Theoretically, if the side effects could be properly balanced, the sleepiness sometimes caused by antihistamines could be cancelled by the stimulation of decongestants . Numerous combinations of antihistamines with decongestants are available; for example:

• Actifed®
• Allegra-D®
• Chlor-Trimeton D®
• Claritin D®
• Contac®
• Co-Pyronil 2®
• Deconamine®
• Demazin®
• Dimetapp®
• Drixoral®
• Isoclor®
• Nolamine®
• Novafed A®
• Ornade®
• Sudafed Plus®
• Tavist D®
• Triaminic®
• Trinalin®

A patient may find one product quite helpful for several months or years, but may need to switch to another one when the first loses its effectiveness. Since no one reacts exactly the same as another to the side effects of these drugs, patients may wish to try their own ideas on adjusting the dosages. You might take the antihistamine only at night and take the decongestant alone in the daytime, or take them together, increasing the dosage of antihistamine at night (while decreasing the decongestant dose) and then doing the opposite for daytime use. For example, take Chlor-Trimeton,®* 4mg, one tablet three times daily and two tablets at bedtime.