Lopinavir

It is a peptidomimetic alternative protease inhibitor, according to the 2011 DHHS treatment guidelines. Lopinavir has very poor intrinsic bioavailability, which is substantially enhanced by including a low dose of ritonavir in the formulation. GI adverse effects and hypertriglyceridemia are the most common side effects for lopinavir, in addition to the other protease inhibitor class side effects.Like other members of the class, lopinavir can inhibit the metabolism of other drugs, resulting in required alterations of drug dosage or the prohibition of combined use. Enzyme inducers as well as St. John’s wort should be avoided, because they lower the plasma concentrations of lopinavir. Because the oral solution contains alcohol, disulfiram or metronidazole administration can cause unpleasant reactions.Lopinavir/ritonavir—In this combination, a subtherapeutic dose of ritonavir acts as a pharmacokinetic enhancer by inhibiting the CYP3A4-mediated metabolism of lopinavir. Patient compliance is improved owing to lower pill burden and the combination is usually well tolerated.