Decongestant<unk>  is used as a decongestant sold as an oral medicine or as a nasal spray. It is a common ingredient in over-the-counter decongestants in the United States.<unk>  is used as an alternative for pseudoephedrine in decongestant medicines due to pseudoephedrine's use in the illicit manufacture of methamphetamine. Its efficacy as an oral decongestant has been questioned, with several independent studies finding that it provided no more relief to sinus congestion than a placebo. A 2007 meta-analysis concluded that the evidence for its effectiveness is insufficient, though another meta-analysis published shortly thereafter by researchers from GlaxoSmithKline found the standard 10-mg dose to be more effective than a placebo; however, the fact that GSK markets many products containing<unk>  has raised some speculation regarding selective publishing and other controversial techniques. A 2007 study by Wyeth Consumer Healthcare notes that 7 studies available in 1976 support the efficacy of<unk>  at a 10 mg dosage. Two studies published in 2009 examined the effects of<unk>  on symptoms of allergic rhinitis by exposing<unk> ople to pollen in a controlled, indoor environment. Neither study was able to distinguish between the effects of<unk>  or a placebo. Pseudoephedrine and loratadine–montelukast therapy were found to be significantly more effective than both<unk>  and placebo. The Food and Drug Administration withdrew the indication "for the temporary relief of nasal congestion associated with sinusitis" in 2007. Pseudoephedrine was previously much more commonly available in the United States, however, provisions of the Combat Methamphetamine Epidemic Act of 2005 placed restrictions on the sale of pseudoephedrine products to prevent the clandestine manufacture of methamphetamine. Since 2004,<unk>  has been increasingly marketed as a substitute for pseudoephedrine; some manufacturers have changed the active ingredients of products to avoid the restrictions on sales.<unk>  has been off patent for some time, and many generic brands are available. Hemorrhoids Hemorrhoids are caused by swollen veins in the rectal area.<unk>  can be used topically to prevent symptoms of hemorrhoids.<unk>  causes the constriction of vascular smooth muscle and is often used in the treatment of hemorrhoids presumably to narrow the swollen veins and relieve the attendant pain. However, veins—unlike arteries—contain less vascular smooth muscle in their walls so the mechanism by which pain relief is achieved is likely related to something other than vascular change alone. Products for treatment may also include substances that will form a protective barrier over the inflamed area, resulting in less pain when feces are passed. Pupil dilation<unk>  is used as an eye drop to dilate the pupil to facilitate visualization of the retina. It is often used in combination with tropicamide as a synergist when tropicamide alone is not sufficient. Narrow-angle glaucoma is a contraindication to<unk>  use. As a mydriatic, it is available in 2.5% and 10% minims.<unk>  eye drops are applied to the eye after a topical anesthetic is applied. Intraocular bleeding<unk>  has been used as an intracameral injection into the anterior chamber of the eye to arrest intraocular bleeding occurring during cataract and glaucoma surgery. Vasopressor<unk>  is commonly used as a vasopressor to increase the blood pressure in unstable patients with hypotension, especially resulting from septic shock. Such use is common in anesthesia or critical-care practices; it is especially useful in counteracting the hypotensive effect of epidural and subarachnoid anesthetics, as well as the vasodilating effect of bacterial toxins and the inflammatory response in sepsis and systemic inflammatory response syndrome. The elimination half life of<unk>  is about 2.5 to 3.0 hours. The clinical effects of a single intravenous bolus dose of<unk>  are short lived and needs to be repeated every 10–15 minutes. Commonly the drug is given as a carefully titrated intravenous infusion with a syringe pump or volumetric pump. Because of its vasoconstrictive effect,<unk>  can cause severe necrosis if it infiltrates the surrounding tissues. Because of this, it should be given through a central line if at all possible. Damage may be prevented or mitigated by infiltrating the tissue with the alpha blocker<unk> entolamine by subcutaneous injection.<unk>  hydrochloride at 0.25% is used as a vasoconstrictor in some suppository formulations. Recently,<unk>  has been used to treat conditions of orthostatic intolerance such as postural orthostatic tachycardia syndrome - where by activation of venous alpha 1 adrenoreceptors increases venous return and stroke volume which improves symptoms. Priapism<unk>  is used to treat priapism. It is diluted with normal saline and injected directly into the corpora cavernosa. The mechanism of action is to cause constriction of the blood vessels entering into the<unk> nis, thus causing decreased blood flow and relieving the priapism. An injection is given every 3–5 minutes. If priapism is not resolved in 1 hour, another form of therapy is considered.
Phenylephrine
Prazosin
Terazosin
Acebutolol
Doxazosin
Oxymetazoline
Metergoline
Clonidine