Endocrine Pharmacology Quick-Reference

Somatropin/Somatrem mechanism

Mimics endogenous GH to stimulate linear bone growth.

Somatropin/Somatrem indications

Pediatric/adult GH deficiency, Turner syndrome, and idiopathic short stature.

Somatropin/Somatrem monitoring

Regularly monitor growth curves, thyroid function, and glucose.

Somatropin/Somatrem contraindications

Closed epiphyses, active neoplasms, and diabetic retinopathy.

Somatropin/Somatrem efficacy timeline

Growth rate typically declines after 2 years of therapy.

Somatropin/Somatrem standout ADR

Hand and foot edema.

Recombinant Growth Hormone clinical use

Treats Turner syndrome and idiopathic short stature.

Octreotide mechanism

Inhibits release of GH, TSH, prolactin, insulin, and glucagon.

Octreotide indications

Acromegaly, carcinoid tumors, VIPomas, and GI bleeds.

Octreotide drug interaction

CYP450 metabolism requires caution with narrow-therapeutic-index drugs.

Octreotide acute effect

Even a single dose can inhibit gallbladder contractility.

Octreotide monitoring

Monitor for gallstones with use up to 1 year.

Octreotide standout ADR

Gallstones and biliary sludge.

Vasopressin mechanism

V1 vasoconstriction and V2 renal water reabsorption activity.

Vasopressin indications

Diabetes insipidus, GI hemorrhage, and vasodilatory shock.

Vasopressin endocrine effect

Stimulates adrenocorticotropic hormone (ACTH) secretion.

Vasopressin IV safety

Watch IV site closely because extravasation causes tissue necrosis.

Vasopressin monitoring

Monitor electrocardiogram (ECG) and fluid/electrolytes.

Vasopressin standout ADR

Ischemia of cardiac, limb, mesenteric, and skin tissues.

Natural ADH drug name

Vasopressin (Pitressin).

Oxytocin mechanism

Stimulates uterine smooth muscle contraction and lactation.

Oxytocin indications

Labor induction and postpartum hemorrhage control.

Oxytocin abortion status

Not the drug of choice for abortion induction.

Oxytocin monitoring

Requires continuous fetal monitoring and fluid intake/output monitoring.

Oxytocin prolonged infusion risk

Severe water intoxication.

Oxytocin standout ADR

Neonatal retinal hemorrhage.

Pitocin clinical use

Labor induction and postpartum hemorrhage control.

Desmopressin mechanism

V2-selective agonist that triggers factor VIII release from endothelium.

Desmopressin indications

Diabetes insipidus, nocturnal enuresis, and von Willebrand disease.

Desmopressin contraindications

Hyponatremia and mild-to-moderate renal impairment.

Desmopressin drug interactions

Hyponatremia risk rises with TCAs, SSRIs, and carbamazepine.

Desmopressin patient education

Drink only enough water to satisfy thirst.

Desmopressin standout ADR

Facial flushing.

DDAVP clinical use

Treats diabetes insipidus and mild hemophilia A.

Glucocorticoids mechanism

Anti-inflammatory, immunosuppressive, and increases gluconeogenesis.

Glucocorticoids indications

Addison's replacement, autoimmune disease, asthma/COPD, and shock.

Glucocorticoids withdrawal rule

Never stop abruptly; taper to avoid adrenal crisis.

Glucocorticoids long-term risks

Osteoporosis, cataracts, and peptic ulcer disease.

Glucocorticoids dosing principle

Use lowest effective dose for the shortest duration.

Glucocorticoids standout ADR

Cushingoid features like moon face and central obesity.

Adrenal crisis prevention

Taper glucocorticoids instead of stopping abruptly.

Fludrocortisone mechanism

Increases sodium reabsorption and potassium loss at renal distal tubule.

Fludrocortisone indications

Addison's disease and salt-wasting adrenal insufficiency.

Fludrocortisone duration rule

High-dose therapy should last only a few weeks with tapering.

Fludrocortisone monitoring

Monitor renin, sodium, and potassium levels.

Fludrocortisone withdrawal symptoms

Anorexia, fever, rebound inflammation, and hypotension.

Fludrocortisone standout ADR

Hirsutism (unusual hair growth).

