Growth hormone in an adult. When this occurs in a child, it leads to gigantism.

Etiology - Pituitary tumor, GHRH producing tumor of the hypothalamus, Ectopic tumor- Pancreas (V.V. rare) and others.

Diagnosis

IGF1 level (insulin like growth factor) is measured in serum - this is the best initial screening test.

Confirmation is done using glucose loading. 2hrs after Glucose loading the GH level should be suppressed in the normal person but not in acromegalics. (Read important principles of endocrinology)

One should scan the pituitary if the diagnosis is confirmed. These are usully macroadenomas thus can cause pressure related signs e.g. optic nerve compression.

30% of acromegalics have sleep apnea so a sleep study should be ordered.








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