Vasopressin

Indications

Vasopressin is used for: Initial control of variceal bleeding, Cranial diabetes insipidus, Abdominal Distention

Adult Dose

Intravenous Initial control of variceal bleeding Adult: 20 units in 100 ml of glucose 5% infused over 15 min. Parenteral Cranial diabetes insipidus Adult: 5-20 units SC/IM every 4 hr. Abdominal Distention Adult: 5 units IM initially; repeated q3-4hr PRN; may be increased to 10 units Hepatic impairment: Lower doses may be required to achieve response

Child Dose

Renal Dose

Administration

IV Preparation Infusion: Dilute to 0.1-1 unit/mL with NS or D5W IV/IM Administration Administered SC or IM or by continuous IV or intra-arterial infusion via controlled infusion device

Contra Indications

Hypersensitivity. Vascular disease especially coronary artery disease; chronic nephritis (until reasonable blood-nitrogen conc attained).

Precautions

Heart failure; migraine; epilepsy; asthma or other conditions which might be exacerbated by fluid retention; renal impairment; hypertension or other conditions that may worse with BP increase. Adjust fluid intake to avoid fluid overload. Lactation, pregnancy (especially 3rd trimester as it may have oxytocic effect).

Pregnancy-Lactation

Pregnancy category: C Lactation: Unknown whether drug is distributed into breast milk; use with caution

Interactions

Carbamazepine, chlorpropamide, clofibrate, urea, fludrocortisone and tricyclic antidepressants may potentiate the antidiuretic action of vasopressin. Demeclocycline, noradrenaline, lithium, heparin and alcohol may decrease antidiuretic action of vasopressin. Ganglionic blockers may increase sensitivity to the pressor effect of vasopressin. Increased risk of QT prolongation with dolasetron.

Adverse Effects

Side effects of Vasopressin : Frequency Not Defined Abdominal cramps Allergic reaction Angina Bronchial constriction Circumoral pallor Diarrhea Nausea Pounding in the head Sweating Tremor Uterine contraction Vertigo

Mechanism of Action

Vasopressin is a posterior pituitary hormone which may be synthetically prepared or extracted from animals. It exerts direct antidiuretic action on the kidneys by increasing tubular reabsorption of water. Vasopressin also acts by constricting the peripheral blood vessels and causes the smooth muscle of the intestine, gall bladder and urinary bladder to contract. Vasopressin is given parenterally or intranasally in the form of argipressin or lypressin. Argipressin is a synthetic type of vasopressin derived from most mammals (including man but excluding pig) while lypressin is vasopressin from pig.