KG - Pharm 2 Exam 3, Thyroid Flashcards
thyroid is regulated by ___ & ____
TSH & IODIDE
thyroid hormones increase ____
basal level of METABOLISM
thyroid hormones are important for ___ & ___
GROWTH & MATURATION (incl CNS)
what could hypothyroidism in children lead to?
CRETINISM
gen info thyroid hormones?
- T4 more prevalent
- T3 secreted by thyroid & is metabolite of T4 by PERIPHERAL CELLS
- T3 3-5X MORE EFFECTIVE THAN T4
- ACT THROUGH NUCLEAR RECEPTORS
signs/symptoms hypothyroidism
- SLOW metabolic rate
- SENSITIVITY TO COLD
- FATIGUE
- puffiness
- high TSH (primary hypo)
- goiter?
levothyroxine sodium?
T4
- DOC = HYPOTHYROIDISM
- DRUG LEVELS MUST BE TITRATED TO PT
- base on symptoms & TSH of pt
liothyronine sodium?
T3
- used for initial therapy, not maintenance
hypothyroidism - side effects/what to do?
- side effects similar to hyperthyroidism
- reduce dosage or stop for few days, resume at lower dose
signs/symptoms hyperthyroidism?
- FAST metabolism
- arrhythmias, TACHYCARDIA
- FATIGUE
- HOT, sweating
- TREMOR
- INSOMNIA
- DIARRHEA, n/v, weight loss
causes hyperthyroidism?
Grave’s dz
- antibodies to TSH receptor
- stim gland to make too much T3/T4
Toxic nodular goiter
- adenoma of thyroid that produces too much thyroid hormone
tx of hyperthyroidism?
- SURGERY
- 131 I (radioactive iodide)
- LOWER T3/T4 w/ thioamides, iodide
- block symptoms w/ BETA BLOCKERS
consequences thyroidectomy & 131I?
hypothyroidism
risk tx w/ 131I?
thyroid storm
DOC Grave’s?
pharmacologic tx
propylthiouracil (PTU) & methimazole - MOA
- decr synthesis/release T4
- effects gradual - use beta blocker until effects seen
- CIRCULATING T3/T4 LASTS A WEEK OR SO
which is more potent - methimazole or PTU?
methimazole
PTU/methimazole - indications/therapeutic effects?
- DOC Grave’s dz
- used w/ other txs - reduces thyroid storm risk
PTU only - MOA
blocks conversion T4 to T3
PTU/methimazole - adverse effects?
- SEVERE LIVER INJURY, ACUTE LIVER FAILURE
- -> use methimazole
- ITCHING/RASH (most common)
- GRANULOCYTOPENIA & AGRANULOCYTOSIS
- ha, nausea, jaundice, myalgia, arthralgia, lymphadenopathy,psychosis
- GOITER
- keep low dose in pregnancy
PTU or methimazole w/ early pregnancy?
PTU
PTU or methimazole w/ allergies?
PTU
iodide - MOA?
- rapidly DECREASE SYNTHESIS & RELEASE T3/T4
- SHORT TERM EFFECT (2-8 wks)
iodide - indications/therapeutic effects?
- DECREASES VASCULARITY and thyroid content of gland
- used 7-10 days before surgery (decr chance of thyroid storm)
- use in RADIOACTIVE EMERGENCIES
131I - MOA?
taken up by gland
- small amts = diagnostic
- large amts = destroys gland
131I - indications/therapeutic effects?
- ELDERLY, pts w/ HEART DISEASE
131I - adverse effects?
- can cause hypothyroidism w/ time
- thyroid storm risk (decr risk by use of thioamide prior to tx)
propranolol - MOA?
beta blocker - INHIBITS PERIPHERAL CONVERSION OF T4 to T3
propranolol - indications/therapeutic effects?
- prepare for surgery
- used while waiting for thioamides & 131I to take effect
- can stop symptoms of hyperthyroidism (tachycardia, tremors, etc)
propranolol - contraindications?
asthma
