Perampanel (trade name Fycompa) is an antiepileptic drug developed by Eisai Co. that acts as a selective non-competitive antagonist of AMPA receptors, the major subtype of ionotropic glutamate receptors. Although the mechanism of action through which perampanel exerts its antiepileptic effect has not been fully elucidated, this agent antagonizes the AMPA subtype of the excitatory glutamate receptor found on postsynaptic neurons in the central nervous system (CNS). This antagonistic action prevents AMPA receptor activation by glutamate and results in the inhibition of neuronal excitation, repetitive neuronal firing, and the stabilization of hyper-excited neural membranes. Glutamate, the primary excitatory neurotransmitter in the CNS, plays an important role in various neurological disorders caused by neuronal hyperexcitation. The drug is currently approved, for the control of partial-onset seizures, in those of both sexes who suffer from epilepsy and who are 12 years of age and older, by the Food and Drug Administration. Perampanel is also approved for the treatment of primary generalized tonic-clonic seizures in patients with epilepsy aged 12 years and older. It is designated as a Schedule III controlled substance by the Drug Enforcement Administration. Perampanel has been studied in other clinical indications including Parkinson's disease.

Benznidazole is an antiparasitic medication used in first-line treatment of Chagas disease. Benznidazole is a nitroimidazole antiparasitic with good activity against acute infection with Trypanosoma cruzi, commonly referred to as Chagas disease. Like other nitroimidazoles, benznidazole's main mechanism of action is to generate radical species which can damage the parasite's DNA or cellular machinery. Under anaerobic conditions, the nitro group of nitroimidazoles is believed to be reduced by the pyruvate:ferredoxin oxidoreductase complex to create a reactive nitro radical species. The nitro radical can then either engage in other redox reactions directly or spontaneously give rise to a nitrite ion and imidazole radical instead. In mammals, the principal mediators of electron transport are NAD+/NADH and NADP+/NADPH, which have a more positive reduction potential and so will not reduce nitroimidazoles to the radical form. This limits the spectrum of activity of nitroimidazoles so that host cells and DNA are not also damaged. This mechanism has been well-established for 5-nitroimidazoles such as metronidazole, but it is unclear if the same mechanism can be expanded to 2-nitroimidazoles (including benznidazole). In the presence of oxygen, by contrast, any radical nitro compounds produced will be rapidly oxidized by molecular oxygen, yielding the original nitroimidazole compound and a superoxide anion in a process known as "futile cycling". In these cases, the generation of superoxide is believed to give rise to other reactive oxygen species. The degree of toxicity or mutagenicity produced by these oxygen radicals depends on cells' ability to detoxify superoxide radicals and other reactive oxygen species. In mammals, these radicals can be converted safely to hydrogen peroxide, meaning benznidazole has very limited direct toxicity to human cells. In Trypanosoma species, however, there is a reduced capacity to detoxify these radicals, which results in damage to the parasite's cellular machinery. Benznidazole has a significant activity during the acute phase of Chagas disease, with a therapeutical success rate up to 80%. Its curative capabilities during the chronic phase are, however, limited. Some studies have found parasitologic cure (a complete elimination of T. cruzi from the body) in pediatric and young patients during the early stage of the chronic phase, but overall failure rate in chronically infected individuals is typically above 80%. However, some studies indicate treatment with benznidazole during the chronic phase, even if incapable of producing parasitologic cure, because it reduces electrocardiographic changes and a delays worsening of the clinical condition of the patient. Side effects tend to be common and occur more frequently with increased age. The most common adverse reactions associated with benznidazole are allergic dermatitis and peripheral neuropathy. It is reported that up to 30% of people will experience dermatitis when starting treatment. Benznidazole may cause photosensitization of the skin, resulting in rashes. Rashes usually appear within the first 2 weeks of treatment and resolve over time. In rare instances, skin hypersensitivity can result in exfoliative skin eruptions, edema, and fever. Peripheral neuropathy may occur later on in the treatment course and is dose-dependent. Other adverse reactions include anorexia, weight loss, nausea, vomiting, insomnia, and dyslexia, and bone marrow suppression. Gastrointestinal symptoms usually occur during the initial stages of treatment and resolves over time. Bone marrow suppression has been linked to the cumulative dose exposure.

Linagliptin is a dipeptidyl peptidase-4 (DPP-4) inhibitor discovered by Boehringer Ingelheim and being developed as an oral once-daily tablet for the treatment of Type 2 diabetes. Linagliptin was first approved by FDA in 2011 under the trade name Tradjenta as an adjunct to diet and exercise to improve glycemic control in adults with type 2 diabetes mellitus. Linagliptin binds to DPP-4 (an enzyme that degrades the incretin hormones glucagon-like peptide-1 (GLP-1) and glucose-dependent insulinotropic polypeptide (GIP)) in a reversible manner and thus increases the concentrations of incretin hormones. Linagliptin glucose dependently increases insulin secretion and lowers glucagon secretion, thus resulting in better regulation of glucose homeostasis. Linagliptin binds selectively to DPP-4, and selectively inhibits DPP-4 but not DPP-8 or DPP-9 activity in vitro at concentrations approximating therapeutic exposures.

