Escitalopram is one of a class of antidepressants known as selective serotonin reuptake inhibitors (SSRIs). Escitalopram, also known by the brand names Lexapro and Cipralex among others, is an antidepressant. The mechanism of antidepressant action of escitalopram, the S-enantiomer of racemic citalopram, is presumed to be linked to potentiation of serotonergic activity in the central nervous system (CNS) resulting from its inhibition of CNS neuronal reuptake of serotonin (5-HT). In vitro and in vivo studies in animals suggest that escitalopram is a highly selective serotonin reuptake inhibitor (SSRI) with minimal effects on norepinephrine and dopamine neuronal reuptake. Escitalopram is at least 100-fold more potent than the R-enantiomer with respect to inhibition of 5-HT reuptake and inhibition of 5-HT neuronal firing rate. LEXAPRO (escitalopram) is indicated for the treatment of major depressive disorder and generalized anxiety disorder .

Desloratadine is an active, descarboethoxy metabolite of loratadine. It acts by selective inhibition of H1 histamine receptor and thus provides relief to patients with allergic rhinitis and chronic idiopathic urticaria. Desloratadine was approved by FDA and it is currently marketed under the name Clarinex (among the others).

Galantamine (RAZADYNE®, galantamine hydrobromide) is a benzazepine derived from norbelladine. It is found in Galanthus and other Amaryllidaceae. It is a reversible, competitive acetylcholinesterase inhibitor that is used for the treatment of mild to moderate dementia of the Alzheimer’s type. Although the etiology of cognitive impairment in Alzheimer’s disease is not fully understood, it has been reported that acetylcholine-producing neurons degenerate in the brains of patients with Alzheimer’s disease. The degree of this cholinergic loss has been correlated with degree of cognitive impairment and density of amyloid plaques (a neuropathological hallmark of Alzheimer’s disease). While the precise mechanism of galantamine’s (RAZADYNE®, galantamine hydrobromide) action is unknown, it is postulated to exert its therapeutic effect by enhancing cholinergic function. This is accomplished by increasing the concentration of acetylcholine through reversible inhibition of its hydrolysis by acetylcholinesterase. If this mechanism is correct, galantamine’s (RAZADYNE®, galantamine hydrobromide) effect may lessen as the disease process advances and fewer cholinergic neurons remain functionally intact. There is no evidence that galantamine (RAZADYNE®, galantamine hydrobromide) alters the course of the underlying dementing process.

Ertapenem is a carbapenem antibiotic marketed by Merck as Invanz. The bactericidal activity of ertapenem results from the inhibition of cell wall synthesis and is mediated through ertapenem binding to penicillin binding proteins (PBPs). In Escherichia coli, it has strong affinity toward PBPs 1a, 1b, 2, 3, 4 and 5 with preference for PBPs 2 and 3. Ertapenem has been designed to be effective against Gram-negative and Gram-positive bacteria. The most common drug-related adverse experiences in patients treated with INVANZ, including those who were switched to therapy with an oral antimicrobial, were diarrhea (5.5%), infused vein complication (3.7%), nausea (3.1%), headache (2.2%), vaginitis in females (2.1%), phlebitis/thrombophlebitis (1.3%), and vomiting (1.1%). The coadministration with probenecid to extend the half-life of ertapenem is not recommended.

Frovatriptan succinate (trade name Frova) is a selective 5-hydroxytryptamine1 (5-HT1B/1D) receptor subtype agonist, and is used for the treatment of migraine attacks with or without aura in adults. Frovatriptan has no significant effects on GABAA mediated channel activity and has no significant affinity for benzodiazepine binding sites. Frovatriptan is believed to act on extracerebral, intracranial arteries and to inhibit excessive dilation of these vessels in migraine. Serious but rare cardiac events have been reported in patients with risk factors predictive of coronary artery disease (CAD). These include coronary artery vasospasm, transient myocardial ischemia, myocardial infarction, ventricular tachycardia and ventricular fibrillation.

