Valsartan (DIOVAN®) is a tetrazole derivative, and specific angiotensin II type 1 (AT1) receptor blocker that is indicated for the treatment of hypertension, to lower blood pressure. Angiotensin II is formed from angiotensin I in a reaction catalyzed by angiotensin-converting enzyme. Angiotensin II is the principal pressor agent of the renin-angiotensin system, with effects that include vasoconstriction, stimulation of synthesis and release of aldosterone, cardiac stimulation, and renal reabsorption of sodium. Valsartan (DIOVAN®) blocks the vasoconstrictor and aldosterone-secreting effects of angiotensin II by selectively blocking the binding of angiotensin II to the AT1 receptor in many tissues, such as vascular smooth muscle and the adrenal gland. Its action is therefore independent of the pathways for angiotensin II synthesis.

Donepezil, marketed under the trade name Aricept, is a medication used in the palliative treatment of Alzheimer's disease. Aricept is indicated for the treatment of dementia of the Alzheimer’s type. Efficacy has been demonstrated in patients with mild to moderate Alzheimer’s Disease, as well as in patients with severe Alzheimer’s Disease. Donepezil 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. Donepezil has been tested in other cognitive disorders including Lewy body dementia and Vascular dementia, but it is not currently approved for these indications. Donepezil has also been studied in patients with Mild Cognitive Impairment, schizophrenia, attention deficit disorder, post-coronary bypass cognitive impairment, cognitive impairment associated with multiple sclerosis, and Down syndrome.

Adapalene is a topical retinoid primarily used in the treatment of acne and is used (off-label) to treat keratosis pilaris as well as other skin conditions. Galderma currently markets it under the trade names Differin in some countries, and Adaferin in India. Adapalene acts on retinoid receptors. Biochemical and pharmacological profile studies have demonstrated that adapalene is a modulator of cellular differentiation, keratinization, and inflammatory processes all of which represent important features in the pathology of acne vulgaris. Mechanistically, adapalene binds to specific retinoic acid nuclear receptors but does not bind to the cytosolic receptor protein. Although the exact mode of action of adapalene is unknown, it is suggested that topical adapalene normalizes the differentiation of follicular epithelial cells resulting in decreased microcomedone formation.

Topotecan, a semi-synthetic derivative of camptothecin (a plant alkaloid obtained from the Camptotheca acuminata tree), is an anti-tumor drug with topoisomerase I-inhibitory activity similar to irinotecan. DNA topoisomerases are enzymes in the cell nucleus that regulate DNA topology (3-dimensional conformation) and facilitate nuclear processes such as DNA replication, recombination, and repair. During these processes, DNA topoisomerase I creates reversible single-stranded breaks in double-stranded DNA, allowing intact single DNA strands to pass through the break and relieve the topologic constraints inherent in supercoiled DNA. The 3'-DNA terminus of the broken DNA strand binds covalently with the topoisomerase enzyme to form a catalytic intermediate called a cleavable complex. After DNA is sufficiently relaxed and the strand passage reaction is complete, DNA topoisomerase reattaches the broken DNA strands to form the unaltered topoisomers that allow transcription to proceed. Topotecan interferes with the growth of cancer cells, which are eventually destroyed. Since the growth of normal cells can be affected by the medicine, other effects may also occur. Unlike irinotecan, topotecan is found predominantly in the inactive carboxylate form at neutral pH and it is not a prodrug. Topotecan has the same mechanism of action as irinotecan and is believed to exert its cytotoxic effects during the S-phase of DNA synthesis. Topoisomerase I relieves torsional strain in DNA by inducing reversible single strand breaks. Topotecan binds to the topoisomerase I-DNA complex and prevents religation of these single strand breaks. This ternary complex interferes with the moving replication fork, which leads to the induction of replication arrest and lethal double-stranded breaks in DNA. As mammalian cells cannot efficiently repair these double strand breaks, the formation of this ternary complex eventually leads to apoptosis (programmed cell death). Topotecan mimics a DNA base pair and binds at the site of DNA cleavage by intercalating between the upstream (−1) and downstream (+1) base pairs. Intercalation displaces the downstream DNA, thus preventing religation of the cleaved strand. By specifically binding to the enzyme–substrate complex, Topotecan acts as an uncompetitive inhibitor. Topotecan is used for the treatment of advanced ovarian cancer in patients with disease that has recurred or progressed following therapy with platinum-based regimens. Also used as a second-line therapy for treatment-sensitive small cell lung cancer, as well as in combination with cisplatin for the treatment of stage IV-B, recurrent, or persistent cervical cancer not amenable to curative treatment with surgery and/or radiation therapy. Topotecan is sold under the trade name Hycamtin.

