NONMEM is a non-linear mixed-effects modeling software package developed by Stuart L. Beal and Lewis B. Sheiner in the late 1970s at

University of California, San Francisco The University of California, San Francisco (UCSF) is a Public university, public Land-grant university, land-grant research university in San Francisco, California, United States. It is part of the University of California system and is dedic ...

, and expanded by Robert Bauer at Icon PLC. Its name is an acronym for nonlinear mixed effects modeling but it is especially powerful in the context of

population pharmacokinetics Pharmacokinetics (from Ancient Greek ''pharmakon'' "drug" and ''kinetikos'' "moving, putting in motion"; see chemical kinetics), sometimes abbreviated as PK, is a branch of pharmacology dedicated to describing how the body affects a specific subs ...

pharmacometrics Pharmacometrics is a field of study of the methodology and application of models for disease and pharmacological measurement. It uses mathematical models of biology, pharmacology, disease, and physiology to describe and quantify interactions between ...

, and

PK/PD models PKPD modeling (pharmacokinetic pharmacodynamic modeling) (alternatively abbreviated as PK/PD or PK-PD modeling) is a technique that combines the two classical pharmacologic disciplines of pharmacokinetics and pharmacodynamics. It integrates a pha ...

. NONMEM models are written in NMTRAN, a dedicated model specification language that is translated into FORTRAN, compiled on the fly and executed by a command-line script. Results are presented as text output files including tables. There are multiple interfaces to assist modelers with housekeeping of files, tracking of model development, goodness-of-fit evaluations and graphical output, such as PsN and xpose and Wings for NONMEM. Current version for NONMEM is 7.5.

Model estimation

NONMEM estimates its models according to principles of

maximum likelihood estimation In statistics, maximum likelihood estimation (MLE) is a method of estimation theory, estimating the Statistical parameter, parameters of an assumed probability distribution, given some observed data. This is achieved by Mathematical optimization, ...

nonlinear mixed-effects model Nonlinear mixed-effects models constitute a class of statistical models generalizing linear mixed-effects models. Like linear mixed-effects models, they are particularly useful in settings where there are multiple measurements within the same sta ...

generally do not have close-formed solutions, and therefore specific estimation methods are applied, such as linearization methods as first-order (FO), first-order conditional (FOCE) or the laplacian (LAPL), approximation methods such as iterative-two stage (ITS), importance sampling (IMP), stochastic approximation estimation (SAEM) or direct sampling.

References

External links

Product site
Numerical software Pharmacodynamics Pharmacokinetics {{pharma-stub