<unk>  is active after oral administration and has a minimal effect on cardiac function due to its α1-adrenergic receptor selectivity. When<unk>  is started, however, heart rate and contractility can increase in order to maintain the pre-treatment blood pressures because the body has reached homeostasis at its abnormally high blood pressure. The blood pressure lowering effect becomes apparent when<unk>  is taken for longer periods of time. The heart rate and contractility go back down over time and blood pressure decreases. The antihypertensive characteristics of<unk>  make it a second-line choice for the treatment of high blood pressure.<unk>  is also useful in treating urinary hesitancy associated with benign prostatic hyperplasia, blocking α1-adrenergic receptors, which control constriction of both the prostate and urethra. Although not a first-line choice for either hypertension or benign prostatic hyperplasia, it is a choice for people who present with both problems concomitantly. During its use for urinary hesitancy in military veterans in the 1990s, Murray A. Raskind and colleagues discovered that<unk>  appeared to be effective in reducing nightmares. Subsequent reviews indicate<unk>  is effective in improving sleep quality and treating nightmares related to post-traumatic stress disorder (PTSD).<unk>  is used off-label in the treatment of insomnia and can produce sedative effects. It has been said to be the only selective α1-adrenergic receptor antagonist which has been used in the treatment of insomnia to any significant degree. It is used at doses of 1 to 12 mg for this purpose. The combination of<unk>  and the beta blocker timolol may produce greater sedative effects than either of them alone. The drug is usually recommended for severe stings from the Indian red scorpion.
Prazosin
Phenylephrine
Acebutolol
Terazosin
Doxazosin
Tamsulosin
Silodosin
Hydrastine