Topiramate is an anticonvulsant indicated in the treatment of epilepsy and migraine. Topiramate enhances GABA-activated chloride channels. In addition, topiramate inhibits excitatory neurotransmission, through actions on kainate and AMPA receptors. There is evidence that topiramate has a specific effect on GluR5 kainate receptors. It is also an inhibitor of carbonic anhydrase, particular subtypes II and IV, but this action is weak and unlikely to be related to its anticonvulsant actions, but may account for the bad taste and the development of renal stones seen during treatment. Its possible effect as a mood stabilizer seems to occur before anticonvulsant qualities at lower dosages. Topiramate inhibits maximal electroshock and pentylenetetrazol-induced seizures as well as partial and secundarily generalized tonic-clonic seizures in the kindling model, findings predective of a broad spectrum of antiseizure activities clinically. The precise mechanism of action of topiramate is not known. However, studies have shown that topiramate blocks the action potentials elicited repetitively by a sustained depolarization of the neurons in a time-dependent manner, suggesting a state-dependent sodium channel blocking action. Topiramate also augments the activity of the neurotransmitter gamma-aminobutyrate (GABA) at some subtypes of the GABAAreceptor (controls an integral chloride channel), indicating a possible mechanism through potentiation of the activity of GABA. Topiramate also demonstrates antagonism of the AMPA/kainate subtype of the glutamate excitatory amino acid receptor. It also inhibits carbonic anhydrase (particularly isozymes II and IV), but this action is weak and unlikely to be related to its anticonvulsant actions. Topiramate is used for the treatment and control of partial seizures and severe tonic-clonic (grand mal) seizures and also for the prevention of migraine headaches. In children it is also used for treatment of Lennox-Gastaut syndrome. Topiramate is sold under the brand name Topamax. A combination product containing phentermine and topiramate extended-release called QSYMIA® is indicated for the management of obesity.

Acitretin is all-Trans-9-(4-methoxy-2, 3, 6¬ trimethylphenyl)-three, 7-dimethyl-2, 4, 6, 8-nonatetraenoic acid. It is a metabolite of exterminate and is related to both retinoic acid and retinol (vitamin A). It is taken orally, and is typically used for psoriasis. The mechanism of action of is unknown. However it is believed to work by targeting specific receptors (retinoid receptors such as RXR and RAR) in the skin, which help normalize the growth cycle of skin cells. Studies on nuclear retinoic acid receptors have shown that acitretin activates all 3 receptor subtypes (RAR-alpha, -beta, and -gamma) without measurable receptor binding; this paradox remains unexplained.

Nisoldipine is a 1,4-dihydropyridine derivative with an outstanding vascular selectivity. As a specific calcium antagonist, it shortens the action potential and causes electromechanical uncoupling in ventricular myocardium. However, this effect, resulting in a negative inotropic action, appears at 100–1000 times higher concentrations of nisoldipine in comparison with its inhibition of calcium-dependent vascular contractions. Detailed analyses of pharmacological effects revealed additional properties such as enhancement of sodium excretion, an interaction with the reninangiotensin-aldosterone system and a protective effect against acute renal ischaemia, that may contribute to its therapeutic efficacy. Nisoldipine was developed at Bayer then licensed to Zeneca and marketed in the United States as SULAR. SULAR is indicated for the treatment of hypertension. It may be used alone or in combination with other antihypertensive agents. The mechanism of the therapeutic effect of nisoldipine is complex. It involves a decrease of the total peripheral vascular resistance (reduction of afterload) and an increase in coronary blood flow. Moreover, nisoldipine obviously normalises the impaired volume homoeostasis by improving renal function and thus reduces the need for activation of the ANP system. In the advanced stages of hypertension, nisoldipine prevents deleterious calcium overload and the resulting tissue damage.

Lamivudine is a reverse transcriptase inhibitor used alone or in combination with other classes of anti-human immunodeficiency virus (HIV) drugs in the treatment of HIV infection. This molecule has two stereo-centers, thus giving rise to four stereoisomers: (+/-)-cis-lamivudine and (+/-)-trans-lamivudine. The latter is considered to be impurity of the pharmaceutically active isomer, (-)-cis-lamivudine.

Riluzole, a member of the benzothiazole class, is indicated for the treatment of patients with amyotrophic lateral sclerosis. Its pharmacological properties include the following, some of which may be related to its effect: 1) an inhibitory effect on glutamate release (activation of glutamate reuptake), 2) inactivation of voltage-dependent sodium channels, and 3) ability to interfere with intracellular events that follow transmitter binding at excitatory amino acid receptors. Common adverse reactions include headache, abdominal pain, back pain, vomiting, dyspepsia, diarrhea, dizziness. Riluzole-treated patients that take other hepatotoxic drugs may be at increased risk for hepatotoxicity.

Anastrozole (marketed under the trade name Arimidex by AstraZeneca) is a drug indicated in the treatment of breast cancer in post-menopausal women. It is used both in adjuvant therapy (i.e. following surgery) and in metastatic breast cancer. It decreases the amount of estrogens that the body makes. Anastrozole belongs in the class of drugs known as aromatase inhibitors. It inhibits the enzyme aromatase, which is responsible for converting androgens (produced by women in the adrenal glands) to estrogens. The growth of many cancers of the breast is stimulated or maintained by estrogens. 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. Anastrozole is a selective non-steroidal aromatase inhibitor. It significantly lowers serum estradiol concentrations and has no detectable effect on formation of adrenal corticosteroids or aldosterone.