vasoconstrictor

A vasoconstrictor is a drug that causes blood vessels to narrow, a process called vasoconstriction. This narrowing increases blood pressure and is a natural bodily response to cold to retain heat, or to heat to release it.1

Vasoconstrictors are prescribed to treat low blood pressure. They are also found in common over-the-counter medications for runny noses and bloodshot eyes. Examples of vasoconstrictors include antihistamines, amphetamines, nicotine, and caffeine.1

The opposite of vasoconstrictors are vasodilators, which cause blood vessels to widen and are used to treat high blood pressure. Adrenergic drugs can mimic or interfere with the sympathetic nervous system, affecting hormones like norepinephrine and epinephrine, which play a role in vasoconstriction.12