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

☞ 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.