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Drugs that affect the Endocrine System

Pharmacology I

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Objective 1: define the term hormone

Objective 2: list the endocrine glands

Objective 3: identify the hormones that are secreted by the anterior pituitary and describe their main functions in the body

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Objective 4: identify the hormones that are released by the posterior pituitary and describe their main functions in the body

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Objective 5: identify the two main thyroid hormones

Objective 6: describe how the body synthesizes the thyroid hormones

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Objective 7: identify the actions of drugs used to treat hyperthyroidism

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Objective 8: list the anti-thyroid agents used to treat hyperthyroidism

Drugs are:◦Iodine-131 (131I)◦Propylthiuracil (PTU, Propacil)◦Methimazole (Tapazole

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Radioactive iodine ◦Taken up by thyroid◦Destroys hyperactive thyroid tissue Essentially no other tissue is affected

Takes 3-6 months for fully assess effect

If more than one dose needed, three months between doses is needed

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Dosing is oralAdd to waterNo colorNo taste Be very careful not to spill (hazardous)

Client can not be pregnant

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Side effects◦Tenderness in thyroid gland◦Hyperthyroidism in 40%, second dose needed

◦Hypothyroidism

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Drug interactions◦Lithium carbonate

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PTU and Tapazole◦Block synthesis of T3 and T4◦Takes days to 3 weeks to see effect

◦Can use long term◦Can use short term pre subtotal thyroidectomy

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Side effects◦Purpuric, maculopapular rash◦Headaches, salivary and lymph node enlargement

◦Bone marrow suppression ◦Hepatotoxicity◦Nephrotoxicity

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Objective 9: identify the hypothyroid conditions

Hypothyroid condition in adults called myxedema

Congenital hypothyroidism called cretinism

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Objective 10: list the thyroid agents

Levothyroxine replaces T3 and T4

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Liothyronine synthetic T3◦Onset of action more rapid than levothyroxine

Liotrix synthetic mixture levothyroxine and liothyronine (4 to 1 ratio)◦Provides consistent levels of T3 and T4

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Thyroid USP◦From beef, pork, or sheep thyroid glands

◦Oldest form available, cheapest◦Lacks purity, uniformity, stability

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Side effects◦Hyperthryoidism

Drug interactions◦Warfarin: larger doses needed◦Digitalis: smaller doses needed◦Hyperglycemia can occur early in therapy

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Objective 11: describe the nursing process associated with administering thyroid or anti-thyroid preparations

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Assessment important◦Clients sensitive to replacement therapy, monitor for adverse effects

◦Levothyroxine started low and dose increased over weeks

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Safe handling, storage and disposal of radioactive materials via institution policy

Blood levels need to be monitored

Clients need to be alert to side effects and report

Clients need to report if no improvement

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Objective 12: name the parts of the adrenal gland

Objective 13: list the types of hormones secreted by the adrenal glands

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Two hormones from adrenal gland◦Mineralcorticoids◦Glucocorticoids

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Mineralcorticoids◦Maintain fluid and electrolyte balance

◦Used to treat adrenal insufficiency Fludrocortisone (Florinef) Aldosterone Act on distal tubules, causes water and sodium retention

Causes excretion of potassium and hydrogen

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Objective 14: describe the metabolic effects of the glucocorticoids, and the consequences of these effects

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Objective 15: describe how glucocorticoids suppress inflammation

Corticosteroids secreted by adrenal cortex of adrenal glandGlucocorticoids

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Glucocorticoids include◦Cortisone, hydrocortisone, prednisone etc.

◦Have antiinflammatory, antiallergic activity

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Also affect glucose, protein and fat metabolismGlucocorticoids secreted in response to stressorsCause release of epinephrine

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Objective 16: identify therapeutic uses of glucocorticoids◦Glucocorticoids used for replacement therapy when adrenal gland not functional

◦High doses used for inflammation, allergy, asthma

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Use of corticosteroids◦Used with caution in those with Diabetes mellitus Heart failure Hypertension Peptic ulcer Mental disturbance Suspected infection

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After one week, discontinue drug slowly (wean off)

Abrupt discontinuation◦Fever; Malaise; Fatigue◦Weakness; orthostatic dizziness, hypotension

