Endocrine (Ex2) Flashcards
What is the goal of therapy for hypothyroidism in dogs?
What drugs are used?
To replace hormone the body is not producing
Liothyronine (T3)
Levothyroxine (T4)
How is Levothyroxine dosed?
Explain the administration
How is it monitored?
Dosed mg/kg, reduce risk of oversupplementation in large patients by dosing mg/m2
- given orally BID for rest of life
- only injectable for rare situations like coma
- monitor by measuring T4 levels, 4 weeks after start of therapy
- some drugs interfere with test results
What are the non-pharmacological treatments for hyperthyroidism in cats?
Surgery: remove abnormal tissue
Radioactive Iodine: destroy abnormal tissue
Diet: Hill’s y/d, prevent iodine uptake
Which drugs are used to treat hyperthyroidism in cats?
Methimazole/Carbimazole
Propylthiouracil
Iodides/Iodinated contrast agents
What kind of drug is Methimazole, and what does it do?
What are 3 types?
Thioureylenes
- inhibit thyroid hormone synthesis
- Tapazole (humans)
- Felimazole
- Transdermal methimazole
What kind of drug is Proplythiouracil, and what does it do?
Thioureylene
- inhibit thyroid hormone synthesis
- inhibit conversion of T3 to T4 in tissues
- higher risk of serious side effects
What are the actions of Iodides/Iodinated contrast agents?
- inhibit thyroid hormone synthesis
- inhibit release of preformed hormone
- inhibit T3 to T4 conversion in periphery
What are some clinical signs of Acute Hypocalcemia?
- hyperesthesia (pawing at face)
- tremors progressing to flaccid paralysis
- seizures
- hyperthermia
- bradycardia
Describe Periparturient Hypocalcemia
- Milk Fever, eclampsia
- sudden increase in calcium usage for which the patient cannot keep up
- associated with birth/lactation
- can replace calcium until the patient catches up
What are the parenteral options for treating acute hypocalcemia?
Which is caustic?
- Ca Gluconate (dilute if giving SQ, better to give IV)
- Ca Chloride (caustic, do not give SQ/IM)
What is given to treat Chronic Hypocalcemia?
How is it administered?
- Ca carbonate, Ca Propprionate
- orally
What is a main cause of Hypocalcemia?
- Hypoparathyroidism
- inability of the body to convert vitamin D to its active form, calcitriol
- so the body cannot absorb calcium
What are the treatments of Acute Hypoglycemia?
- diet: frequent, small meals with complex carbs
- dextrose 50% solution to mucus membranes (not SQ, IV bolus in emergencies)
- ongoing IV dextrose 5%
- Glucagon IV
What are the usual causes of Hyperglycemia?
- something that does not require therapy (stress, exercise, steroids)
- Diabetes Mellitus
What is the primary goal in treating Diabetes Mellitus?
to address the insulin deficiency, not bring down blood glucose
What do Oral Hypoglycemic Agents cause?
What are they used to treat?
How do they work?
- cause hypoglycemia
- treat type 2 diabetes (only in cats)
- stimulate insulin secretion by the pancreatic beta cells via blocking K+ channels
- increase tissue sensitivity to insulin
What is Glipizide?
oral medication for diabetes mellitus
Explain the process of insulin release and its actions
- formed by beta islet cells of pancreas
- when blood glucose rises, energy-dependent K+ channels close, causing depolarization of membrane and insulin release
- in peripheral tissues, insulin binds to insulin receptors, which make available glucose transporters that allow glucose into the cells
Short-Acting Insulin
- which drugs
- administration
- use
- Regular Insulin (Humulin-R)
- IV, IM, or SQ (only one IV)
- used for hospitalized patients not eating
Intermediate-Acting Insulin
- which drugs
- administration
- use
- NPH (Humulin-H), Lente, Vetsulin/Caninsulin
- only SQ
- good starting insulin for canines
Long-Acting Insulin
- which drugs
- administration
- feature of each drug
- Protamine Zinc/PZI, Glargine, Detemir
- only SQ
- Prot: vet approved so 40 IU/mL
- Glarg: microprecipitates so gradual absorption
- Det: higher potency in dog
What type of steroid does each of the zones of the adrenal cortex produce?
Glomerulosa: mineralocorticoids
Fasciculata: glucocorticoids
Reticularis: sex steroids
Glucocorticoids
- produced by?
- endogenous hormone
- regulated by?
- main effect
- drugs
- zona fasciculata
- Cortisol
- regulated by hypothalamus/pituitary through release of CRH and ACTH
- anti-inflammatory
- prednisone, prednisolone, dexamethasone, triamcinolone, methylprednisolone
What are the physiologic effects of glucocorticoids?
- increase calcium excretion
- reduce fever
- suppress immune response
- lymphotoxic
