SODIUM IODIDE I-123 BK - GE Healthcare

1 CL IN ICA L PHARMACOL OGYS odium Io dide is rea dily ab sorb ed fr om th e uppergastroi ntes ti nal llow ing absorp ti on, the io did e is dist ribu ted pri marily wit hin the ext rac el lu larfl ui d of the body . It is co nc ent ratedand organ ica lly bou nd by th e th yroi d andco ncen tra ted by the sto mach, cho ro id plexu s, an d salivarygla nds . It is al sopr omp tl y ex creted by the ki dney s. Th e no rm al ra ng e of urin ary exc retio n in 24ho urs is repo rted to be 37-75% of the admin ist ered do se, va ryi ng wi th thyro idan d ren al func ti on. The iodi de co nc ent rat ing mech anis m of the th yro id , vari ou slytermedthe io dide t ra p or pump, ac co unt s for an IODIDE concen tra tion some25 times tha t of the plas ma level , but may increase to as much as 500 timesund er cer ta in con di tio ns.

2 T ra pped iodi de is oxi dized to io dine an d org an ica lly in co rp ora ted so ra pidly thatthe tra p co nt ain s less th an fr ee iod id e in co mparison to organically bo undiod in e. Th is proce ss re su lts in a fu rther concen tra tion of iod in e in the th yro idgl and to abo ut 50 0 fold that of bl ood . Th e iod in at ed organ ic compo unds cons istchie fl y of thyroxi ne (T4) an d triio do thyron in e (T3), whi ch ar e boun d toth yro gl ob uli n in the foll icu lar colloid. The T4an d T3ar e re leas ed by en zy mat icpr oteoly sis of th yroglobuli n int o the blood,wh ere th ey are sp ecif ica ll y bo un dand tra nsp ort ed by pla sm a th yr oi d bind ing pro te ins. Th es e reactions aremo st ly un de r the cont rol of ant er ior- pit uit ary thy ro id st imu lat ing ho rmo ne (TS H)and hy pot hala mic th yr oid rel ea sing fa cto r (T RF).

3 Thy roid up tak e is us ua llyinc reas ed in hy pert hyro idis m andin go ite r with imp air ed hor mon esyn th es is . Up ta ke is usu all y dec rea sed in hy pothy roid is m and no rma l ordecreasedin hy pe rt hy ro idi sm treat ed with iod id e. It shouldbe noted that th eup ta ke of tr ace r io dine is a fun ction of stableiodidecon cent ratio n in theser um as wel l as of altera tio ns in thyr oi d ph ys iolog DI CAT ION S AN D US AGES odiu m Io dide I-12 3 is ind ica ted for use in the evaluat ion of thy ro id funct ionan d/ or mo rp hol TRA IN DI CAT ION SNo ne kno wn .WA RNIN GSFem ales of chi ld beari ng age and ped ia tric pat ient s under 18 sho uld not bestudiedunles s the ben ef its an ticipated fromthe perf ormance of th e te stou twei gh th e po ssible ri sk of ex posure to the amo un t of ion izi ng ra di at io nas so ci ated with th e test.

4 PRECA UT ION SGeneralThe co nt ent s of the capsuleare radioact iv e. Adeq ua te sh ie ldi ng of th epr ep ara tio n mus t be maint ain ed at all tim es . Do not use after th e exp ira tion timean d date (24 ho urs aft er ca li brat ion tim e) sta ted on the labe upta ke of I-123ma y be decr eas ed by rec ent ad min is tra tio n of io di nat edcontras t mate rial s, by in takeof sta bl e iod ine in any form, or by thyro id,antith yro id, and ce rtai n oth er dr rdi ngl y, the pa ti ent sh oul d beques tio ned caref ully reg ard in g diet, pre viou s me dica tion,an d proceduresin vo lvi ng ra diogra phi c con tra st med m Io dide I-123 ,as wel l as ot her rad io act ive dr ugs, mus t be handled withca re, an d appropri ate saf ety mea sures sh ou ld be used to min im ize ra diati onexp os ur e to cli nic al perso nn el.

5 Ca re sho uld also be tak en to mini mize radi at ionexp os ur e to th e pa ti en t con si sten t with pro per pat ien t man agem en diop ha rma ceu ti cal s sh ou ld be used only by ph ysicians who are qualif ied bytr aini ng and ex peri enc e in th e sa fe us e and handlin g of rad io nu cl id es and wh os eexp erien ce and tra in ing ha ve been appro ved by the app ro pri ate govern mentag enc y aut ho ri zed to licens e th e us e of ra dion uclid ci no genesis, Mut ag enesis,Impairmentof Fer tilityNo lon g-termani mal st ud ies hav e been per formedto eva luate carcin ogen icpo tent ial , mutag eni c potent ial, or effec ts on fert il it y in ma le or fem ale eg nancy Cat eg ory CAni ma l rep rod uc ti on st udies ha ve no t been co ndu ct ed wit h this dru g.

