Candesartan is classified as an angiotensin II receptor type 1 antagonist. Candesartan is an orally active lipophilic drug and possesses rapid oral absorption. It causes a reduction in blood pressure and is used in the treatment of hypertension. It is also used in the treatment of congestive heart failure and given as prophylaxis to reduce the severity and duration of migraine. Candesartan cilexetil, a prodrug of Candesartan, is available in the market under the trade names Atacand, Amias. Candesartan cilexetil is rapidly converted to candesartan, its active metabolite, during absorption from the gastrointestinal tract. Candesartan confers blood pressure lowering effects by antagonizing the hypertensive effects of angiotensin II via the RAAS (renin–angiotensin–aldosterone system). RAAS is a homeostatic mechanism for regulating hemodynamics, water, and electrolyte balance. During sympathetic stimulation or when renal blood pressure or blood flow is reduced, renin is released from granular cells of the juxtaglomerular apparatus in the kidneys. Renin cleaves circulating angiotensinogen to angiotensin I, which is cleaved by angiotensin converting enzyme (ACE) to angiotensin II. Angiotensin II increases blood pressure by increasing total peripheral resistance, increasing sodium and water reabsorption in the kidneys via aldosterone secretion, and altering the cardiovascular structure. Angiotensin II binds to two receptors: type-1 angiotensin II receptor (AT1) and type-2 angiotensin II receptor (AT2). Candesartan selectively blocks the binding of angiotensin II to AT1 in many tissues including vascular smooth muscle and the adrenal glands. This inhibits the AT1-mediated vasoconstrictive and aldosterone-secreting effects of angiotensin II and results in an overall decrease in blood pressure. Candesartan is greater than 10,000 times more selective for AT1 than AT2.

Risedronic acid is a pyridinyl bisphosphonate that inhibits osteoclast-mediated bone resorption and modulates bone metabolism. The action of risedronate on bone tissue is based partly on its affinity for hydroxyapatite, which is part of the mineral matrix of bone. Risedronate also targets farnesyl pyrophosphate (FPP) synthase. It is FDA approved for the treatment of postmenopausal osteoporosis, osteoporosis in men, glucocorticoid-induced osteoporosis and Paget’s disease. Calcium, antacids, or oral medications containing divalent cations interfere with the absorption of Risedronic acid. Common adverse reactions include rash, abdominal pain, constipation, diarrhea, indigestion, nausea, backache, urinary tract infectious disease and influenza-like illness.

Tiagabine (trade name Gabitril) is an anticonvulsant medication used in the treatment of Partial Seizures. The precise mechanism by which Tiagabine exerts its antiseizure effect is unknown, although it is believed to be related to its ability to enhance the activity of gamma-aminobutyric acid (GABA), the major inhibitory neurotransmitter in the central nervous system. Tiagabine binds to recognition sites associated with the GABA uptake carrier. It is thought that, by this action, Tiagabine blocks GABA uptake into presynaptic neurons, permitting more GABA to be available for receptor binding on the surfaces of post-synaptic cells. Tiagabine is approved by U.S. Food and Drug Administration (FDA) as an adjunctive treatment for partial seizures in individuals of age 12 and up. It may also be prescribed off-label by physicians to treat anxiety disorders and panic disorder as well as neuropathic pain (including fibromyalgia). For anxiety and neuropathic pain, tiagabine is used primarily to augment other treatments. Tiagabine may be used alongside selective serotonin reuptake inhibitors, serotonin-norepinephrine reuptake inhibitors, or benzodiazepines for anxiety, or antidepressants, gabapentin, other anticonvulsants, or opioids for neuropathic pain. The most common side effect of tiagabine is dizziness. Other side effects that have been observed with a rate of statistical significance relative to placebo include asthenia, somnolence, nervousness, memory impairment, tremor, headache, diarrhea, and depression.

