RE: Calculation of half life
You can add formulas to NONMEM code. All individual noncompartmental parameters can be calculated within NONMEM. An example of the NONMEM code is below. tH
DADT(6) = A(8) ;calculates AUC if A is concentration
DATD(8) = [put here the right part of the differential equation which calculates concentration]
CONC=A(8)
AUC =A(6)
AUCT=A(12)
IF (CONC.GT.1E-20) THEN
LAM=-([put here the right part of the
differential equation which calculates concentration]/CONC
ELSE
LAM=666666666
ENDIF
IF (AUC.GT.1E-20) THEN
MRT=AUCT/AUC
ELSE
MRT=666666666;
ENDIF
IF (AUC.GT.1E-20.AND.MWT.GE.0.000001) THEN
CL =DKG*BIO/(AUC*MWT)
ELSE
CL =666666666
ENDIF
VSS=MRT*CL
IF (DABS(LAM).GT.1E-20) THEN
IHL=0.693147/LAM
ELSE
LAM=666666666
IHL=666666666
ENDIF
IF (DABS(LAM).GT.1E-10.AND.AUC.GE.1E-10) THEN
VZ =DKG*BIO/(LAM*AUC*MWT)
ELSE
VZ =666666666
ENDIF
AQ=1;
BQ=K23+K32+KED;
CQ=K32*KED;
DQ=BQ**2-4*AQ*CQ;
BET2=666666666
IF (DQ.GE.0) BET2=(-BQ+SQRT(DQ))/(2*AQ);
BHLK= KED*(K32/(K32 + K23))
IF (BET2.LT.-1E-10) THEN
BHL=-LOG(2)/BET2;
ELSE
BHL=666666666
ENDIF
IF (DABS(A1).GE.1E10) A1=6666666
IF (DABS(A2).GE.1E10) A2=6666666
IF (DABS(A3).GE.1E10) A3=6666666
IF (DABS(A4).GE.1E10) A4=6666666
IF (DABS(A5).GE.1E10) A5=6666666
IF (DABS(IHL).GE.1E10) IHL=6666666
IF (DABS(MRT).GE.1E10) MRT=6666666
IF (DABS(CL).GE.1E10) CL=6666666
IF (DABS(VSS).GE.1E10) VSS=6666666
IF (DABS(LAM).GE.1E10) LAM=6666666
IF (DABS(VZ).GE.1E10) VZ=6666666
IF (DABS(BHL).GE.1E10) BHL=6666666
IF (DABS(BHLK).GE.1E10) BHLK=6666666
Quoted reply history
On Wed, Mar 30, 2016 at 11:40 AM, Santosh wrote:
Dear all,
I am looking for ways to calculate t[1/2,lamda,z] the elimination phase half life, using a 3-compartment model. ADVAN 12 and TRANS6 seems to be a way. However, I am using the intercompartment clearance and volumes based parameterization, e.g. Q3,V3 etc..
half.life = log(2)/gamma
Could anyone please share NONMEM code to compute the half-life based on gamma?
Thanks so much in advance.
Best regards,
Santosh