Questran

Action

Combines with bile acid in GI tract to form insoluble complex excreted in feces. Complex regulates and increases cholesterol synthesis, thereby decreasing serum cholesterol and low-density lipoprotein levels.

Availability

Powder for suspension; powder for suspension with aspartame: 4 g cholestyramine/packet or scoop

Indications and dosages

➣ Primary hypercholesterolemia and pruritus caused by biliary obstruction; primary hyperlipidemia

Adults: Initially, 4 g P.O. once or twice daily. May increase as needed and tolerated, up to 24 g/day in six divided doses.

Off-label uses

• Antibiotic-induced pseudomembranous colitis

• Adjunct in infantile diarrhea

• Digoxin toxicity

Contraindications

• Hypersensitivity to drug, its components, or other bile-acid sequestering resins

• Complete biliary obstruction

• Phenylketonuria (suspension containing aspartame)

Precautions

Use cautiously in:

• history of constipation or abnormal intestinal function

• pregnant patients

• children.

Administration

• Mix powder with soup, cereal, pulpy fruit, juice, milk, or water.

• Administer 1 hour before or 4 to 6 hours after other drugs.

• Be aware that fat-soluble vitamin supplements may be necessary with long-term drug use.

Adverse reactions

CNS: headache, anxiety, vertigo, dizziness, insomnia, fatigue, syncope

EENT: tinnitus

GI: nausea, vomiting, constipation, abdominal discomfort, fecal impaction, flatulence, hemorrhoids, perianal irritation, steatorrhea

GU: hematuria, dysuria, diuresis, burnt odor to urine

Hematologic: anemia, ecchymosis

Hepatic: hepatic dysfunction

Metabolic: vitamin A, D, E, and K deficiencies; hyperchloremic acidosis

Musculoskeletal: joint pain, arthritis, back pain, muscle pain

Respiratory: wheezing, asthma

Skin: hypersensitivity reaction (irritation, rash, urticaria)

Other: tongue irritation

Interactions

Drug-drug. Acetaminophen, amiodarone, clindamycin, clofibrate, corticosteroids, digoxin, diuretics, fat-soluble vitamins (A, D, E, and K), gemfibrozil, glipizide, imipramine, methotrexate, methyldopa, mycophenolate, niacin, nonsteroidal anti-inflammatory drugs, penicillin, phenytoin, phosphates, propranolol, tetracyclines, tolbutamide, thyroid preparations, ursodiol, warfarin: decreased absorption and effects of these drugs

Drug-diagnostic tests. Alkaline phosphatase: increased level

Hemoglobin: decreased value

Prothrombin time: increased

Patient monitoring

• Monitor CBC with white cell differential and liver function test results.

• If bleeding or bruising occurs, monitor prothrombin time. Drug may reduce vitamin K absorption.

• Watch for constipation, especially in patients with coronary artery disease. Take appropriate steps to prevent this problem.

Patient teaching

See Instruct patient to immediately report yellowing of skin or eyes or easy bruising or bleeding.

• Tell patient to take drug 1 hour before or 4 to 6 hours after other drugs.

• Teach patient about role of diet in controlling cholesterol level and preventing constipation.

• Instruct patient to avoid inhaling or ingesting raw powder. Tell him to mix powder with food, juice, or milk before consuming.

• As appropriate, review all other significant and life-threatening adverse reactions and interactions, especially those related to the drugs and tests mentioned above.