◦Dyspnea; hypoglycemia

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Topical: apply as directed, may use occlusive dressing

Alternate –day therapy: give between 6 & 9 AM; give with meals

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Side Effects◦Electrolyte imbalance, fluid accumulation

◦Susceptibility to infection◦Behavioral changes◦Hyperglycemia◦Peptic ulcer formation◦Delayed wound healing

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Drug interactions◦Loop diuretics: can enhance electrolyte loss

◦Warfarin: can have increased or decreased effect

◦Hyperglycemia: diabetics and children need to be monitored

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Objective 17: list the glucocorticoid preparations

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Various drugs for topical, oral, injection, inhalation◦Cortisone◦Dexamethasone (Decadron, Dexone)

◦Fludrocortisone (Florinef)-also mineralcorticoid

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Fluocinonide (Lidex)Hydrocortisone (Cortef, Solu-Cortef)

Methlprednisolone (Solu-Medrol, Depo-Medrol)

Prednisolone (Delta-Cortef)Prednisone (Deltasone, Apo-Prednisone)

Triamcinolone (Aristocort, Kenalog)

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Objective 18: describe nursing care responsibilities associated with administering glucocorticoids

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Objective 19: identify the functions of insulin in the body

Objective 20: define diabetes mellitus

Objective 21: identify the site of insulin production in the body

Objective 22: list the types of diabetes

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Objective 23: explain the functions of insulin◦Hormone from beta cells of the pancreas (islets of Langerhans) Normally: 0.5 – 1 unit per hour secreted

Adult: 30-50 units per day Insulin transports glucose into cells; helps metabolize protein and fat. Diabetes is a metabolic disorder: all body systems affected

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Objective 24: identify the onset, the peak, and the duration of action for rapid, intermediate, long acting and fixed combinations of insulin

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Lispro and Aspart◦Most rapid acting of insulins◦They are synthetic insulin analogs Give within 10-15 minutes of a meal Onset: 10 minutes Peak: 30 to 60 min Duration: 5 hours

Rapid-Acting Insulin

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Regular insulin◦Human regular insulin available, not just animal derivation Give within 30-60 minutes of meals Onset: 30 minutes Peak: 2.5-5 hours Duration: 5-10 hours Administration: subcutaneous or IV

Short-Acting Insulin

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Neutral protamine Hagedorn (NPH)◦Contains regular insulin and protamine Protamine binds to insulin: slow release Onset: 1-4 hours (pork is 1-1.5 hrs)

Peak: 8-12 hours (pork: 8-12 hrs) Duration: 18-24 hours (pork: 24 hrs)

Intermediate-Acting Insulin

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Lispro: can be mixed with protamine◦Humalog mix 75/2575% Lispro with protamine25% LisproRapid acting insulin with intermediate duration of action (12-24 hours)

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Humulin Ultralente◦Crystalline form of Lente insulinOnset: 4-8 hoursPeak: 12-18 hoursDuration: 24-28 hours

Long-Acting Insulin

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Insulin-Glargine solution (Lantus)◦Biosynthetic Absorbed in a uniform manner-no large fluctuations of insulin levels = reduction in possible hypoglycemiaOnset: 5 hoursPeak: no pronounced peak activity

Duration: 24 hoursDo NOT mix with other insulins

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Objective 25: describe the local tissue responses that can occur with repeated insulin injections

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Two problems can occur◦Allergic reactionsFrom proteins in insulin, alcohol, the insulin itselfSwitch types of insulinUse unscented alcoholWill resolve

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◦LipodystrophiesAtrophy or hypertrophy of subcutaneous fatUse the area because of anesthesia effect

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◦Use of the site decreases insulin absorption

◦Causes erratic absorption of insulin

◦Is cosmetic problem

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Objective 26: list the symptoms of insulin shock

Hypoglycemia ◦Headache◦Nausea◦Weakness◦Hunger

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LethargyDecreased coordinationGeneral apprehensionSweatingConfusion Blurred or double visionCan progress to coma and death

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Objective 27: discuss glucose elevating drugs◦The drug used to raise blood sugarGlucagon Glucose

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Glucagon◦Hormone from alpha cells of pancreas Breaks down stored glycogen to glucose

