Raloxifene (marketed as Evista by Eli Lilly and Company) is an oral selective estrogen receptor modulator (SERM) that has estrogenic actions on bone and anti-estrogenic actions on the uterus and breast. Raloxifene binds to estrogen receptors, resulting in differential expression of multiple estrogen-regulated genes in different tissues. Raloxifene produces estrogen-like effects on bone, reducing resorption of bone and increasing bone mineral density in postmenopausal women, thus slowing the rate of bone loss. The maintenance of bone mass by raloxifene and estrogens is, in part, through the regulation of the gene-encoding transforming growth factor-β3 (TGF-β3), which is a bone matrix protein with antiosteoclastic properties. Raloxifene activates TGF-β3 through pathways that are estrogen receptor-mediated but involve DNA sequences distinct from the estrogen response element. The drug also binds to the estrogen receptor and acts as an estrogen agonist in preosteoclastic cells, which results in the inhibition of their proliferative capacity. This inhibition is thought to contribute to the drug's effect on bone resorption. Other mechanisms include the suppression of the activity of the bone-resorbing cytokine interleukin-6 promoter activity. Raloxifene also antagonizes the effects of estrogen on mammary tissue and blocks uterotrophic responses to estrogen. By competing with estrogens for the estrogen receptors in reproductive tissue, raloxifene prevents the transcriptional activation of genes containing the estrogen response element. As well, raloxifene inhibits the estradiol-dependent proliferation of MCF-7 human mammary tumor cells in vitro. The mechanism of action of raloxifene has not been fully determined, but evidence suggests that the drug's tissue-specific estrogen agonist or antagonist activity is related to the structural differences between the raloxifene-estrogen receptor complex (specifically the surface topography of AF-2) and the estrogen-estrogen receptor complex. Also, the existence of at least 2 estrogen receptors (ERα, ERβ) may contribute to the tissue specificity of raloxifene. Raloxifene is indicated for the treatment and prevention of osteoporosis in postmenopausal women. It is also used for reduction of risk and treatment of invasive breast cancer, and it also reduces breast density. For either osteoporosis treatment or prevention, supplemental calcium and/or vitamin D should be added to the diet if daily intake is inadequate. Common adverse events considered to be drug-related were hot flashes and leg cramps.

Letrozole (trade name Femara), a nonsteroidal aromatase inhibitor. Femara is indicated for the adjuvant treatment of postmenopausal women with hormone receptor positive early breast cancer. Also is indicated for the extended adjuvant treatment of early breast cancer in postmenopausal women, who have received 5 years of adjuvant tamoxifen therapy. Femara has to be used for first-line treatment of postmenopausal women with hormone receptor positive or unknown, locally advanced or metastatic breast cancer and for the treatment of advanced breast cancer in postmenopausal women with disease progression following antiestrogen therapy. Treatment of breast cancer thought to be hormonally responsive (i.e., estrogen and/or progesterone receptor positive or receptor unknown) has included a variety of efforts to decrease estrogen levels (ovariectomy, adrenalectomy, hypophysectomy) or inhibit estrogen effects (antiestrogens and progestational agents). These interventions lead to decreased tumor mass or delayed progression of tumor growth in some women. In postmenopausal women, estrogens are mainly derived from the action of the aromatase enzyme, which converts adrenal androgens (primarily androstenedione and testosterone) to estrone and estradiol. The suppression of estrogen biosynthesis in peripheral tissues and in the cancer tissue itself can therefore be achieved by specifically inhibiting the aromatase enzyme. Letrozole inhibits the conversion of androgens to estrogens. Letrozole selectively inhibits gonadal steroidogenesis but has no significant effect on adrenal mineralocorticoid or glucocorticoid synthesis. Letrozole inhibits the aromatase enzyme by competitively binding to the heme of the cytochrome P450 subunit of the enzyme, resulting in a reduction of estrogen biosynthesis in all tissues. Treatment of women with letrozole significantly lowers serum estrone, estradiol and estrone sulfate and has not been shown to significantly affect adrenal corticosteroid synthesis, aldosterone synthesis, or synthesis of thyroid hormones. Letrozole is rapidly and completely absorbed from the gastrointestinal tract and absorption is not affected by food. Metabolism to a pharmacologically inactive carbinol metabolite (4,4'¬ methanol-bisbenzonitrile) and renal excretion of the glucuronide conjugate of this metabolite is the major pathway of letrozole clearance. In human microsomes with specific CYP isozyme activity, CYP3A4 metabolized letrozole to the carbinol metabolite while CYP2A6 formed both this metabolite and its ketone analog. In human liver microsomes, letrozole strongly inhibited CYP2A6 and moderately inhibited CYP2C19. The most common side effects are sweating, hot flashes, arthralgia (joint pain), and fatigue

