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Levothyroxine

21 interactions on record

Levothyroxine has 21 known drug interactions based on U.S. FDA drug labeling data. 5 are classified as major interactions requiring close medical supervision. Notable interactions include combinations with Colesevelam, Colesevelam Hydrochloride, Epinephrine 0.3 Adults. Patients taking Levothyroxine should inform their healthcare provider of all current medications — including over-the-counter drugs and supplements — to avoid potentially harmful combinations. Data sourced from OpenFDA and the NIH National Library of Medicine.

Total: 21
Major: 5
Moderate: 14
Minor: 2

Major (5)

Levothyroxine + Colesevelam— Colesevelam may decrease exposure of levothyroxine. In vivo studies showed decreased levothyroxine exposure; postmarketi…
Levothyroxine + Colesevelam Hydrochloride— In vivo studies showed decreased levothyroxine exposure. Postmarketing reports of elevated TSH in patients on thyroid ho…
Levothyroxine + Epinephrine 0.3 Adults— Effects of epinephrine may be potentiated by levothyroxine sodium.
Levothyroxine + Lanthanum Carbonate— Lanthanum carbonate decreases levothyroxine bioavailability by approximately 40%. Administer at least 2 hours before or …
Levothyroxine + Orlistat— Hypothyroidism reported with concomitant use. Patients should be monitored for changes in thyroid function. Administer a…

Moderate (14)

Levothyroxine + Albuterol Sulfate— Levothyroxine sodium potentiates the effects of epinephrine.
Levothyroxine + Cholestyramine Light— Cholestyramine may delay or reduce the absorption of thyroxine preparations.
Levothyroxine + Cholestyramine Powder For Suspension— Cholestyramine may delay or reduce the absorption of thyroxine preparations.
Levothyroxine + Choleystyramine Light— Cholestyramine may delay or reduce absorption of thyroxine.
Levothyroxine + Epinephrine— Levothyroxine sodium may potentiate the effects of epinephrine.
Levothyroxine + Patiromer— Patiromer binds levothyroxine, potentially reducing systemic exposure and clinical efficacy. Separate dosing by at least…
Levothyroxine + Salsalate— Salicylate competes with thyroxine for protein binding sites, potentially affecting drug levels.
Levothyroxine + Semaglutide— Semaglutide tablet increased levothyroxine exposure by 33%. Monitor effects and consider increased clinical monitoring w…
Levothyroxine + Sevelamer Carbonate— Sevelamer carbonate may reduce bioavailability of levothyroxine, which could have clinically significant effect on safet…
Levothyroxine + Sevelamer Carbonate For Oral Suspension— Reduction in bioavailability may have clinically significant effect on safety or efficacy; consider separation of admini…
Levothyroxine + Sevelamer Hydrochloride— Sevelamer may reduce bioavailability of levothyroxine, which has clinically significant effects on safety or efficacy. C…
Levothyroxine + Sodium Iodide I 131— Natural or synthetic thyroid hormone that interferes with radioiodide accumulation. Discontinue 4 weeks before procedure…
Levothyroxine + Sodium Polystyrene Sulfonate— Sodium Polystyrene Sulfonate may bind thyroxine and decrease its gastrointestinal absorption. Administer at least 3 hour…
Levothyroxine + Sucroferric Oxyhydroxide— Levothyroxine should be taken at least 4 hours before sucroferric oxyhydroxide to avoid reduced bioavailability.

Minor (2)

Levothyroxine + Alendronate Sodium— Bioavailability of alendronate was slightly decreased when co-administered with levothyroxine.
Levothyroxine + Sodium Zirconium Cyclosilicate— In vivo testing showed no clinically significant changes in levothyroxine exposure when co-administered with LOKELMA.

Levothyroxine + Colesevelam⚠️Major

Colesevelam may decrease exposure of levothyroxine. In vivo studies showed decreased levothyroxine exposure; postmarketing reports of elevated TSH.

Levothyroxine + Colesevelam Hydrochloride⚠️Major

In vivo studies showed decreased levothyroxine exposure. Postmarketing reports of elevated TSH in patients on thyroid hormone replacement therapy.

Levothyroxine + Epinephrine 0.3 Adults⚠️Major

Effects of epinephrine may be potentiated by levothyroxine sodium.

Levothyroxine + Lanthanum Carbonate⚠️Major

Lanthanum carbonate decreases levothyroxine bioavailability by approximately 40%. Administer at least 2 hours before or after lanthanum carbonate and monitor TSH levels.

Levothyroxine + Orlistat⚠️Major

Hypothyroidism reported with concomitant use. Patients should be monitored for changes in thyroid function. Administer at least 4 hours apart.

Levothyroxine + Albuterol Sulfate🟡Moderate

Levothyroxine sodium potentiates the effects of epinephrine.

Levothyroxine + Cholestyramine Light🟡Moderate

Cholestyramine may delay or reduce the absorption of thyroxine preparations.

Levothyroxine + Cholestyramine Powder For Suspension🟡Moderate

Cholestyramine may delay or reduce the absorption of thyroxine preparations.

Levothyroxine + Choleystyramine Light🟡Moderate

Cholestyramine may delay or reduce absorption of thyroxine.

Levothyroxine + Epinephrine🟡Moderate

Levothyroxine sodium may potentiate the effects of epinephrine.

Levothyroxine + Patiromer🟡Moderate

Patiromer binds levothyroxine, potentially reducing systemic exposure and clinical efficacy. Separate dosing by at least 3 hours.

Levothyroxine + Salsalate🟡Moderate

Salicylate competes with thyroxine for protein binding sites, potentially affecting drug levels.

Levothyroxine + Semaglutide🟡Moderate

Semaglutide tablet increased levothyroxine exposure by 33%. Monitor effects and consider increased clinical monitoring with concomitant use.

Levothyroxine + Sevelamer Carbonate🟡Moderate

Sevelamer carbonate may reduce bioavailability of levothyroxine, which could have clinically significant effect on safety or efficacy. Consider separation of administration timing.

Levothyroxine + Sevelamer Carbonate For Oral Suspension🟡Moderate

Reduction in bioavailability may have clinically significant effect on safety or efficacy; consider separation of administration timing.

Levothyroxine + Sevelamer Hydrochloride🟡Moderate

Sevelamer may reduce bioavailability of levothyroxine, which has clinically significant effects on safety or efficacy. Consider separation of administration timing.

Levothyroxine + Sodium Iodide I 131🟡Moderate

Natural or synthetic thyroid hormone that interferes with radioiodide accumulation. Discontinue 4 weeks before procedure.

Levothyroxine + Sodium Polystyrene Sulfonate🟡Moderate

Sodium Polystyrene Sulfonate may bind thyroxine and decrease its gastrointestinal absorption. Administer at least 3 hours before or after Sodium Polystyrene Sulfonate.

Levothyroxine + Sucroferric Oxyhydroxide🟡Moderate

Levothyroxine should be taken at least 4 hours before sucroferric oxyhydroxide to avoid reduced bioavailability.

Levothyroxine + Alendronate Sodium🟢Minor

Bioavailability of alendronate was slightly decreased when co-administered with levothyroxine.

Levothyroxine + Sodium Zirconium Cyclosilicate🟢Minor

In vivo testing showed no clinically significant changes in levothyroxine exposure when co-administered with LOKELMA.

Data sourced from U.S. FDA drug labeling via openFDA and the NIH National Library of Medicine. For informational purposes only. Always consult your pharmacist or physician.