Not the same issue, but issues of a similar nature. Most of the time, it is due to a discrepancy between the model structure and the dataset. Among ChatGPT's suggestions below, and I would bet on #1 (relative F between the two formulations not defined correctly):
1. Bioavailability Fraction Parameter: Ensure that the bioavailability fraction (F) parameter is correctly defined in the $PK record. A negative value might indicate an issue with how the parameter is calculated or defined in the model. 2. Dataset Errors: Verify that your dataset is correctly formatted. Non-numeric cells, NA values, and unsorted time columns can cause errors in NONMEM. Ensure that all cells in the dataset are numeric and properly formatted. 3. Additional Parameters: Check the additional parameters in your model, such as absorption lag time, relative bioavailability fraction, rate parameter for zero-order input, duration parameter of that input, and scaling parameter. Incorrect specification or estimation of these parameters can lead to errors. Cheng From: [email protected] <[email protected]> On Behalf Of Marie Rajerison Sent: Tuesday, March 11, 2025 9:50 AM To: [email protected]; [email protected] Subject: [EXTERNAL] [NMusers] RE: NONMEM and Bioavailability fraction Dear NM users I am running an extravascular pop PK model with dual absorption and got the following message from NM: [cid:[email protected]] Has anyone experienced the same issue and how to fix it? Thank you in advance for your help Marie