Repaglinide is antidiabetic drug, which is sold under several names including, Prandin in the U.S., Surepost in Japan and GlucoNorm in Canada. It is an oral blood glucose-lowering drug of the meglitinide class used in the management of type 2 diabetes mellitus (also known as non-insulin dependent diabetes mellitus or NIDDM). Repaglinide lowers blood glucose levels by stimulating the release of insulin from the pancreas. This action is dependent upon functioning beta (ß) cells in the pancreatic islets. Insulin secretion by pancreatic β cells is partly controlled by cellular membrane potential. Membrane potential is regulated through an inverse relationship between the activity of cell membrane ATP-sensitive potassium channels (ABCC8) and extracellular glucose concentrations. Extracellular glucose enters the cell via GLUT2 (SLC2A2) transporters. Once inside the cell, glucose is metabolized to produce ATP. High concentrations of ATP inhibit ATP-sensitive potassium channels causing membrane depolarization. High glucose concentrations cause ATP-sensitive potassium channels to close resulting in membrane depolarization and opening of L-type calcium channels. The influx of calcium ions stimulates calcium-dependent exocytosis of insulin granules. Repaglinide closes ATP-dependent potassium channels in the ß-cell membrane by binding at characterizable sites. This potassium channel blockade depolarizes the ß-cell, which leads to an opening of calcium channels. The resulting increased calcium influx induces insulin secretion. The ion channel mechanism is highly tissue selective with low affinity for heart and skeletal muscle. Repaglinide is completely metabolized by oxidative biotransformation and direct conjugation with glucuronic acid after either an IV or oral dose.

Tazarotene is a prodrug and a member of the acetylenic class of retinoids. Following topical application, tazarotene undergoes esterase hydrolysis to form its active metabolite, tazarotenic acid. When treating acne tazarotene may be taken in conjunction with an oral antibiotic. Tazarotene has been shown in peer-reviewed double blinded studies to reduce: mottling and hyperpigmentation, sallowness, fine wrinkling and coarse wrinkling in sun damaged skin. Histological studies have shown that long term (greater than 1 year) use of Tazarotene is associated with a significant reduction in atypical melanocytes and keratocytes - cells considered to be precursors of skin cancer. Some studies have shown long term use of Tazarotene to be associated with increased collagen production and better organization of skin collagen bundles. Although the exact mechanism of tazarotene action is not known, studies have shown that the active form of the drug (tazarotenic acid) binds to all three members of the retinoic acid receptor (RAR) family: RARa, RARb, and RARg, but shows relative selectivity for RARb, and RARg and may modify gene expression. It also has affinity for RXR receptors. Tazarotene is used to treat psoriasis, acne and sun damaged skin (photodamage). Tazarotene is marketed as Tazorac, Avage, Zorac, and Fabior.

Cefdinir is an extended-spectrum, semisynthetic cephalosporin, for oral administration. As with other cephalosporins, bactericidal activity of cefdinir results from inhibition of cell wall synthesis. Cefdinir is stable in the presence of some, but not all, β-lactamase enzymes. Cefdinir is indicated for the treatment of: Community-Acquired Pneumonia, Acute Exacerbations of Chronic Bronchitis, Acute Maxillary Sinusitis, Pharyngitis/Tonsillitis and Uncomplicated Skin and Skin Structure Infections. Side effects include diarrhea, vaginal infections or inflammation, nausea, headache, and abdominal pain. Concomitant administration of 300-mg cefdinir capsules with 30 mL Maalox® TC suspension reduces the rate (Cmax) and extent (AUC) of absorption by approximately 40%. As with other β-lactam antibiotics, probenecid inhibits the renal excretion of cefdinir.

Bromfenac is a topical, nonsteroidal anti-inflammatory drug (NSAID) for ophthalmic use. It is indicated for the treatment of postoperative inflammation and reduction of ocular pain in patients who have undergone cataract surgery. The mechanism of its action is thought to be due to its ability to block prostaglandin synthesis by inhibiting cyclooxygenase 1 and 2. The most commonly reported adverse reactions in 3 to 8% of patients were anterior chamber inflammation, foreign body sensation, eye pain, photophobia and vision blurred.

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.

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.