Pimecrolimus, an ascomycin macrolactam derivative, is an inhibitor of T-cell and mast-cell activation, developed and launched by Novartis for the potential treatment of psoriasis and allergic, irritant and atopic dermatitis. The topical formulation had been launched in the US by February 2002 for mild-to-moderate atopic dermatitis in patients aged two years and older. Pimecrolimus is an immunomodulating agent. The mechanism of action of pimecrolimus in atopic dermatitis is not known. While the following have been observed, the clinical significance of these observations in atopic dermatitis is not known. It has been demonstrated that pimecrolimus binds with high affinity to macrophilin-12 (FKBP-12) and inhibits the calcium dependent phosphatase, calcineurin. Therefore, it inhibits T cell activation by blocking the transcription of early cytokines. In particular, pimecrolimus inhibits at nanomolar concentrations Interleukin-2 and interferon gamma (Th1-type) and Interleukin-4 and Interleukin-10 (Th2-type) cytokine synthesis in human T-cells. In addition, pimecrolimus prevents the release of inflammatory cytokines and mediators from mast cells in vitro after stimulation by antigen/IgE. Following the administration of a single oral radiolabeled dose of pimecrolimus numerous circulating O-demethylation metabolites were seen. Studies with human liver microsomes indicate that pimecrolimus is metabolized in vitro by the CYP3A sub-family of metabolizing enzymes. No evidence of skin mediated drug metabolism was identified in vivo using the minipig or in vitro using stripped human skin.

Imatinib (GLEEVEC®) is a tyrosine kinase inhibitor and antineoplastic agent that inhibits the BCR-ABL tyrosine kinase, the constitutive abnormal tyrosine kinase created by the Philadelphia chromosome abnormality in chronic myeloid leukaemia (CML). It inhibits proliferation and induces apoptosis in BCR-ABL positive cell lines as well as fresh leukemic cells from Philadelphia chromosome positive CML. Imatinib (GLEEVEC®) inhibits colony formation in assays using ex vivo peripheral blood and bone marrow samples from CML patients. It is also an inhibitor of the receptor tyrosine kinases for platelet-derived growth factor (PDGF) and stem cell factor (SCF), c-kit, and inhibits PDGF- and SCF-mediated cellular events. In vitro, imatinib (GLEEVEC®) inhibits proliferation and induces apoptosis in gastrointestinal stromal tumor (GIST) cells, which express an activating c-kit mutation.

Almotriptan is a triptan drug for the treatment of migraine headaches. Almotriptan is marketed under the trade name Axert. Almotriptan is used for treating acute migraine headaches with or without aura (eg, dark spots, flashing lights, wavy lines). Almotriptan binds with high affinity to 5-HT1D, 5-HT1B, and 5-HT1F receptors. Almotriptan has weak affinity for 5-HT1A and 5-HT7 receptors, but has no significant affinity or pharmacological activity at 5-HT2, 5-HT3, 5-HT4, 5-HT6; alpha or beta adrenergic; adenosine (A1, A2); angiotensin (AT1, AT2); dopamine (D1, D2); endothelin (ETA, ETB); or tachykinin (NK1, NK2, NK3) binding sites.

Dutasteride is a synthetic 4-azasteroid compound that is a selective inhibitor of both the type 1 and type 2 isoforms of steroid 5 alpha-reductase (5AR), intracellular enzymes that convert testosterone to 5 alpha-dihydrotestosterone (DHT). Type I 5a-reductase is predominant in the sebaceous glands of most regions of skin, including scalp, and liver. Type I 5a-reductase is responsible for approximately one-third of circulating DHT. The Type II 5a-reductase isozyme is primarily found in prostate, seminal vesicles, epididymides, and hair follicles as well as liver, and is responsible for two-thirds of circulating DHT. Dutasteride inhibits the conversion of testosterone to 5 alpha-dihydrotestosterone (DHT), which is the androgen primarily responsible for the initial development and subsequent enlargement of the prostate gland. Testosterone is converted to DHT by the enzyme 5 alpha-reductase, which exists as 2 isoforms, type 1 and type 2. Dutasteride is a competitive and specific inhibitor of both type 1 and type 2 5 alpha-reductase isoenzymes, with which it forms a stable enzyme complex. Dissociation from this complex has been evaluated under in vitro and in vivo conditions and is extremely slow. Used for the treatment of symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate gland to improve symptoms, and reduce the risk of acute urinary retention and the need for surgery. Marketed under the brand name Avodart.

Cevimeline is a cholinergic agonist, which binds to muscarinic receptors. Muscarinic agonists in sufficient dosage can increase secretion of exocrine glands, such as salivary and sweat glands and increase tone of the smooth muscle in the gastrointestinal and urinary tracts. Cevimeline is indicated for the treatment of symptoms of dry mouth in patients with Sjögren’s Syndrome. Known side effects include nausea, vomiting, diarrhea, excessive sweating, rash, headache, runny nose, cough, drowsiness, hot flashes, blurred vision, and difficulty sleeping. Cevimeline should be administered with caution to patients taking beta adrenergic antagonists, because of the possibility of conduction disturbances. Drugs with para-sympathomimetic effects administered concurrently with cevimeline can be expected to have additive effects. Cevimeline might interfere with desirable antimuscarinic effects of drugs used concomitantly.