Levothyroxine Capsules and Questran
Determining the interaction of Levothyroxine Capsules and Questran and the possibility of their joint administration.
In the database of official manuals used in the service creation an interaction registered by statistical results of studies was found, which can either lead to negative consequences for the patient health or strengthen a mutual positive effect. A doctor should be consulted to address the issue of joint drug administration.
Consumer:Taking the levothyroxine and cholestyramine doses too close together may interfere with the absorption of levothyroxine and reduce its effectiveness. To prevent or minimize the interaction, levothyroxine and cholestyramine should be taken at least four hours apart. Contact your doctor if you experience signs and symptoms of reduced thyroid function such as fatigue; sluggishness; constipation; depression; hoarseness; unexplained weight gain; sensitivity to cold; pale, dry skin; muscle aches, weakness, or tenderness; joint pain, stiffness, or swelling; heavier than normal menstruation periods; or brittle fingernails and hair. It is important to tell your doctor about all other medications you use, including vitamins and herbs. Do not stop using any medications without first talking to your doctor.
Professional:ADJUST DOSING INTERVAL: Bile acid sequestrants may bind to and decrease the gastrointestinal absorption of thyroid hormones. There have been isolated reports of worsening hypothyroidism and increased TSH levels following the addition of cholestyramine in patients receiving thyroid replacement therapy.
MANAGEMENT: Thyroid hormone preparations and bile acid sequestrants should be administered at least 4 hours apart. Close clinical and laboratory monitoring of thyroid function is recommended during coadministration, since adjusting the dosing interval may not completely prevent the interaction.
- Cashin-Hemphill L, Spencer CA, Nicoloff JT, Blankenhorn DH, Nessim SA, Chin HP, Lee NA "Alterations in serum thyroid hormonal indices with colestipol-niacin therapy." Ann Intern Med 107 (1987): 324-9
- "Product Information. Synthroid (levothyroxine)." Abbott Pharmaceutical, Abbott Park, IL.
- Harmon SM, Seifert CF "Levothyroxine-cholestyramine interaction reemphasized." Ann Intern Med 115 (1991): 658-9
- Northcutt RC, Stiel JN, Hollifield JW, Stant EG "The influence of cholestyramine on thyroxine absorption." JAMA 208 (1969): 1857-61
- "Product Information. Questran (cholestyramine)." Par Pharmaceutical Inc, Chestnut Ridge, NY.
Generic Name: levothyroxine
Brand name: Levoxyl, Synthroid, Tirosint, Unithroid, Euthyrox, Levothroid, Tirosint-Sol
Synonyms: Levothyroxine
Generic Name: cholestyramine
Brand name: Cholestyramine Light, Prevalite, Questran, Questran Light, Locholest, Locholest Light, Questran Light Packets, Prevalite Packets, Questran Packets
Synonyms: n.a.
In the course of checking the drug compatibility and interactions, data from the following reference sources was used: Drugs.com, Rxlist.com, Webmd.com, Medscape.com.
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