Endocrine Flashcards
For hypoglycemia?
Dextrose
For hypocalcemia
Calcium Gluconate
For hypothyroidism
Levothyroxine
For hypoadrenocorticism (Addison’s disease)
DOCP/Fludrocortisone and prednisone
For diabetes mellitus?
Insulin
For hypocalcemia from low PTH?
Vitamin D/Calcitriol
Side effects are typically related to excess of the_______ substances in these cases
endogenous
Targets for Drug Action - Hyper
What is the underlying cause of the excess?
- Lack of response to normal feedback Hyperplasia
- Benign neoplasia (adenoma)
- Malignant neoplasia (carcinoma)
There may be multiple targets for drug therapy; Destroy the abnormal tissue / get rid of the source?
I131(thyroid), mitotane (adrenal)
Inhibit production of the substance?
Methimazole (thyroid)
Trilostane (adrenal)
Enhance elimination of the substance? examples
Saline diuresis (calcium)
Inhibit function of the substance Receptor blockers (\_\_\_\_\_\_for treating the effects of pheochromocytoma)
phenoxybenzamine
Did the homeostatic disruption happen quickly or gradually?
Generally, if there is an acute change it needs to be reversed acutely. If it is an extremely gradual change then it should be reversed over a period of time.
What are the consequences of correcting it too quickly?
(rebound effects, transient clinical signs, risk of toxicity)
Hypothyroidism in dogs
Goal of therapy:
Replace hormone the body is not producing.
Levothyroxine (T4)
Pharmacologic considerations:
Levothyroxine requires?
Route of Administration?
Levothyroxine requires less frequent dosing and has lower risk of causing thyrotoxicosis (excessive T4 levels) than liothyronine
Reduce risk of over supplementation in large patients (>50lb)
Given orally BID (sometimes SID – half-life is variable) Injectable only used for rare situations like myxedema coma
How long with Levothyroxine be given for hypothyroidism in dogs?
Pharmacologic considerations:
Must be given for the rest of the patient’s life
Monitored by measuring T4 levels
Timing of sample is important
Start measuring about 4 weeks after starting therapy, be mindful of drugs that could interfere with thyroid test results (e.g. Phenobarbital, zonisamide, sulfonamides, glucocorticoids, phenylbutazone, quinidine and others)
Thyro-tabs are currently the only veterinary approved product.
Hyperthyroidism in cats
Goal of therapy:
Stop excessive hormone production
Target for surgical thyroidectomy (hyperthyroidism in cats?) along with radioactive iodine?
Remove abnormal tissue
Target for Hills y/d (hyperthyroidism in cats??
Prevent production (iodine uptake)
Target for pharmacologic (hyperthyroidism in cats??
Prevent production (interfere with synthesis)
Prevent release of preformed hormone
Prevent conversion of T4 to T3 in tissues
_______ Inhibit thyroid hormone synthesis
Methimazole
