Endocrine/Thyroid Flashcards
Hypothyroidism PATHO/CAUSES
HYPO = DEC thyroid hormone = SLOW
Causes:
iodine deficiency
hashimoto thyroiditis
TX hyperthyroidism
Drugs: amiodarone, lithium
Deficit of thyroid hormone
Hypothyroidism SX
slow mind, body
weak heartbeat
constipation
slow reflexes
hair thinning
depression
thin skin
dry skin
cold intolerance
Hypothyroidism DIAGNOSTIC CRITERIA
TSH - test of choice (elevated)
T4 and T3 - DEC
Hypothyroidism GOALS OF THERAPY
return patient to euthyroid state
TREATMENT is LIFELONG
Hypothyroidism MONITOR RESPONSE
Serum TSH every 6-8 wks
TSH every 6 months once euthyroid
Hypothyroidism DRUG THERAPY
Levothyroxine (T4)
Brand: Synthroid
Do NOT switch b/w brand and generic
Dosage:
START: 1.6mcg/kg/day
Adjust in 25mcg intervals every 4-6 wks
TSH 1-3
Hypothyroidism: DRUG AE/EDUCATION
Pregnancy = need INC dosage until delivery
AE: Sx hyperthyroidism
education:
1) should not expect immediate relief in sx: takes 2-4 wks
2) Lifelong therapy
3) periodic lab testing
Hyperthyroidism PATHO/CAUSES
HYPER = INC thyroid hormone = FAST
Causes:
Graves disease
toxic nodular goiter
thyrotoxicosis
drug related
pituitary tumor
Hyperthyroidism SX
wide pulse pressure
sweating
anxiety
fine tremors
brink reflexes
diarrhea
weight loss
afib
Hyperthyroidism DIAGNOSTIC CRITERIA
LOW TSH
HIGH free T4 or T3
Free T4 - most useful and preferred to confirm dx (elevated)
Hyperthyroidism GOALS OF THERAPY
return to euthyroid state
therapy usually 1-2 years
Hyperthyroidism TREATMENT OPTIONS
1) meds
2) radioactive iodine ablation (NO PREGNANCY)
3) complete or partial thyroidectomy
Screen for hypothyroidism after RAI or surgery
Hyperthyroidism DRUG THERAPY
Methimazole (Tapazole)
Propylthoiuracil (PTU)
MOA: inhibit organification, block conversion of T4 to T3
Methimazole longer acting = less frequent dosing
Drugs may be used pre RAI or surgery
AE: minimal, rash, arthralgias, itching
BLACK BOX: Liver injury
Hyperthyroidism ADJUVANT MEDS
1) BB - DEC sx of adrenergic stimulation from INC T4
2) Iodine-containing compounds - SSKI, treat thyroid storm
3) Lithium - block release of thyroid hormone
4) Glucocorticoids - reduce conversion of T4 to T3
DM Patho
supply and demand
1) beta cell destruction (T1)
2) decreased production (T2)
3) insulin not recognized or resisted
4) altered hepatic metabolism of glucose
DM2 TREATMENT OPTIONS
prevent macro and microvascular complications
TLC’s
Education
Glucose monitor, strips, stylets
foot care
GOALS of therapy:
HgbA1C <6.9, preferably <6.5
Preprandial glucose: 90-130
Postprandial glucose: <180
Oral agent: Biguanides
MOA/USES
Metformin (Glucophage)
FIRST-LINE TX
MOA:
1) INC peripheral glucose uptake and utilization
2) DEC hepatic glucose production
3) DEC intestinal absorption
Excreted unchanged in urine
Oral agent: Biguanides Benefits/Dosing
Bene:
No hypoglycemia
No weight gain
Combines w/ other agents
Dosing: MAX dose is 2,550mg/day, but NO additional benefit when dose exceeds 2000mg
Oral agent: Biguanides
CONTRAINDICATIONS/AE/Monitoring
Contraindications:
1)renal dysfunction, metabolic acidosis
2) CAUTION HF, dehydration, resp failure, ETOH, liver damage
3) hold for 48 hrs w/ iodine study
AE: GI disturbance (take w/ food), usually 2 wk limitation, STOP if risk of DEHYDRATION
Lactic acidosis
Monitoring: renal function before tx and annually, HgbA1C q3 months, home glucose monitoring
Oral agent: Sulfonylureas
MOA/USES
Oldest
2nd gen: more potent, more safe
MOA: stimulates insulin release from beta cells
Oral agent: Sulfonylureas CONTRAINDICATIONS/AE/monitoring
Contraindications: SULFA allergy, THIAZIDE diuretic
AE: hypoglycemia, weight gain, hyperinsulinemia, GI disturbances, photosensitivity
Monitoring: HgbA1C, home monitoring
Oral agent: Sulfonylureas INTERACTIONS
