Flashcards in Pharm2 3 Thyroid pt2 Deck (28)
Adverse Effects of all hypothyroid Medications (8)
Cardiac palpitation and arrhythmias, tachycardia (especially w/ thyroid storm), weight loss, tremor, headache, insomnia, and heat intolerance
Do what differently is the patient has a history of hypothyroidism or ischemic heart disease?
be slower in titrating them upwards
These patients should be started on a low dose and then are slowly titrated of hormone replacement over several months
What must you do In patients who have both hypothyroidism and adrenal insufficiency?
Must adjust their corticosteroid replacement before any thyroid hormones are given.
Just List 4 Drug interactions of Hypothyroid hormone meds.
DM agents (Insulin and PO agents)
What's the interaction of hypoThyroid hormone + Sympathomimetics:
Coronary insufficiency is increased in patients with coronary artery disease who are taking sympathomimetic agents (sudafed) and thyroid hormones
What's the interaction of Thyroid hormone + Warfarin/anticoagulants?
What will you do about it?
anticoagulants effects are enhanced because thyroid hormones increase the catabolism of vitamin k-dependent clotting factors
Dose of anticoagulant may have to be reduced
What may you do if you give Thyroid hormone along with Diabetes agents?
Diabetes mellitus patients may need an increase in insulin or oral hypoglycemic agents due to start of thyroid hormones
What may you need to do if you give Thyroid hormone + Digitoxin, Digoxin?
Digitalized patients who use cardiac glycosides (Digitoxin, Digoxin) may need a larger dose
What 2 drugs can cause hypothyroidism?
Amiodarone & lithium
Most widely used beta blocker in hyperthyroidism?
Improves many of the manifestations of Thyrotoxicosis (thyroid storm) (Hyperthyroidism)
Toxic solitary thyroid nodules
Toxic mulitnobular goiter
Subacute (De Quervain’s) thyroidits
5 therapeutic effects of Propanolol:
Reduces tachycardia, palpitations, tremor, sweating, heat intolerance, and anxiety
Contraindications (4). What would you use instead in these patients?
CI: asthma, COPD, heart block, CHF.
in these pts use Metoprolol instead.
While this is cardioselective and you wouldn't want to use it if a pt had bradycardia, hyperthyroid patients will have TACHYcardia. You can test their response to betablockers with esmolol.
If a patient has thyroid storm, what drugs will take care of it? What is each drug's role?
Propanolol inhibits the symptoms
Thionamides are what actually stops it.
Iodinated contrast agents for the most severe thyroid storm cases?
2 examples of Thionamides
Propylthiouracil (PTU), Methimazole
What do they do?
What is PTU's mech of action?
Decrease thyroid hormone production
Inhibit thyroid hormone synthesis and over time secretion
Propylthiouracil is used to ease sever thyrotoxicosis rapidly because it (inhibits D1) which deiodinates T4 to T3
How do you deal with a pregnant patient with hyperthyroidism?
PTU, minimal dose to avoid inducing infantile hypothyroidism and thyroid enlargement.
What are the half lives of the main 2 Thionamides?
PTU: 1.5 hours
Methimazole: 6 hours
single dose lasts how long?
Most serious side effect of Thionamides (2)
it's usually seen after how long?
granulocytopenia and agranulocytosis
usually seen w/in 3 months
Iodinated Contrast Agents (not being used as contrast agents)
Who are they for?
Mech of Action?
These are for the sickest of your thyroid storm patients. Used w/ large doses of antithyroid drugs
(Inhibit D1 and D2), resulting in a rapid fall in plasma T3 in seriously thyrotoxic patients
Big adverse effect of Iodinated Contrast Agent?
Acute Renal Failure
What does it do?
What if they are taking Methimazole or PTU?
Used to destroy overactive thyroid tissue (thyroid ablation) for hyperthyroidism.
Not used in pregnant women
Grave’s disease patients who are on Methimazole or Propylthiouracil may fail treatment
In such cases Methimazole and Proylthiouracil is DISCONTINUE FOR 6 days before treatment
What is the 2nd most common cause of hypothyroidism in the US?
Use of radioactive iodine. It takes a hyperthyroid patient and makes 'em hypothyroid, where they get thyroid hormone meds from then on.
What can Radioactive iodine do to the hyperthyroidism sx (one specifically)
How does smoking affect this? (2)
may worsen Grave's opthalmopathy in 15%, never improves it (unlike Methimazole).
But if you give Prednisone after, it improves it in 67%.
Smokers are encouraged to quit before radioactive iodine therapy because smoking increases a flare up in ophthalmopathy
Smoking also decreases the effectiveness of prednisone treatment
What is its normal use?
When would you use it in a thyroid patient?
This is normally used for bipolar disease.
Used to control thyrotoxicosis in patients. There is no advantage to control thyrotoxicosis UNLESS they are allergic to the other drugs, so this is a 3rd or 4th line drug.
Big risk factor for Lithium.
5 CI for Lithium in a thyroid patient.
Narrow therapeutic range
CI: cardiovascular and renal disease, debilitation or dehydrations, sodium depletion, or brain damage
Name 3 drugs used in Hypothyroidism