Florinef clinical class

Mineralocorticoid replacement.

Aminoglutethimide mechanism

Blocks corticosteroid synthesis broadly across all adrenal steroid classes.

Aminoglutethimide indications

Cushing's syndrome, adrenal carcinoma, and hormone-sensitive cancers.

Aminoglutethimide and ACTH

Compensatory ACTH rise can override blockade unless hydrocortisone is co-given.

Aminoglutethimide cessation

Adrenal steroid synthesis returns approximately 72 hours after stopping.

Aminoglutethimide limitation

Effectiveness fades after 3 months in pituitary-dependent Cushing's.

Aminoglutethimide standout ADR

Transient first-week rash that resolves in 5 to 8 days.

Cytadren drug class

Adrenal steroid synthesis blocker.

Anastrozole mechanism

Blocks conversion of androgens to estrogen.

Anastrozole indications

Breast cancer in postmenopausal women only.

Anastrozole pregnancy warning

Contraindicated; absorbed through skin so do not handle tablets.

Anastrozole metabolic effects

Can lower bone mineral density and raise LDL/total cholesterol.

Anastrozole age restriction

Safety is not established for premenopausal women.

Anastrozole standout ADR

Hot flashes and vaginal bleeding.

Arimidex drug class

Aromatase inhibitor.

Levothyroxine indication

Drug of choice for primary and secondary hypothyroidism.

Levothyroxine dosing advantage

Long half-life allows once-daily dosing.

Levothyroxine administration

Take 30 minutes before breakfast and never switch brands.

Levothyroxine absorption interference

Bile acid sequestrants, iron, and antacids decrease absorption.

Levothyroxine regulatory warning

Carries a Black Box Warning.

Levothyroxine standout ADR

Urticaria.

Synthroid generic name

Levothyroxine (T4).

Liothyronine potency

Four times more potent than natural T3.

Liothyronine indications

Myxedema and pre-thyroid-cancer-surgery TSH suppression.

Liothyronine absorption speed

Faster onset than levothyroxine; 95% absorbed within 4 hours.

Liothyronine warfarin interaction

Increases catabolism of vitamin-K clotting factors, potentiating warfarin.

Liothyronine diabetic adjustment

May require increased doses of insulin or oral hypoglycemics.

Liothyronine standout ADR

Arrhythmias (more prominent than with levothyroxine).

Cytomel generic name

Liothyronine (T3).

Liotrix therapeutic value

No therapeutic advantage over levothyroxine alone.

Liotrix market status

Discontinued from the market in 2018.

Liotrix administration spacing

Separate mineral, soy, or sucralfate dosing by at least 4 hours.

Liotrix onset and peak

Onset within hours with maximum effect at 2 to 3 days.

Liotrix contraindications

Older patients with cardiac comorbidities.

Liotrix standout ADR

Menstrual irregularities.

Propylthiouracil mechanism

Blocks iodine oxidation and peripheral T4 to T3 conversion.

Propylthiouracil preferred uses

First-trimester pregnancy and thyroid storm.

Propylthiouracil onset and labs

Onset 24 to 36 hours; requires CBC monitoring.

Propylthiouracil limitation

Does not destroy existing circulating T3 and T4.

Propylthiouracil monitoring

Weigh the patient 2 to 3 times per week.

Propylthiouracil standout ADR

Agranulocytosis progressing to fatal hepatitis.

PTU drug class

Thioamide antithyroid drug.

Methimazole dosing advantage

Once-daily dosing improves adherence compared to PTU.

Methimazole indication

Drug of choice for non-pregnant hyperthyroidism.

Methimazole pregnancy warning

Crosses the placenta; avoid in the first trimester.

Methimazole protein binding

Not protein-bound (unlike PTU).

Methimazole lactation status

Preferred postpartum and during lactation.

Methimazole standout ADR

Loss of taste.

Tapazole generic name

Methimazole.

Cinacalcet mechanism

Increases sensitivity of calcium-sensing receptors, decreasing PTH secretion.

Cinacalcet indications

Secondary hyperparathyroidism in CKD/dialysis and parathyroid carcinoma.

Cinacalcet contraindications

Serum calcium level below 8.4 mg/dL.

Cinacalcet administration

Take with food anyway, though high-fat meals decrease absorption.