The document discusses bile acid sequestrants, which are resins that bind bile acids in the gastrointestinal tract. They work by exchanging anions for bile acids, removing them from circulation and increasing bile acid production from cholesterol. This lowers LDL cholesterol levels. They are used to treat hypercholesterolemia, pruritus in liver disease, and C. difficile infections. Side effects include gastrointestinal issues. They may also interact with other drugs or bind vitamins. Examples given are cholestyramine, colestipol, and colesevelam.

1. WEST BENGAL UNIVERSITY OF
ANIMAL AND FISHERY SCIENCES
FACULTY OF FISHERY SCIENCES
A SEMINAR ON: BILE ACID
SEQUESTRANTS
SUBMITTED TO:
Dr. Supratim Choudhury
Dept. of FPT
SUBMITTED BY:
Shirsak Mondal
B.F.Sc 1st Year 2nd semester

2. INTRODUCTION
• The bile acid sequestrants are a group of
resins used to bind certain components of bile
in the gastrointestinal tract.
• They disrupt the enterohepatic circulation of
bile acids by combining with bile constituents
• In general, they are classified as
hypolipidemic agents,
• They are used in the treatment of chronic
diarrhea due to bile acid malabsorption.

3. MECHANISM
• Bile acid sequestrants are polymeric compounds that serve
as ion-exchange resins
• Bile acid sequestrants exchange anions such as chloride
ions for bile acids. By doing so, they bind bile acids and
sequester them from the enterohepatic circulation. then more
bile acids are produced to replace those that have been lost.
Because the body uses cholesterol to make bile acids, this
reduces the amount of LDL cholesterol circulating in the
blood.
• Bile acid sequestrants are large polymeric structures, and
they are not significantly absorbed from the gut into the
bloodstream.

4. Medical uses
• Hyperlipidemia
As bile acids are biosynthesized from cholesterol, disruption of bile
acid reabsorption will decrease cholesterol levels, in particular, low-
density lipoprotein (commonly known as "bad cholesterol") in blood.
Consequently, these drugs have been used for the treatment of
hypercholesterolemia and dyslipidemia.
• In chronic liver diseases such as cirrhosis, bile acids may deposit in
the skin, causing pruritus (itching). Hence, bile acid sequestrants
may be used for the prevention of pruritus in patients with chronic
liver disease.
• Cholestyramine has been used in the treatment of Clostridium
difficile infections, in order to absorb toxins A and B.

5. Side-effects
As bile acid sequestrants are systemic side-effects.
However, they may cause problems in the
gastrointestinal tract (GI tract), such as constipation,
diarrhea, bloating and flatulence. Some patients
complain of the bad taste.
designed to stay in the gut, in general, they do not
have

7. Drug interactions
• In addition to bile acids, bile acid sequestrants
may also bind drugs in the GI tract, preventing
their absorption into the bloodstream. For this
reason, it is generally advised that bile acid
sequestrants be spaced several hours apart from
other drugs.
• . They can also bind fat-soluble vitamins, such as
vitamin A, vitamin D, vitamin E, and vitamin K.
This effect could result in a vitamin deficiency,
and so checking blood levels and possible
supplementation has been suggested.

8. Examples
Three drugs are members of this class; all are
synthetic polymeric resins:
* Cholestyramine (Questran and other
propriety names)
* Colestipol (Colestid, Colestipid)
* Colesevelam (Cholestagel in Europe,
Welchol in the USA)