I tilfælde af samtidig indgift af ritonavir (100 mg to gange daglig) og indinavir (800 mg to gange daglig) er der grund til forsigtighed, da risikoen for nephrolithiasis kan øges.
In cases of co-administration of ritonavir (100 mg twice daily) and indinavir (800 mg twice daily) caution is warranted as the risk of nephrolithiasis may be increased.