Ukuphila kwengxenye yezidakamizwa ezahlukene kuyahluka kakhulu.
Akukho muthi ohlala ohlelweni lwakho kuze kube phakade. Ku-pharmacology, isikhathi esithatha ukuba umuthi wehlise ngesigamu se-plasma (i-blood) ukuhlushwa okubizwa ngokuthi yi-half-life (t 1/2 ). (Ukucacisa ukuthi sikhuluma ngokuphila kwengxenye yezinto eziphilayo kuyisihluthulelo ngoba isigamu sempilo ingumqondo ongaqondile emithini yemithi. Ngokwesibonelo, encwadini ye-nyukliya, ukuphila kwehafu kusho ukubola kwe-radioactive.)
Ngokuvamile, ukuhlolwa kwesigamu sempilo kubonisa isilinganiso se-pharmacokinetics. I-Pharmacokinetics ibhekisela ekutadisheni ukuthi isidakamizwa sidlulela kanjani emzimbeni-ukungena kwayo, ukusatshalaliswa nokuqedwa. Bobabili amakhemikhali kanye nodokotela bakhathazekile ngemigomo yokuphila njengethemric. Noma kunjalo, njengabasebenzisi abanolwazi, kuhle ukuthi wonke umuntu azi kancane mayelana nokuphila kwengxenye.
I-Half-Life Formula
Nasi ifomula yokuphila kwengxenye:
t 1/2 = [(0.693) (Umqulu Wokusabalalisa)] / Ukusula
Njengoba kuboniswe ifomula, isigamu sempilo yesidakamizwa sincike ngokuqondile emtatsheni wokusatshalaliswa kwayo noma ukuthi umuthi wande kangakanani kuwo wonke umzimba. Ngamanye amazwi, ngokugcwele kakhulu umuthi uhambisa emzimbeni wakho, isikhathi eside siwuyingxenye yokuphila. Ngaphezu kwalokho, lesi sigaba sempilo esifanayo semithwalo yemithi sincike ekuhambeni kwayo emzimbeni wakho. Lokhu kusho ukuthi uma izinga lemvume yesidakamizwa emzimbeni wakho liphakeme, khona-ke isigamu sempilo sincane.
Inothi, izidakamizwa zisuswa kokubili izinso zakho nesibindi.
Izibonelo zeHhafu-Ukuphila
Nazi ezinye izidakamizwa ezivamile kanye nokuphila kwabo okuyingxenye:
- I-Oxycodone (imithi yobuhlungu): amahora amabili kuya kwangu-3
- I-Zoloft (i-anti-depressant): amahora angu-26
- I-Phenobarbital (imishanguzo ye-antiseizure): amahora angu-53 kuya kwangu-118
- I-Celebrex (i-NSAID noma imithi yobuhlungu): amahora angu-11.2
AmaKinetics
Njengengxenye enemininingwane ye-pharmacokinetics, ukuphila kwehafu kuyasebenza kwezidakamizwa ezinekinetic zokuqala. I-kinetics yoku-oda yokuqala ithi ukuqedwa kwezidakamizwa ngokuqondile kuxhomeke emthamo wokuqala wezidakamizwa. Ngomthamo wokuqala ophezulu, izidakamizwa eziningi zisuliwe. Izidakamizwa eziningi zilandela ikinetics yokuqala.
Ngakolunye uhlangothi, izidakamizwa ezine- zero-order kinetics zihlulwa ngokuzimela ngendlela ehambisanayo. Utshwala yisibonelo somuthi oqedwa yi-zero-order kinetics. Okuphawulayo, lapho izindlela zokugudluza izidakamizwa zigcwele, njengoba kwenzeka ngokudlula ngokweqile, izidakamizwa ezilandela i-kinetics yokuqala-oda zishintshela ku-zero-order kinetics.
Ubudala
Kubantu asebekhulile, isigamu sempilo yezidakamizwa (i-fat-soluble) yandisa umuthi ngenxa yokunyuka kwezinga lokusabalalisa. Abantu asebekhulile kaningi banezicubu ezincane kakhulu kunezintsha. Ubudala, noma kunjalo, bunomthelela olinganiselwe ku-imvume ye-hepatic ne-renal imvume. Ngenxa yesikhathi esiningi sokuphila kwezidakamizwa, abantu asebekhulile bavame ukudinga izidakamizwa eziphansi noma ezingaphansi kwesidakamizwa kunabantu abasha. Encwadini ehlobene, abantu abakhuluphele banomqulu ophezulu wokusabalalisa, futhi.
Ngokuphathwa okuqhubekayo (isibonelo i-BID noma i-dosing ngosuku kabili ngosuku), ngemva kokuphela kweminyaka engaba ngu-4 kuya kwezingu-5 ubudala, isidakamizwa sifinyelela ekugxilweni okuqhubekayo lapho inani lemithi eliqedwa lilinganiswa inani elinikezwayo.
Isizathu sokuthi izidakamizwa zithatha isikhathi "ukusebenza" kungenxa yokuthi zidinga ukufinyeleleka kulokhu okugxilwe kanzima kombuso. Encwadini ehlobene, ithatha futhi phakathi kwempilo engama-4 kuya kwemihlanu ngomuthi ozosuswa ohlelweni lwakho.
Ngaphezu kokucubungula ngokucophelela ukulinganisa kwabantu asebekhulile abathola isikhathi eside sokudla kwezidakamizwa, abantu abanezimvume kanye nezinkinga zokuzikhethela kufanele baphinde babekwe ngokuhlakanipha ngokuchazwa kwabo odokotela, futhi. Isibonelo, umuntu onesifo sokuqeda isiteji sokugcina (izinso ezimele) angathola ubuthi obuvela ku-digoxin, imithi ye-heart, emva kwesonto ukwelashwa okungaba ngu-0.25 mg ngosuku noma ngaphezulu.
Imithombo:
U-Hilmer SN, i-Ford GA. Isahluko 8. Okujwayelekile Imigomo Yokwelapha. Ku: Halter JB, Ouslander JG, Tinetti ME, Studenski S, High KP, Asthana S. eds. I-Geriatric Medicine and Gerontology, 6e . ENew York, NY: McGraw-Hill; 2009.
Holford NG. Isahluko 3. I-Pharmacokinetics & Pharmacodynamics: Ukuhleleka Kwemvelo Nokuzijabulisa Kwesikhathi. Ku: Katzung BG, Masters SB, Trevor AJ. ama-eds. I-Basic & Clinical Pharmacology, 12e . ENew York, NY: McGraw-Hill; 2012.
Morgan DL, DJ Borys. Isahluko 47. Ubuthi. Ku: Stone C, Humphries RL. ama-eds. Ukuhlolwa Kwe-CURRENT & Ukwelapha Emergency Medicine, 7e . ENew York, NY: McGraw-Hill; 2011.
Murphy N, Murray PT. Ukunakekelwa Okunzima Kwezokwelapha. Ku: Hall JB, Schmidt GA, Kress JP. ama-eds. Izimiso Zokunakekelwa Okubalulekile, 4e . ENew York, NY: McGraw-Hill; 2015.
Roden DM. Izimiso Zomtholampilo Wezokwelapha. Ku: Kasper D, Fauci A, Hauser S, Longo D, Jameson J, Loscalzo J. eds. I-Harrison's Principals of Internal Medicine, 19e . ENew York, NY: McGraw-Hill; 2015.