Retapamulin is a topical antibiotic which was approved by FDA (Altabax brand name) for the treatment of impetigo due to Staphylococcus aureus (methicillin-susceptible isolates only) or Streptococcus pyogenes. Retapamulin exerts its antibacterial action by binding to 50S subunit of the bacterial ribosome.

Sitagliptin (MK-0431), chemically (2R)-4-Oxo-4-[3- (trifluoromethyl)-5,6-dihydro[1,2,4]triazolo[4,3-a]pyrazin- 7(8H)-yl]-1-(2,4,5-trifl uorophenyl)butan-2-amine has a very high selectivity towards DPP-4, with an IC(50) of 18 nM. There is no affinity towards other DDP enzymes (DPP- 8 and DPP-9). It has been approved for the treatment of type 2 diabetes in the USA and Europe and is registered by the name Januvia (Merck Pharmaceuticals, Whitehouse Station, NJ, USA). In healthy volunteers and in patients with type 2 diabetes of different ethnic background, the tolerability of different doses given once or twice daily is good. The drug works to competitively inhibit a protein/enzyme, dipeptidyl peptidase 4 (DPP-4), that results in an increased amount of active incretins (GLP-1 and GIP), reduced amount of release of glucagon (diminishes its release) and increased release of insulin. Sitagliptin is an incretin enhancer and the first marketed medication belonging to the gliptin class. In fact, no published literature exists regarding incidence or severity of hypoglycemia when sitagliptin is used off-label in combined with insulin therapy. However, is recommended to use methods to avoid hypoglycemia when using this off-label combination. Approximately 79% of sitagliptin is excreted unchanged in the urine with metabolism being a minor pathway of elimination. Elimination of sitagliptin occurs primarily via renal excretion and involves active tubular secretion. Sitagliptin is a substrate for human organic anion transporter-3 (hOAT-3), which may be involved in the renal elimination of sitagliptin

Ciclesonide is a glucocorticoid receptor agonist indicated for the treatment of allergic rhinitis (Omnaris nasal spray) and asthma (Alvesco). It was also developed by Byk Gulden for chronic obstructive pulmonary disease (COPD), but no development had been reported for this indication since 1999. Ciclesonide is a pro-drug and rapidly metabolized to C21-desisobutyryl-ciclesonide which is more potent toward GR receptor than the parent drug.

Sunitinib (marketed as Sutent by Pfizer, and previously known as SU11248) is an oral, small-molecule, multi-targeted receptor tyrosine kinase inhibitor that was approved by the FDA for the treatment of renal cell carcinoma (RCC) and imatinib-resistant gastrointestinal stromal tumor. Sunitinib was evaluated for its inhibitory activity against a variety of kinases and was identified as an inhibitor of platelet-derived growth factor receptors (PDGFRa and PDGFRb), vascular endothelial growth factor receptors (VEGFR1, VEGFR2, and VEGFR3), stem cell factor receptor (KIT), Fms-like tyrosine kinase-3 (FLT3), colony-stimulating factor receptor Type 1 (CSF-1R), and the glial cell-line derived neurotrophic factor receptor (RET). Sunitinib adverse events are considered somewhat manageable and the incidence of serious adverse events low. The most common adverse events associated with sunitinib therapy are fatigue, diarrhea, nausea, anorexia, hypertension, yellow skin discoloration, hand-foot skin reaction, and stomatitis. In the placebo-controlled Phase III GIST study, adverse events which occurred more often with sunitinib than placebo included diarrhea, anorexia, skin discoloration, mucositis/stomatitis, asthenia, altered taste, and constipation. Dose reductions were required in 50% of the patients studied in RCC in order to manage the significant toxicities of this agent.

