Ask A Scientist© Zoology Archive

name         TIM
status     other
age        30s

Question -         I KNOW WE HAVE ACID IN OUR STOMACH'S SO WHEN WE
TAKE A PILL LIKE PROZAC OR LUVOX THAT ARE MEANT TO GO TO THE BRAIN IS THE
BRAIN AFFECTIVE BY THE ACID ? THANK YOU.

The stomach is acidic. In particular HCl, with a pH between about 2-4. 
Depending upon its chemical composition, a particular medication may 
affect (or be affected by) the acidic environment of the stomach.
Pharmaceutical manufacturers study this in the course of the development 
of the drug. One of the following outcomes is possible:
1. No effect. The drug can be taken without regard to the contents of 
the stomach
2. The drug is activated by stomach acid, so the label may advise 
taking the medication on an empty                stomach, or advises 
against the use of antacids some number of before and after the drug is taken.
3. The drug is de-activated by stomach acid. In this case the label 
may instruction may advise taking with        milk.
4. The medication may be enterically coated. That means that the drug 
is encased in a coating that will            not dissolve at the low pH 
in the stomach, but does so in the small intestine, which is alkaline.

There are other possibilities, but I think you get the picture.

FYI: The acid is confined to the stomach unless one has what is called 
acid reflux in which the sphincter [muscle valve] between the stomach and 
the esophogus doesn't close properly. This is a fairly common condition 
and can be serious.

FYI: The acidic environment is necessary for proper digestion. In 
addition, the low pH kills many pathogens that are ingested, thus 
protecting the body from some potential disease conditions.

FYI: The lining of the stomach excretes several layers of mucous which 
protect the stomach lining from the acid, unless one develops a peptic 
ulcer which exposes to attack by the acid. The esophogus contains no such 
mucous excreting glands, and hence is subject attack if the person has 
acid reflux.

Vince Calder
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