|
Vasopressin
Vasopressin (Pitressin Synthetic)
Vasopressin
(vay-so-PRESS-in)
Pregnancy Category: C
Pitressin Synthetic
Pressyn
(Rx)
Classification:
Pituitary (antidiuretic) hormone
Action/Kinetics:
Released from the anterior pituitary gland; regulates water conservation by promoting reabsorption of water by increasing the permeability of the collecting ducts in the kidney. Depending on the concentration, the hormone acts on both V1 and V2 receptors. Also causes vasoconstriction (pressor effect) of the splanchnic and portal vessels (and to a lesser extent of peripheral, cerebral, pulmonary, and coronary vessels). Also increases the smooth muscular activity of the bladder, GI tract, and uterus. IM, SC: Onset, variable; duration, 2-8 hr. t1/2: 10-20 min. Effective plasma levels: 4.5-6 microunits.
Uses:
Neurogenic (central) diabetes insipidus (ineffective when diabetes insipidus is of renal origin--nephrogenic diabetes insipidus). Relief of postoperative intestinal gaseous distention, to dispel gas shadows in abdominal roentgenography. Investigational: Bleeding esophageal varices.
Contraindications:
Vascular disease, especially when involving coronary arteries; angina pectoris. Chronic nephritis until reasonable blood nitrogen levels are attained. Never give the tannate IV.
Special Concerns:
Pediatric and geriatric clients have an increased risk of hyponatremia and water intoxication. Use caution during lactation and in the presence of asthma, epilepsy, migraine, CAD, and CHF.
Side Effects:
GI: N&V;, increased intestinal activity (e.g., belching, cramps, urge to defecate), abdominal cramps, flatus. Miscellaneous: Facial pallor, tremor, sweating, allergic reactions vertigo, skin blanching, bronchoconstriction, anaphylaxis ``pounding'' in head, water intoxication (drowsiness, headache, coma, convulsions).
IV use of vasopressin may result in severe vasoconstriction; local tissue necrosis if extravasation occurs. IM use of tannate may cause pain and sterile abscesses at site of injection.
Overdose Management:
Symptoms: Water intoxication. Treatment: Withdraw vasopressin until polyuria occurs. If water intoxication is serious, administration of mannitol (i.e., an osmotic diuretic), hypertonic dextrose, or urea alone (or with furosemide) is indicated.
Drug Interactions:
Carbamazepine, chlorpropamide, or clofibrate may  antidiuretic effects of vasopressin.
How Supplied:
Injection: 20 U/mL.
Dosage
•IM, SC
Diabetes insipidus.
Adults: 5-10 U b.i.d.-t.i.d.; pediatric: 2.5-10 U t.i.d.-q.i.d.
Abdominal distention.
Adults, initial: 5 U IM; then, 10 U IM q 3-4 hr; pediatric: individualize the dose (usual: 2.5-5 U).
Abdominal roentgenography.
IM, SC: 2 injections of 10 U each 2 hr and 1/2 hr before X rays are taken.
Esophageal varices.
Initial: 0.2 U/min IV or selective IA; then, 0.4 U/min if bleeding continues. The maximum recommended dose is 0.9 U/min.
•Intranasal (Using Injection Solution)
Diabetes insipidus.
Individualize the dose using the injection solution on cotton pledgets, by nasal spray, or by dropper. |
|
|
Discuss prescriptions and health topics in the new 