Pharmacological Profiles of Several Common Drugs

Pharmacological Profiles of Several Common do drugss2.3 Profile of Pheniramine Maleate (31)Chemical name (3RS)-N,N-Di methyl radical-3-phenyl-3-(pyridine-2-yl)propan-1-amine(Z)-butenedioateEmpirical formula C20H24N2O4Chemical structure designing 2.3Structure of Pheniramine Maleate2.3.1 Physical properties molecular weight 356.4 demeanor and colour White or almost white crystalised powder.Solubility Very soluble in water, freely soluble in ethanol (96 %)in methanol and in methylene chloride.Therapeutic categoryPheniramine maleate belongs to H1-antagonist pharmacological group on the basis of mechanism of action and also classified in Antihistamine, Decongestant.Dosage Tablet , Powder, Solution2.3.2 PharmacologyPheniramine maleate is an antihistamine use for alleviation of allergy symptoms. Manufacturers frequently list the over-the-counter medication as pheniramine maleate or a differential gear. Drug industries also often combine the formulation with other medications for relief of other symptoms. Consumers thunder mug generally find the ingredient in an oral solution or tablet form. Certain ophthalmic solutions also contain pheniramine maleate, which provides relief from allergy symptoms associated with the eyes.Allergic reactions be autoimmune responses to certain antigens. When allergens enter the strainstream, the body releases histamine, which binds with and activates receptor sites, fixed throughout the body, producing physical symptoms. The pharmacological action of pheniramine maleate involves blocking the receptor sites for the histamine H1, found in the heart, of import nervous system, smooth muscle, and vascular endothelium cells. Blocking the receptor sites reduces or inhibits the symptoms.The antihistamine is frequently used for seasonal allergies, such as hay fever, or environmental allergies, such as animal dander. By blocking histamine receptor sites, pheniramine maleate can reduce or eliminate itching, watery eyes, runny noses, and skin i rritations. Allergy related skin irritations might include the itching, redness, and swelling associated with eczema or uticaria, commonly referred to as hives (40).The medication whitethorn produce a sedative effect when binding to sites in the central nervous system. It also may produce an anticholinergic drug effect by dilating or relaxing smooth muscle. These side effects sometimes allow pheniramine maleate to be used as treatment for motion sickness or the inner ear condition known as Menieres disease.2.4 Profile of Phenylephrine Hydrochloride (78)Chemical name(R)-(-)-1-(3-Hydroxyphenyl)-2-methylaminoethanol hydrochlorideEmpirical formulaC9H13NO2HCLChemical structureFigure 2.4 Structure of Phenylephrine Hydrochloride2.4.1 Physical propertiesMolecular weight203.67Appearance and colour White or practically white odourless crystalsSolubility Freely soluble in water and alcoholTherapeutic category Phenylephrine is a sympathomimetic amine that acts predominantly on -adrenergic re ceptors. It is mainly used to treat nasal congestion, but may also be useful in treating hypotension and shock, hypotension during spinal anaesthesia, prolongation of spinal anaesthesia, paroxysmal supraventricular tachycardia, symptomatic relief of external or internal hemorrhoids, and to increase blood pressure as an aid in the diagnosis of heart murmurs.Dosage Cream, Solution, Ointment, Injection, Liquid, Tablet, Suppository2.4.2 PharmacologyIn general, 1-adrenergic receptors mediate contraction and hypertrophic growth of smooth muscle cells. 1-receptors are 7-transmembrane domain receptors coupled to G proteins, Gq/11. Three 1-receptor subtypes, which share approximately 75% homology in their transmembrane domains, have been identified 1A (chromosome 8), 1B (chromosome 5), and 1D (chromosome 20). Phenylephrine appears to act similarly on all trio receptor subtypes. All three receptor subtypes appear to be involved in maintaining vascular tone. The 1A-receptor maintains basal va scular tone while the 1B-receptor mediates the vasocontrictory effects of exogenous 1-agonists. Activation of the 1-receptor activates Gq-proteins, which results in intracellular stimulation of phospholipases C, A2, and D. This results in mobilization of Ca2+ from intracellular stores, activation of mitogen-activated kinase and PI3 kinase pathways and subsequent vasoconstriction. Phenylephrine produces its local and systemic actions by acting on 1-adrenergic receptors fringy vascular smooth muscle. Stimulation of the 1-adrenergic receptors results in contraction arteriolar smooth muscle in the periphery. Phenylephrine decreases nasal congestion by acting on 1-adrenergic receptors in the arterioles of the nasal mucosa to produce constriction this leads to decreased edema and increased drainage of the sinus cavities.2.5 Profile of Dextromethorphan (79)Chemical name(1R,9R,10R) 4 methoxy 17 methyl 17 azatetracyclo7.5.3.01,10.02,7heptadeca-2,4,6-trieneEmpirical formulaC18H25NOChem ical structureFigure 2.5 Structure of Dextromethorphan2.5.1 Physical propertiesMolecular weight271.39Appearance and colour It is a White crystalline powderSolubility 1-5 g/100 mL at 21 CTherapeutic category Dextromethorphan usually used in the treatment of respiratory infections and allergic conditionsDosage Tablet , Syrup, Capsule, Suspension2.5.2 PharmacologyDextromethorphan is an opioid-like drug that binds to and acts as antagonist to the NMDA glutamatergic receptor, it is an agonist to the opioid sigma 1 and sigma 2 receptors, it is also an alpha3/beta4 nicotinic receptor antagonist and targets the serotonin reuptake pump. Dextromethorphan is rapidly absorbed from the gastrointestinal tract, where it enters the bloodstream and crosses the blood-brain barrier. The first-pass through the hepatic portal vein results in some of the drug being metabolized into an active metabolite of dextromethorphan, dextrorphan, the 3-hydroxy derivative of dextromethorphan.2.6 Profile of Diphenhy dramine (80)Chemical name 2-(diphenylmethoxy)-N,N-dimethylethanamineEmpirical formulaC17H21NO HCLChemical structureFigure 2.6 Structure of Diphenhydramine2.6.1 Physical propertiesMolecular weight291.82Appearance and colour It is a White crystalline powderSolubility Soluble in DMSO, acetone, waterTherapeutic category Diphenhydramineis a first-generationantihistamine possessing anticholinergic, antitussive, antiemetic, and sedative properties that is mainly used to treat allergies. It is also used in the management of drug-induced parkinsonism and other extrapyramidal symptoms. The drug has a strong hypnotic effect and is FDA-approved as a non-prescription eternal sleep aid, especially in the form of diphenhydramine citrateDosage Capsule2.6.2 PharmacologyDiphenhydramine is an inverse agonist of the histamineH1receptor. It is a member of the ethanolamine class of antihistaminergic agents. By blocking the effects of histamine on the capillaries, it can reduce the intensity of allergic symptoms. Diphenhydramine also crosses the bloodbrain barrier (BBB) and antagonizes the H1 receptors centrally. Its effects on central H1 receptors draw drowsiness.Like many other first-generation antihistamines, diphenhydramine is also a potent antimuscarinic (a competitive antagonist of muscarinic acetylcholine receptors), and, as such, at high doses can cause anticholinergic syndrome. The utility of diphenhydramine as