Atazanavir is the first once-daily protease inhibitor for the treatment of human immunodeficiency virus type 1 infection and should be used only in combination therapy, as part of a highly active antiretroviral therapy (HAART) regimen. In addition to being the most potent protease inhibitor in vitro, atazanavir has a distinct cross-resistance profile that does not confer resistance to other protease inhibitors. However, resistance to other protease inhibitors often confers clinically relevant resistance to atazanavir.

NAMENDA (marketed under the brands Namenda among others) is an N-methyl-D-aspartate (NMDA) receptor antagonist indicated for the treatment of moderate to severe dementia of the Alzheimer’s type. Persistent activation of central nervous system N-methyl-D-aspartate (NMDA) receptors by the excitatory amino acid glutamate has been hypothesized to contribute to the symptomatology of Alzheimer’s disease. Memantine is postulated to exert its therapeutic effect through its action as a low to moderate affinity uncompetitive (open-channel) NMDA receptor antagonist which binds preferentially to the NMDA receptor-operated cation channels. There is no evidence that memantine prevents or slows neurodegeneration in patients with Alzheimer’s disease. Memantine showed low to negligible affinity for GABA, benzodiazepine, dopamine, adrenergic, histamine and glycine receptors and for voltage-dependent Ca2+, Na+ or K+ channels. Memantine also showed antagonistic effects at the 5HT3 receptor with a potency similar to that for the NMDA receptor and blocked nicotinic acetylcholine receptors with one-sixth to one-tenth the potency. In vitro studies have shown that memantine does not affect the reversible inhibition of acetylcholinesterase by donepezil, galantamine, or tacrine.

Epinastine (brand names Alesion, Elestat, Purivist, Relestat) is a second-generation antihistamine and mast cell stabilizer. Epinastine is a topically active, direct H1-receptor antagonist and an inhibitor of the release of histamine from the mast cell. Epinastine is selective for the histamine H1-receptor and has affinity for the histamine H2 receptor. Epinastine also possesses affinity for the α1-, α2-, and 5-HT2 –receptors. Epinastine does not penetrate the blood/brain barrier and, therefore, is not expected to induce side effects of the central nervous system. Elestat ophthalmic solution is indicated for the prevention of itching associated with allergic conjunctivitis.

Bortezomib is the therapeutic proteasome inhibitor. First, which is tested in humans. The boron atom in bortezomib binds the catalytic site of the 26S proteasome with high affinity and specificity. Bortezomib is approved in the U.S. for treating relapsed multiple myeloma and mantle cell lymphoma. The 26S proteasome degrades various proteins critical to cancer cell survival, such as cyclins, tumor suppressors, BCL-2, and cyclin-dependent kinase inhibitors. Inhibition of these degradations sensitizes cells to apoptosis. Bortezomib is a potent inhibitor of 26S proteasome, which sensitizes activity in dividing multiple myeloma and leukemic cells, thus inducing apoptosis. Most commonly reported adverse reactions (incidence ≥30%) in clinical studies include asthenic conditions, diarrhea, nausea, constipation, peripheral neuropathy, vomiting, pyrexia, thrombocytopenia, psychiatric disorders, anorexia and decreased appetite, neutropenia, neuralgia, leukopenia and anemia. Co-administration of ketoconazole, a potent CYP3A inhibitor, increased the exposure of bortezomib. Co-administration of melphalan-prednisone increased the exposure of bortezomib. However, this increase is unlikely to be clinically relevant.

Aprepitant (brand name: Emend (the brand name used in all English-speaking countries an antiemetic, is a substance P/neurokinin 1 (NK1) receptor antagonist which, in combination with other antiemetic agents, is indicated for the prevention of acute and delayed nausea and vomiting associated with initial and repeat courses of highly emetogenic cancer chemotherapy. Aprepitant has little or no affinity for serotonin (5-HT3), dopamine, and corticosteroid receptors, the targets of existing therapies for chemotherapy-induced nausea and vomiting. Aprepitant has been shown to inhibit emesis induced by cytotoxic chemotherapeutic agents, such as cisplatin, via central actions. Animal and human Positron Emission Tomography (PET) studies with aprepitant have shown that it crosses the blood brain barrier and occupies brain NK1 receptors.

