Final Flashcards
Ant Pit/Hypothalamic Hormones-Receptors
GH and Prl activate?
TSH/FSH/LH/ACTH activate?
GH and Prl activate JAK-STAT
TSH/FSH/LH/ACTH activate GPCR
Explain regulation of pituitary and hypothalamic hormones
TRH, TSH, T3/4
GnRH, FSH/LH, E/P
CRH, ACTH, cortisol
GHRH, GH/IGF1, somatostatin
Thyrotrophin-RH, secretin, glucagon, VIP, GIP, Prl, and dopamine
TRH stim TSH which stim T3/4 which inhibits TRH and TSH
GnRH stim FSH/LH which stim E/P which inhibit GnRH and FSH/LH
CRH stim ACTH which stim cortisol which inhibits CRH and ACTH
GHRH stim GH and IGF1 which inhibit GHRH; SST inhibits GHRH
ThyrotrophicRH, secretin, glucagon, VIP, and GIP stim Prl which is inhibited by dopamine
GH Drug- Somatropin Kinetics? MOA? Uses? (4) AE? (Kids and adults) CI?
Somatropin
Kinetics- somatropin is a rhGH, metabolized by liver, and induces p450
MOA- binds GH-R, activates JAK-STAT, leads to IGF1 mediated affects
Uses- GH deficiency (make short children nml size and reverse symptoms seen in adults like obesity and loss of m mass); short stature assoc w/ Prader Willi, Turners, or Noonan; wasting in AIDS pt; pt w/ short bowel syndrome
AE- kids- intracranial HTN, scoliosis, otitis media in Turners, hypothyroidism, gynecomastia, and pancreatitis
AE- adults- edema, myalgia, arthralgi, and carpal tunnel
CI- malignancy
Mecasermin Uses? What is it made of? How is it given? AE? How to prevent
Mecasermin
Used in children w/ growth failure whohave severe IGF1 deficiency not responsive to exogenous GH
Complex made of rhIGF1 and rhIGFBP3 (inc half life of rhIGF1)
Give subQ
AE- hypoglycemia (eat 20 min before injection)
GH Antagnoists
What are the 2 classes
What is the use?
GH Antagonists
SST Analogs (reotides) and Pegvisomant
used for somatotroph adenomas
SST (somatostatin)Analogs
MOA
What are the 2 drugs and their uses
AE
SST Analogs
MOA- inhibit GH, glucagon, insulin, and gastrin
Octreotide- give subQ, use for acromegaly, carcinoid syndrome, gastrinomas, glucagonomas, VIPomas
Lanreotide- use for acromegaly
AE- GI, gallstones, b12 deficiency, and bradycardia
Peqvisomant
MOA
Uses
Peqvisomant
MOA- GH-R antagonist, binds GH-R but doesnt activate JAK-STAT
Uses- acromegaly
Dopamine Agonists (2)
MOA
Uses
AE (when do you discontinue)
Dopamine Agonists Bromocriptine and Cabergoline MOA- D2R agonist uses- hyperprolactinemia AE- NV, HA, hypotension, fatigue Discontinue if prego w/ microadenoma
Oxytocin uses?
Induce labor, limit post partum bleeding, and elicit milk ejection
ADH Agonists (2) Kinetics MOA Uses AE (use caution with which one in pt with what condition?)
ADH Agonists
Vasopressin and Desmopressin
Kinetics- desmopressin has longer half life and minimal V1 activity
MOA- activate GPCR V1R and V2R; V1 vasoconstricts; V2 inc water reabsorption
Uses- Central DI (desmo) and hemophilia A or von willebrand disease (desmo)
AE- HA, NV, abdominal pain, hyponatremia, seizure; use vasopressin w caution in pt with CAD
ADH Antagonists
Kinetics
MOA
Uses
ADH Antagonists
Vaptans (T and C)
T vaptan is v2 selective; metabolized by cyp3A4
MOA- inc water excretion w/o changing electrolyte excretion
Uses- hyponatremia and CHF (T vaptan dec wt and dec dyspnea; C vaptan inc water excretion w/o affecting vascular resistance)
Explain effects of hyper/hypothyroidism on T3/4 clearnace and T3/4 half life
Hyperthyroid- inc clearance and dec half life
Hypothyroid- inc half life and dec clearance
What agents prevent the conversion of T4 into T3?
Iopanoic acid, ipodate, amiodarone, b-blockers, and corticosteroids
What agents dec T4 absorption?
Antacids, ferrous sulfate, cholestyramine, and colestipol
What agents induce cyp450 to inc metabolism of T4/3?
Rifampin
What are thyroid hormone drugs MOA?
T4/3 enter cell -> T4 converted to T3 -> T3 enters nucleus and binds TR -> complex binds RXR ->gene transcription -> effects after a lag period
What is the 1st line choice for T4 replacement?
Levothyroxine
Thioamides (2)
Kinetics (kinetics of each then explain their use during pregnancy)
MOA
AE (when do you discontinue)
Thioamides
Propylthiouracil and methimazole
Kinetics- PTU- radpily absorbed, fast acting, 1st pass effect, requires multi doses
Kinetics- methimazole- completely absorbed, take once a day
Kinetics- can cross placenta and accumulate in fetal thyroid; take PTU in 1st trimester; methimazole in 2nd and 3rd trimester
MOA- inhibit thyroid peroxidase and iodide organification; inhibit thyroid hormone synthesis/release; PTU blocks conversion of t4 to t3; DOES NOT block iodide uptake
AE- maculopapular rash, urticarial rash, vasculitis, LAD, hepatitis (PTU), and jaundice (methimazole); agranulocytosis-reverse by discontinuing
Lugols Iodide Solution
MOA
Uses
AE
Lugols Iodide Solution
MOA- inhibit organification and hormone release; dec size and vascularity of thyroid
Uses- thyroid storm, preop reduction of hyperthryoid gland, and block uptake of radioactive isotopes
AE- acneiform rash, swollen salivary glands, ulcers, conjunctivitis, and metallic taste
Radioactive Iodine
Uses and kinetics
CI
Radioactive Iodine
I131
Used for thyrotoxicosis; give PO, rapidly absorbed; destroys parenchyma
CI- prego or breast feeding
B-Blockers for thyroid
Uses
B-blockers
Propranolol, metoprolol, atenolol
Uses- improve symptoms, reduce T3 (propranolol) by preventing conversion of T4 to T3
Explain the treatment of Hypothyroidism Drug of choice? How do you give it? If drug induced? Myxedema coma? Myxedema and CAD? Prego?
Mgmt of Hypothyroidism
Levothyroxine is 1st choice; give on empty stomach
Drug induced- remove drug or add levo
Myxedema coma- large loading dose of levo followed by IV dosing
Myxedema and CAD-use levo w/ caution to avoid arrhythmia or MI
Prego- maintain nml level for fetal brain development
Explain mgmt of Graves When do you use drugs? What drug is preferred? When do you perform thyroidectomy? When do you use radioiodine? What are the adjuvant therapies?
Graves Mgmt
Use methimaxole in young pt
Thyroidectomy in pt w/ large thyroid or multinodular goiter
Use radioiodine in pt over 21 unless pt has heart disease or if elderly w/ thyroid storm
Adjuvant therapy- beta blockers for cardiac effects
Explain multidrug therapy of thyroid storm
B-blockers for arrhythmias
K iodine to prevent thyroid hormone synthesis
PTU or methimazole to prevent synthesis
Hydrocortisone to prevent shock and block conversion of t4 to t3
Plasmapheresis or dialysis to dec t4