From the Guidelines
Cholestyramine therapy is associated with several side effects, including gastrointestinal symptoms such as constipation, bloating, abdominal pain, nausea, and flatulence, and should be managed with gradual dose titration and careful monitoring of lipid and vitamin levels 1. The most common side effects of cholestyramine include:
- Constipation, affecting up to 30% of patients
- Bloating and abdominal pain
- Nausea and flatulence
- Decreased absorption of fat-soluble vitamins (A, D, E, K), which may lead to deficiencies over time
- Interference with the absorption of certain medications
To manage these side effects, the following strategies are recommended:
- Gradually increase the dose of cholestyramine, starting with 4 grams once or twice daily and slowly titrating up to the therapeutic dose of 4 grams three to four times daily 1
- Encourage adequate fluid intake and dietary fiber to minimize constipation
- Take cholestyramine with meals to maximize bile acid binding, but administer other medications either 1 hour before or 4-6 hours after cholestyramine to prevent reduced absorption 1
- Consider supplementation with fat-soluble vitamins during long-term therapy
- Mix the powder formulation thoroughly with 4-6 ounces of water or non-carbonated beverage before consumption to improve palatability
- Regularly monitor lipid levels, vitamin levels, and medication efficacy in patients on cholestyramine therapy 1
It is essential to note that cholestyramine may interact with other medications, including cyclosporin, oral contraceptives, olmesartan, phenytoin, sulfonylureas, thyroid replacement therapy, and warfarin, and may increase exposure to metformin 1. Therefore, careful consideration of potential drug interactions and monitoring of patients on concomitant medications is crucial.
From the FDA Drug Label
ADVERSE REACTIONS The most common adverse reaction is constipation. When used as a cholesterol-lowering agent predisposing factors for most complaints of constipation are high dose and increased age (more than 60 years old). Most instances of constipation are mild, transient and controlled with conventional therapy. Some patients require a temporary decrease in dosage or discontinuation of therapy Less Frequent Adverse Reactions - Abdominal discomfort and/or pain, flatulence, nausea, vomiting, diarrhea, eructation, anorexia, steatorrhea, bleeding tendencies due to hypoprothrombinemia (Vitamin K deficiency) as well as Vitamin A (one case of night blindness reported) and D deficiencies, hyperchloremic acidosis in children, osteoporosis, rash and irritation of the skin, tongue and perianal area. Rare reports of intestinal obstruction, including two deaths, have been reported in pediatric patients. Other events (not necessarily drug related) reported in patients taking cholestyramine resin include: Gastrointestinal GI-rectal bleeding, black stools, hemorrhoidal bleeding, bleeding from known duodenal ulcer, dysphagia, hiccups, ulcer attack, sour taste, pancreatitis, rectal pain, diverticulitis. Laboratory Test Changes Liver function abnormalities Hematologic Prolonged prothrombin time, ecchymosis, anemia. Hypersensitivity Urticaria, asthma, wheezing, shortness of breath. Musculoskeletal Backache, muscle and joint pains, arthritis. Neurologic Headache, anxiety, vertigo, dizziness, fatigue, tinnitus, syncope, drowsiness, femoral nerve pain, paresthesia. Eye Uveitis. Renal Hematuria, dysuria, burnt odor to urine, diuresis.
The side effects of cholestyramine include:
- Gastrointestinal: constipation, abdominal discomfort and/or pain, flatulence, nausea, vomiting, diarrhea, eructation, anorexia, steatorrhea
- Bleeding tendencies: due to hypoprothrombinemia (Vitamin K deficiency)
- Vitamin deficiencies: Vitamin A and D deficiencies
- Other: hyperchloremic acidosis in children, osteoporosis, rash and irritation of the skin, tongue and perianal area, intestinal obstruction (rare reports in pediatric patients)
- Laboratory Test Changes: liver function abnormalities, prolonged prothrombin time, ecchymosis, anemia
- Hypersensitivity: urticaria, asthma, wheezing, shortness of breath
- Musculoskeletal: backache, muscle and joint pains, arthritis
- Neurologic: headache, anxiety, vertigo, dizziness, fatigue, tinnitus, syncope, drowsiness, femoral nerve pain, paresthesia
- Eye: uveitis
- Renal: hematuria, dysuria, burnt odor to urine, diuresis Management of these side effects may include temporary decrease in dosage or discontinuation of therapy 2.
From the Research
Side Effects of Cholestyramine
- The most common side effects of cholestyramine include gastrointestinal symptoms such as bloating, as evidenced by a study on colestyramine, a similar bile acid sequestrant, which found that it increased bloating in healthy subjects 3.
- Other potential side effects may include constipation, abdominal pain, and nausea, although the study on colestyramine found no effect on ratings of nausea 3.
- Cholestyramine may also slow gastric emptying of liquids, which could lead to feelings of fullness or discomfort 3.
Management of Cholestyramine Therapy
- To minimize side effects, patients should be instructed to take cholestyramine with plenty of water and to maintain a high-fiber diet to prevent constipation.
- Patients should also be monitored for signs of gastrointestinal distress, such as abdominal pain or bloating, and the dose of cholestyramine adjusted as needed.
- The use of cholestyramine may be beneficial in managing diabetes mellitus and diarrhea from bile acid malabsorption, in addition to its primary use in treating hypercholesterolemia 4.