Ethanol has been detected in outer space, forming an icy coating around dust grains in interstellar clouds. Minute quantity amounts (average 196 ppb) of endogenous ethanol and acetaldehyde were found in the exhaled breath of healthy volunteers. Auto-brewery syndrome, also known as gut fermentation syndrome, is a rare medical condition in which intoxicating quantities of ethanol are produced through endogenous fermentation within the digestive system. Production
Ethanol is produced both as a petrochemical, through the hydration of ethylene and, via biological processes, by fermenting sugars with yeast. Which process is more economical depends on prevailing prices of petroleum and grain feed stocks. In the 1970s most industrial ethanol in the United States was made as a petrochemical, but in the 1980s the United States introduced subsidies for corn-based ethanol and today it is almost all made from that source. In India ethanol is made from sugarcane. Ethylene hydration
Ethanol for use as an industrial feedstock or solvent (sometimes referred to as synthetic ethanol) is made from petrochemical feed stocks, primarily by the acid-catalyzed hydration of ethylene:

C2H4 + H2O → CH3CH2OHThe catalyst is most commonly phosphoric acid, adsorbed onto a porous support such as silica gel or diatomaceous earth. This catalyst was first used for large-scale ethanol production by the Shell Oil Company in 1947. The reaction is carried out in the presence of high pressure steam at 300 °C (572 °F) where a 5:3 ethylene to steam ratio is maintained.
One phenomenon associated with prazosin is known as the "first dose response", in which the side effects of the drug –  specifically orthostatic hypotension, dizziness, and drowsiness –  are especially pronounced in the first dose.Orthostatic hypotension and syncope are associated with the bodys poor ability to control blood pressure without active α-adrenergic receptors. People on prazosin should be told to rise to stand up slowly, since their poor baroreflex may cause them to faint if their blood pressure is not adequately maintained during standing. The nasal congestion is due to dilation of vessels in the nasal mucosa. Pharmacology
Pharmacodynamics
Prazosin is an α1-blocker that acts as a non-selective inverse agonist at α1-adrenergic receptors, including of the α1A-, α1B-, and α1D-adrenergic receptor subtypes. It binds to these receptors with affinity (Ki) values of 0.13 to 1.0 nM for the α1Α-adrenergic receptor, 0.06 to 0.62 nM for the α1B-adrenergic receptor, and 0.06 to 0.38 nM for the α1D-adrenergic receptor. It has much lower affinity for the α2-adrenergic receptors (Ki = 210–5,012 nM for the α2A-adrenergic receptor, 13–398 nM for the α2B-adrenergic receptor, and 10–200 nM for the α2C-adrenergic receptor). The α1-adrenergic receptors are found in vascular smooth muscle, where they are responsible for the vasoconstrictive action of norepinephrine. They are also found throughout the central nervous system. α1-Adrenergic receptors have additionally been found on immune cells, where catecholamine binding can stimulate and enhance cytokine production.