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Diazepam, first marketed as Valium, is a medicine of the benzodiazepine family that typically produces a calming effect. It is commonly used to treat a range of conditions including anxiety, alcohol withdrawal syndrome, benzodiazepine withdrawal syndrome, muscle spasms, seizures, trouble sleeping, and restless legs syndrome. It may also be used to cause memory loss during certain medical procedures. It can be taken by mouth, inserted into the rectum, injected into a muscle, or injected into a vein. When given into a vein, effects begin in one to five minutes and last up to an hour. By mouth, effects may take 40 minutes to begin.
Diazepam was the second benzodiazepine invented by Leo Sternbach of Hoffmann-La Roche at the company’s Nutley, New Jersey, facility following chlordiazepoxide (Librium), which was approved for use in 1960. Released in 1963 as an improved version of Librium, diazepam became incredibly popular, helping Roche to become a pharmaceutical industry giant. It is 2.5 times more potent than its predecessor, which it quickly surpassed in terms of sales. After this initial success, other pharmaceutical companies began to introduce other benzodiazepine derivatives.
Alprazolam, available under the trade name Xanax, is a potent, short-acting benzodiazepine anxiolytic—a minor tranquilizer. It is commonly used for the treatment of anxiety disorders, especially of panic disorder, but also in the treatment of generalized anxiety disorder (GAD) or social anxiety disorder. In 2010 it was the 12th most prescribed medicine in the United States. Alprazolam, like other benzodiazepines, binds to specific sites on the GABAA receptor. It possesses anxiolytic, sedative, hypnotic, skeletal muscle relaxant, anticonvulsant, amnestic, and antidepressant properties. Alprazolam is available for oral administration as compressed tablets (CT), orally disintegrating tablet (ODT) and extended-release tablets (XR).
Greatest alleviation of generalized anxiety disorder (GAD) may take up to a week. It has been suggested that there is tolerance to the anxiolytic and antipanic effects of the drug, but not all authorities agree; tolerance will, however, develop to the sedative and hypnotic effects within a couple of days. Withdrawal symptoms or rebound symptoms may occur after ceasing treatment abruptly following a few weeks or longer of steady dosing and may necessitate a gradual dose reduction. Other risks include increased rates of suicide, possibly due to disinhibition.
Sildenafil, sold as the brand name Viagra among others, is a medication used to treat erectile dysfunction and pulmonary arterial hypertension. Its effectiveness for treating sexual dysfunction in women has not been demonstrated.
Common side effects include headaches and heartburn, as well as flushed skin. Caution is advised in those who have cardiovascular disease. Rare but serious side effects include prolonged erections, which can lead to damage to the penis, and sudden-onset hearing loss. Sildenafil should not be taken by people who take nitrates such as nitroglycerin (glycerin trinitrate), as this may result in a severe and potentially fatal drop in blood pressure.
Sildenafil acts by inhibiting cGMP-specific phosphodiesterase type 5 (phosphodiesterase 5, PDE5), an enzyme that promotes degradation of cGMP, which regulates blood flow in the penis.
Pfizer scientists Andrew Bell, David Brown, and Nicholas Terrett originally discovered sildenafil as a treatment for various cardiovascular disorders. Since becoming available in 1998, sildenafil has been a common treatment for erectile dysfunction; its primary competitors are tadalafil (trade name Cialis) and vardenafil (Levitra).