ADMINISTRATION ROUTES:
IV
ALTERNATIVE NAMES:
Pitressin
ICU INDICATIONS:
- Refractory septic shock
- Severe vasoplegia after cardiopulmonary bypass
PRESENTATION AND ADMINISTRATION:
IV:
20 units in 1 mL glass vials.
Administer by IV infusion. Make 20 units of vasopressin up to a total of 20 mL of compatible IV fluid. Compatible with the following IV fluids: 5% dextrose, 0.9% saline
Must only be administered via a central line. Store at room temperature.
Note: Section 29 drug (requires specific notification to Director-General of Health)
DOSAGE:
IV:
0 - 3 units/hr
DOSAGE IN RENAL FAILURE AND RENAL REPLACEMENT THERAPY:
Dose as in normal renal function
DOSAGE IN PAEDIATRICS:
IV:
Vasopressin has been shown to increase the risk of death in children with septic shock. It should only be used on the advice of a Paediatric Intensive Care Specialist.
CLINICAL PHARMACOLOGY:
Vasopressin is a potent vasopressor which is an analogue of the posterior pituitary hormone ADH. Vasopressin binds to different receptors than catecholamine pressors so augments the response to catecholamine therapy. Profound vasodilatory shock may be due to relative endogenous vasopressin deficiency when stores are depleted; supplementation replaces these. Vasopressin may provide a more effective vasoconstriction response than catecholamines in patients with severe acidosis.
Vasoconstrictor effects are through the V1 vascular receptors. The clinical effect is apparent within a few minutes with a duration of action up to 20 minutes.
CONTRAINDICATIONS:
- Hypersensitivity to vasopressin
WARNINGS:
See PRECAUTIONS
PRECAUTIONS:
General:
Vasopressin is a potent vasoconstrictor. Due to its effect on afterload, vasopressin may increase myocardial oxygen demand and lead to myocardial ischaemia.
Laboratory Tests:
No tests are required in addition to routine ICU tests.
Drug/Laboratory Test Interactions:
None known
IMPORTANT DRUG INTERACTIONS IN ICU:
Vasopressin acts via different receptors than other vasoconstrictor agents; it may lead to significant reductions in noradrenaline requirements.
ADVERSE REACTIONS:
Cardiovascular:
Arrhythmias including asystole, hypertension, reduced cardiac output, chest pain, MI, venous thrombosis
Neurological:
Pounding in head, fever, vertigo
Dermatologic:
Ischaemic skin lesions, circumoral pallor, urticaria
Gastrointestinal:
Abdominal cramps, flatulence, mesenteric ischemia, nausea, vomiting
Genitourinary:
Uterine contraction
Neuromuscular & skeletal:
Tremor
Respiratory:
Bronchial constriction
Metabolic:
Hyponatraemia & water retention