Adult: In non-nephrogenic origin: 5-20 units (0.25-1 mL) via SC or IM inj 4 hourly.
Intravenous Initial control of variceal bleeding
Adult: 20 units in 100 mL of dextrose 5% infused over 15 minutes.
Adult: In hypotensive patients with vasodilatory shock who remain hypotensive despite fluids and catecholamines: Postcardiotomy shock: Initially, 0.3 unit/min. Max: 0.1 unit/min. Septic shock: Initially, 0.01 unit/min. Max: 0.07 unit/min. All doses are titrated up by 0.005 unit/min at 10-15 minutes intervals until the target blood pressure is reached.
Hướng dẫn pha thuốc
IV infusion: Dilute 50 units (2.5 mL) vasopressin with 500 mL of 0.9% NaCl or 5% dextrose in water to a final concentration of 0.1 unit/mL. For fluid-restricted patients: Dilute 100 units (5 mL) vasopressin with 100 mL of 0.9% NaCl or 5% dextrose in water to a final concentration of 1 unit/mL.
Chống chỉ định
Hypersensitivity to vasopressin and chlorobutanol. Coronary artery disease, chronic nephritis with nitrogen retention.
Patient with CV disease, vascular disease, heart failure, migraine, asthma, or epilepsy. Renal impairment. Pregnancy and lactation.
Tác dụng không mong muốn
Significant: Reversible diabetes insipidus (following discontinuation of treatment), water intoxication; extravasation; decreased cardiac output. Blood and lymphatic system disorders: Decreased platelet count, intractable bleeding. Cardiac disorders: Angina, cardiac arrest, atrial fibrillation, bradycardia, myocardial ischaemia, right heart failure. Gastrointestinal disorders: Nausea, vomiting, diarrhoea, flatulence, abdominal pain, mesenteric ischaemia. General disorders and admin site conditions: Non-cardiac chest pain. Immune system disorders: Hypersensitivity, anaphylaxis. Investigations: Increased serum bilirubin Metabolism and nutrition disorders: Hyponatraemia. Nervous system disorders: Headache, vertigo, tremor. Renal and urinary disorders: Fluid retention, acute renal insufficiency. Respiratory, thoracic and mediastinal disorders: Bronchospasm. Skin and subcutaneous tissue disorders: Gangrene, hyperhidrosis, urticaria, ischaemic lesions. Vascular disorders: Hypertension, pallor, peripheral ischaemia, haemorrhagic shock.
Monitor serum and urine Na, urine and serum osmolality, urine specific gravity, urine output, fluid input and output, blood pressure, heart rate, digital or extremity perfusion during therapy. Monitor electrolytes, fluid status, and urine output after vasopressin discontinuation. Monitor BUN levels in patients with chronic nephritis.
Symptoms: Abdominal cramps, nausea, vomiting, dizziness, ventricular tachycardia, rhabdomyolysis, hyponatraemia, cerebral oedema, anginal pain; severe water intoxication manifesting as drowsiness, listlessness, headache, and convulsions or coma. Management: Symptomatic treatment. Restrict fluids. Closely monitor electrolytes, circulation and fluid balance. May administer urea, furosemide, mannitol or hypertonic saline in severe water intoxication; amyl nitrite via inhalation or glyceryl trinitrate sublingually in cases of anginal pain.
Enhanced therapeutic effect with indometacin specifically on cardiac index and systemic vascular resistance. Enhanced effect on mean arterial blood pressure with ganglionic blocking agents (e.g. mecamylamine). Increased pressor and antidiuretic effects with drugs suspected of causing SIADH (e.g. TCAs, SSRIs, carbamazepine, haloperidol, chlorpropamide, methyldopa, enalapril, clofibrate, fludrocortisone, urea, pentamidine, ifosfamide, cyclophosphamide, vincristine, felbamate). Decreased pressor and antidiuretic effects with drugs suspected of causing diabetes insipidus (e.g. clozapine, lithium, foscarnet, demeclocycline, heparin, alcohol, norepinephrine).
Description: Mechanism of Action: Vasopressin is a posterior pituitary hormone which may be synthetically prepared or extracted from animals. It stimulates V1 receptor and increases systemic vascular resistance and mean arterial blood pressure resulting in decreased heart rate and cardiac output. It also stimulates V2 receptor which increases cyclic adenosine monophosphate (cAMP) thus increasing water permeability at the renal tubule resulting in increased osmolality and decreased urine volume. At pressor doses, vasopressin causes smooth muscle contraction in the gastrointestinal tract by stimulating V1 receptors, and release of prolactin and ACTH via V3 receptors.
Synonym: argipressin; antidiuretic hormone (ADH). Onset: Antidiuretic: 1-2 hours. Vasopressor effect: Within 15 minutes (IV). Duration: Antidiuretic: 2-8 hours (SC). Vasopressor: Within 20 minutes (IV). Pharmacokinetics: Distribution: Volume of distribution: 140 mL/kg. Metabolism: Metabolised in the liver and kidney into inactive metabolites. Excretion: Via urine (approx 5% as unchanged drug [SC]; approx 6% as unchanged drug [IV]). Elimination half-life: 10-20 minutes.
Store between 2-8°C. Do not freeze. Protect from light.