Editing Pharmacology (section)

=== Endocrine ===

* '''Insulin''': the only insulin given intravenously is '''regular''' insulin. Approximate profiles: rapid acting (lispro, aspart, glulisine) onset about 15 minutes, peak about 1 hour, give with the meal in front of the patient; short acting regular onset about 30 to 60 minutes, peak about 2 to 4 hours; intermediate NPH onset about 1 to 2 hours, peak about 4 to 12 hours (the only cloudy insulin, and the only one routinely mixed); long acting glargine and detemir with no pronounced peak and no mixing with other insulins. When mixing, draw '''clear before cloudy''' (regular before NPH) after injecting air into both vials. Hypoglycemia signs: shakiness, diaphoresis, tachycardia, hunger, confusion, irritability. Treat a conscious patient with 15 grams of fast-acting carbohydrate, recheck in 15 minutes, and repeat as needed; treat an unconscious patient with intravenous dextrose or glucagon.
* '''Oral antidiabetics''': metformin does not cause hypoglycemia alone and carries a risk of lactic acidosis; hold it before and after iodinated contrast studies per protocol and check renal function. Sulfonylureas (glipizide, glyburide) '''do''' cause hypoglycemia. SGLT2 inhibitors (''-flozin'') cause genital mycotic and urinary infections and euglycemic ketoacidosis. GLP-1 agonists (''-tide'') cause nausea and delay gastric emptying.
* '''Levothyroxine''': take in the morning on an empty stomach with water, at least 30 to 60 minutes before food, and separate from calcium, iron, and antacids by about 4 hours. Signs of excess dose mimic hyperthyroidism: tachycardia, palpitations, weight loss, heat intolerance, insomnia. Lifelong therapy.
* '''Corticosteroids''' (prednisone, methylprednisolone): expect hyperglycemia, immunosuppression and masked infection, fluid retention, hypokalemia, mood changes, osteoporosis and cushingoid features with long-term use, and delayed wound healing. Take with food. '''Never stop abruptly''' after prolonged therapy because adrenal insufficiency can result; taper.