6 It is al sono t kno wn whet her Sod ium Io di de I-123can cau se fet al harm wh en administeredto a pregn ant wo man or can aff ec t rep rod uct ion cap acit y. So diu m Iod ide I-123sho ul d be given to a pregn ant wo ma n only if clearlyneed ea lly, ex ami na ti ons usi ng ra diopha rma ceutica ls , esp ecial ly tho se elect ive inna tur e, in wo men of chi ldbea ri ng cap abilitysh ou ld be per form ed durin g the firs tfew (a pp roxi ma tel y 10) da ys following th e onset of men ses .Nu rs ing Mo thersSinc e I-123is ex cr eted in hum an milk, form ula- feed in g shou ld be subst itu ted fo rbr ea st -feed ing if th e agent mus t be ad min ist er ed to the mot her duri ng lactati on .Pedi at ri c UseSafet y and eff ect iv enes s in ped ia tric patient s have not beenest ab li sh ed.

7 Geri at ri c UseCl ini cal studi es of Sodi um Io di de I-1 23 Caps ules did not incl ude su ff ic ien tnum bersof subj ec ts ag ed 65 and over to det erm ine whet her they respondSo diumIo dide1-123 DESCRIPTI ONGE Heal thca re (M edi- Phys ic s, In c.) Sod ium Iodi de I-1 23 for dia gn ost ic us e issu ppliedas ca psul es for ora l admi ni stration. At ca li brati on tim e, ea ch capsulehas an activity of MB q (10 0 Ci ) or MBq (20 0 Ci ). Ea ch gela tin capsu lecon tainsno t more than20 g of so diumhydroxideand not mo re tha n 1 g ofsu cros e. Each cap su le als o con ta in s FD&CYell ow No. e I-123is an odo rl ess co mp ound , freelyso lublein water. Th eI-1 23 is pro du ced in an acc el eratorby bo mb ardmentof enriched Xe-1 24 withprotons [X e-1 24 (p ,2n) Cs-123Xe-1 23I-123 ].

8 The radionuc lidic com pos itionat cal ib ratio n timeis no t less 23 and not mor e th an l othernucli des (Te- 121 , I-1 25 , I-1 31, I-126 ,I-1 24 , I-1 30 , I- 12 1 an d Na-24). Th e ra dio nucli di c compositi on at exp ira tion time isno t les s th an d not moreth an othernuclid es(T e-12 1, I- 12 5, I- 131, I-126,I-124 , I- 130 , I- 121 and Na- 24).Molecular for mula : Na123 IMolecular Weig ht : ICALCHA RACTERISTICSI odine-123 deca ys by elec tr on capt ure with a physical hal f-life of ho urs. Th epho ton tha t is usefu l for det ec tio n and imag ing studi es is li sted in Ta ble ble 1. Pri nci pal RadiationEmiss ion Data1 RadiationMe an %/Disin tegrationMea n Energy(k eV)Gam 91Ko cher,Davi d C.

9 , Radi oac tive De ca y DataTabl es , DOE/TI C-11026, 12 2(1 98 1)EX TERNAL RADI ATI ONTh e specificga mma ray con stan t for I-1 23 is C/ Kg-MBq-hr(1 .6 R/h r-mCi)at1 cm. The fir st ha lf valueth icknessof lead (Pb) for I-1 23 is cm . A ran ge ofcoef ficients of att enu ationof th e rad iat ion emit ted by this ra di on uclidecan beach ievedby th e int erposition of variousthicknessesof pb and is sho wn in table2. For exa mp le, the use of cm of lead wil l decrease the exter na l radiationex pos ur e by a fa ct or of abo ut 1, 000 .Ta ble 2. Ra dia ti on Att en uationby Lead Shielding2 Shie ld ThicknessCoef fici ent of(Pb) cmAtten ua tio 810-42 Met hod of Calc ul ation : Datasu ppli ed by OakRi dge As soci atedUn iversities,Radi opha rmac eutic al In te rnal Do se Information Center,19 permitcor rect ion for the phy sical decayof I- 123 , the fracti ons tha t rem ain atse lecte d int er vals aft er th e time of ca lib rati on are sho wn in Ta bl e ble 3.

10 PhysicalDecayCha rt: Iod in e-123,Ha lf -L if e Ho ursHo ur sFract ionRem ai ni ng0*1. 00030. 85460. 73090. 623120. 533150. 455180. 389210. 332240. 284*Cali brationTi meFor Oral AdministrationRxONL YPr oduct Num be rs: 2031 , 203 2 Sodi um Io dide I- 12 3 Capsu lesdif ferently fro m you nge r subj her rep ort ed clinical exp erien ce has notid en tifie d differ en ce s in respon ses betweenth e el derlyand youn ger era l, do se selection for an elderly pa tient shouldbe cauti ous, usu al ly startingat the lo w en d of the do sin g ran ge, ref lecti ng the grea ter frequency of decreasedhepatic, rena l or car diac fu nctio n, and of concomitant di seaseor other dru gth erap is dr ug is kn ow n to be su bst an ti all y excretedby th e kid ney.