Endocrine Flashcards
What are the targets of drugs action to treat a hypo endocrine disorder?
Replacing an endogenous substance
- > hypoglycemia - dextrose
- > hypocalcemia - calcium gluconate
Indirectly helps body to regain normal homeostasis
-> hypocalcemia -> VitD/Calcitrol
What is the usual underlying cause to cause excess of a substance in the body?
Lack of response to normal feedback
- hyperplasia
- benign neoplasia
- malignant neoplasia
What are the drug targets to treat hyper endocrine disorders?
Destroy abnormal tissue/get ride of the source
Inhibit production of substance
Enhance elimination of substance
Inhibit function of substance
Generally, acute changes should be addressed (slowly/fast) and chronic changes should be reversed (slowly/fast)
Fast; slow
What is the function of thyroid?
Increase metabolic rate and O2 consumption
Positive inotropic and chronotropic (increase # and affinity of B adrenergic receptors)
Enhance catecholamine response
Catabolic effects on muscle and adipose tissue
Stimulate erythropoiesis
Increase body temp
Regulate cholesterol
Essential for growth and development
Most commonly you will see dogs with ______-thyroidism and cats with ________-thyroidism
Hypo; hyper
What is the goal of therapy to treat hypothyroidism in dogs?
Replace hormone the body is not producing
Liothyronine (T3) or Levothyroxine (T4)
What thyroid replacement drug requires less dosing and has a lower risk of causing thyrotoxicosis (excess T4)
levothyroxine (t4)
In large patients, dosing of levothyroxine is usually done in what measurements?
Mg/m^2
Body surface area reflects metabolism
How is hypothyroidism monitored?
By measuring T4
What is the only Veterinary approved produce to treatment of hypothyroidism?
Thyro-tabs
What is the goal of therapy to treat hyperthyroidism in cats?
Stop excessive hormone production
What are non-pharmacological ways of treating hyperthyroidism?
Diet -prevent production (iodine uptake)
Surgery
Radioactive iodine
What are the targets for pharmacological therapies for hyperthyroidism?
Prevent production/interfere with synthesis
Prevent release of preformed hormone
Prevent conversion of T4 to T3 in tissue
What drugs will inhibit thyroid hormone synthesis
Methimazole, carbimazole, propylthiouracil
What drug will inhibit thyroid hormone synthesis and inhibit conversation of T4 to T3?
Propylthiouracil
Iodines and iodinated contrast agents have what effect?
Inhibit thyroid hormone synthesis
Inhibit release of preformed hormone
Inhibit T4 to T3 conversion (contrast agents)
What do we use in practice to treat hyperthyroidism in cats. Why is it the best choice?
Methimazole
Consistently efficacious
Side effects are uncommon and most are manageable
What products contain the active methimazole
Tapazole
Felimazole
Transdermal methimazole (not a product -> compounded
What are the side effects of methimazole
Mild/common: GI signs (vomiting) and transient hematologist changes on CBC
Severe/uncommon: refractory GI signs, idiosyncratic rxn (facial excoriation, hepatopathy, bone marrow suppression)
Can severe and acute hypocalcemia be life-threatening
Yep
What are clinical signs of hypocalcemia?
Hyperesthsia/pawing at face Tremors -> flaccid paralysis Seizures Hyperthermia Bradycardia
What do you call hypocalcemia due to a sudden increased use of calcium, generally associated with birth and lactation
Eclampsia
milk fever
What route of administration should be used if our need emergency calcium replacement?
Parenteral
What are the parenteral calcium options?
Ca Gluconate
Ca Chloride
Can you give Ca Chloride SQ or IM?
Caustic
Irritating to tissue
What can occur if your give Ca too rapidly?
Arrhythmia -Monitor ECG
What are the oral Ca options
Ca Carbonate (small animal)
Ca Propionate (large animal)
Hypoparathyroidism results in inability of the body to covert vitamin D to ___________
Calcitriol
What is the biggest potential side effect of calcitriol?
Hypercalcemia
How do you treat acute/transient hypoglycemia
Diet
Dextrose 50% solution
Glucagon
How would you treat hypoglycemia with diet?
Frequent small meals with complex carbohydrates
How do you administer glucagon?
IV (dosed in nanograms)
How is dextrose administered?
Mucosal absorption IV bolus (emergency)
An IV dextrose should not be more than ______ concentration.
5%