Vasoconstrictor drugs cause contraction of muscle cells in the walls of blood vessels, narrowing their internal diameter and raising blood pressure. This effect makes these medications useful for the treatment of low blood pressure, typically in an intensive care or surgical setting. Less potent vasoconstrictors are used as nasal decongestants.
Medicinal epinephrine is a man-made form of a naturally occurring substance of the same name. Epinephrine, also called adrenalin, is responsible for the "fight or flight" response that occurs when you are startled or frightened. When administered medicinally, epinephrine causes widespread vasoconstriction, which increases blood pressure. Other actions of epinephrine include increased heart rate and dilation (widening) of the airways.
Epinephrine is used in life-threatening medical situations. It raises critically low blood pressure due to trauma or overwhelming infection (septic shock). The Surviving Sepsis Campaign's "International Guidelines for Management of Severe Sepsis and Septic Shock, 2008" recommends epinephrine as a first alternative medication for the treatment of shock associated with overwhelming infection. It is most commonly used when there is insufficient response to norepinephrine. Epinephrine also reverses the airway constriction associated with severe allergic reactions and asthma attacks.
Norepinephrine is chemically similar to epinephrine and has similar effects on the body. It is a potent vasoconstrictor and raises blood pressure. It also increases the force of the muscular contractions of the heart. Norepinephrine is typically used in people who are critically ill with a profoundly low blood pressure, such as those who have had a massive heart attack or are suffering from septic shock. In a report on the use of norepinephrine for the treatment of septic shock published in the journal Chest, Dr. Claude Martin and his colleagues concluded norepinephrine is reliable and effective in this critical medical circumstance.
Medicinal vasopressin is a man-made form of the naturally occurring pituitary hormone of the same name. This hormone increases blood pressure by causing intense, widespread vasoconstriction. It also promotes water retention in the kidneys, which further contributes to re-establishing adequate blood pressure.
Low-dose phenylephrine is a common component of many over-the-counter cold, allergy and sinus medicines. Phenylephrine causes vasoconstriction in the nose and sinuses leading to reduced swelling of the tissues and decongestion. The efficacy and potency of high-dose, injectable phenylephrine as a vasocontricting agent is well-established. This form of phenylephrine is often used to combat low blood pressure during surgeries performed under spinal anesthesia.
The vasoconstrictor pseudoephedrine is included in several nonprescription and prescription products for the treatment of nasal congestion associated with colds, allergies and sinusitis. Federal law requires keeping nonprescription pseudoephedrine products behind the pharmacy counter. Legal identification is required to purchase these products, and records are kept to ensure limited quantities are available to any given individual.
- Update in Anaesthesia: Pharmacology of Vasopressors and Inotropes
- GlobalRPh.com: Vasopressors and Inotropes
- Institute for Healthcare Improvement: Apply Vasopressors for Ongoing Hypotension
- Elmhurst College, Virtual Chembook: Adrenergic Drugs II
- Chest: Norepinephrine or Dopamine for the Treatment of Hyperdynamic Septic Shock?