terazosin, Hytrin (cont.)

Pharmacy Author:
Medical and Pharmacy Editor:

DRUG INTERACTIONS: PDE-5 inhibitors used primarily for erectile dysfunction (for example, vardenafil [Levitra, Staxyn], Adcirca, tadalafil [Cialis], sildenafil [Viagra, Revatio) add to the blood pressure lowering effects of terazosin and may result in orthostatic or postural hypotension. (See Side Effects.) Individuals who take terazosin should be on a stable dose before a PDE-5 inhibitor is started, and the PDE-5 inhibitor should be started at the lowest dose. If the patient is already taking a PDE-5 inhibitor terazosin should be started at the lowest dose.

PREGNANCY: There are no adequate studies of terazosin in pregnancy. It is not recommended during pregnancy unless the benefits justify the potential but unknown risks to the fetus

NURSING MOTHERS: It is not known whether terazosin is excreted in breast milk.

SIDE EFFECTS: Besides postural hypotension and dizziness, side effects include weakness, fatigue, headaches, swelling of the legs (edema), palpitations, nasal congestion, sleepiness, decreased libido, impotence, and blurred vision. By relaxing the smooth muscles and dilating the arteries, terazosin can cause a marked lowering of the blood pressure especially when the patient stands up (orthostatic or postural hypotension). Postural hypotension can cause the patient to faint upon standing. Postural hypotension and fainting usually are associated with the first dose or the first few days of treatment. Hypotension and fainting also can occur when doses of medication are increased abruptly or another blood pressure medication is added. In order to decrease the likelihood of excessive hypotension and fainting, terazosin is initiated low doses. Prostate cancer and prostatic hypertrophy both cause similar symptoms of obstruction to the flow of urine. Prostate cancer and prostatic hypertrophy can co-exist. Therefore, patients being treated for prostate hypertrophy should be evaluated to exclude the presence of prostate cancer.

Reference: FDA Prescribing Information


Last Editorial Review: 3/2/2012



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