From what I have read dry mouth can be quite common among those taking anti-depressants, even though I don't suffer from it taking Lexapro (now). From your other posts I infer that you may live in the KSA and are concerned about the fast during Ramadan (and perhaps at other times) and that your dry mouth is persistent throughout the day and evening hours, such that changing when you take the medication may not be useful. Making up for the fast wouldn't seem to be an option, and I don't know if alms are an answer for you in substitution, being no expert on either your situation or on the strictures that govern such exceptions. I don't know if chewing gum would be permissible, but I am thinking, no. Have you discussed if lowering the dosage would be a possibility, perhaps combined with another drug such as Abilify to increase effectiveness of the Lexapro? Of course, that might not help, either. In the end, all I can say is that I am sympathetic to your situation and hope you may find a solution that is both medically and religiously suitable.