Pseudoephedrine acts indirectly on the adrenergic receptor system, whereas phenylephrine and oxymetazoline are direct agonists. The effects are not limited to the nose, and these medicines may cause hypertension (high blood pressure) through vasoconstriction; it is for this reason that people with hypertension are advised to avoid them. Most decongestants, however, are not pronounced stimulants, due to lack of response from the other adrenoreceptors.