Pharmacology - Endocrine Drugs

Pharmacology of the Selected Endocrine Drugs

2005

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Endocrine Medications

Hormonal replacement


Anti-diuretic hormones

• Enhance re-absorption of water in the kidneys

• Increases water permeability in the renal collecting ducts

• Also stimulates VASOCONSTRICTION and increases the blood pressure


Therapeutic Indications

1. Hormonal replacement

2. Used in diagnostic procedure

3. Used to control the hemorrhage in variceal bleeding

4. Treatment of enuresis


Used in DI

• 1. Desmopressin and Lypressin intranasally

• 2. Pitressin IntraMuscularly


Anti-diuretic hormones

SIDE-effects• Flushing and headache• Water intoxication• CVS: heart block, MI• Renal: hyponatremia• Gangrene due to vasoconstriction

Thyroid Medications

Thyroid hormones

• These products are used to treat the manifestations of hypothyroidism

• Replace hormonal deficit in the treatment of HYPOTHYROIDSM

Thyroid Medications

Thyroid hormones

• Levothyroxine (Synthroid)

• Liothyroxine (Cytomel)

• Thyroid dessicated

• Liotrix (Thyrolar)

Thyroid Medications

Thyroid hormones: Actions

• Replaces both T3 and T4

• Increases metabolic rate

Thyroid Medications

Thyroid hormones: Actions

• Increase the metabolic rate

• Increase O2 consumption

• Increase HR, RR, BP

Thyroid Medications

Thyroid hormones: Indications

Hypothyroidism

Diagnostic suppression test

Thyroid Medications

Thyroid hormones

Side-effects

1. Nausea and Vomiting

2. Signs of increased metabolism= tachycardia, hypertension, cardiac arrhythmias, anxiety, headache, tremors, palpitations

Thyroid Medications

Thyroid hormones : Nursing responsibility

1. Monitor weight, VS

2. Instruct client to take daily medication the same time each morning WITHOUT FOOD

Monitor blood tests to check the activity of thyroid

Thyroid Medications

Thyroid hormones: Nursing responsibility

3. Advise to report palpitation, tachycardia, and chest pain

4. Instruct to avoid foods that inhibit thyroid secretions like cabbage, spinach and radishes

ANTI-Thyroid Medications

ANTI-THYROID medications

• The thyroid becomes oversaturated with iodine and stop producing thyroid hormone



• Drugs used to BLOCK the thyroid hormones and treat hyperthyroidism

• Inhibit the synthesis of thyroid hormones



1. Methimazole (Tapazole)

2. PTU (prophylthiouracil)

3. Iodine solution- SSKI and Lugol’s solution


ANTI-THYROID medications: Indications

1. Grave’s dosease

2. Thyrotoxicosis


ANTI-THYROID medications:

• Absorption is good orally


ANTI-THYROID medicationsSide-effects of thionamides

–N/V, drowsiness, lethargy, bradycardia, skin rash

–GI complaints–Arthralgia, myalgia–AGRANULOCYTOSIS

• Most important to monitor

ANTI-Thyroid MedicationsANTI-THYROID medicationsSide-effects of Iodine solutions

Lugol’s–Most common adverse effects is

HYPOTHYROIDISM– Iodism= metallic taste, burning in

the mouth, sore teeth and gums, diarrhea, stomach upset


ANTI-THYROID medicationsNursing responsibilities• 1. Monitor VS, T3 and T4,

weight• 2. The medications WITH

MEALS to avoid gastric upset


ANTI-THYROID medications Nursing responsibilities

• 3. Instruct to report SORE THROAT or unexplained FEVER

• 4. Monitor for signs of hypothyroidism. –Instruct not to stop abrupt

medication

ANTI-Thyroid MedicationsANTI-THYROID medicationsLugol’s Solution• Used to decrease the vascularity and size of

the thyroid (in preparation for thyroid surgery)

• T3 and T4 production diminishes• Given per orem, can be diluted with juice,

administered WITH foods• Use straw to decrease staining• Monitor iodism

STEROIDS

• Replaces the steroids in the body

• Cortisol, cortisone, betamethasone, and hydrocortisone

STEROIDS

• These drugs enter the cells and bind to receptors

• They inhibit the enzyme phospholipase

STEROIDS• Corticosteroids are used topically

and locally to achieve the desired anti-inflammatory effects at a particular site

Examples:PrednisoneBethamethasonePrednisoloneFludrocortisone

STEROIDSSide-effects

–HYPERglycemia–Increased susceptibility to

infection (immunosuppression)

–Hypokalemia–Edema–Peptic ulceration

STEROIDS

Side-effects–If high doses- osteoporosis, growth retardation, peptic ulcer, hypertension, cataract, mood changes, hirsutism, and fragile skin

