Endocrine clinical Flashcards
(16 cards)
How does glargine insulin cause a long duration of action?
Glargine structure is soluble at acidic pH and not soluble at neutral pH. When injected into neutral SC, forms microprecipitates which slows absorption and delays onset of action
What is the origin of glargine insulin? Describe its structure.
Glargine is a recombinant human insulin analogue.
Position A21 of human insulin is normally asparagine - changed to glycine
2 positively charged arginines added to the C terminal of the B chain
What is the origin of detemir? Describe its structure.
Detemir is a recombinant human insulin analogue.
Changes happen in B chain of insulin:
Position 30: amino acid threonine removed
Position 29: 14 carbon chain myristic acid added to AA lysine
How does detemir achieve its long duration of action?
Structure allows reversible binding to albumin which slows its absorption
Is detemir more or less potent in dogs than other insulin types? Dosing care with which size of dog?
Detemir is MORE potent than other insulin types (approx 4x more potent in dogs). Therefore very small starting doses needed (0.1 U/kg q12h).
As such small doses CARE with SMALL dogs - use diluent provided by company to help dose
What decrystallisation agent is lente porcine insulin (caninsulin, vetsulin)? What does this mean you need to do prior to injecting?
Zinc
Need to reconstitute - roll prior to drawing up
Is PZI an intermediate or long acting insulin in dogs?
Long acting
What decrystallisation agent(s) are added to PZI? What does this mean you need to do prior to injecting?
Protamine and zinc
Need to reconstitute - roll prior to drawing up
What is the origin of PZI?
Recombinant human insulin
What is the origin of NPH? What decrystallisation agent is added and therefore what do you need to do prior to injecting?
Recombinant human insulin with protamine added
Need to reconstitute - roll prior to drawing up
What is the origin and structure of degludec insulin?
Recombinant human insulin
B chain altered - position 30 threonine removed and hexadeconic acid added to lysine at position 29
What is the mechanism of action of carbimazole/methimazole?
TPO inhibitors
What are some non-life threatening side effects of carbimazole/methimazole?
How should these be treated?
GI signs eg vomiting, diarrhoea, anorexia fairly common. Tend to self resolve so mostly no Tx needed. If do not resolve then reduce dose by 50%
Pruritus
What are some life threatening side effects of carbimazole/methimazole?
Treatment?
Toxic hepatopathy
Blood dycrasias - thrombocytopenia, agranulocytosis, neutropenia
Interference with VitK synthesis - VitK dependent clotting factors reduced (II, VII, IX, X)
Stop drug, supportive care for each condition as needed
Why is T3 measurement not useful for diagnosis of hyperthyroidism in cats?
Lots of overlap between healthy and hyperthyroid cats
What is the most common haematological change in cats with untreated hyperthyroidism?
Erythrocytosis in non dehydrated cat - due to thyroid hormone stim on BM/increased O2 demand stim EPO production
