Hormonal regulation drugs

Thyroid hormones MoA (Levothyroxine)

Levothyroxine is a synthetic form of thyroxine (T4) used as a replacement of or supplementation to endogenous thyroid hormones. The principal effect is increasing the metabolic rate of body tissues: promoting gluconeogenesis, increasing utilization and mobilization of glycogen stores, stimulating protein synthesis, promoting cell growth and differentiation, and aiding in the development of the brain and the central nervous system (CNS).

Therapeutic Effects: Replacement in hypothyroidism to restore normal hormonal balance and suppression of thyroid cancer.

What is the onset, peak, and duration of levothyroxin (PO)

Onset: unknown

Peak: 1-3 wks

Duration: 1-3 wks

What is the onset, peak, and duration of levothyroxin (IV)

Onset: 6-8 hours

Peak: 24 hours

Duration: unknown

Side affects of Levothyroxin

Side effects are seen only when the dose is excessive and causes hyperthyroid symptoms.

Side effects include angina, arrhythmias, tachycardia, heat intolerance, menstrual irregularities, abdominal cramps, diarrhea, vomiting, weight loss, headache, insomnia, and irritability.

Consider assessing these for patients taking Levothyroxin

Assess apical pulse and blood pressure prior to and throughout therapy. Assess for tachyarrhythmias and/or chest pain.

Taking Levothyroxin with Cholestyramine, colesevelam, colestipol, and sodium polystyrene sulfonate

May bind to and decrease absorption of orally administered levothyroxine; administer levothyroxine ≥ 4 hours prior to these medications or monitor TSH levels.

Taking Levothyroxin with Orlistat, proton pump inhibitors, sucralfate, antacids, and simethicone

May decrease absorption of levothyroxine.

Taking Levothyroxin with Phenobarbital and rifampin

May increase metabolism of and decrease efficacy of levothyroxine; may need to increase levothyroxine dosage.

Levothyroxine may increase the effects of...

warfarin.

Taking Levothyroxin with calcium, iron, magnesium, or zinc supplements or food

may bind levothyroxine and prevent complete absorption

Taking Levothyroxin with Grapefruit juice...

May delay absorption

Estrogen Hormone MoA (Estradiol)

Estrogens promote growth and development of female sex organs and the maintenance of secondary sex characteristics in women. Metabolic effects include reduced blood cholesterol, protein synthesis, and sodium and water retention.

Estradiol Duration (PO, IM, Topical)

Duration: Unknown

Estradiol Duration (Transdermal)

Duration: 3-7 Days

Estradiol Duration (Vaginal Insert)

Duration: 3-4 days

Estradiol Duration (Vaginal Ring)

Duration: 90 Days

Side effects of Estradiol

Cardiovascular (CV): edema, hypertension, oily skin, intolerance to contact lenses, gynecomastia (men), nausea, weight changes, amenorrhea, dysmenorrhea, erectile dysfunction, testicular atrophy, headache, and breast tenderness.

Adverse reactions of Estradiol

Myocardial infarction (MI), thromboembolism, stroke, malignancy (breast, endometrial, and ovarian)

Consider assessing these for patients taking Estradiol

Assess blood pressure before and periodically during therapy.

Monitor intake and output ratios and weekly weight. Report significant discrepancies or steady weight gain.

Menopause: Assess the frequency and severity of vasomotor symptoms.

Taking Estradiol with Warfarin, Oral hypoglycemic agents, or insulins

May alter the requirements for these drugs

Taking Estradiol with Barbiturates or rifampin

May decrease effectiveness

Taking Estradiol while Smoking

Increases risk of adverse Cardiovascular (CV) reactions

Antidiuretic hormones MoA (Vasopressin)

Vasopressin alters the permeability of the renal collecting ducts, allowing water reabsorption. This causes decreased urine output and increased urine osmolality in diabetes insipidus. It acts as a peripheral vasoconstrictor in high doses and increases blood pressure. The effect is increased blood pressure when given in high doses. Vasopressin also directly stimulates the musculature of the gastrointestinal system (which can cause nausea or abdominal cramps).

