Coadministration has not been studied but based on metabolism and clearance a pharmacokinetic interaction is unlikely. Lithium is mainly eliminated unchanged through the kidneys and is freely filtered at a rate that is dependent upon the glomerular filtration rate. Rilpivirine has been associated with prolongation of the QTc interval at supra-therapeutic doses but these are unlikely to occur when coadministered with lithium. However, the product label for rilpivirine indicates that rilpivirine should be used with caution in combination with drugs with a known risk of Torsade de Pointes. Lithium has a possible risk of QTc prolongation and/or TdP on the CredibleMeds.org website.