Fomepizole (4-methylpyrazole) is a competitive ADH inhibitor. Fomepizole has been shown in vitro to block alcohol dehydrogenase enzyme activity in dog, monkey and human liver. Fomepizole is indicated as an antidote for ethylene glycol (such as antifreeze) or methanol poisoning, or for use in suspected ethylene glycol or methanol ingestion, either alone or in combination with hemodialysis. It should be given when a known or suspected toxic ethylene glycol or methanol ingestion has occurred and the patient has metabolic acidosis and elevated osmolar gap. The most frequent adverse events reported as drug-related or unknown relationship were headache (14%), nausea (11%), and dizziness, increased drowsiness, and bad taste/metallic taste. Reciprocal interactions may occur with concomitant use of fomepizole and drugs that increase or inhibit the cytochrome P450 system (e.g. phenytoin, carbamazepine, cimetidine, ketoconazole). Fomepizole has been shown to induce the expression of CYP2E1 and to inhibit its activity. These effects were enhanced in rats that had been exposed to ethanol. Fomepizole may also inhibit other CYP enzymes and therefore may alter the exposure to other drugs that are metabolised by CYP enzymes.

Zafirlukast is an oral leukotriene receptor antagonist (LTRA) for the maintenance treatment of asthma, often used in conjunction with an inhaled steroid and/or long-acting bronchodilator. It is available as a tablet and is usually dosed twice daily. Zafirlukast is indicated for the prophylaxis and chronic treatment of asthma. Patients with asthma were found in one study to be 25-100 times more sensitive to the bronchoconstricting activity of inhaled LTD4 than nonasthmatic subjects. In vitro studies demonstrated that zafirlukast antagonized the contractile activity of three leukotrienes (LTC4, LTD4 and LTE4) in conducting airway smooth muscle from laboratory animals and humans. Zafirlukast prevented intradermal LTD4-induced increases in cutaneous vascular permeability and inhibited inhaled LTD4-induced influx of eosinophils into animal lungs. Zafirlukast is a selective and competitive receptor antagonist of leukotriene D4 and E4 (LTD4 and LTE4), components of slow-reacting substance of anaphylaxis (SRSA). Cysteinyl leukotriene production and receptor occupation have been correlated with the pathophysiology of asthma, including airway edema, smooth muscle constriction, and altered cellular activity associated with the inflammatory process, which contribute to the signs and symptoms of asthma. Zafirlukast is marketed by Astra Zeneca with the brand names Accolate, Accoleit, and Vanticon. It was the first LTRA to be marketed in the USA and is now approved in over 60 countries, including the UK, Japan, Taiwan, Italy, Spain, Canada, Brazil, China and Turkey.

Midodrine is a prodrug, i.e., the therapeutic effect of orally administered midodrine is due to the major metabolite desglymidodrine formed by deglycination of midodrine. Desglymidodrine diffuses poorly across the blood-brain barrier, and is therefore not associated with effects on the central nervous system. Administration of midodrine results in a rise in standing, sitting, and supine systolic and diastolic blood pressure in patients with orthostatic hypotension of various etiologies. Standing systolic blood pressure is elevated by approximately 15 to 30 mmHg at 1 hour after a 10-mg dose of midodrine, with some effect persisting for 2 to 3 hours. Midodrine has no clinically significant effect on standing or supine pulse rates in patients with autonomic failure. Midodrine forms an active metabolite, desglymidodrine, that is an alpha1-agonist, and exerts its actions via activation of the alpha-adrenergic receptors of the arteriolar and venous vasculature, producing an increase in vascular tone and elevation of blood pressure. Desglymidodrine does not stimulate cardiac beta-adrenergic receptors. Midodrine is used for the treatment of symptomatic orthostatic hypotension (OH). Midodrine is marketed under the brand names Amatine, ProAmatine, Gutron.

