vasopressin

Contraindicated in:

Hypersensitivity to 8-L arginine vasopressin or chlorobutanol (only in multidose vial);
Chronic renal failure.

Use Cautiously in:

Perioperative polyuria (↑ sensitivity to vasopressin effects);
Comatose patients;
Seizures;
Migraine headaches;
Asthma;
HF;
Cardiovascular disease;
Renal impairment;
OB: Higher doses (0.07 units/min) for vasodilatory shock may be needed in 2nd and 3rd trimesters;
Lactation: Safety not established in breastfeeding;
Geri: Older adults may have ↑ sensitivity to effects.

Adv. Reactions/Side Effects ⬆ ⬇

CV: angina, chest pain, MI

Derm: ↑sweating, paleness, perioral blanching

Endo: diabetes insipidus

F and E: F and E, water intoxication (higher doses)

GI: abdominal cramps, belching, diarrhea, flatulence, heartburn, nausea, vomiting

Neuro: “pounding” sensation in head, dizziness, trembling

Misc: allergic reactions, fever

Interactions ⬆ ⬇

Drug-drug:

Antidiuretic effect may be ↓ by concurrent administration of clozapine, lithium, demeclocycline, and foscarnet.
Antidiuretic effect may be ↑ by concurrent administration of cyclophosphamide, enalapril, felbamate, haloperidol, ifosfamide, pentamidine, tricyclic antidepressants, SSRIs, or vincristine.
Vasopressor effect may be ↑ by concurrent administration of ganglionic blocking agents, indomethacin, or catecholamines.
Furosemide↑ urine flow.

Availability ⬆ ⬇

(Generic available)

Premixed infusion: 20 units/100 mL D5W or 0.9% NaCl; 40 units/100 mL D5W or 0.9% NaCl
Solution for injection: 20 units/mL

Route/Dosage ⬆ ⬇

Diabetes Insipidus

IM SUBQ (Adults ): 5–10 units 2–4 times daily.
IM SUBQ (Children ): 2.5–10 units 2–4 times daily.
IV (Adults and Children ): 0.0005 units/kg/hr; double dose every 30 min as needed to a maximum of 0.01 units/kg/hr.

Vasodilatory Shock

IV (Adults ): 0.01 units/min; titrate by 0.005 units/min every 10–15 min until target BP achieved (max dose = 0.07 units/min).
IV (Infants and Children): 0.0003–0.002 units/kg/min, titrate to effect.

GI Hemorrhage

IV (Adults ): 0.2–0.4 units/min; then titrate to maximum dose of 0.9 units/min; if bleeding stops, continue same dose for 12 hr; then taper off over 24–48 hr.
IV (Children ): 0.002–0.005 units/kg/min then titrate to maximum dose of 0.01 units/kg/min; if bleeding stops, continue same dose for 12 hr; then taper off over 24–48 hr.

US Brand Names ⬆ ⬇

~~Pitressin,~~ Vasostrict

Action ⬆ ⬇

Alters the permeability of the renal collecting ducts, allowing reabsorption of water.
Directly stimulates musculature of GI tract.
In high doses, acts as a nonadrenergic peripheral vasoconstrictor.

Therapeutic effects:

Decreased urine output and increased urine osmolality in diabetes insipidus.
Increased BP.

Classifications ⬆ ⬇

Therapeutic Classification: hormones

Pharmacologic Classification: antidiuretic hormones, vasopressors

Pharmacokinetics ⬆ ⬇

Absorption: IM absorption may be unpredictable. IV administration results in complete bioavailability.

Distribution: Well distributed to tissues.

Metabolism/Excretion: Rapidly degraded by the liver and kidneys; <5% excreted unchanged by the kidneys.

Half-Life: <10 min.

Time/Action Profile ⬆ ⬇

( antidiuretic effect)

ROUTE		ONSET		PEAK		DURATION
IM, SUBQ		unknown		unknown		2–8 hr
IV		unknown		unknown		30–60 min

Patient/Family Teaching ⬆ ⬇

Explain purpose of vasopressin to patient.
Advise patient of rationale for drinking water at time of administration to minimize side effects. Inform patient that these side effects are not serious and usually disappear quickly.
Caution patient to avoid concurrent use of alcohol while taking vasopressin.
Rep: Advise women of reproductive potential to notify health care provider if pregnancy is planned or suspected or if breastfeeding. Due to ↑ clearance of vasopressin in the 2nd and 3rd trimester, the dose of vasopressin may need to be ↑. May produce tonic uterine contractions that could threaten the continuation of pregnancy.
Patients with diabetes insipidus should carry identification at all times describing disease process and medication regimen.

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Indications ⬇

Contraind./Precautions ⬆ ⬇