Tranexamic acid is an antifibrinolytic that competitively inhibits the activation of plasminogen to plasmin. Tranexamic acid is a competitive inhibitor of plasminogen activation, and at much higher concentrations, a noncompetitive inhibitor of plasmin, i.e., actions similar to aminocaproic acid. Tranexamic acid is about 10 times more potent in vitro than aminocaproic acid. Tranexamic acid binds more strongly than aminocaproic acid to both the strong and weak receptor sites of the plasminogen molecule in a ratio corresponding to the difference in potency between the compounds. Tranexamic acid in a concentration of 1 mg per mL does not aggregate platelets in vitro. In patients with hereditary angioedema, inhibition of the formation and activity of plasmin by tranexamic acid may prevent attacks of angioedema by decreasing plasmin-induced activation of the first complement protein (C1). Tranexamic acid is used for use in patients with hemophilia for short term use (two to eight days) to reduce or prevent hemorrhage and reduce the need for replacement therapy during and following tooth extraction. It can also be used for excessive bleeding in menstruation, surgery, or trauma cases.

Famotidine, a competitive histamine H2-receptor antagonist, is used to treat gastrointestinal disorders such as gastric or duodenal ulcer, gastroesophageal reflux disease, and pathological hypersecretory conditions. Famotidine inhibits many of the isoenzymes of the hepatic CYP450 enzyme system. Other actions of Famotidine include an increase in gastric bacterial flora such as nitrate-reducing organisms. Famotidine binds competitively to H2-receptors located on the basolateral membrane of the parietal cell, blocking histamine affects. This competitive inhibition results in reduced basal and nocturnal gastric acid secretion and a reduction in gastric volume, acidity, and amount of gastric acid released in response to stimuli including food, caffeine, insulin, betazole, or pentagastrin.

Levobunolol is a non-cardioselective beta-adrenoceptor blocking agent, equipotent at both beta1 and beta2 adrenergic receptors. Levobunolol is greater than 60 times more potent than its dextro isomer in its beta-blocking activity, yet equipotent in its potential for direct myocardial depression. Accordingly, the levo isomer, levobunolol, is used. Levobunolol does not have significant local anesthetic (membrane-stabilizing) or intrinsic sympathomimetic activity. Levobunolol, sold under the brand name Betagan, has been shown to be an active agent in lowering elevated as well as normal intraocular pressure (IOP) whether or not accompanied by glaucoma. Levobunolol is contraindicated in those individuals with bronchial asthma or with a history of bronchial asthma, or severe chronic obstructive pulmonary disease sinus bradycardia; second and third-degree atrioventricular block; overt cardiac failure cardiogenic shock; or hypersensitivity to any component of these products.

Ribavirin is a synthetic nucleoside analogue, which was first discovered and developed in 1970 by researchers from the International Chemical & Nuclear Corporation (ICN), today known as Valeant Pharmaceuticals. Ribavirin was initially approved for use in humans to treat pediatric respiratory syncytial virus infections (RSV). In cell cultures the inhibitory activity of ribavirin for RSV is selective. The mechanism of action is unknown. Reversal of the in vitro antiviral activity by guanosine or xanthosine suggests ribavirin may act as an analogue of these cellular metabolites. There were no other significant advancements in the treatment of hepatitis C until 1998, when the combination of ribavirin and interferon-alpha gained approval. Clinically, ribavirin showed a small, additive antiviral effect in combination with interferon, but its main effect was dose-dependent prevention of virological relapse. The mechanism by which the combination of ribavirin and an interferon product exerts its effects against the hepatitis C virus has not been fully established. However, it could be thorough the inhibition of inosine monophosphate dehydrogenase (IMPDH), which is the key step in de novo guanine synthesis, a requirement for viral replication.

Pimozide (Orap) is a diphenylbutylpiperidine that is effective as an antipsychotic agent and as an alternative to haloperidol for the suppression of vocal and motor tics in patients with Tourette syndrome. It is not intended as a treatment of first choice nor is it intended for the treatment of tics that are merely annoying or cosmetically troublesome. It should be reserved for use in Tourette’s Disorder patients whose development and/or daily life function is severely compromised by the presence of motor and phonic tics. Evidence supporting approval of pimozide for use in Tourette’s Disorder was obtained in two controlled clinical investigations, which enrolled patients between the ages of 8 and 53 years. Most subjects in the two trials were 12 or older. Pimozide is an orally active antipsychotic drug product, which shares with other antipsychotics the ability to blockade dopaminergic receptors on neurons in the central nervous system. Although its exact mode of action has not been established, the ability of pimozide to suppress motor and phonic tics in Tourette’s Disorder is thought to be a function of its dopaminergic blocking activity. However, receptor blockade is often accompanied by a series of secondary alterations in central dopamine metabolism and function which may contribute to both pimozide’s therapeutic and untoward effects. In addition, pimozide, in common with other antipsychotic drugs, has various effects on other central nervous system receptor systems which are not fully characterized.

