Re: model dynamic data with $DES subroutine

If you are using NONMEM v6 or later, add this line before $DES A_0(1)= KIN/KOUT Sam Liao Pharmax Research > Dear NMusers, > > I have a question I would like your help. The data I have is only the dynamic data since we didn't give dose to the animal. I am trying to capture the nature of disease progression. And the PD decrease with time. I have seen people model only the PD data use $PRED subroutine but they use the explicit equation.But I want to use a differential equation like dA/dt= kin(1-dis)-kout*A while A0=kin/kout. When I ran the control stream, the gradient for most of the parameters are 0. And the only parameter estimation I got is the sigma. The output of Y is 0. I guess it's because I don't have dose to compartment(PDK) but I don't know how should I fix the problem. Any suggestion is appreciated! > > The control stream I wrote is: > > $PROB Demo for turn over PD model > $INPUT ID TIME AMT PDK=DV EVID > $DATA demo.csv IGNORE=# > > $ESTIM MAXEVAL=3000 NOABORT PRINT=1 > METHOD=COND INTERACTION SIG=5 MSFO=save.msf > > $COV MATRIX=S SLOW > > $SUBROUTINE ADVAN6 TOL=5 > > $MODEL > COMP=(PDK) > > $PK > KIN=THETA(1)*EXP(ETA(1)) > KOUT=THETA(2) > DIS=THETA(3)*EXP(ETA(2)) > > $DES > DADT(1)=KIN*(1-DIS)-KOUT*A(1) > > $ERROR > Y = F + ERR(1) > > ; Fixed effects > $THETA 174 FIX ; KIN > $THETA 77 FIX ; KOUT > $THETA (0,0.28,1) ; AGE_EFFECT_PDK > > ; Random effects > $OMEGA 0 FIX; BSVKIN_PDK > $OMEGA 0 FIX; BSVDIS_PDK > > $SIGMA 0.1 > > $TABLE ID TIME PDK Y > NOPRINT ONEHEADER FILE=DEMO.fit > > And my data looks like: > #ID TIME AMT PDK EVID > 101 4 . 1.49 0 > 102 4 . 1.58 0 > 61 8 . 0.57 0 > 62 8 . 2.03 0 > 63 8 . 1.58 0 > 64 8 . 1.52 0 > 109 12 . 0.71 0 > 110 12 . 1.18 0 > 21 12 . 1.25 0 > > -Jing > > This e-mail and any files transmitted with it, are intended solely for the use of the individual or entity to whom they are addressed.?If you have received this e-mail in error, please reply to this message and let the sender know. > > ------------------------------------------------------------------------ > > Chat with Messenger straight from your Hotmail inbox. Check it out < http://www.microsoft.com/windows/windowslive/hotmail_bl1/hotmail_bl1.aspx?ocid=PID23879::T:WLMTAGL:ON:WL:en-ww:WM_IMHM_4:092009 >