Efavirenz (brand names Sustiva® and Stocrin®) is a non-nucleoside reverse transcriptase inhibitor (NNRTI) and is used as part of highly active antiretroviral therapy (HAART) for the treatment of a human immunodeficiency virus (HIV) type 1. For HIV infection that has not previously been treated, efavirenz and lamivudine in combination with zidovudine or tenofovir is the preferred NNRTI-based regimen. Efavirenz is also used in combination with other antiretroviral agents as part of an expanded postexposure prophylaxis regimen to prevent HIV transmission for those exposed to materials associated with a high risk for HIV transmission.

Montelukast (SINGULAIR®) is a selective and orally active leukotriene D4 (LTD4) receptor antagonist that inhibits the cysteinyl leukotriene CysLT1 receptor. It is indicated for the prophylaxis and chronic treatment of asthma, for prevention of exercise-induced bronchoconstriction, and for the relief of symptoms of seasonal allergic rhinitis. LTD4 is a product of arachidonic acid metabolism and is released from various cells, including mast cells and eosinophils. This eicosanoid binds to CysLT1 receptor found in the human airway (including airway smooth muscle cells and airway macrophages) and on other pro-inflammatory cells (including eosinophils and certain myeloid stem cells). Cysteinyl leukotriene receptors (CysLTs) have been correlated with the pathophysiology of asthma and allergic rhinitis. In asthma, leukotriene-mediated effects include airway edema, smooth muscle contraction, and altered cellular activity associated with the inflammatory process. In allergic rhinitis, CysLTs are released from the nasal mucosa after allergen exposure during both earlyand late-phase reactions and are associated with symptoms of allergic rhinitis. Montelukast (SINGULAIR®) binds with high affinity and selectivity to the CysLT1 (in preference to other pharmacologically important airway receptors, such as the prostanoid, cholinergic, or beta-adrenergic receptor). It inhibits physiologic actions of LTD4 at the CysLT1 receptor without any agonist activity.

Fosfomycin (marketed under the trade names Monurol and Monuril) is a broad-spectrum antibiotic. Monurol (fosfomycin tromethamine) sachet contains fosfomycin tromethamine, a synthetic, broad spectrum, bactericidal antibiotic for oral administration. Monurol is indicated only for the treatment of uncomplicated urinary tract infections (acute cystitis) in women due to susceptible strains of Escherichia coli and Enterococcus faecalis. Fosfomycin is a phosphoenolpyruvate analogue produced by Streptomyces that irreversibly inhibits enolpyruvate transferase (MurA), which prevents the formation of N-acetylmuramic acid, an essential element of the peptidoglycan cell wall.

Dorzolamide is a sulfonamide and a highly specific carbonic anhydrase II (CA-II) inhibitor, which is the main CA isoenzyme involved in aqueous humor secretion. Dorzolamide is marketed under the trade name Trusopt, indicated in the treatment of elevated intraocular pressure in patients with ocular hypertension or open-angle glaucoma. Carbonic anhydrase (CA) is an enzyme found in many tissues of the body including the eye. It catalyzes the reversible reaction involving the hydration of carbon dioxide and the dehydration of carbonic acid. In humans, carbonic anhydrase exists as a number of isoenzymes, the most active being carbonic anhydrase II (CA-II), found primarily in red blood cells (RBCs), but also in other tissues. Inhibition of carbonic anhydrase in the ciliary processes of the eye decreases aqueous humor secretion, presumably by slowing the formation of bicarbonate ions with subsequent reduction in sodium and fluid transport. The result is a reduction in intraocular pressure (IOP). TRUSOPT Ophthalmic Solution contains dorzolamide hydrochloride, an inhibitor of human carbonic anhydrase II. Following topical ocular administration, TRUSOPT reduces elevated intraocular pressure. Elevated intraocular pressure is a major risk factor in the pathogenesis of optic nerve damage and glaucomatous visual field loss.

Bisoprolol is a cardioselective beta1-adrenergic blocking agent. It lower the heart rate and blood pressure and may be used to reduce workload on the heart and hence oxygen demands. This results in a reduction of heart rate, cardiac output, systolic and diastolic blood pressure, and possibly reflex orthostatic hypotension. Bisoprolol can be used to treat cardiovascular diseases such as hypertension, coronary heart disease, arrhythmias, ischemic heart diseases, and myocardial infarction after the acute event. General side effects are: fatigue, asthenia, chest pain, malaise, edema, weight gain, angioedema. Concurrent use of rifampin increases the metabolic clearance of bisoprolol fumarate, shortening its elimination half-life.