Nicotine is a natural alkaloid obtained from the dried leaves and stems of the nightshade family of pants, such as Nicotiana tabacum and Nicotiana rustica, where it occurs in concentrations of 0.5-8%. Cigarette tobacco varies in its nicotine content, but common blends contain 15-25 mg per cigarette, with a current trend towards lower levels. Nicotine is highly addictive substance, it exhibits a stimulant effect when adsorbed at 2 mg. Administration of higher doses could be harmful. Action of nicotine is mediated by nicotinic cholinergic receptors. Nicotine binds to the interface between two subunits of the receptors, opens the channel and allows the entry of sodium or calcium. The principal mediator of nicotine dependence is α4β2 nicotine receptor.

Glyburide, a second-generation sulfonylurea antidiabetic agent, lowers blood glucose acutely by stimulating the release of insulin from the pancreas, an effect dependent upon functioning beta cells in the pancreatic islets. With chronic administration in Type II diabetic patients, the blood glucose lowering effect persists despite a gradual decline in the insulin secretory response to the drug. Extrapancreatic effects may be involved in the mechanism of action of oral sulfonyl-urea hypoglycemic drugs. The combination of glibenclamide and metformin may have a synergistic effect, since both agents act to improve glucose tolerance by different but complementary mechanisms. In addition to its blood glucose lowering actions, glyburide produces a mild diuresis by enhancement of renal free water clearance. Glyburide is twice as potent as the related second-generation agent glipizide. Sulfonylureas such as glyburide bind to ATP-sensitive potassium channels on the pancreatic cell surface, reducing potassium conductance and causing depolarization of the membrane. Depolarization stimulates calcium ion influx through voltage-sensitive calcium channels, raising intracellular concentrations of calcium ions, which induces the secretion, or exocytosis, of insulin. Glyburide is indicated as an adjunct to diet to lower the blood glucose in patients with NIDDM whose hyperglycemia cannot be satisfactorily controlled by diet alone. Glyburide is available as a generic, is manufactured by many pharmaceutical companies and is sold in doses of 1.25, 2.5 and 5 mg under many brand names including Gliben-J, Daonil, Diabeta, Euglucon, Gilemal, Glidanil, Glybovin, Glynase, Maninil, Micronase and Semi-Daonil. It is also available in a fixed-dose combination drug with metformin that is sold under various trade names, e.g. Bagomet Plus, Benimet, Glibomet, Gluconorm, Glucored, Glucovance, Metglib and many others.

Indapamide is an antihypertensive and a diuretic. It contains both a polar sulfamoyl chlorobenzamide moiety and a lipid- soluble methylindoline moiety. Indapamide blocks the slow component of delayed rectifier potassium current (IKs) without altering the rapid component (IKr) or the inward rectifier current. Specifically it blocks or antagonizes the action the proteins KCNQ1 and KCNE1. Indapamide is also thought to stimulate the synthesis of the vasodilatory hypotensive prostaglandin PGE2. Indapamide is used for the treatment of hypertension, alone or in combination with other antihypertensive drugs, as well as for the treatment of salt and fluid retention associated with congestive heart failure or edema from pregnancy (appropriate only in the management of edema of pathologic origin during pregnancy when clearly needed). Also used for the management of edema as a result of various causes.

Acyclovir is a synthetic antiviral nucleoside analogue. A screening program for antiviral drugs begun at Burroughs Wellcome in the 1960s resulted in the discovery of acyclovir in 1974. Preclinical investigation brought the drug to clinical trials in 1977 and the first form of the drug (topical) was available to physicians in 1982. Activity of acyclovir is greatest against herpes 1 and herpes 2, less against varicella zoster, still less against Epstein-Barr, and very little against cytomegalovirus. Acyclovir is an antiviral agent only after it is phosphorylated in infected cells by a viral-induced thymidine kinase. Acyclovir monophosphate is phosphorylated to diphosphate and triphosphate forms by cellular enzymes in the infected host cell where the drug is concentrated. Acyclovir triphosphate inactivates viral deoxyribonucleic acid polymerase.

Mrtoprolol is a beta-adrenergic receptor blocking agent. In vitro and in vivo animal studies have shown that it has a preferential effect on beta-1 adrenoreceptors, chiefly located in cardiac muscle. Clinical pharmacology studies have confirmed the beta-blocking activity of metoprolol in man, as shown by (1) reduction in heart rate and cardiac output at rest and upon exercise, (2) reduction of systolic blood pressure upon exercise, (3) inhibition of isoproterenol-induced tachycardia, and (4) reduction of reflex orthostatic tachycardia. Mrtoprolol is indicated for the treatment of hypertension, angina pectoris and myocardial infarction