Vasopressin

• Antidiuretic hormone
• Vassopressor

• Reabsorbs water through collecting ducts of nephrons concentrating urine
• Vasoconstriction of smooth muscles in capillaries and small arterioles

• Asystole, ventricular fibrillation, pulseless ventricular fibrillation (alternative vasopressor to 1^st or 2^nd dose of epinephrine during cardiac arrest)
• Neurogenic (central) diabetes insipidus
• Dehydration Test for diabetes insipidus
• GI hemorrhage from gastric ulcer or esophageal varices
• Adjunct to norepinephrine in severe septic shock

• Duration:  30 – 60 minutes (IV)
• Half-Life: 10 – 20 minutes

• (life threatening) hypertension, angina/ MI, heart failure, dysrhythmias, bowel ischemia, TIA/CVA, anaphylaxis
• Tremor, circumoral and facial pallor, pounding in the head, water intoxication, sweating, angioneurotic edema
• Eructations (belching), flatus, nausea, vomiting, heartburn, abdominal cramps, uterine cramps
• Tissue necrosis if IV infiltration occurs!

• (life threatening) hypertension, angina/ MI, heart failure, dysrhythmias, bowel ischemia, TIA/CVA, anaphylaxis

• Not recommended after 2^nd dose of epinephrine has been given during cardiac arrest.
• Ischemic heart disease/coronary artery disease (same thing)
• Not indicated for nephrogenic diabetes insipidus.
• Nephritis with nitrogen retention
• Not safe during pregnancy or lactation (Category X).
• Cautious warnings with epilepsy, migraine, asthma, heart failure, angina pectoris, kidney disease (acute or chronic renal failure), older adults, children, lactation.

• 40 units IV bolus (may give intraosseous or via endotracheal tube) for one single dose

GI Bleed:

• (loading dose) 20 units slow IV bolus over 20 minutes
• (IV drip infusion) 0.2-0.4 units/min titrated up to maximum of 0.9 units/minute

Diabetes Insipidus:

• 5 – 10 units SQ or IM 3-4 times daily

Severe Septic Shock: (adjunct to norepinephrine infusion)

• (IV drip infusion) 0.03 units/minute

• Drug Interactions:  1) Alcohol, demeclocycline, epinephrine, heparin, lithium, and phenytoin may decrease ADH effects of vasopressin; 2) Guanethidine and neostigmine increase vasopressor effect of vasopressin; 3) Chlorpropamide, clofibrate, carbamazepine, and thiazide diuretics may increase the anti-diuretic effect of vasopressin.
• Drug Incompatibilities:  Do not mix with other drugs.
• Monitor vital signs, especially blood pressure, hourly during intravenous infusion.
• Monitor urine output and specific gravity.
• Assess patient closely for signs of chest discomfort or TIA.  Look for signs of life-threatening conditions!
• If anginal or ischemic episodes occur with intravenous infusion, a concurrent IV infusion of nitroglycerin may relieve these adverse effects.
• Watch patients for fluid volume alterations.  If vasopressin dose for DI is insufficient, the patient can become dehydrated.  If vasopressin dose for DI is too large, the patient can become overhydrated (fluid intoxication).  Children, especially infants, and elderly are more susceptible to fluid alterations.
• IV infusions should be administered through a central venous line if possible.
• Watch peripheral IV sites closely for early signs of infiltration.  Extravasation of vasopressin may cause tissue necrosis to skin.  Therefore, monitor IV site every hour.  Have phentolamine (Regitine^®) close to the bedside of the patient.
• An alternative for diabetes insipidus treatment is desmopressin (DDAVP) which may be given intra-nasally BID and has less vasopressor effect than vasopressin.