Atorvastatin calcium (LIPITOR®) is a pyrrole and heptanoic acid derivative, a synthetic lipid-lowering agent. Atorvastatin is a selective, competitive inhibitor of 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase. This enzyme catalyzes the conversion of HMG-CoA to mevalonate, an early and rate-limiting step in cholesterol biosynthesis. Atorvastatin is used to reduce serum levels of LDL(low-density lipoprotein)-cholesterol; apolipoprotein B; and triglycerides and to increase serum levels of HDL(high-density lipoprotein)-cholesterol in the treatment of hyperlipidemias and prevention of cardiovascular disease in patients with multiple risk factors.

Remifentanil (marketed by Abbott as Ultiva) is a potent ultra short-acting synthetic opioid analgesic drug. It is given to patients during surgery to relieve pain and as an adjunct to an anaesthetic. ULTIVA is a µ-opioid agonist with rapid onset and peak effect, and short duration of action. The µ-opioid activity of ULTIVA is antagonized by opioid antagonists such as naloxone. ULTIVA is indicated for IV administration: 1. As an analgesic agent for use during the induction and maintenance of general anesthesia for inpatient and outpatient procedures. 2. For continuation as an analgesic into the immediate postoperative period in adult patients under the direct supervision of an anesthesia practitioner in a postoperative anesthesia care unit or intensive care setting. 3. As an analgesic component of monitored anesthesia care in adult patients.

Cefepime is a fourth-generation cephalosporin antibiotic, which was developed in 1994. Cefepime has a broad spectrum in vitro activity that encompasses a wide range of Gram-positive and Gram-negative bacteria. Within bacterial cells, the molecular targets of cefepime are the penicillin binding proteins (PBP). It is FDA approved for the treatment of pneumonia, febrile neutropenia, uncomplicated UTI, uncomplicated skin infection and complicated intraabdominal infections. Common adverse reactions include rash, hypophosphatemia, diarrhea. Cefepime is metabolized to N-methylpyrrolidine (NMP) which is rapidly converted to the N-oxide (NMP-N-oxide). Urinary recovery of unchanged cefepime accounts for approximately 85% of the administered dose. Less than 1% of the administered dose is recovered from urine as NMP, 6.8% as NMP-N-oxide, and 2.5% as an epimer of cefepime. Because renal excretion is a significant pathway of elimination, patients with renal dysfunction and patients undergoing hemodialysis require dosage adjustment.

Cabergoline is a long-acting dopamine receptor agonist with a high affinity for D2 receptors. Results of in vitro studies demonstrate that cabergoline exerts a direct inhibitory effect on the secretion of prolactin by rat pituitary lactotrophs. It is FDA approved for the treatment of hyperprolactinemic disorders, either idiopathic or due to pituitary adenomas. Common adverse reactions include constipation, nausea, dizziness, headache and fatigue. Cabergoline should not be administered concurrently with D-antagonists, such as phenothiazines, butyrophenones, thioxanthenes, or metoclopramide.

Fexofenadine is a second-generation, long lasting H1-receptor antagonist (antihistamine) which has a selective and peripheral H1-antagonist action. Histamine is a chemical that causes many of the signs that are part of allergic reactions, such as the swelling of tissues. Histamine is released from histamine-storing cells (mast cells) and attaches to other cells that have receptors for histamine. The attachment of the histamine to the receptors causes the cell to be "activated," releasing other chemicals which produce the effects that we associate with allergy. Fexofenadine blocks one type of receptor for histamine (the H1 receptor) and thus prevents activation of cells by histamine. Unlike most other antihistamines, Fexofenadine does not enter the brain from the blood and, therefore, does not cause drowsiness. Fexofenadine lacks the cardiotoxic potential of terfenadine, since it does not block the potassium channel involved in repolarization of cardiac cells. Fexofenadine is sold under the trade name Allegra among others. ALLEGRA is indicated for the relief of symptoms associated with seasonal allergic rhinitis in adults and children 2 years of age and older.