Finasteride is a synthetic 4-azasteroid compound. This drug is a competitive and specific inhibitor of Type II 5a-reductase, an intracellular enzyme that converts the androgen testosterone into 5α-dihydrotestosterone (DHT). Two distinct isozymes are found in mice, rats, monkeys, and humans: Type I and II. Each of these isozymes is differentially expressed in tissues and developmental stages. In humans, 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. Although finasteride is 100-fold more selective for type II 5a-reductase than for the type I isoenzyme, chronic treatment with this drug may have some effect on type I 5a-reductase. Finasteride is used for the treatment of symptomatic benign prostatic hyperplasia (BPH) in men with an enlarged prostate to: Improve symptoms, reduce the risk of acute urinary retention, reduce the risk of the need for surgery including transurethral resection of the prostate. Also used for the stimulation of regrowth of hair in men with mild to moderate androgenetic alopecia (male pattern alopecia, hereditary alopecia, common male baldness). Finasteride is sold under the brand names Proscar and Propecia among others.

Simvastatin is a HMG-CoA Reductase Inhibitor that is FDA approved for the treatment of hypercholesterolemia and for the reduction in the risk of cardiac heart disease mortality and cardiovascular events. It reduces levels of "bad" cholesterol (low-density lipoprotein, or LDL) and triglycerides in the blood, while increasing levels of "good" cholesterol (high-density lipoprotein, or HDL). Common adverse reactions include abdominal pain, constipation, nausea, headache, upper respiratory infection. Cases of myopathy/rhabdomyolysis have been observed with simvastatin co-administered with lipid-modifying doses ( ≥ 1 g/day niacin) of niacin-containing products. The risk of myopathy, including rhabdomyolysis, is increased by concomitant administration of amiodarone, dronedarone, ranolazine, or calcium channel blockers such as verapamil, diltiazem, or amlodipine.

Lovastatin acid is an active metabolite of hypolipidemic drug Lovastatin. Lovastatin acid inhibits HMG-CoA reductase. This enzyme catalyzes the conversion of HMG-CoA to mevalonate, which is an early and rate limiting step in the biosynthesis of cholesterol. Lovastatin has been shown to reduce both normal and elevated low-density lipoprotein cholesterol (LDL-C). Lovastatin in approved for prevention of cardiovascular events and hypercholesterolemia. Off-label use of lovastatin includes treatmetn of diabetic dyslipidemia, familial dysbetalipoproteinemia, familial combined hyperlipidemia, or nephrotic hyperlipidemia. Lovastatin was tested in clinical trials agains radioation injury during therapy of prostate cancer.

Lisinopril is a potent, competitive inhibitor of angiotensin-converting enzyme (ACE). Lisinopril is marketed under the brand name ZESTRIL. ZESTRIL is indicated for the treatment of hypertension. It may be used alone as initial therapy or concomitantly with other classes of antihypertensive agents. It is also indicated as adjunctive therapy in the management of heart failure in patients who are not responding adequately to diuretics and digitalis. Lisinopril inhibits angiotensin-converting enzyme (ACE) in human subjects and animals. ACE is a peptidyl dipeptidase that catalyzes the conversion of angiotensin I to the vasoconstrictor substance, angiotensin II. Angiotensin II also stimulates aldosterone secretion by the adrenal cortex. The beneficial effects of lisinopril in hypertension and heart failure appear to result primarily from suppression of the renin-angiotensin-aldosterone system. Inhibition of ACE results in decreased plasma angiotensin II which leads to decreased vasopressor activity and to decreased aldosterone secretion. While the mechanism through which ZESTRIL lowers blood pressure is believed to be primarily suppression of the renin-angiotensin-aldosterone system, ZESTRIL is antihypertensive even in patients with low-renin hypertension.

PRIMAXIN® is a combination of cilastatin and imipenem. Cilastatin is a specific and reversible renal dehydropeptidase-I inhibitor. Imipenem is a penem antibacterial drug. Since the antibiotic, imipenem, is hydrolyzed by dehydropeptidase-I, which resides in the brush border of the renal tubule, cilastatin is administered with imipenem to block the metabolism and thus the inactivation of imipenem so that antibacterial levels of imipenem can be attained in the urine. However, cilastatin in and of itself does not have any antibacterial activity. It also prevents the metabolism of leukotriene D4 to leukotriene E4 through the inhibition of leukotriene D4 dipeptidase.