ETOH produces Antabuse type reaction
NO ETOH
Take same time each day
Oral agent: Alpha-glucosidase inhibitor
MOA/USES
Acarbose and Miglitol
MOA: inhibit absorption of complex carbs from small bowel
DEC post-prandial glucose
Uses:
1) post-prandial hyperglycemia
2) High HgbA1C
3) poor dietary adherence
4) High CHO diet ethnicities
Oral agent: Alpha-glucosidase inhibitor
CONTRA/AE/Monitoring
Must be taken w/ first bite food
Contraindications:
1) bowel disease
2) absorptive disorders
3) cirrhosis
AE: GI effects d/t fermentation: flatulence, bloating, distension, diarrhea (try slow titration of dose to DEC effects)
Monitoring: before tx and annually assess RENAL function, SERUM TRANSAMINASE, FBG, HgbA1C q3 months
combo w/ sulfonylureas = RISK HYPOGLYCEMIA
Oral agent: TZDs
-glitazone
MOA/USES
Pioglitazone (Actos), Rosiglitazone (Avandia)
NOT initial therapy
Used in 2-3 drug combo, NEVER monotherapy
MOA: improve insulin sensitivity of cells
Oral agent: TZDs
CONTRA/INTERACTION/Monitoring
Contraindications:
1) liver disease
2) HF (fluid retention)
3) BLACK BOX: cardiotoxicity
Interactions: DEC oral contraceptive concentration
Monitoring: ALT before and q2 months
D/C if ALT levels are x3 upper limit of normal
MONITOR LIVER FUNCTION
Oral agent: Meglitinides MOA/USES
Short-acting insulin secretagogues
used to lower post-prandial BG levels
works similar to sliding scale insulin
used as adjunct therapy
MOA:
1) INC secretion of insulin by beta cells
2) Rapid acting: take 20 mins before meals, peaks in 1 hr
Oral agent: Meglitinides
CONTRA/AE
Contraindications:
CAUTION in renal and hepatic patients
CAUTION Pregnancy
AE: risk for hypoglycemia
Oral agent: Meglitinides
INTERACTION/MONITORING
Interactions:
1) CYP inducers: INC metabolism
2) CYP inhibitors: DEC metabolism = hypoglycemia
Monitoring: FBG, HgbA1C q3 months
Do NOT take if meal is skipped
Oral agent: Glucagon-Like Peptide Agonists (Incretins)
MOA/USES
MOA: Bind to GLP-1 receptors on beta cells to imitate an incretin to potentiate glucose-stimulated insulin secretion
SLOW gastric emptying INC satiety
Injectable only
Oral agent: Glucagon-Like Peptide Agonists
CONTRA/AE/Monitor
Contraindications: pancreatitis, severe renal impairment, severe GI disease
AE: N/V/D, may subside over time
Interactions: warfarin, serum level of OC’s DEC
Monitor for PANCREATITIS
Separate from other meds that rely on rapid absorption from GI
Oral agent: DDP-4
-gliptins
MOA/USES
Sitagliptin, Saxagliptin, Linagliptin, Alogliptin
MOA: blocks the enzyme used to breakdown the body’s own GLP-1
well tolerated
Can be used as MONOTHERAPY
Oral administration, expensive
Oral agent: DDP-4
CONTRA/AE
Contraindications: impaired renal function = dose adjustment, pancreatitis hx
AE: hypoglycemia may occur in combo w/ sulfonylureas, insulin
Oral agent: Amylin Agonist
MOA/USES
Pramlintide (Symlin)
Injectable: subq
MOA: works like GLP-1 agonists: DEC glucagon secretion, SLOW gastric emptying, suppresses appetite
DEC caloric intake = INC satiety = weight loss
2nd LINE for those using INSULIN at mealtimes
USES: tx DM T1/T2
Oral agent: Amylin Agonist
CONTRA/AE/Interactions
Contraindications: gastroparesis, drugs stimulate GI motility
AE: hypoglycemia w/ insulin, DEC insulin by 50%
BLACK BOX: hypoblycemia
Interactions: anticholinergics, garlic, chromium, gymnema
Oral agent: SGLT-2
MOA/USEs
newest class
Canagliflozin (Invokana), Dapglifozin (Farxiga), Pagliflozin (Jardiance)
1st CHOICE after Metformin
MOA: lowers reabsorption of plasma glucose concentration in the kidneys = INC glucose excretion
possible renal protective role
Adjunct to diet/exercise
Administer same time everyday, before first meal
Oral agent: SGLT-2
CONTRA/AE/Interactions
Contraindications:
1) severe renal impairment or ESRD