Sorafenib (BAY 43-9006), marketed as Nexavar by Bayer, is a drug approved for the treatment of advanced renal cell carcinoma (primary kidney cancer, hepatocellular carcinoma and for the treatment of patients with locally recurrent or metastatic, progressive, differentiated thyroid carcinoma (DTC) that is refractory to radioactive iodine treatment. It has also received "Fast Track" designation by the FDA for the treatment of advanced hepatocellular carcinoma (primary liver cancer), and has since performed well in Phase III trials. Sorafenib was shown to interact with multiple intracellular (CRAF, BRAF and mutant BRAF) and cell surface kinases (KIT, FLT- 3, VEGFR- 2, VEGFR- 3, and PDGFR- ß). Several of these kinases are thought to be involved in angiogenesis. Thus, sorafenib may inhibit tumor growth by a dual mechanism, acting either directly on the tumor (through inhibition of Raf and Kit signaling) and/or on tumor angiogenesis (through inhibition of VEGFR and PDGFR signaling). Sorafenib inhibited tumor growth of the murine renal cell carcinoma, RENCA, and several other human tumor xenografts in athymic mice. A reduction in tumor angiogenesis was seen in some tumor xenograft models.

Iloprost is a second generation structural analog of prostacyclin (PGI) with about ten-fold greater potency than the first generation stable analogs, such as carbaprostacyclin. Iloprost binds with equal affinity to human prostacyclin (Prostanoid IP) and prostaglandin EP1 receptors. Iloprost constricts the ilium and fundus circular smooth muscle as strongly as prostaglandin E2 (PGE2) itself. Iloprost inhibits the ADP, thrombin, and collagen-induced aggregation of human platelets. In whole animals, iloprost acts as a vasodilator, hypotensive, antidiuretic, and prolongs bleeding time. All of these properties help to antagonize the pathological changes that take place in the small pulmonary arteries of patients with pulmonary hypertension. Used for the treatment of pulmonary arterial hypertension.

Solifenacin is a competitive muscarinic acetylcholine receptor antagonist. The binding of acetylcholine to these receptors, particularly the M3 receptor subtype, plays a critical role in the contraction of smooth muscle. By preventing the binding of acetylcholine to these receptors, solifenacin reduces smooth muscle tone in the bladder, allowing the bladder to retain larger volumes of urine. It is FDA approved for the treatment of overactive bladder with symptoms of urge urinary incontinence, urgency, and urinary frequency. Common adverse reactions include constipation, Xerostomia. Inhibitors of CYP3A4 may increase the concentration of Solifenacin. Vice versa, CYP3A4 Inducers decrease concentration.

Erlotinib hydrochloride (trade name Tarceva, Genentech/OSIP, originally coded as OSI-774) is a drug used to treat non-small cell lung cancer, pancreatic cancer and several other types of cancer. Similar to gefitinib, erlotinib specifically targets the epidermal growth factor receptor (EGFR) tyrosine kinase. It binds in a reversible fashion to the adenosine triphosphate (ATP) binding site of the receptor. Erlotinib has recently been shown to be a potent inhibitor of JAK2V617F activity. JAK2V617F is a mutant of tyrosine kinase JAK2, is found in most patients with polycythemia vera (PV) and a substantial proportion of patients with idiopathic myelofibrosis or essential thrombocythemia. The study suggests that erlotinib may be used for treatment of JAK2V617F-positive PV and other myeloproliferative disorders. The mechanism of clinical antitumor action of erlotinib is not fully characterized. Erlotinib inhibits the intracellular phosphorylation of tyrosine kinase associated with the epidermal growth factor receptor (EGFR). Specificity of inhibition with regard to other tyrosine kinase receptors has not been fully characterized. EGFR is expressed on the cell surface of normal cells and cancer cells.

Vardenafil (Levitra) is an oral therapy for the treatment of erectile dysfunction. It is a selective inhibitor of cyclic guanosine monophosphate (cGMP)-specific phosphodiesterase type 5 (PDE5). Penile erection is a hemodynamic process initiated by the relaxation of smooth muscle in the corpus cavernosum and its associated arterioles. During sexual stimulation, nitric oxide is released from nerve endings and endothelial cells in the corpus cavernosum. Nitric oxide activates the enzyme guanylate cyclase resulting in increased synthesis of cyclic guanosine monophosphate (cGMP) in the smooth muscle cells of the corpus cavernosum. The cGMP in turn triggers smooth muscle relaxation, allowing increased blood flow into the penis, resulting in erection. The tissue concentration of cGMP is regulated by both the rates of synthesis and degradation via phosphodiesterases (PDEs). The most abundant PDE in the human corpus cavernosum is the cGMPspecific phosphodiesterase type 5 (PDE5); therefore, the inhibition of PDE5 enhances erectile function by increasing the amount of cGMP.

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.