<prompt> Unorable interaction of drug and substrate in human beings are all except:Omeprazole reduces stomach acidMethotrexate inhibiting folateBarbiturates decreases B 12 absorptionRetinoic acid inhibits vitamin E  <response>: Ans. a. Omeprazole reduces stomach acid Omeprazole reduces stomach acid secretion: This interaction is beneficial for patients suffering from GERD without having any associated complications. Rest three interactions has a bad impact on the normal healthy individuals. Methotrexate inhibiting folate Barbiturates decreases 13,2 absorption Retinoic acid inhibits vitamin E 