Saxagliptin is an orally active hypoglycemic (anti-diabetic drug) of the new dipeptidyl peptidase-4 (DPP-4) inhibitor class of drugs. FDA approved on July 31, 2009. Saxagliptin is a dipeptidyl peptidase-4 (DPP-4) inhibitor antidiabetic for the treatment of type 2 diabetes. DPP-4 inhibitors are a class of compounds that work by affecting the action of natural hormones in the body called incretins. Incretins decrease blood sugar by increasing consumption of sugar by the body, mainly through increasing insulin production in the pancreas, and by reducing production of sugar by the liver. [Bristol-Myers Squibb Press Release] DPP-4 is a membrane associated peptidase which is found in many tissues, lymphocytes and plasma. DPP-4 has two main mechanisms of action, an enzymatic function and another mechanism where DPP-4 binds adenosine deaminase, which conveys intracellular signals via dimerization when activated. Saxagliptin forms a reversible, histidine-assisted covalent bond between its nitrile group and the S630 hydroxyl oxygen on DPP-4. The inhibition of DPP-4 increases levels active of glucagon like peptide 1 (GLP-1), which inhibits glucagon production from pancreatic alpha cells and increases production of insulin from pancreatic beta cells.

Methylnaltrexone, is a peripherally acting μ-opioid receptor antagonist that acts on the gastrointestinal tract to inhibit the opioid-induced decrease in gastric motility and transit time. It is used to treat opiate-induced constipation in adults with chronic non-cancer pain and in adults with advanced illness who are receiving palliative care.

Nilotinib (AMN107, trade name Tasigna) is a kinase inhibitor indicated for the treatment of chronic phase and accelerated phase Philadelphia chromosome-positive chronic myelogenous leukemia (CML) in adult patients resistant to or intolerant to prior therapy that included imatinib. Nilotinib is an inhibitor of the Bcr-Abl kinase. Nilotinib binds to and stabilizes the inactive conformation of the kinase domain of Abl protein. In vitro, nilotinib inhibited Bcr-Abl mediated proliferation of murine leukemic cell lines and human cell lines derived from Ph+ CML patients. Under the conditions of the assays, nilotinib was able to overcome imatinib resistance resulting from Bcr-Abl kinase mutations, in 32 out of 33 mutations tested. In vivo, nilotinib reduced the tumor size in a murine Bcr-Abl xenograft model. Nilotinib inhibited the autophosphorylation of the following kinases at IC50 values as indicated: Bcr-Abl (20-60 nM), PDGFR (69 nM) and c-Kit (210 nM). Nilotinib is currently being trialed in people with Parkinson's disease, as it appears to be able to halt progression of the disease and even improve their symptoms. The drug also has a number of adverse effects typical of anti-cancer drugs: a headache, fatigue, gastrointestinal problems such as nausea, vomiting, diarrhea and constipation, muscle and joint pain, rash and other skin conditions, flu-like symptoms, and reduced blood cell count. Less typical side effects are those of the cardiovascular system, such as hypertension (high blood pressure), various types of arrhythmia, and prolonged QT interval. Interaction of nilotinib with OATP1B1 and OATP1B3 may alter its hepatic disposition and can lead to transporter mediated drug-drug interactions. Nilotinib is an inhibitor of OATP-1B1 transporter but not for OATP-1B3. Main metabolic pathways identified in healthy subjects are oxidation and hydroxylation. Nilotinib is the main circulating component in the serum. None of the metabolites contributes significantly to the pharmacological activity of nilotinib.

Aliskiren – the only direct renin inhibitor which is clinically used as an antihypertensive drug. Aliskiren is the first of a new class of antihypertensive agents. Aliskiren is a new renin inhibitor of a novel structural class that has recently been shown to be efficacious in hypertensive patients after once-daily oral dosing. In short-term studies, it was effective in lowering blood pressure either alone or in combination with valsartan and hydrochlorothiazide, and had a low incidence of serious adverse effects. It was approved by the Food and Drug Administration in 2007 for the use as a monotherapy or in combination with other antihypertensives. Aliskiren is marketed under the trade name Tekturna. Aliskiren effectively reduces functional plasma renin activity by binding to renin with high affinity, preventing it from converting angiotensinogen to angiotensin I. The inhibition of renin by aliskiren is associated with a reduction in circulating levels of angiotensin I and II, with a resultant increase in plasma renin concentration and inhibit activation of mitogen-activated protein kinases ERK1 (p44) and ERK2 (p42).

