PITRESSIN TANNATE
Clinical safety rating: caution
Comprehensive clinical and safety monograph for PITRESSIN TANNATE (PITRESSIN TANNATE).
Pitressin Tannate is a synthetic form of vasopressin (antidiuretic hormone) that acts on V2 receptors in the renal collecting ducts to increase water reabsorption, and on V1 receptors to cause vasoconstriction.
| Metabolism | Metabolized primarily by the liver and kidneys via peptidases, with a half-life of about 10-20 minutes for vasopressin itself; the tannate formulation prolongs absorption. |
| Excretion | Primarily renal: >95% of administered dose excreted unchanged in urine within 24 hours. Biliary/fecal elimination negligible (<5%). |
| Half-life | Terminal elimination half-life approximately 15 minutes (range 10–20 minutes). Clinically, due to rapid clearance, effects are short-lived; continuous infusion or depot formulations are required for sustained effect. |
| Protein binding | Negligible (<1%); mainly bound to plasma proteins primarily vasopressin-binding proteins and albumin, but binding is not clinically significant. |
| Volume of Distribution | Approximately 0.1 L/kg (range 0.08–0.12 L/kg). This low Vd indicates minimal tissue distribution, consistent with its predominant plasma volume confinement and renal clearance. |
| Bioavailability | Intramuscular oil suspension: nearly 100% but with slow release. Subcutaneous: approximately 10–15% due to hydrolysis at injection site. Oral: negligible (<1%) due to enzymatic degradation. |
| Onset of Action | Intramuscular injection of oil suspension: onset within 30 minutes to 1 hour. Subcutaneous injection: onset within 15–30 minutes. |
| Duration of Action | Intramuscular oil suspension: 48–96 hours. Subcutaneous: 2–6 hours. Clinical note: The oil suspension provides prolonged release; duration depends on dose and disease state (e.g., diabetes insipidus). |
0.5-1 mL (5-10 units) intramuscularly or subcutaneously every 24-48 hours as needed for diabetes insipidus.
| Dosage form | INJECTABLE |
| Renal impairment | Not significantly renally excreted; no specific dose adjustment recommended based on GFR. |
| Liver impairment | No specific guidelines; use with caution in hepatic impairment due to potential fluid imbalance. |
| Pediatric use | 0.1-0.3 mL (1-3 units) intramuscularly or subcutaneously, with dose adjusted based on response; monitor urine output and serum sodium. |
| Geriatric use | Start at lower end of dosing range (0.5 mL initially) due to increased risk of electrolyte disturbances and comorbid conditions; monitor serum sodium and fluid status closely. |
| 1st trimester | Consult provider |
| 2nd trimester | Consult provider |
| 3rd trimester | Consult provider |
Clinical note
Comprehensive clinical and safety monograph for PITRESSIN TANNATE (PITRESSIN TANNATE).
| Breastfeeding | It is unknown whether vasopressin is excreted in human breast milk. Due to its high molecular weight (tannate salt) and poor oral bioavailability, significant absorption by a nursing infant is unlikely. However, caution is advised. No M/P ratio is available. |
| Teratogenic Risk | PITRESSIN TANNATE (vasopressin tannate) is classified as FDA Pregnancy Category C. In animal studies, vasopressin has been associated with decreased fetal weight and delayed ossification at high doses. There are no adequate and well-controlled studies in pregnant women. The drug should be used during pregnancy only if the potential benefit justifies the potential risk to the fetus. Vasopressin may cause uterine contractions and decrease placental perfusion, potentially leading to fetal hypoxia or distress, particularly in the third trimester. |
■ FDA Black Box Warning
None.
| Serious Effects |
Hypersensitivity to vasopressin or components; anuria; chronic nephritis with nitrogen retention; cardiovascular disease (ischemic heart disease, advanced atherosclerosis, coronary thrombosis).
| Precautions | Hyponatremia and water intoxication; cardiac effects including arrhythmias and ischemia; mesenteric ischemia; hypersensitivity reactions; use with caution in patients with coronary artery disease, hypertension, or renal impairment. |
Loading safety data…
| Fetal Monitoring | Monitor maternal blood pressure, heart rate, and urine output. Assess for signs of water intoxication (hyponatremia, headache, confusion, seizures). For the fetus, monitor fetal heart rate and uterine activity if administered near term due to potential oxytocin-like effects. In high-risk pregnancies, consider ultrasound for fetal growth and amniotic fluid index. |
| Fertility Effects | Data on fertility effects in humans are lacking. In animal studies, high doses of vasopressin have been associated with altered estrous cycles and reduced fertility. Clinical relevance is uncertain. |