STEROIDS

• Nursing responsibilities

1. Monitor VS, electrolytes, glucose

2. Monitor weight edema and I/O

STEROIDS• Nursing responsibilities

3. Protect patient from infection

4. Handle patient gently

5. Instruct to take meds WITH MEALS to prevent gastric ulcer formation

STEROIDS• Nursing responsibilities

6. Caution the patient NOT to abruptly stop the drug

7. Drug is tapered to allow the adrenal gland to secrete endogenous hormones

STEROIDS

Evaluation:

The drugs are effective if there is:

1. Relief of signs and symptoms of inflammation

2. Return of adrenal function to normal

DM Drug therapy

DRUG THERAPY and MANAGEMENT

• Usually, this type of management is employed if diet modification and exercise cannot control the blood glucose level.


• These agents are employed to control the blood glucose level

• They can be insulin and oral agents

• These are given to replace the hormone in the body

• If hormone is still present BUT decreased, Oral agents are given

Diabetes Mellitus


• Because the patient with TYPE 1 DM cannot produce insulin, exogenous insulin must be administered for life.

Diabetes Mellitus


• TYPE 2 DM may have decreased insulin production, ORAL agents that stimulate insulin production are usually employed.

Diabetes Mellitus

PHARMACOLOGIC INSULIN• This may be grouped into several

categories according to:1. Source- Human, pig, or cow2. Onset of action- Rapid-acting, short-acting, intermediate-acting, long-acting and very long acting

Diabetes Mellitus

PHARMACOLOGIC INSULIN

• This may be grouped into several categories according to:

3. Pure or mixed concentration

4. Manufacturer of drug

Diabetes Mellitus

GENERALITIES

• 1. Human insulin preparations have a shorter duration of action than animal source

Diabetes Mellitus

GENERALITIES

• 2. Animal sources of insulin have animal proteins that may trigger allergic reaction and they may stimulate antibody production that may bind the insulin, slowing the action

Diabetes Mellitus

• 3. ONLY Regular insulin can be used INTRAVENOUSLY!

Diabetes Mellitus

• 4. Insulin are measured in INTERNATIONAL UNITS or “iu”

• 5. There is a specified insulin injection calibrated in units

Diabetes Mellitus

• Mixed insulin are also available

• The msot common of which is the 70-30 insulin

• Made up of :70% NPH and 30% regular insulin in the vial

Comparison of Insulin Peak action

Insulin Type Example Onset PEAK

ULTRA-acting Lispro 15 minutes

1 hour

RAPID acting Regular Insulin

1 hour 2-4 hrs

Intermediate acting

NPH and Lente

1 ½ to 2 hrs

6-8 hrs

to 12 hrs

Long Acting Ultra-lente 4-8 hrs 10-20 hrs

Diabetes Mellitus

RAPID ACTING INSULIN

• Lispro (Humalog) and Insulin Aspart (Novolog)

• Produces a more rapid effect and with a shorter duration than any other insulin preparation

Diabetes Mellitus

RAPID ACTING INSULIN

• ONSET- 5-15 minutes

• PEAK- 1 hour

• DURATION- 3 hours

• Instruct patient to eat within 5 to 15 minutes after injection

Diabetes Mellitus

REGULAR INSULIN

• Also called Short-acting insulin

• “R”

• Usually Clear solution administered 30 minutes before a meal

Diabetes Mellitus

REGULAR INSULIN• ONSET- 30 minutes to 1

hour• PEAK- 2 to 4 hours• DURATION- 4 to 6 hours

Diabetes Mellitus

INTERMEDIATE ACTING INSULIN

• Called “NPH” or “LENTE”

• Appears white and cloudy

Diabetes Mellitus

INTERMEDIATE ACTING INSULIN

• ONSET- 2-4 hours• PEAK- 4 to 6-12 hours• DURATION- 16-20 hours

Diabetes Mellitus

LONG- ACTING INSULIN• “UltraLENTE”• Referred to as “peakless”

insulin

Diabetes Mellitus

LONG- ACTING INSULIN

• ONSET- 6-8 hours

• PEAK- 12-16 hours

• DURATION- 20-30 hours

Diabetes Mellitus

HEALTH TEACHING

Regarding Insulin SELF- Administration

• 1. Insulin is administered at home subcutaneously

Diabetes Mellitus

HEALTH TEACHING Regarding Insulin SELF- Administration

• 2. Cloudy insulin should be thoroughly mixed by gently inverting the vial or ROLLING between the hands

Diabetes Mellitus

HEALTH TEACHING Regarding Insulin SELF- Administration

• 3. Insulin NOT IN USE should be stored in the refrigerator, BUT avoid freezing/extreme temperature

Diabetes Mellitus

• 4. Insulin IN USE should be kept at room temperature to reduce local irritation at the injection site