The potential antiviral effect of adefovir, an acyclic nucleoside phosphonate analog of 2′-deoxyadenosine monophosphate, was first studied by Holý and De Clercq in 1980s. Adefovir is an acyclic nucleotide analog of adenosine monophosphate which is phosphorylated to the active metabolite adefovir diphosphate by cellular kinases. Adefovir diphosphate inhibits HBV DNA polymerase (reverse transcriptase) by competing with the natural substrate deoxyadenosine triphosphate and by causing DNA chain termination after its incorporation into viral DNA. Oral adefovir dipivoxil is effective and generally well tolerated in HBeAg-positive and -negative patients chronically infected with wild-type or lamivudine-resistant HBV.

Atomoxetine is indicated for the treatment of Attention-Deficit/Hyperactivity Disorder. The precise mechanism by which atomoxetine produces its therapeutic effects in Attention-Deficit/Hyperactivity Disorder (ADHD) is unknown, but is thought to be related to selective inhibition of the pre-synaptic norepinephrine transporter. Most common adverse reactions are: nausea, vomiting, fatigue, decreased appetite, abdominal pain, and somnolence, constipation, dry mouth, dizziness, erectile dysfunction, and urinary hesitation. Atomoxetine is a substrate for CYP2D6 and hence concurrent treatment with CYP2D6 inhibitors such as bupropion (Wellbutrin) or fluoxetine (Prozac) is not recommended, as this can lead to significant elevations of plasma atomoxetine levels.

Treprostinil (marketed under the trade names Remodulin for infusion) is a vasodilator that is used for the treatment of pulmonary arterial hypertension. Pulmonary arterial hypertension (PAH) is a disease in which blood pressure is abnormally high in the arteries between the heart and lungs. PAH is characterized by symptoms of shortness of breath during physical exertion. The condition can ultimately lead to heart failure. Treprostinil is a potent oral antiplatelet agent. The major pharmacologic actions of treprostinil are direct vasodilation of pulmonary and systemic arterial vascular beds and inhibition of platelet aggregation. In animals, the vasodilatory effects reduce right and left ventricular afterload and increase cardiac output and stroke volume. Other studies have shown that treprostinil causes a dose-related negative inotropic and lusitropic effect. No major effects on cardiac conduction have been observed. Treprostinil had high affinity for the Prostaglandin D2 receptor (DP1), Prostaglandin E2 receptor EP2 subtype (EP2) and Prostaglandin D2 receptor (IP) receptors (Ki 4.4, 3.6 and 32 nM, respectively), low affinity for EP1 and EP4 receptors and even lower affinity for EP3, Prostaglandin F (FP) and thromboxane (TP) receptors. Treprostinil has demonstrated a unique effect on PPAR gamma, a transcription factor important in vascular pathogenesis as a mediator of proliferation, inflammation and apoptosis. Through a complementary, yet cyclic AMP-independent pathway, treprostinil activates PPARs, another mechanism that contributes to the anti-growth benefits of the prostacyclin class.

Aripiprazole is the first next-generation atypical antipsychotic. The unique actions of aripiprazole in humans are likely a combination of "functionally selective" activation of D(2) (and possibly D(3))-dopamine receptors and serotonin 5-HT(1A) receptors, coupled with inhibition of 5-HT(2A) receptors. Aripiprazole was approved by FDA (Abilify trade name) for the treatment of schizophrenia; manic and mixed episodes associated with bipolar I disorder; major depressive disorder; irritability associated with autistic disorder; Tourette’s disorder and agitation associated with schizophrenia or bipolar mania.

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