Vasopressin (Pitressin ®)
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Standard Dilutions [Amount of drug] [Infusion volume] [Infusion rate]
| Acceptable concentration: (0.1 - 1.0 u/ ml)
[100 units] [100 to 500 ml]
[200 units] [250 ml]
Infusion rate: as directed
ICU - Vasodilatory shock/septic shock
Stability / Miscellaneous
| Stability: Trissels: No drug-solution combinations have been tested. 
Vasodilatory shock/septic shock: Vasopressin may be used in patients with refractory shock despite adequate fluid resuscitation and the use of high-dose conventional catecholamines such as norepinephrine and dopamine, however, further studies are needed to determine its exact place in therapy. Current evidence does not support the use of vasopressin as a replacement for norepinephrine or dopamine as a first-line agent. The recommended infusion rate for vasopressin in the treatment of shock in adults is 0.01– 0.03 units/min. This dosage range is reported to be effective in about 85% of patients with norepinephrine resistant hypotension. Doses greater than 0.04 units/min may lead to cardiac arrest.
Bleeding esophageal varices and other types of upper GI bleeds:
MOA: ADH and pressor activity. Portal blood pressure is significantly decreased. A decrease in porto-systemic collateral flow and an increase in the muscular tone of the lower esophagus reduces blood flow to esophageal varices. The smooth muscle of the GI tract is also effected by large doses and peristaltic activity of the bowel and smooth muscles of the uterus are stimulated.
DOSAGE AND ADMINISTRATION
Ten units of vasopressin (0.5mL) will usually elicit full physiologic response in adult patients: 5units will be adequate in many cases. Vasopressin should be given intramuscularly at three-or four-hour intervals as needed. The dosage should be proportionately reduced for children.(For an additional discussion of dosage, consult the sections below.)
When determining the dose of vasopressin for a given case, the following should be kept in mind.
It is particularly desirable to give a dose not much larger than is just sufficient to elicit the desired physiologic response. Excessive doses may cause undesirable side effects - blanching of the skin, abdominal cramps, nausea, which, though not serious, may be alarming to the patient. Spontaneous recovery from such side effects occurs in a few minutes. It has been found that one or two glasses of water given at the time vasopressin is administered reduce such symptoms.
Abdominal Distention: In the average postoperative adult patient, give 5 units (0.25 mL) initially, increase to 10 units (0.5mL) at subsequent injections if necessary. It is recommended that vasopressin be given intramuscularly and that injections be repeated at three-or four-hour intervals as required. Dosage to be reduced proportionately for children.
Vasopressin used in this manner will frequently prevent or relieve postoperative distension. These recommendations apply also to distention complicating pneumonia or other acute toxemias.
Abdominal Roentgenography: For the average case, two injections of 10 units each (0.5 mL) are suggested . These should be given two hours and one-half hour, respectively, before films are exposed. Many roentgenologists advise giving an enema prior to the first dose of vasopressin.
Diabetes Insipidus: Vasopressin may be given by injection or administered intranasally on cotton pledgets, by nasal spray, or by dropper. The dose by injection is 5 to 10 units (0.25 to 0.5mL) repeated two or three times daily as needed. When vasopressin is administered intranasally by spray or on pledgets, the dosage and interval between treatments must be determined for each patient.
Parenteral drug products should be inspected visually for particulate matter and discoloration prior to use, whenever solution and container permit.
For intramuscular or subcutaneous use:
10 units per 0.5 mL multiple dose vial Boxes of 25
Store at controlled room temperature 15°-30° C (59°-86° F).
Source: [package insert]