Diabetes Mellitus

• 5. INSULIN may be kept at room temperature up to 1 month

Diabetes Mellitus

• 6. Select syringes that match the insulin concentration.–U-100 means 100 units per mL

Diabetes Mellitus

• 7. Instruct the client to draw up the REGULAR (clear) Insulin FIRST before drawing the intermediate acting (cloudy) insulin

Diabetes Mellitus

• 8. Pre-filled syringes can be prepared and should be kept in the refrigerator with the needle in the UPRIGHT position to avoid clogging the needle

Diabetes Mellitus

• 9. The four main areas for insulin injection are- ABDOMEN, UPPER ARMS, THIGHS and HIPS

Diabetes Mellitus

• Insulin is absorbed fastest in the abdomen and slowest in the hips

• Instruct the client to rotate the areas of injection, but exhaust all available sites in one area first before moving into another area.

Diabetes Mellitus

• 10. Alcohol may not be used to cleanse the skin

• 11. Utilize the subcutaneous injection technique- commonly, a 45-90 degree angle.

Diabetes Mellitus

• 12. No need to instruct for aspirating the needle

• 13. Properly discard the syringe after use.

Diabetes Mellitus

T-I-E

Test blood Inject insulin Eat food

Diabetes Mellitus

ORAL HYPOGLYCEMIC AGENTS

• These may be effective when used in TYPE 2 DM that cannot be treated with diet and exercise

• These are NEVER used in pregnancy!

Diabetes Mellitus

ORAL HYPOGLYCEMIC AGENTS• There are several agents:

–Sulfonylureas–Biguanides–Alpha-glucosidase inhibitors–Thiazolidinediones–Meglitinides

Diabetes Mellitus

ORAL HYPOGLYCEMIC AGENTS• These drugs are given per orem and

are effective only in type 2 DM

• Common adverse effects include:– Hypoglycemia– Diarrhea, jaundice, nausea and

heartburn– Anemia , photosensitivity

Diabetes Mellitus

ORAL HYPOGLYCEMIC AGENTSGeneral Nursing Consideration1. Observe for manifestations of

hypoglycemia2. Assess for allergic reaction3. Instruct to take the medication at the

same time each day4. Caution to avoid taking other drugs

without consultation with physician

Diabetes Mellitus

ORAL HYPOGLYCEMIC AGENTSGeneral Nursing Consideration5. THESE medications SHOULD NEVER

be given to pregnant women, so rule out pregnancy

6. Instruct to wear sunscreen7. Advise to bring simple sugar to be

taken when hypoglycemic episodes occur

Diabetes Mellitus

SULFONYLUREAS• MOA- stimulates the beta

cells of the pancreas to secrete insulin

• Classified as to generations- first and second generations

Diabetes Mellitus

SULFONYLUREAS

• FIRST GENERATION- Acetoheximide, Chlorpropamide, Tolazamide and Tolbutamide

• SECOND GENERATION- Glipizide, Glyburide, Glibenclamide, Glimepiride

Diabetes Mellitus: Sulfonylureas

• The most common side –effects of these medications are Gastro-intestinal upset and dermatologic reactions.

• HYPOGLYCEMIA is also a very important side-effect

• Given 30 minutes before meals- breakfast

Diabetes Mellitus: Sulfonylureas

• Chlorpropamide has a very long duration of action. This also produces a disulfiram-like reaction when taken with alcohol

• Second generation drugs have shorter duration with metabolism in the kidney and liver and are the choice for elderly patients

Diabetes Mellitus

BIGUANIDES• MOA- Facilitate the action of

insulin on the peripheral receptors

• These can only be used in the presence of insulin

Diabetes Mellitus

BIGUANIDES= “formin”• They have no effect on the

beta cells of the pancreas • Metformin (Glucophage) and

Phenformin are examples

Diabetes Mellitus: Biguanides

• The most important side effect is LACTIC ACIDOSIS!

• These are not given to patient with renal impairment

Diabetes Mellitus: Biguanides

• These drugs are usually given with a sulfonylurea to enhance the glucose-lowering effect more than the use of each drug individually

Diabetes Mellitus

ALPHA-GLUCOSIDASE INHIBITORS• MOA- Delay the absorption of glucose in

the GIT • Result is a lower post-prandial blood

glucose level• They do not affect insulin secretion or

action!• Side-effect: DIARRHEA and

FLATULENCE

Diabetes Mellitus

• Examples of AGI are Acarbose and Miglitol

• They are not absorbed systemically and are very safe

• They can be used alone or in combination with other OHA

Diabetes Mellitus

• Side-effect if used with other drug is HYPOGLYCEMIA

• Note that sucrose absorption is impaired and IV glucose is the therapy for the hypoglycemia

