PHA Final Exam Fall 2001

Size: px

Start display at page:

Download "PHA Final Exam Fall 2001"

Dwayne Green
6 years ago
Views:

1 PHA 5127 Final Exam Fall 2001 On my honor, I hav nithr givn nor rcivd unauthorizd aid in doing this assignmnt. Nam Qustion/Points 1. /12 pts 2. /8 pts 3. /12 pts 4. /20 pts 5. /27 pts 6. /15 pts 7. /20 pts 8. /25 pts 9. /15 pts 10. /6 pts 11. /5 Bonus pts TOTAL /160 (out 165 possibl) 1

2 1.) Mark th following statmnts as Tru or Fals (12 points) T F Dcrasing dosing intrval ( ) will caus stady-stat to b rachd fastr. T F Incrasing plasma protin binding will dcras th volum of distribution. T F Th absorption rat constant (ka) is always largr than th limination rat constant (k). T F Rout of administration (.g., i.v., i.m., p.o.) will affct th AUC (assum bioavailability is 100% for all routs). T F Th maximum valu of rnal claranc is gratr than th maximum valu of hpatic claranc. T F Loading doss ar mainly givn for drugs with long half-livs. 2

3 2.) Which graph(s) bst dpicts a two-compartmnt body modl drug? (8 points) A B Ln(C p ) Ln(C p ) C Tim D Tim Ln(C p ) Ln(C p ) Tim Tim Answr(s): 3

4 3.) With mor popl xrcising, th qustion ariss, dos xrcis altr th pharmacokintics of drugs? Using th following information, answr th procding qustions. (12 points) Tabl 1 : Changs in blood flow during xrcis according to intnsity of xrcis. Blood Flow (ml min -1 ) Tissu Rst Light Exrcis Modrat Exrcis Intns Exrcis Livr Muscl Kidny Basd on Tabl 1, answr th following qustions A. Circl th corrct answr. Intns xrcis would chang th hpatic claranc of a: High Extraction Drug Low Extraction Drug Both a High and Low Extraction Drug Exrcis would hav no ffct. B. Fill in th blank. Intns xrcis would th xtraction ratio of a low xtraction drug? a) Incras b) Dcras c) Not Chang C. Fill in th blank. Intns xrcis would th bioavailability of a high xtraction drug? a) Incras b) Dcras c) Not Chang D. Fill in th blank. Intns xrcis would th onst of action of a lipophilic muscl rlaxant. a) Shortn b) Lngthn c) Not Chang 4

5 4.) Mr. D. Johnson from th Univrsity of Miami, nds to gain wight for his upcoming lad-rol in Th Scorpion King. His physician, Dr. Adam, puts Mr. Johnson (Rocky to his frinds) on th oral anabolic stroid, Dianabol, 5 mg vry 6 hours. Dianabol has th following pharmacokintic paramtrs: VD = 100 L, ka = 1 h -1, t1/2 = 3 h, and bioavailability is 80%. Assum first ordr kintics. (20 points) A. What is th AUC for a singl dosing intrval at stady-stat? B. What is th avrag stady-stat concntration? 5

6 4 cont d.) Mr. Johnson dcids h dosn t lik oral anabolic stroid du to thir sid ffcts. Dr. Adam prscribs th intramuscular stroid Dca-Durabolin which is administrd onc a day. Th trminal half-lif of this drug aftr intramuscular injction is much longr than if it was givn as an iv. bolus. C. Explain th diffrncs in trminal half-lif btwn th 2 routs of administration. D. Can this xplain th onc a day dosing rgimnt? 6

7 5.) A 26 yar-old whit mal, AMP, is admittd to th mrgncy room with a rupturd appndix. Bfor surgry (vn though AMP had no halth insuranc), you ar askd to bgin this patint on a nw antibiotic. (Assum 1-compartmnt body modl). (27 points) Usful Information Drug is prdominatly liminatd by kidny AMP is 5 10, 70 kg and a cratinin claranc (CrCL) of 89 ml min -1 VD=0.25 L kg -1 Population stimat of K = *(CrCL in ml min -1 ) (k is in h -1 ) Basd on th Population stimat of K, AMP is start of th following dosing schdul K0 = 1000 mg h -1 Dosing intrval ( = 6 hours Infusion tim (T) = 1h Dsird stady stat plasma rang: 60 mg L -1 to 12 mg L -1 Blood sampls ar takn during th first dos to vrify propr dosing schdul was calculatd-: Cp 1 hour aftr stop of infusion = 36.5 mg L -1. Cp 3 hour aftr stop of infusion = 20 mg L -1. A. Calculat th half-lif for this drug in AMP. Do you think th dosing schdul nds to b radjustd for Adam basd on his valu and th xpctd population stimat? 7

