VASOPRESSIN IN SODIUM CHLORIDE 0.9%
Clinical safety rating: safe
Other drugs that can cause water intoxication may have additive effects Can cause hyponatremia and tissue necrosis with extravasation.
Vasopressin is an antidiuretic hormone that acts on V1 and V2 receptors. V1 receptor activation causes vasoconstriction via phospholipase C and IP3/DAG signaling in vascular smooth muscle. V2 receptor activation in renal collecting ducts increases water permeability via aquaporin-2 insertion, leading to antidiuresis.
| Metabolism | Primarily hepatic and renal metabolism via peptidases; small amount excreted unchanged in urine. |
| Excretion | Primarily renal (approximately 65% of administered dose excreted unchanged in urine); minor biliary/fecal elimination (~5%) |
| Half-life | 10–20 minutes (terminal half-life); clinical context: continuous IV infusion required to maintain steady-state concentrations |
| Protein binding | ~30% bound to plasma proteins (no specific binding proteins identified; binds to V1a and V2 receptors, not carrier proteins) |
| Volume of Distribution | 0.05–0.2 L/kg (confined primarily to extracellular fluid, consistent with water-soluble peptide) |
| Bioavailability | IV: 100% (only route of administration for vasopressin in clinical use; oral and intranasal not applicable) |
| Onset of Action | IV: 5–15 minutes for vasopressor effect |
| Duration of Action | 30–60 minutes (dose-dependent, shorter at higher doses); clinical notes: sustained effect requires continuous infusion |
| Molecular Weight | 1084.23 |
IV infusion: 0.01–0.04 units/min, titrated to effect; typical septic shock dose: 0.03 units/min. Administered as continuous IV infusion via central line.
| Dosage form | SOLUTION |
| Renal impairment | eGFR < 30 mL/min/1.73 m²: Use with caution; no specific dose adjustment defined. Monitor fluid and electrolyte balance closely. |
| Liver impairment | Child-Pugh Class A/B/C: No specific dose adjustment; however, hepatic insufficiency may impair vasopressin metabolism; monitor for prolonged effect and avoid in severe hepatic dysfunction. |
| Pediatric use | IV infusion: 0.0003–0.002 units/kg/min (0.0003–0.002 U/kg/min); titrate to effect. Maximum dose: 0.002 units/kg/min. Administer via central line. |
| Geriatric use | Initiate at lower end of dosing range (0.01 units/min); titrate cautiously due to increased risk of hyponatremia, fluid overload, and coronary or mesenteric ischemia. Monitor hemodynamics and electrolytes frequently. |
| 1st trimester | Vasopressin is generally avoided in the first trimester unless clearly needed. Animal studies have shown fetal harm at high doses, but human data are limited. Use only if potential benefit justifies potential risk. |
| 2nd trimester | Same as first trimester. No adequate human studies; animal studies indicate risk. Use with caution only when clearly indicated. |
| 3rd trimester | Vasopressin may cause uterine contractions and reduced placental blood flow. Avoid near term unless necessary for life-threatening conditions. Fetal bradycardia and hypoxia have been reported. |
Clinical note
Other drugs that can cause water intoxication may have additive effects Can cause hyponatremia and tissue necrosis with extravasation.
| FDA category | Animal |
| Placental transfer | Vasopressin crosses the placenta in limited amounts. Studies in pregnant sheep show low placental transfer (less than 1-2% of maternal dose). Human data are minimal. |
■ FDA Black Box Warning
None.
| Common Effects | vasodilatory shock |
| Serious Effects |
Hypersensitivity to vasopressin or any component of the formulation
| Precautions | Use caution in patients with cardiovascular disease (risk of myocardial ischemia, arrhythmias)., Monitor fluid/electrolyte balance and urine output., Risk of severe hyponatremia and seizures., Extravasation risk—administer via central line for concentrated solutions., Use caution in elderly and patients with seizure disorders or migraine. |
| Food/Dietary | No known food interactions. However, monitor sodium intake due to 0.9% sodium chloride content. Avoid excessive salt use. |
Loading safety data…
| Breastfeeding | Vasopressin is not orally bioavailable and is rapidly degraded in the gastrointestinal tract, so exposure to the infant via breast milk is unlikely. However, due to limited data, use with caution in breastfeeding women, especially if high doses are required. |
| Lactation Rating | L3 (Moderately Safe) |
| Teratogenic Risk | First trimester: Limited data, but vasopressin is a natural hormone and exogenous administration at high doses may cause uterine contractions and placental hypoperfusion. Second trimester: Risk of decreased placental blood flow and fetal hypoxia. Third trimester: Potential for uterine hypertonicity, fetal distress, and preterm labor. Overall, FDA Pregnancy Category C: Animal studies show adverse effects; no adequate human studies; use only if benefit outweighs risk. |
| Fetal Monitoring | Maternal: Continuous heart rate, blood pressure, fluid balance, and uterine activity monitoring. Fetal: Continuous fetal heart rate monitoring for signs of distress. Assess for hyponatremia, fluid overload, and signs of ischemia (e.g., chest pain, abdominal pain). |
| Fertility Effects | No specific studies; vasopressin is involved in fluid homeostasis. High doses may disrupt normal hormonal balance, but no evidence of direct impairment of fertility in humans. |
| Clinical Pearls | Vasopressin in 0.9% sodium chloride is used intravenously for vasodilatory shock (e.g., septic shock). Administer via central line due to risk of extravasation causing ischemia. Monitor urine output, serum sodium, and fluid balance. Dose titration: 0.01-0.04 U/min, not to exceed 0.1 U/min. Coadministration with norepinephrine may be required. Contraindicated in coronary artery disease and mesenteric ischemia. Extravasation treatment: phentolamine infiltration. |
| Patient Advice | Report any chest pain, shortness of breath, or severe headache immediately. · Notify nurse if you experience burning or pain at IV site. · This medication is used to maintain blood pressure; do not stop suddenly. · Avoid salty foods unless directed; monitor fluid intake. · Possible side effects: pale skin, nausea, stomach cramps. |