The CMPTMODEL statement computes predicted concentrations from a specified one-, two-, or three-compartment model. The CMPTMODEL statement includes three types of options:
The following required-options are required: PCONC=, TIME=, NCOMPS=, ADMTYPE=, and PARMTYPE=.
The following conditionally-required-options are conditionally required depending on the specification of the required-options: CLn=, VOLn=, K12=, K21=, K13=, K31=, KA=, Kn0=, RATE=, and DURN=.
The following options are optional: DOSEn=, SCALEn=, PCONC0=, PCONC2=, and PCONC3=.
You must specify the following required-options:
-
ADMTYPE=IVB | INF | ORAL
-
specifies the administration type. You can specify the following values:
- IVB
specifies the bolus type of administration.
- INF
specifies the infusion type of administration.
- ORAL
specifies the oral type of administration.
-
NCOMPS=1 | 2 | 3
specifies the number of compartments in a model.
-
PARMTYPE=1 | 2
PTYPE=1 | 2
-
specifies the parameterization type. You can specify the following values:
- 1
parameterizes the compartment model in terms of elimination and transfer rate constants.
- 2
parameterizes the compartment model in terms of clearance and volume constants.
-
PCONC=variable
PCONC1=variable
specifies the outcome variable that is the predicted concentration in the first or central compartment at each time point.
-
TIME=variable
specifies the time value at which the predicted concentrations are computed, where variable can be a data set variable or a defined variable.
You can combine the NCOMPS=, ADMTYPE=, and PARMTYPE= options to fit a compartment model (one-, two-, or three- compartments) with different administration methods (bolus, infusion, or oral) using different parameterizations. The PCONC= variable is the outcome that is the evaluated predicted concentration at the TIME= value. You can use this variable in model specification in your program.
You might need to specify one or more of the following conditionally-required-options based on what you specify in the required-options:
-
CLn=variable
-
specifies the clearance value for the nth compartment, where n takes the values of 1, 2, or 3. (CL is an alias for CL1.) This option is valid only in models that require clearance (PARMTYPE=2). The variable can be a data set variable or a defined variable.
You must specify a CL1= option when you specify a one-compartment model (NCOMPS=1)
You must specify CL1= and CL2= options when you specify a two-compartment model (NCOMPS=2)
You must specify CL1=, CL2=, and CL3= options when you specify a three-compartment model (NCOMPS=3)
-
DURN=variable
specifies the duration of the infusion. This option is valid only in infusion models (ADMTYPE=INF). The variable can be a data set variable or a defined variable. In an infusion model, you must specify either this option or the RATE= option.
-
KA=variable
specifies the absorption rate constant. This option is valid only for the oral type of compartment models (ADMTYPE=ORAL).
-
K12=variable
specifies the transfer rate constant from the first (central) compartment to the second compartment. This option is valid only in models that require transfer rate (PARMTYPE=1). The variable can be a data set variable or a defined variable. You must specify this option in a two- or three-compartment model.
-
K21=variable
specifies the transfer rate constant from the second compartment to the first (central) compartment. This option is valid only in models that require transfer rate (PARMTYPE=1). The variable can be a data set variable or a defined variable. You must specify this option in a two- or three- compartment model.
-
K13=variable
specifies the transfer rate constant from the first (central) compartment to the third compartment. This option is valid only in models that require transfer rate (PARMTYPE=1). The variable can be a data set variable or a defined variable. You must specify this option in a three-compartment model.
-
K31=variable
specifies the transfer rate constant from the third compartment to the first (central) compartment. This option is valid only in models that require transfer rate (PARMTYPE=1). The variable can be a data set variable or a defined variable. You must specify this option in a three-compartment model.
-
Kn0=variable
-
specifies the elimination rate constant for the nth compartment, where n takes the values of 1, 2, or 3. (Ke is an alias for K10.) This option is valid only in models that require elimination rate (PARMTYPE=1). The variable can be a data set variable or a defined variable.
You must specify a K10= option when you specify a one-compartment model (NCOMPS=1)
You must specify a K10= option and you can optionally specify a K20= option when you specify a two-compartment model (NCOMPS=2)
You must specify a K10= option and you can optionally specify K20= and K30= options when you specify a three-compartment model (NCOMPS=3)
-
RATE=variable
specifies the rate of the infusion. This option is valid only in infusion models (ADMTYPE=INF). The variable can be a data set variable or a defined variable. In an infusion model, you must specify either this option or the DURN= option.
-
VOLn=variable
-
specifies the apparent volume of distribution of a drug in the nth compartment, where n takes the values of 1, 2, or 3. (VOL is an alias for VOL1.) This option is valid only in models that require volume (PARMTYPE=2). The variable can be a data set variable or a defined variable.
You must specify a VOL1= option when you specify a one-compartment model (NCOMPS=1)
You must specify VOL1= and VOL2= options when you specify a two-compartment model (NCOMPS=2)
You must specify VOL1=, VOL2=, and VOL3= options when you specify a three-compartment model (NCOMPS=3)
You can also specify the following optional options:
-
DOSEn=variable
-
specifies the amount of the dose for the nth compartment, where n takes the values of 0, 1, 2, or 3. (DOSE is an alias for DOSE1.) The DOSE0= option specifies the amount of dose in the zero (depot) compartment, and is valid only in oral models (ADMTYPE=ORAL). The variable can be a data set variable or a defined variable.
DOSE1= is optional and valid for one-, two-, and three-compartment models
DOSE2= is optional and valid only for two-, and three-compartment models
DOSE3= is optional and valid only for a three-compartment model
When ADMTYPE=ORAL is specified, DOSE0=1, DOSE1=0, DOSE2=0, and DOSE3=0 by default. Otherwise, DOSE1=1, DOSE2=0, and DOSE3=0 by default.
-
PCONC0=variable
specifies the outcome variable that is the predicted concentration of the zero (depot) compartment. This option is valid only when the ADMTYPE= ORAL option is specified.
-
PCONC2=variable
specifies the outcome variable that is the predicted concentration of the second compartment. This option is valid only in two- and three-compartment models.
-
PCONC3=variable
specifies the outcome variable that is the predicted concentration of the second compartment. This option is valid only in three-compartment models.
-
SCALEn=variable
-
specifies the scale value for the nth compartment. The variable can be a data set variable or a defined variable. SCALE0= option is valid only in oral models (ADMTYPE=ORAL).
SCALE1= is optional and valid for one-, two-, and three-compartment models
SCALE2= is optional and valid only for two-, and three-compartment models
SCALE3= is optional and valid only for a three-compartment model
By default, all optional SCALEn values are set to 1.
For more information, see the section Compartment Models.