Drug-drug Interactions

Drug-drug interactions between protease inhibitors (PIs) and levothyroxine have been reported in which the effectiveness of treatment for hypothyroidism is reduced. Such interactions include levothyroxine with:

  • indinavir1
  • lopinavir, ritonavir

Additionally, a statistically significant link has been observed between therapy with the non-nucleoside reverse transcriptase inhibitor (NNRTI) efavirenz and the development of hyperthyroidism. Based on the observations in this area, screening of thyroid function in HIV-infected patients receiving HAART may be beneficial.3

See the HIV drug interactions website 



  1. Lanzafame M, Trevenzoli M, Faggian F, et al. Interaction between levothyroxine and indinavir in a patient with HIV infection. Infection. 2002;30(1):54–55.
  2. Touzot M, Beller CL, Touzot F, Louet AL, Piketty C. Dramatic interaction between levothyroxine and lopinavir/ritonavir in a HIV-infected patient. AIDS. 2006;20(8):1210–1212.
  3. Nelson M, Powles T, Zeitlin A, et al. Thyroid Dysfunction and Relationship to Antiretroviral Therapy in HIV-Positive Individuals in the HAART Era. J Acquir Immune Defic Syndr. 2009;50(1):113–114.