Aids in gluconeogenesis Must have glycogen available or drug will not work

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◦May see 50% glucose administered

◦ IV◦Raises blood sugarUse when no glycogen is stored

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Objective 28: describe what is meant by sliding scale insulin administration

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Sliding scale insulin◦Physician orders doses of insulin based upon blood glucose level

◦Regular insulin is usedSliding scale is “catch-up”Read the orders carefully

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Blood sugar Insulin

0-150 0 units151-200 2 units

201-300 5 units

Over 300, call physician

Example

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Objective 29: describe the action of the oral antidiabetic agents◦Some act on the cells to decrease resistance

◦Some act on the beta cells to increase production

◦Some inhibit glucose absorption

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Objective 30: identify the conditions under which an oral antidiabetic agent would be used◦Type 2 diabetesNo control with diet/exercise

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Objective 31: list the oral antidiabetic agents

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◦Classifications are Biguanide oral hypoglycemic agents

Sulfonylurea oral hypoglycemic agents

Meglitinide oral hypoglycemic agents

Thiazolidinedione oral hypoglycemic agents

Antihyperglycemic agents

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Metformin (Glucophage)◦Does not stimulate insulin release◦Will not cause hypoglycemia◦Can be used in combination with sulfonylureas

◦Decreases serum triglycerides and LDL

◦Slightly increases HDL

Biguanide Oral Hypoglycemics

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Initial dose: 500 mg BID◦Can go up to 2500 mg dailyUse divided doses If blood sugar not controlled, add another agent

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Side effects to expect◦N/V◦Anorexia◦Abdominal cramps◦Flatulence Will resolve Take with meals to decrease SE

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SE to report◦Malaise◦Myalgias◦Respiratory distress◦HypotensionLactic acidosis can occurMore if renal failure or excess alcohol intake

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Drug interactions◦Drugs that depend upon kidney for excretion can block metformin excretionCan have lactic acidosis develop

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Drugs that cause hyperglycemia with metformin◦OBC◦Corticosteroids◦Phenothiazines◦Diuretics◦Thyroid replacement

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Stimulate release of insulinUse when pancreas can still secrete insulin

Sulfonylurea Oral Hypoglycemic Agents

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Two generations◦First generationExample: Dymelor (500 mg daily)

◦Second generationExample: Glucotrol (2.5-5 mg daily)

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Allergy: if allergic to sulfonamides, probably allergic to sulfonylureas◦Do not administer

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SE to expect◦N/V◦Anorexia◦Abdominal crampsUsually mildDecrease with continued therapy

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SE to report◦HypoglycemiaMonitor blood sugarTreat with glucose source

◦HepatotoxicityAnorexia, N/V, jaundice, increased liver function tests

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◦Blood dyscrasiasRBC, WBCMonitor for sore throat, fever, purpura, jaundice

◦Dermatologic reactionsRash or pruritus If occurs: hold drug, call MD

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Drug interactions◦Various drugs can cause hypoglycemia such as Warfarin, ethanol

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◦Hyperglycemia with corticosteroids, phenothiazines and others

◦Beta-adrenergic blockers: cause hypoglycemia or mask the symptoms

◦Alcohol: Antabuse-like reaction

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Stimulate release of insulin from pancreas

Can be used alone or in combination◦Have short duration of action◦Must take up to QID

Meglitinide Oral Hypoglycemics

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Examples of drugs◦Repaglinide (Prandin)◦Nateglinide (Starlix)

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Dosing ◦Can take 1-30 minutes before a meal

◦Must take up to QID: compliance

◦If skip meal, skip dose

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SE to expect and report◦HypoglycemiaDose adjustments may be needed

Monitoring of blood glucose important

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Drug interactions◦HypoglycemiaEthanol, NSAIDs, Warfarin, MAOIs

◦Hyperglycemia Corticosteroids, phenothiazines, estrogens

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B-blockers: cause hypoglycemia or mask symptoms

Tegretol and others: increase repaglinide metabolism

Some macrolides and antifungals can inhibit repaglinide metabolism

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Increase sensitivity of muscle and fat tissue to insulin◦Allows more glucose to enter cells

◦Inhibit gluconeogenesisDecreases hepatic output of glucose

◦Do not increase insulin output

Thiazolidinedione OHA

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Can be used alone or in combination with other OHA’s or insulin