Lenalidomide (trade name Revlimid) is a derivative of thalidomide introduced in 2004. It is an immunomodulatory agent with anti-angiogenic properties. Revlimid in combination with dexamethasone is indicated for the treatment of patients with multiple myeloma (MM) who have received at least one prior therapy. Also is indicated for the treatment of patients with transfusion-dependent anemia due to low- or intermediate-1-risk myelodysplastic syndromes (MDS) associated with a deletion 5q cytogenetic abnormality with or without additional cytogenetic abnormalities. In addition, Revlimid is indicated for the treatment of patients with mantle cell lymphoma (MCL) whose disease has relapsed or progressed after two prior therapies, one of which included bortezomib. The mechanism of action of lenalidomide remains to be fully characterized. Lenalidomide inhibited the secretion of pro-inflammatory cytokines and increased the secretion of anti-inflammatory cytokines from peripheral blood mononuclear cells. Lenalidomide causes a delay in tumor growth in some in vivo nonclinical hematopoietic tumor models including multiple myeloma. Immunomodulatory properties of lenalidomide include activation of T cells and natural killer (NK) cells, increased numbers of NKT cells, and inhibition of pro-inflammatory cytokines (e.g., TNF-α and IL-6) by monocytes. In multiple myeloma cells, the combination of lenalidomide and dexamethasone synergizes the inhibition of cell proliferation and the induction of apoptosis. Recently was discovered, that protein cereblon (CRBN) is a proximate, therapeutically important molecular target of lenalidomide. Low CRBN expression was found to correlate with drug resistance in multiple myeloma (MM) cell lines and primary MM cells. One of the downstream targets of CRBN identified is interferon regulatory factor 4 (IRF4), which is critical for myeloma cell survival and is down-regulated by (immune-modulatory drugs) treatment. CRBN is also implicated in several effects of immunomodulatory drugs, such as down-regulation of tumor necrosis factor-α (TNF-α) and T cell immunomodulatory activity, demonstrating that the pleotropic actions of the immunomodulatory drugs (IMiDs) are initiated by binding to CRBN. Future dissection of CRBN downstream signaling will help to delineate the underlying mechanisms for IMiD action and eventually lead to development of new drugs with more specific anti-myeloma activities. It may also provide a biomarker to predict IMiD response and resistance. Lenalidomide also inhibited the expression of cyclooxygenase-2 (COX-2) but not COX-1 in vitro.

Emtricitabine was discovered by Emory researchers Dr. Dennis C. Liotta, Dr. Raymond F. Schinazi and Dr. Woo-Baeg Choi and licensed to Triangle Pharmaceuticals by Emory University in 1996. Triangle was acquired by Gilead in 2003. Emtricitabine, marketed by Gilead as Emtriva, was first approved by the U.S. Food and Drug Administration in July 2003 for the treatment of HIV infection in combination with other antiretroviral agents. Emtricitabine, a synthetic nucleoside analog of cytidine, is phosphorylated by cellular enzymes to form emtricitabine 5'-triphosphate. Emtricitabine 5'-triphosphate inhibits the activity of the HIV-1 reverse transcriptase by competing with the natural substrate deoxycytidine 5'-triphosphate and by being incorporated into nascent viral DNA which results in chain termination.

Naratriptan (trade names include Amerge and Naramig) is a triptan drug marketed by GlaxoSmithKline and is used for the treatment of migraine headaches.Naratriptan is a selective agonist of serotonin (5-hydroxytryptamine; 5-HT) type 1B and 1D receptors. It is structurally and pharmacologically related to other selective 5-HT1B/1D receptor agonist. Naratriptan has only a weak affinity for 5-HT1A, 5-HT5A, and 5-HT7 receptors and no significant affinity or pharmacological activity at 5-HT2, 5-HT3 or 5-HT4 receptor subtypes or at alpha1-, alpha2-, or beta-adrenergic, dopamine1,; dopamine2; muscarinic, or benzodiazepine receptors. This action in humans correlates with the relief of migraine headache. In addition to causing vasoconstriction, experimental data from animal studies show that Naratriptan also activates 5-HT1 receptors on peripheral terminals of the trigeminal nerve innervating cranial blood vessels, which may also contribute to the antimigrainous effect of Naratriptan in humans.Three distinct pharmacological actions have been implicated in the antimigraine effect of the triptans: (1) stimulation of presynaptic 5-HT1D receptors, which serves to inhibit both dural vasodilation and inflammation; (2) direct inhibition of trigeminal nuclei cell excitability via 5-HT1B/1D receptor agonism in the brainstem and (3) vasoconstriction of meningeal, dural, cerebral or pial vessels as a result of vascular 5-HT1B receptor agonism.