Cholestyramine

Uses

As an adjunct to dietary therapy & exercise to decrease elevated serum cholesterol in the management of type IIa & type IIb hyperlipoproteinaemia & reduce the risk of atherosclerotic coronary artery disease & MI. Symptomatic control of diarrhoea caused by increased bile acids due to short bowel syndrome. Relief of pruritus associated with partial biliary obstruction.

Cholestyramine is also used to associated treatment for these conditions: Atherosclerosis, Primary Hypercholesterolemia, Pruritus

How Cholestyramine works

Cholestyramine forms a resin that acts as a bile acid sequestrant to limit the reabsorption of bile acids in the gastrointestinal tract. Cholestyramine resin is a strong anion exchange resin, allowing it to exchange its chloride anions with anionic bile acids present in the gastrointestinal tract and form a strong resin matrix. Cholestyramine consists of a functional group, which is a quaternary ammonium group attached to an inert styrene-divinylbenzene copolymer, in the anion exchange resin.

Dosage

Cholestyramine dosage

Adult: Initially 4 gm 1 to 6 times daily. May be taken with or without food. Do not take in the dry form. Mix with 120-180 ml of water or fruit juice, stir to a uniform consistency before taking.

Side Effects

Constipation, faecal impaction &/or haemorrhoids with or without bleeding, steatorrhoea, hyperchloraemic acidosis, increased urinary calcium excretion, irritation of skin, tongue & perianal area.

Toxicity

Overdose may result in blockage of intestine or stomach.

Precaution

Prolonged use may increase bleeding tendency. Not to be used as monotherapy in patients with hyperlipidaemias associated with hypertriglyceridaemia. Folic acid, vit A & D supplement may be needed in long-term use. Lactation, pregnancy & elderly.

Interaction

Binds & may delay or reduce absorption of thyroid hormones, digitoxin, digoxin, warfarin, Fe salts, chenodiol, phenylbutazone, thiazide diuretics, phenobarb, tetracycline, loperamide, penicillin G, HMG-CoA reductase inhibitors. Admin other drugs 1 hr before or 4-6 hr after cholestyramine.

Food Interaction

• Take with fluids. Do not take with carbonated fluids.
• Take with food. Take with a meal unless this interferes with other medications.

Cholestyramine multivitamins interaction

[Moderate] ADJUST DOSING INTERVAL: Bile acid sequestrants and the phosphate binder, sevelamer, can decrease the absorption of fat-soluble vitamins A, D, E, and K.

In non-clinical safety studies, rats administered colesevelam at doses greater than 30-fold the projected human clinical dose developed hemorrhage in association with vitamin K deficiency.

In a crossover study involving healthy subjects, coadministration of sevelamer with calcitriol resulted in a significant reduction in bioavailability for calcitriol (calcitriol with sevelamer vs calcitriol alone: AUC 137 pg*h
Oral vitamin supplements should be administered at least 4 hours before colesevelam and either 1 hour before or 4 to 6 hours after other bile acid sequestrants and sevelamer.

Cholestyramine Drug Interaction

Moderate: levothyroxine, levothyroxine, cholecalciferol, cholecalciferolMinor: aspirin, aspirin, acetaminophen, acetaminophenUnknown: duloxetine, duloxetine, omega-3 polyunsaturated fatty acids, omega-3 polyunsaturated fatty acids, pregabalin, pregabalin, cyanocobalamin, cyanocobalamin, ascorbic acid, ascorbic acid, cetirizine, cetirizine

Cholestyramine Disease Interaction

Major: biliary obstructionModerate: constipation, hyperchloremia, PKU, vitamin/folate deficiency

Elimination Route

Not absorbed from the gastrointestinal tract following oral administration.

Half Life

6 minutes

Elimination Route

Cholestyramine resin adsorbs and combines with the bile acids in the intestine to form an insoluble complex which is excreted in the feces.

Pregnancy & Breastfeeding use

Pregnancy Category- Not Classified

Contraindication

Complete biliary obstruction.

Innovators Monograph

You find simplified version here Cholestyramine