- Diarrhea is the most common side effect of Metamucil and other bulk-forming laxatives. This is because Metamucil contains fiber, which facilitates the movement of substances through the digestive tract. For this reason, Metamucil should only be used to treat occasional constipation unless specifically prescribed by a physician for an alternative purpose. Other side effects include bloating and abdominal fullness.
- Metamucil does not have any severe drug interactions associated with its use. However, caution should be used with certain medications such as tetracycline. Because of its mechanism of action, Metamucil prevents the absorption of tetracycline into the bloodstream and therefore renders the drug ineffective at treating infection.
- People who have certain conditions should use Metamucil with caution. Because of its high sugar content, Metamucil can increase blood sugar levels in those with diabetes. In addition, Metamucil also contains high amounts of sodium. This can increase blood pressure, so people with hypertension should also use Metamucil cautiously.
- Metamucil should not be used in children under 6 years old unless prescribed by a physician. Also, people with certain digestive problems, such as intestinal blockage, should not take Metamucil to avoid worsening the condition.
- According to the American Pregnancy Association, Metamucil is listed as a category B medication. This means that it is considered safe for use during pregnancy. However, due to its high sodium and sugar content, it should be used only for relief of occasional constipation.