8 5 cont d.) B. Is th dsird CMAX at stady stat (60 mg L -1 ) bing obtaind in AMP? C. Suppos (at stady stat), th nurs starts th infusion an hour lat. What will b th plasma lvls whn th infusion is startd? 8

9 6.) Th following concntration tim profils wr obsrvd aftr multipl i.v. bolus injctions of a drug. Th two curvs diffr in on of th input paramtrs (Dos, CL, Vd ). (15 points) Original Idntify th input paramtr that diffrs. Explain your rasoning in on or two sntncs. What is th numric valu of this paramtr? 9

10 7.) Considr th following quation. (20 points) Cp Dos Volum (1 1 k τ ) k τ a) What dos this quation dscrib? b) What do th blockd parts of th quation rprsnt? Dos Volum 1 (1 k ) k 10

11 8.) Du to th strss of finals, th ntir 2PD class coms down with th flu and studnts ar admittd to Shands Hospital. All th studnts ar to b givn an antiviral thrapy by IV infusion (continuous constant rat infusion, not multipl short trm infusions). Th avrag population t1/2 is 2 h, th avrag VD is 80 L, and th ffctiv plasma concntration is 15 mg L -1. (25points) A. Rcommnd an infusion rat in milligrams pr hour to rach th stady stat concntration of 15 mg L -1. B. Approximatly how long will it tak to rach this concntration? 11

12 8 cont d.) On studnt, J.R., dos not sm to rspond to thrapy. Plasma protin binding for th drug is normally 20% (fu=0.8) xcpt in J.R. whos protin binding was 40% (fu = 0.6). Tissu binding is similar to th rst of th class C. (Circl bst answr) A possibl rason why J.R. is not rsponding to thrapy is: A. Th drug is a high xtraction drug and lowring fu will incras claranc and plasma lvls will bcom sub-thraputic B. Th drug is a low xtraction drug and lowring fu will incras claranc and plasma lvls will bcom sub-thraputic. C. Th drug is a high xtraction drug. Claranc will not chang but hr is lss fr-drug causd by incrasd protin binding and it is fr-drug that is activ. D. Th drug is a high xtraction drug. Claranc will b incrasd and th total and fr drug lvls will b dcrasd. D. (Circl th bst answr) Th volum of distribution in JR is LARGER THAN / SMALLER THAN / THE SAME AS th rst of th class. E. (Circl th bst answr) To achiv th sam fr plasma stady-stat concntrations, th daily dos in JR should b LARGER THAN / SMALLER THAN / THE SAME AS th rst of th class. 12

13 9.) Fill in th blank with th most appropriat answr. (15 points) A. is th nam of th mathmatical tchniqu usd to sparat and calculat th absorption rat constant (ka) from a concntrationtim profil. B. Drugs that ar unionizd and can cross mmbrans asily. C. To incras th rnal claranc of an acidic drug that is ionizabl, you would want to th ph of th urin. D. Drugs lik thanol follow -ordr limination bcaus a constant amount of thanol is liminatd in a givn tim. E. In pharmacokintics,, is a masur of th activity of hpatic nzyms. 13

14 10.) What is th diffrntial quation dscribing th chang in drug concntration aftr an i.v. bolus administration for a on-compartmnt body modl drug. (assum first ordr kintics). (6 points) 11) Today (Dc 12 th ) is an xtrmly important day bcaus (5 Bonus points) A. It is th last day th 2PD class has finals B. It is th v of Frank Sinatra s birthday C. Only 13 days till Christmas (or th third day of Hanukkah) D. It is Dr. Hochhaus and Adam s birthday (ag 21 and 16, rspctivly). E. All th abov F. Non of th abov 14

PHA Final Exam Fall 2007

PHA Final Exam Fall 2007 PHA 5127 Final Exam Fall 2007 On my honor, I hav nithr givn nor rcivd unauthorizd aid in doing this assignmnt. Nam Plas transfr th answrs onto th bubbl sht. Th qustion numbr rfrs to th numbr on th bubbl