OverviewTadalafil(Tadalafil)hasamolecularformulaofC22H19N3O4andamolecularweightof389.4.Ithasbeenwidelyusedtotreatmaleerectiledysfunctionsince2003,anditstradenameisCialis.In2008,EliLillyandCompanysoldthecommercialdevelopmentrightsofthisproductforPAHtreatmenttoUnitedTherapeutics.InJune2009,theFDAapprovedtadalafilforthetreatmentofpatientswithpulmonaryarterialhypertension(PAH)intheUnitedStates,underthetradenameAdcirca.Tadalafilwaslaunchedin2003asadrugtotreatED.Ittakeseffect30minutesafteradministration,butitsbesteffectis2hoursaftertheonsetofeffect.Theeffectcanlastfor36hours,anditseffectisnotaffectedbyfood.Thedosageoftadalafilis10or20mg.Therecommendedinitialdoseis10mg.Thedoseadjustmentisbasedonthepatient'sresponseandadversereactions.Preliminarymarketresearchshowsthatafter12weeksoforaladministrationof10or20mgoftadalafil,theeffectiveratesare67%and81%respectively.ManystudieshaveshownthattadalafiliseffectiveintreatingED.IndicationsTadalafilisusedtotreaterectiledysfunction(ED)andpulmonaryhypertensioninmen.MechanismErectiledysfunction:Tadalafilandsildenafilbothbelongtotheselectivephosphodiesterasetype5(PDE5),buttheirstructureisdifferentfromthelatter,andhigh-fatdietwillnotinterferewithitsabsorption.Undertheactionofsexualstimulation,nitricoxidesynthase(NOS)inpenilenerveendingsandvascularendothelialcellscatalyzesthesynthesisofnitricoxide(NO)fromthesubstrateL-arginine.NOactivatesguanylylcyclase,whichconvertsguanosinetriphosphateintocyclicguanosinemonophosphate(cGMP),therebyactivatingcyclicguanosinemonophosphate-dependentproteinkinase,resultinginadecreaseincalciumionconcentrationinsmoothmusclecells,causingthecorpuscavernosumtoSmoothmusclesrelaxanderectionoccurs.Phosphodiesterasetype5(PDE5)degradescGMPintophysiologicallyinactiveproducts,causingthepenistoenteraweakstate.TadalafilinhibitsthedegradationofPDE5,causingtheaccumulationofcGMPandrelaxingthesmoothmusclesofthecorpuscavernosum,leadingtopenileerection.SincenitratesareNOdonors,theircombinedusewithtadalafilwillsignificantlyincreasecGMPlevelsandcauseseverehypotension.Therefore,thecombineduseofthetwoiscontraindicatedinclinicalpractice.medicineinteractionsTadalafilaffectsPDESbyinhibitingit.GMPdegrades,sowhenusedincombinationwithnitrates,itmaycauseanextremChemicalbookedropinbloodpressureandincreasetheriskofsyncope.CY3PA4inducerswillreducethebioavailabilityoftadalafil,andcombinedusewithrifampicin,cimetidine,erythromycin,clarithromycin,itracanvail,ketoconvail,HVIproteaseinhibitors,etc.mayincreasethebioavailabilityofthisproduct.bloodconcentration,attentionshouldbepaidtoadjustingthedose.Sofar,therearenoreportsthatthehumanpharmacokineticparametersofthisproductareaffectedbydietandalcohol.preparationUsingD-tryptophanasrawmaterial,methylesterificationreactionisperformedfirst,andthegeneratedD-tryptophanmethylesterhydrochlorideundergoesPictet-spenglerreactionwithpiperonalinisopropanoltoobtaincis-tetrahydrocarbolinecompound.Itwasthenreactedwithchloroacetylchlorideandmethylamineinsequence,withatotalyieldof56%.Afterscreening,glacialaceticacidwasusedasarecrystallizationsolventforfurtherpurification.Thespecificreactionequationisasfollows:DrugstoTreatMaleErectileDysfunctionCialisisTadalafil.ItisanoraldrugforthetreatmentofmaleerectiledysfunctiondevelopedbyEliLillyandCompanyoftheUnitedStates.Itisasecond-generationphosphodiesterase5inhibitor.Researchreportsshowthatitiscomparabletosildenafil.ComparedwithCialis,Cialistakeseffectveryquickly,takingeffectinabout15to20minutes,andhaslong-lastingeffects,upto36hours.T1/2is17.5h.Inastudyinvolving348menwithmildtosevereerectiledysfunction,thepatientswererandomizedtotaketadalafil20mgoraplacebo.Theresultsshowedthatcomparedwithplacebo,sexualintercoursewasmoresuccessful24and36hoursaftertakingthedrug.Sexualintercoursewasimproved,andmostmenwereabletosuccessfullyhavesexualintercoursetwicewithin36hours.Therewasnodifferenceintheincidenceandseverityofadversedrugreactionscomparedwithplacebo.Morethan5%ofmenintheTadalafilgroupexperiencedheadachesandindigestion.

[AdverseReactions]Therearenoseriousadversereactions,includingfacialflushingandvisualabnormalitiesaftertakingit.Occasionally,headacheandindigestionmayoccur.[Precautions]Itiscontraindicatedforpatientswhoaretakingnitratedrugs,haveanginapectoris,heartdisease,uncontrolledhighbloodpressureorhypotension,andthosewhohavehadastrokeinthepast6months.usePhosphodiesterase5inhibitorsareusedtotreatmaleerectiledysfunction.Second-generationphosphodiesterase5inhibitorsareusedtotreatmaleerectiledysfunction.