Examples ◦Pioglitazone (Actos)◦Rosiglitazone (Avandia)

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Baseline labs: liver function and alkaline phosphatase, CBC, WBC, HDL, LDL, triglycerides

Premenopausal, anovulatory females◦Ovulation may resume

Nursing Process for TZD’s

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SE to expect◦N/V◦Anorexia ◦Abdominal crampsMildResolve with continued therapy

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SE to report◦Hypoglycemia◦Hepatotoxicity ◦Weight gain

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Drug interactions◦Various drugs can cause an increase in hypoglycemia or hyperglycemia

◦B-adrenergics can mask hypoglycemia or cause it

◦Pioglitazone can enhance metabolism of ethinyl estradiol and norethindroneOvulate, become pregnant

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Two drugs◦Acarbose (Precose)◦Miglitol (Glyset)◦They inhibit pancreatic and GI enzymes from digesting sugars This delays glucose absorption and decreases postprandial hyperglycemia

Antihyperglycemic Agents

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Acarbose ◦Does not cause hypoglycemia◦Can be used with sulfonylureas or metformin

◦DosingTID at start of main meals

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SE to expect◦Abdominal cramps◦Diarrhea◦FlatulenceCaused by metabolism of carbohydrates in gut

Usually mild, resolve

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SE to report◦Hypoglycemia◦Hepatotoxicity Can cause increased AST, ALTHas caused hyperbilirubinemia

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Hyperglycemia can occur with some drugs such as corticosteroids, phenothiazines, OBC, thyroid

Digestive enzymes and intestinal adsorbents reduce effect of acarbose

Acarbose can decrease absorption of digoxin

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Miglitol (Glyset)◦Used alone or with sulfonylureas

◦Check liver function before treatment

◦Assess for malabsorption syndrome or obstruction in gut

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Dosing ◦Take with first bite of food◦Start with 25 mg TID

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SE to expect◦Abdominal cramps◦Diarrhea◦Flatulence

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SE to report◦Hypoglycemia

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Drug interactions◦Hyperglycemia with various agents such as cortisone, phenothiazines

◦Propranolol, Ranitidine not absorbed with concurrent miglitol

◦Digestive enzymes, intestinal adsorbents reduce effect of miglitol

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Objective 32: describe the nursing interventions associated with teaching the diabetic about the treatment

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Objective 33: list the therapeutic uses of estrogen and progesterone◦Stimulate maturation of female sex organs

◦Responsible for menstrual cycle◦Drugs used for replacement, birth control, control of prostate cancer, breast cancer, osteoporosis (controversial use)

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Objective 34: name the estrogen preparations◦Various estrogens Conjugated estrogen (Premarin) Esterified estrogens (Estratab) Estradiol (Estrace) Estropipate (Ogen) Ethinyl estradiol (Estinyl)

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Objective 35: name the progesterone preparations◦Progestins inhibit ovulation Norethindrone Ethynodiol diacetateDesogestrelLevonorgestrel

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Objective 36: identify the most commonly used ovulatory agents

Clomiphene citrate (Clomid)◦Structurally similar to natural estrogens Stimulates ovaries to release ova Used for women with reduced circulating estrogen

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Objective 37: describe the actions of the oral contraceptives◦Estrogens and progestins induce contraception by inhibiting ovulation Estrogen blocks pituitary release of FSH

Progestin inhibits LH Both alter cervical mucus May change endometrial wall

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Minipill is progestin-only◦Must take every day

Combination pill ◦Take in 21 day cycle

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Complete physical needed before therapy

SE expected: nausea, weight gain, spotting, changed menstrual flow, missed periods, depression, mood changes, chloasma, headaches

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SE to report: vaginal discharge, breakthrough bleeding, yeast infections

Blurred vision, severe headaches, dizziness, leg pain, chest pain, shortness of breath, acute abdominal pain

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Various drugs can decrease effect of OBC◦Barbiturates, Tegretol, St. John’s Wort, antibacterial agents

Drugs enhance effect and toxic effects◦Some antifungals, Warfain, phenytoin, thyroid hormones, benzodiazepines

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Objective 38: identify the nursing process for clients with conditions for which female hormones are used