vasopressin (Vasostrict, ADH)

Dosing and uses of Vasostrict, ADH (vasopressin)

• Adult
• Pediatric

 

Adult dosage forms and strengths

injection solution

• 20 units/mL

 

Abdominal Distention

5 units IM initially; repeated q3-4hr PRN; may be increased to 10 units

 

Diabetes Insipidus

5-10 units IM/SC q8-12hr

Titrate dose on basis of serum sodium, serum osmolality, fluid balance, and urine output

 

Abdominal Roentgenography

10 units (0.5mL) IM/SC 2 hours before procedure, then 10 units IM 30 minutes before procedure

May give enema priotr to first dose of vasopressin

 

Dosage modifications

Hepatic impairment: Lower doses may be required to achieve response

 

Gastrointestinal Hemorrhage (Off-label)

0.2-0.4 unit/min IV initially; may be increased to 0.8 unit/min IV PRn

 

Vasodilatory Shock (Off-label)

0.01-0.04 unit/min IV

 

Pediatric dosage forms and strengths

injection solution

• 20 units/mL

 

Abdominal Distention

Proportionately reduced adult dosage

 

Diabetes Insipidus

2.5-10 units IM/SC/intranasally q8-12hr

Continuous IV infusion: 0.0005 unit/kg/hr initially, then double dose q30min to reach desired effect; not to exceed 0.01 unit/kg/hr

Titrate dose on basis of serum sodium, serum osmolality, fluid balance, and urine output

 

Gastrointestinal Hemorrhage (Off-label)

0.3 units/kg IV; not to exceed 20 units

0.002-0.005 unit/kg/min IV initially; may be increased to 0.01 unit/kg/min IV PRn

If bleeding controlled for 12-24 hr, taper off over 24-36 hr

 

Vasostrict, ADH (vasopressin) adverse (side) effects

Frequency not defined

Abdominal cramps

Allergic reaction

Angina

Bronchial constriction

Circumoral pallor

Diarrhea

Nausea

Pounding in the head

Sweating

Tremor

Uterine contraction

Vertigo

 

Warnings

Contraindications

Hypersensitivity

 

Cautions

With gastrointestinal (GI) bleeding, infusion should be continued for 12-24 hours after bleeding has stopped, and dosage should then be tapered over 24-48 hours

Continuous infusion should be administered via controlled infusion device

Use caution in chronic nephritis with nitrogen retention

Pre- and postoperative patients with polyuria

Use caution in patients with seizure, migraine, asthma, heart failure, vascular disease, angina pectoris, coronary thrombosis, renal disease

Use in pregnant women only when clearly needed

 

Pregnancy and lactation

Pregnancy category: C

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

 

Pregnancy categories

A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.

B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk.

C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done.

D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk.

X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist.

NA: Information not available.

 

Pharmacology of Vasostrict, ADH (vasopressin)

Mechanism of action

Vasoconstrictor without inotropic or chronotopic effects; stimulates smooth muscle in GI tract to cause peristalsis

 

Absorption

Bioavailability: Destroyed by trypsin in GI tract; must be administered parenterally or intranasally

Onset (antidiuretic activity): IM/SC, 2-8 hr

Onset (pressor activity) IV, 30-60 min

 

Metabolism

Metabolized in liver and kidney; rapidly removed from plasma

 

Elimination

Half-life: 10-20 min (parenteral)

Excretion: Urine (5-10%)

 

Administration

IV Compatibilities

Additive: VerapamiL

Y-site: Amiodarone, diltiazem, dobutamine, dopamine, epinephrine, heparin, lidocaine, milrinone, nitroglycerin, norepinephrine, phenylephrine, procainamide

 

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

 

Storage

Clear, colorless, or nearly colorless solution

Unopened vials

• Refrigerate at 2-8°C (36-46°F); do not freeze, OR
• Controlled room temperature 20-25°C (68-77°F) for 12 months or manufacturer expiration date (whichever is earlier); do not store above 25°C (77°F)

Opened vials (after first puncture)

• Once opened, may store for 48 hr
• Do not store above 25°C (77°F)