PARALDEHYDE  , in

medicine, a clear colourless liquid (for the chemistry see ALDEHYDES), soluble in 1 in ro of water and freely in alcohol . Paraldehyde is a powerful hypnotic, giving a refreshing quiet sleep which is not followed by unpleasant I after effects . As it does not depress the heart when used in medicinal doses, it may be given to patients suffering from cardiac disease . It is much used to produce sleep in the insane . As it is largely excreted by the lungs it may be found useful in bronchial asthma . When taken continuously the drug soon loses its power as a hypnotic . Its unpleasant taste usually prevents the formation of a paraldehyde habit, but it occasionally occurs with symptoms resembling delirium tremens . When taken in an overdose paraldehyde kills by producing respiratory failure .