Final answer:
Pseudoephedrine and phenylephrine are decongestants with different mechanisms of action. Pseudoephedrine works as a non-selective adrenergic agonist, while phenylephrine is an α₁-adrenergic agonist. Both have potential side effects including increased blood pressure and nervousness.
Step-by-step explanation:
Pseudoephedrine and phenylephrine are common sympathomimetic drugs used for their decongestant properties. Pseudoephedrine acts as a nasal/sinus decongestant and is also used to promote wakefulness. It exerts its effects primarily by acting as a non-selective alpha and beta adrenergic agonist, thereby reducing the swelling of nasal mucosa. Its clinical uses include providing relief from congestion due to colds, allergies, and sinus infections, and it is found in many over-the-counter medications in combination with other drugs like antihistamines and expectorants. Potential toxicities can involve nervousness, dizziness, and increased blood pressure.
Phenylephrine, an α₁-adrenergic agonist, is used to relieve nasal congestion and also for dilating the pupil during eye exams. However, it is less effective orally due to partial breakdown in the digestive tract before absorption. Its uses extend to increasing blood pressure during anesthesia or septic shock. Potential toxicities include headache, reflex bradycardia, and rarely, hypertension.