What effect does pseudoephedrine typically have on blood pressure?

Pseudoephedrine is a sympathomimetic drug primarily used as a decongestant. It works by stimulating alpha-adrenergic receptors, leading to vasoconstriction in blood vessels. This vasoconstriction results in an increase in systemic vascular resistance, which subsequently raises blood pressure. Therefore, the effect of pseudoephedrine is to increase blood pressure, particularly in individuals with pre-existing hypertension or in those who may be more sensitive to adrenergic stimulation.

In contrast, other options do not accurately represent the pharmacological effects of pseudoephedrine. It does not typically cause a decrease in blood pressure, nor is there an expected random fluctuation in blood pressure levels associated with its use. Additionally, stating that it has no effect on blood pressure overlooks the known adrenergic activity that leads to increased vascular tone and pressure.