Amprenavir is an inhibitor of HIV-1 protease. Amprenavir binds to the active site of HIV-1 protease and thereby prevents the processing of viral gag and gag-pol polyprotein precursors, resulting in the formation of immature non-infectious viral particles. Amprenavir-containing combination regimens have shown virological efficacy, and have generally been well tolerated, in patients with HIV infection (primarily treatment-naive or protease inhibitor-naive). Fosamprenavir (GW433908, Lexiva, Telzir) is an oral prodrug of amprenavir, with a reduced daily pill burden. The use of protease inhibitors has also been associated with dyslipidemia and an increased risk of cardiovascular disease. Amprenavir activates Pregnane X receptor to mediate dyslipidemia.

Voriconazole (vor-i-KON-a-zole, brand name Vfend, Pfizer) is a triazole antifungal medication. VFEND® (voriconazole) is available as film-coated tablets for oral administration, and as a lyophilized powder for solution for intravenous infusion. Voriconazole is a triazole antifungal agent indicated for use in the treatment of fungal infections including invasive aspergillosis, esophageal candidiasis, and serious fungal infections caused by Scedosporium apiospermum (asexual form of Pseudallescheria boydii) and Fusarium spp. including Fusarium solani. Fungal plasma membranes are similar to mammalian plasma membranes, differing in having the nonpolar sterol ergosterol, rather than cholesterol, as the principal sterol. Membrane sterols such as ergosterol provide structure, modulation of membrane fluidity, and possibly control of some physiologic events. Voriconazole effects the formation of the fungal plasma membrane by indirectly inhibiting the biosynthesis of ergosterol. This results in plasma membrane permeability changes and inhibition of growth. The primary mode of action of voriconazole is the inhibition of fungal cytochrome P-450-mediated 14 alpha-lanosterol demethylation, an essential step in fungal ergosterol biosynthesis. The accumulation of 14 alpha-methyl sterols correlates with the subsequent loss of ergosterol in the fungal cell wall and may be responsible for the antifungal activity of voriconazole. Voriconazole has been shown to be more selective for fungal cytochrome P-450 enzymes than for various mammalian cytochrome P-450 enzyme systems. The most common side effects associated with voriconazole include transient visual disturbances, fever, rash, vomiting, nausea, diarrhea, headache, sepsis, peripheral edema, abdominal pain, and respiratory disorder. Unlike most adverse effects, which are similar to other azole antifungal agents, visual disturbances (such as blurred vision or increased sensitivity to light) are unique to voriconazole. Though rare, there have been cases of serious hepatic reactions during treatment with voriconazole (a class effect of azole antifungal agents). Liver function tests should be evaluated at the start of and during the course of therapy. Voriconazole is phototoxic. It has been associated with an increased risk of squamous-cell carcinoma of the skin

Clarithromycin is an antibacterial drug which is used either in combination with lansoprazole and amoxicillin (Prevpac), in combination with omeprazole and amoxicillin (Omeclamox) or alone (Biaxin) for the treatment of broad range of infections. The drug exerts its action by binding to 23s rRNA (with nucleotides in domains II and V). The binding leads to the protein synthesis inhibition and the cell death.

Cyclosporins are cyclic polypeptide macrolides that were originally derived from the soil fungus Tolypocladium inflatum. Cyclosporine (also known as cyclosporine A) was discovered by Sandoz and developed for the tretment of immune disorders. The drug was approved by FDA for such diseases as Rheumatoid Arthritis, Psoriasis (Neoral), Keratoconjunctivitis sicca (Restasis) and prevention of transplant rejections (Neoral and Sandimmune). Cyclosporine’s primary immunosuppressive mechanism of action is inhibition of T-lymphocyte function. Upon administration cyclosporine binds to cyclophilin A and thus inhibits calcineurin, leading to immune system suppression.

MX-100 (also known as PL-100) is a benzenesulfonamide derivative patented by Pharmacor Inc as HIV aspartyl protease inhibitor. MX-100 retained excellent antiviral activity against almost all of these protease inhibitor-resistant viruses and that its performance in this regard was superior to those of atazanavir, amprenavir, indinavir, lopinavir, nelfinavir, and saquinavir. In almost every case, the increase in the EC50 for MX-100 observed with viruses containing multiple mutations in protease was far less than that obtained with the other drugs. Preclinical studies showed that MX-100 possessed suboptimal solubility and pharmacokinetic, (PK) properties, possibly hindering further development. MX-100 successfully completed preclinical and clinical development (phase I in healthy volunteers) and have been licensed to Merck in 2006