Diabetes/Endocrine (Thyroid/Noninsulin agents) Flashcards
Anti-Thyroid Foods
GOITROGENS
-Broccoli, cauliflower, kale, cabbage, brussel sprouts, cassava, millet, soybeans
Iodine Sources in Diet
Common Sources of Dietary Iodine
Cheese Cows milk Eggs Frozen Yogurt Ice Cream Iodine-containing multivitamins Iodized table salt Saltwater fish Seaweed (including kelp, dulce, nori) Shellfish Soy milk Soy sauce Yogurt
LEVOTHYROXINE (Levothyroid, Levoxyl, Synthroid)
The prototype
THYROID REPLACEMENT DRUGS (Hypothyroidism)
- Synthetic preparation of T4 equivalent to the naturally occurring thyroid hormone
- MOA: Some of the T4 is converted to T3 and therefore replacement of both T4 and T3 occurs
-Indications for usage:
Hypothyroidism due to any cause; cretinism, myxedema coma, insufficient TSH, TRH, post surgical removal of the thyroid gland, radiation effects, and treatment with anti-thyroid drugs.
- A/E:
- In proper dosage, rarely has problems.
- Too much thyroid results in THYROTOXICOSIS** causing symptoms of hyperthyroidism, especially rapid heart rate, atrial fibrillation, angina, tremors, weight loss, diarrhea.
- Patient education:
- **TAKE ON AN EMPTY STOMACH 30-60 MINUTES before breakfast since food interferes with absorption.
DO NOT CHANGE BRAND NAMES
Liothyronine (T3)
-works faster, therefore may be used in myxedema, when fast action is needed
Nursing Implications for Hypothyroidism:
- Monitor effects
- Patient teaching
- Monitor TSH levels every 3 months until regulated, then once a year
Drugs for Hyperthyroidism:
- Propylthiouracil (PTU)
- Methimazole (Tapazole)
Propylthiouracil (PTU)
- PTU is one of two prototype antithyroid drugs.
- MOA – inhibits thyroid hormone synthesis & also decreases the conversion of T4 to T3, the active form of thyroid hormone
- Very short half-life, must be administered 2-3 times a day
- Usually given to patients in thyrotoxicosis
- Serious potential A/E;
- Agranulocytosis
- PTU can be used in the 1st trimester only if absolutely necessary (otherwise avoid in pregnant women)
Methimazole (Tapazole)
- Safer and more convenient than PTU
- MOA: prevents oxidation of iodine and incorporation of iodine into tyrosine; inhibits peroxidase, the enzyme that catalyzes the oxidation process.
- Indications: Sole form of therapy for Graves Disease, Adjunct to radiation therapy, used before surgery for removal of thyroid;
- Adverse effects: agranulocytosis, contraindicated in pregnancy
Oral Hypoglycemic Agents
- Biguanides
- Sulfonylureas
- Meglitinides
- DPP-4 Enzyme Inhibitors
- Exenatide
- Liraglutide
- Thiazolidinedione
- Alpha-glucosidase enzyme inhibitor
- SGLT-2 Inhibitors
Class: 2nd Generation Sulfonylureas
- Glimepiride
- Glipizide
- Glyburide
- MOA: Lowers blood glucose by stimulating release of insulin from the pancreas; increases sensitivity to insulin at receptor sites; may decrease hepatic glucose production
- s/e:HYPOGLYCEMIA, WEIGHT GAIN, disulfiram like reaction with alcohol, GI disturbances (#1 S/E), drug/drug interactions with beta-blockers, antifungals, corticosteroids, thiazide diuretics, and cyclic antidepressants
Approved for PREGNANCY
Class: Biguanides
Drug Name: METFORMIN (Glucophage)
- Preferred starting agent for T2DM
- Approved for use in children 10 years old and greater with T2DM and in pregnancy.
- MOA: Increases sensitivity to insulin; decreases hepatic production of glucose; decreases intestinal absorption of glucose
- Decreases amount of insulin needed by T2DM
- Lowers Basal and postprandial BGs
Biguanides (Metformin) Cont.
s/e: diarrhea, decreased appetite, nausea, lactic acidosis; GI effects subside in time but some may not be able to tolerate
***DOES NOT CAUSE HYPOGLYCEMIA; AIDS IN WEIGHT LOSS (nearly perfect drug)
Biguanides (Metformin) Cont…
- Nursing Implications: Don’t use in acutely ill, renal disease, receiving tests involving IV admin of dyes
- Discontinue drugs several days before and afterwards (48 hours) for dye procedures
- LACTIC ACIDOSIS: Metformin inhibits mitochondrial oxidation of lactic acid which allows it to build up in the bloodstream. s/s include hyperventilation, myalgia, malaise and unusual sleepiness
Drug interaction: Alcohol and cimetidine (tagamet) can lead to lactic acidosis
Class: Thiazolidinediones (Glitazones; TZD’s)
- Pioglitazone (Actos)
- Rosiglitazone (Avandia)
- Pioglitazone DECREASES INSULIN RESISTANCE increasing insulin action at receptors and post receptor level in hepatic and peripheral tissue
- Rosiglitazone only available under a restricted program
Thiazolidinediones Cont.