Vasopressin duration (IM, Subq)

Duration: 2-8 hours

Vasopressin duration (IV)

Duration 30-60 mins

Vasopressin side effects

Water intoxication can occur if not monitored carefully. Signs and symptoms of water intoxication include: confusion, drowsiness, headache, weight gain, difficulty urinating, seizures, and coma.

Nausea

Abdominal cramps

Vasopressin Adverse reactions

Myocardial infarction (MI)

Desired outcome of vasopressin

The desired outcome is a decrease in urine output, an increase in urine osmolality, and relief of polyuria for clients with diabetes insipidus.

If vasopressin is for hypotension, there may be an increase in blood pressure

Things to monitor while on vasopressin

It is important to monitor blood pressure, heart rate, and ECG during therapy.

How to reduce certain side effects of vasopressin

The client should drink 1-2 glasses of water with the medication dose to reduce abdominal cramping and/or nausea

Somatostatin Hormones MoA (Octreotide)

Octreotide suppresses the secretion of serotonin and gastroenterohepatic peptides. It increases absorption of fluid and electrolytes from the gastrointestinal (GI) tract and increases transit time. It decreases levels of serotonin metabolites. It also suppresses growth hormone, insulin, and glucagon.

Octreotide duration (IV, Subq)

Duration: 2-8 hours

Octreotide duration (IM)

Duration: up to 4 weeks

Octreotide duration (PO)

Duration: Unknown

Side effects of Octreotide

Cardiovascular (CV): edema, increased sweating, flushing

Eye, ear, nose, throat (EENT): sinusitis

Endocrinology: hyperglycemia, hypoglycemia

Gastrointestinal (GI): abdominal pain, cholelithiasis, diarrhea, nausea, vomiting

Multiple sclerosis (MS): arthralgia

Neurology: headache

Misc: decreases vitamin B12 levels

Adverse reactions of Octreotide

Ileus

Pancreatitis

Octreotide with Insulin and oral hypoglycemic agents

May alter requirements for insulin or oral hypoglycemic agents.

Octreotide with Cyclosporine and digoxin

May decrease levels of cyclosporine and digoxin; closely monitor levels and adjust the dose as needed.

Octreotide with Beta blockers, digoxin, diltiazem, ivabradine, and verapamil

May increase the risk of bradycardia.

Octreotide with Proton pump inhibitors, H2 receptor antagonists, and antacids

May decrease absorption and levels of orally administered octreotide; may need to increase the dosage.

Octreotide with Lisinopril

May increase levels of lisinopril; closely monitor BP.

Octreotide with Levonorgestrel

May decrease levels of levonorgestrel; advise clients to use nonhormonal contraceptives or a backup method.

Octreotide with Bromocriptine

May increase levels of bromocriptine; may need to decrease the dose.

Octreotide with Lutetium Lu 177 dotatate

May increase the effectiveness; discontinue long-acting octreotide ≥ 4 wk and short-acting octreotide ≥ 24 hr prior to each dose.

Antithyroid MoA (Methimazole)

Methimazole inhibits the synthesis of thyroid hormones.

What is the Onset, Peak, And Duration of Methimazole (PO)

Onset: 1 week

Peak 4-10 weeks

Duration: 1-2 weeks

Side effects of Methimazole

Dermatology: rash, skin discoloration, urticaria

Gastrointestinal (GI): diarrhea, loss of taste, nausea, parotitis, vomiting

Hematology: anemia, leukopenia, thrombocytopenia

Multiple sclerosis (MS): arthralgia

Neurology: drowsiness, headache, vertigo

Misc: fever, lymphadenopathy

Adverse effects of Methimazole

Hepatotoxicity

Agranulocytosis

Things to monitor with Patients who are on Methimazole

Monitor WBC and differential counts periodically during therapy. Agranulocytosis may develop rapidly; usually occurs during the first 2 months and is more common in clients over 40 years of age, and those receiving > 40 mg/day. This necessitates discontinuation of therapy.

When Methimazole is taken with antineoplastics or radiation therapy this leads to?

Additive bone marrow depression

What can decrease the antithyroid effect of Methimazole?

Potassium iodide or amiodarone

What is the risk associated with phenothiazines with Methimazole?

Increases the risk of agranulocytosis

How may Methimazole alter the response to warfarin and digoxin?

It may alter response to both medications.