Diabetes Mellitus

THIAZOLIDINEDIONES• MOA- Enhance insulin

action at the receptor site• They do not stimulate

insulin secretion

Diabetes MellitusTHIAZOLIDINEDIONES

• Examples- Rosiglitazone, Pioglitazone• These drugs affect LIVER FUNCTION• Can cause resumption of OVULATION

in peri-menopausal anovulatory women

Diabetes Mellitus

MEGLITINIDES• MOA- Stimulate the

secretion of insulin by the beta cells

• Examples- Repaglinide and Nateglinide

Diabetes Mellitus

MEGLITINIDES

• They have a shorter duration and fast action

• Should be taken BEFORE meals to stimulate the release of insulin from the pancreas

Diabetes Mellitus

MEGLITINIDES• Principal side-effect of

meglitinides- hypoglycemia• Can be used alone or in

combination

Reproductive Hormones

• Gonadal hormones include agents that affect the female and male reproductive cycle

• Female hormones include ESTROGENS, PROGESTINS and ovarian hormones

• Male hormones include ANDROGENS and anabolic steroids


The GENERAL Mechanism of Action

• These hormones interfere with the normal cycle of hormone balance


INDICATIONS

1. FEMALE: Hormonal replacement therapy, oral contraception, treatment of infertility and management of some tumors

2. MALE: replacement therapy, metabolic stimulators and treatment of some tumors


Estrogens

• Conjugated estrogen

• Estradiol

• Ethinyl estradiol

• Diethylstilbesterol (DES)

• Clomiphene


Progestins• Medroxyprogesterone acetate

(Provera)• Megestrol• Norethindrone• Levonorgestrel (Norplant)• Norgestrel• Norethindrone acetate


Androgens

• Testosterone cypionate

• Methyltestosterone

• Fluoxymesterone

• Aqueous testosterone


Oral Contraceptive Pills

• Two types are available: Combination estrogen and progesterone AND progestins only


Oral Contraceptive Pills: DYNAMICS

• Inhibits OVULATION by altering the hypothalamus and gonadotropin axis

• Alters the MUCUS to prevent sperm entry

• Alters the uterine endometrium to prevent implantation

• Suppresses the ovaries


Oral Contraceptive Pills: Indicators

• Suppression of ovulation for prevention of pregnancy

• Regulation of menstrual cycle and management of dysfunctional bleeding

• Treatment of endometriosis


Oral Contraceptive Pills: Kinetics

• Easily absorbed orally

• NORPLANT provides 5 years of contraception

• Provera provides 3 months of protection

• Metabolized and excreted in liver


Oral Contraceptive Pills:

• Not to be used in patients with history of, hypertension, thromboemoblic or CVA disease

• Not given in certain cancers

• Contraindicates in pregnancy

• SMOKING should be avoided when under therapy


Oral Contraceptive Pills: Drug Interaction

• Rifampicin, penicillin and tetracycline REDUCE effectiveness of contraception

• Benzodiazepines decrease the levels of OCP


Oral Contraceptive Pills:

Side effects

• CNS: headache

• CV: Thromboembolic disease, MI, hypertension and pulmonary edema

• NAUSEA and cholestatic JAUNDICE

• Breast tenderness, weight gain, edema, breakthrough bleeding, acne

Reproductive hormones

Nursing Considerations1. Assess for risk factors and the ability to

comply with medications2. Determine the type of OCP used• Monophasic pills provide constant dosing

of BOTH estrogen and progestin• Biphasic pills provide constant estrogen

but varying progestin doses• Triphasic pills provide varying Estrogen

and Progesterone

Reproductive hormones

Nursing Considerations3. Teach the common side-effects and re-

assure that these will decrease in time4. Instruct to use other means of

contraception if antibiotics and anticonvulsants are also taken

5. WARNT the client to avoid smoking because this will increase the risk for embolic episodes

Clomiphene

• A synthetic, non-steroidal estrogen

• Increases the secretion of gonadotropins and initiates the secretion of FSH and LH

• OVULATION will occur

• Used in the treatment of infertility

• Readily absorbed orally

Clomiphene

• Side effects can be:

• Risk for Multiple pregnancy

• Nausea, breast discomfort, headache and GI disturbances

• Visual disturbances

• Enlargement of the ovaries

Viagra (Sildenafil)

• A medication used for penile erectile dysfunction

• Selectively inhibits receptors and enzyme Phosphodiesterase E

• This increases the nitrous oxide levels allowing blood flow into the corpus cavernosum

Viagra (Sildenafil)

• Contraindicated in patients with bleeding disorders and with penile implants

• Caution: Coronary Artery Disease and concomitant use of nitrates

• Side-effects: PRIAPISM, headache, flushing, dyspepsia, UTI, diarrhea and dizziness

Viagra (Sildenafil)

• Nursing consideration

• Assess for risk factors

• Instruct to take the drug ONE hour before sexual act

• Drug is taken orally

Pharmacology - Endocrine Drugs

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