-a/e: upper respiratory infection, headache, sinusitis, myalgia, FLUID RETENTION (can worsen heart failure is person already has heart failure), HYPOGLYCEMIA
-Nursing Implications:
Monitor for weight gain and /or fluid retention, shortness of breath, chest pain; can be used in mild CHF only
-may decrease effect of oral contraceptives; usually given with insulin or sulfonylurea but can be used as monotherapy; check liver enzymes q 2 months for first year
Class: Alpha-Glucosidase Enzyme Inhibitors
Drugs:
- Miglitol (glyset)
- Acarbose (Precose)
–MOA:
delay the breakdown of CHO in the small intestine, thus the rise in postprandial glucose (PPG) is diminished and delayed; They do NOT increase insulin secretion
Alpha-Glucosidase Enzyme Inhibitors Cont.
Miglitol (glyset) & Acarbose (Precose)
- May block or reduce weight gain
- Helpful in reducing postprandial BG
- s/e: Abdominal pain, flatulence, diarrhea
- Give 3 times a day before meals
- Large number of drug/drug interactions
Class: Meglitinides (GLINIDES)
Drugs:
- Repaglinide (Prandin)
- Nateglinide (Starlix)
- MOA: STIMULATES INSULIN SECRETION via closing or inhibition of ATP-sensitive K channels in beta cells
Meglitinides (GLINIDES) cont.
-Dosing: take before each meal; medication is very short lived and will stop acting on the beta cells shortly after the meal (1.5 hours half life); should not be given if no meal is consumed.
a/e: hypoglycemia; bronchitis, rhinitis, N/V, diarrhea/constipation, headache, chest pain, UTI’s
-Usually given with metformin; many possible drug/drug interactions that may increase or decrease effects
Class: DDP-4 Enzyme Inhibitors (GLIPTINS)
Drugs:
- Sitagliptin (Januvia)
- MOA: blocks DDP-4 enzyme inhibitors and thereby increases the release of insulin after blood glucose rises (glucose dependent). The inhibitors are GLP-1 and GIP, released by the intestines throughout the day; levels are increased in response to a meal but the hormones are normally quickly deactivated by the enzyme DPP-4 . By giving these drugs more insulin can be released. (Can only be used if the patient is producing normal or elevated levels of insulin).
- s/e: Less potential for hypoglycemia, headache, pharyngitis, arthritis
Class: Sodium-Glucose Co-Transporter 2 (SGLT-2) Inhibitors
Drugs:
- Canagliflozin (Invokana)
- Dapaglifoxin (Farxiga)
-MOA:
Blocks reabsorption of glucose in the renal tubules. (The transport of glucose from the tubule into the tubular epithelial cells is by means of the sodium glucose co-transporters which accounts for 90% of glucose reabsorption by the kidneys.
SGLT-2 Inhibitors Cont..
Canagliflozin (Invokana) & Dapaglifoxin (Farxiga)
-A/E:
Most common were female genital fungal infections (due to increased glucose in the urine) , UTI’s, and increased urination. Postural hypotension and dizziness especially in older adults on diuretics. Not indicated in those with GFR < 45 mL/min/1.73 m2.
Non-Insulin Injectables for Type 2 DM
*Incretin Mimetics (Injection)
Drugs:
- Exenatide (Byetta)
- Liraglutide (Victoza)
-MOA:
Activates Receptors for GLP- 1 and thus causes same effects as ENDOGENOUS incretins; Slows gastric emptying, stimulates glucose-depend ent release of insulin, inhibits postprandial release of glucagon, suppresses appetite
-Indications: Adjunctive therapy to improve glucose control in T2DM
Incretin Mimetics (Injection)
- Exenatide (Byetta) & Liraglutide (Victoza)
- a/e: Dose related hypoglycemia especially with a sulfonylurea and; N&V, diarrhea, injection site irritation, pancreatitis, renal impairment, fetal harm (use only if risk outweighs benefit, Category C, ), anaphylaxis, angioedema. Liraglutide may cause thyroid C-cell tumors
-Interactions:
may slow absorption of other oral drugs, especially oral contraceptives and antibiotics, give oral drugs one hour before giving exenatide; Can cause hypoglycemia when taken with alcohol.
comes in prefilled injector pens, 5 or 10 mcg/ml
Give subq before AM and evening meals