2) Allergy
3) TX of DKA or DM T1
AE: genital fungal infections, UTI, hypotension, INC LDL, bladder cancer
Interactions:
1) monitor digoxin
2) may INC effect of ACE/ARB
Insulin
pancreatic hormone
fosters the influx of glucose out of the bloodstream and into the cell
Only therapy for DM T1
DM T1 PATHO
autoimmune process destroys beta cells
No insulin produced = No glucose into cells
Demand > Supply
DM T2 eventually progresses to beta cell failure = insulin required
Actions of Insulin
1) INC storage of glucose in the liver
2) Promotes TG synthesis
3) INC uptake K+ and phosphate in the liver
4) Promote glycogen synthesis in muscles
5) DEC protein catabolism and ketosis
6) DEC circulation of free fatty acids and INC storage of TGs
Onset, Peak, Duration: RAI
Lispro, Aspart
Onset: 15-30 min
Peak: 1-3 hrs
Duration: 3-5 hrs
Onset, Peak, Duration: Short-acting insulin
Regular
Onset: 30-60 min
Peak: 2-4 hrs
Duration: 3-7 hrs
Onset, Peak, Duration: Intermediate-acting
NPH
Onset: 1-2 hrs
Peak: 4-12 hrs
Duration: 10-16 hrs
Onset, Peak, Duration: Long-acting
Detemir,
Glargine (no peak)
Onset: 3-6 hrs
Peak: 3-9 hrs
Duration: 20-24 hrs
Insulin Regimens
GOAL: mimic endogenous insulin
Basal insulin:
1) for maintenance (chronic/prophylaxis)
2) NPH, Lente, Glargine, Detemir
3) provides constant multi-hour coverage
Bolus insulin:
1) for quick actions (acute/abortive)
2) aspart, lispro, regular
3) RAI, SAI
Inhaled Insulin
Afrezza
inhalation powder
rapid acting insulin
TX T1/T2
preprandial dosing
dispensed in 4-unit and 8-unit cartridges
Inhaled insulin: BLACK BOX
1) asthma and COPD = acute bronchospasm
CONTRAINDICATED: chronic lung disease
before starting, detailed medical hx, physical exam, spirometry (FEV1) must be done to ID potential lung disease
Inhaled insulin: CONTRA/AE
NOT recommended for tx DKA
NOT recommended in smokers or who have quit for less than 6 months
CONTRAINDICATIONS:
hypoglycemia, COPD, hypersensitivity
AE: hypoglycemia, cough, throat pain or irritation, HA
Insulin AE/INTERACTIONS
AE:
hypoglycemia
hypokalemia
lipodystrophy
local reactions
bronchospasm w/ inhaled
Interactions: corticosteroids, thyroid hormone, estrogens, thiazide diuretics, ETOH, BB
DM Pediatrics
T2 rising
look for acanthosis nigricans, dark pigmentation in skin creases and flexural areas
insulin and metformin only drugs approved for adolescents
Gestational DM
screen between 24-28 wks
control w/ diet and exercise
if not controlled, insulin (ADA standards)
Metformin and Glyburide:
1) trials support short-term safety and efficacy
2) crosses placenta
3) metformin slightly INC risk prematurity
When goal of treatment is NOT MET
patient can be at target but remain uncontrolled
metformin + incretin + basal insulin
target = blood glucose level
control = HgbA1C
Starting BASAL INSULIN
continue Metformin + noninsulin agent
START: 10U/day or 0.1-0.2U/kg/day
Adjust every 1-2 wks: 10-15% or 2-4 units
If becomes hypoglycemic, DEC by 4 units
Reg + NPH Dosing
Starting two insulins BID (NPH + reg)
1) AM: give 2/3 total dose w/ 2:1 ratio NPH: reg
2) PM: give 1/3 total dose in 1:1 ratio
adjust response in 1-2 unit increments
Which one to adjust:
look at peak and duration times
AM dose given at breakfast
1) reaction within 1st 4 hours: REG
2) reaction within 5-8 hrs: NPH
DM T1 DOC
ALWAYS INSULIN
patients do NOT make insulin, must be supplied
variety of routes: SubQ, inhaled, pumps
will be started and managed by endocrine
DM T2 DOC
Managed in primary care
1st Line: Metformin
Add-Ons: GLP-2 or SGLT-2
Alternatives: sulfonylureas, TZDs, DDP-4s
4th step: basal insulin
Special cases: BG > 400
1) go to insulin
2) do not pass metformin
3) do not forget to collect HgbA1C
Once glucose is under control, then attempt to titrate back to oral agents alone
