Just came across this on the CNN website (http://www.cnn.com/HEALTH/9802/09/antihistamine.reut/) In particular, note the potential for trouble when using hismanal with prozac etc. (sorry about the weird spacing) Mary Rack [log in to unmask] "The new labeling provides information about a specific warning against simultaneously using Hismanal with other types of drugs such as the hypertension drug Posicor (mibefradil) and the antibiotics Biaxin (clarithromycin) and TAO (troleandomycin)." Other drugs Hismanal should not be taken with include HIV protease inhibitor drugs such as Crixivan (indinavir), Norvir (ritonavir) and Viracept (nelfinavir), anti-depressants in the SSRI class such as Prozac, known generically as fluoxetine, Zoloft or sertraline, and Paxil or paroxetine. It should also not be combined with Zyflo or zileuton, an asthma drug, or with grapefruit juice, which is known to make some drugs act more effectively in the body.