Which of the following drug is commonly responsible for ohostatic hypotension: March 2010

Ans. D: Prazosin Side effects of prazosin include ohostatic hypotension, syncope, and nasal congestion. The ohostatic hypotension and syncope are associated with the body's poor ability to control blood pressure without active alpha-adrenergic receptors. Patients on prazosin should be told not to stand up too quickly, since their poor baroreflex may cause them to faint as all their blood rushes to their feet. The nasal congestion is due to dilation of vessels in the nasal mucosa. One phenomenon associated with prazosin is known as the "first dose response", in which the side effects of the drug, especially ohostatic hypotension and fainting, are especially pronounced after the first dose. Another common side effect of prazosin (and doxazosin) is priapism.