PeaK

Getting started

Choose a medication or formulation from Model. The available controls, units, covariates and overlays will change according to the selected model.

The description below the model name summarises the model and formulation. Select Sources to view the pharmacokinetic, pharmacodynamic and product references used for that model.

Changing the model in the active tab resets that tab’s regimen and covariates to the selected model defaults.

Building a regimen

Use Active regimen to choose whether you are editing Regimen A or Regimen B.

A default regimen is loaded with the selected model. Adjust the required regimen fields as needed:

• Default dose
• Default number of doses
• Default interval
• Tail after last dose
• Display from dose #, if required

Valid changes are applied after pressing Enter or moving out of the field.

The interval units and available options vary between models. Some formulations may also provide loading doses, injection sites, needle lengths, patch duration or other model-specific settings.

Display from dose # hides earlier doses from the chart but still includes them in the pharmacokinetic calculation.

Use Reset all to restore both regimens and the model covariates to their defaults.

Comparing two regimens

Create or edit Regimen A, then switch Active regimen to Regimen B and create the comparison regimen.

Both regimens are displayed on the chart. Regimen A and Regimen B remain independently editable.

The currently selected active regimen is also the regimen used when saving a snapshot or exporting data.

Covariates

The Covariates panel contains the model covariates and settings supported by the selected model, such as weight, renal function, sex, smoking status or metabolic phenotype.

Changes are applied to the simulation after the value is committed by pressing Enter or moving out of the field.

Use Clear overrides to remove manually entered overrides and restore the model’s default or automatically derived values.

Available covariates and accepted ranges vary between models. Invalid values are not applied.

Editing individual doses

Open Selected Dose, then select a dose from the dose list or select its marker on the chart.

Depending on the model, you may be able to edit:

• dose time
• dose amount
• interval from the previous dose
• injection site
• needle option
• patch or wear duration
• other formulation-specific settings

Press Enter or move out of the field to apply a valid change. Invalid entries are not committed.

The first dose has no previous interval, so its Interval from previous control is unavailable.

Applying changes to later doses

After editing the selected dose, choose one or more options under Apply selected changes to future doses:

• Interval
• Dose
• Site, when supported

The summary shows the selected dose and the number of later doses that will be affected. Select Apply to future doses to apply those properties to the selected dose and all remaining doses.

The button is unavailable when no property is selected, the edited value is invalid, or there are no later doses to update.

Using the chart

The chart displays predicted concentration over time for Regimen A and Regimen B, together with their dose markers. These outputs are simulated model outputs, not measured patient concentrations.

Some models also display an active moiety, metabolite or receptor-occupancy curve using a secondary vertical axis.

Hover over the chart to inspect values.

A dose marker can be dragged to change the timing of one dose. Hold Shift while dragging to move that dose and the later doses together. Press Escape during a drag to cancel it.

Chart units and additional series depend on the selected model.

Medication slots

Slots 1–9 allow several medication models to be loaded for combined system-level displays.

Select a slot before choosing or editing its model, covariates or regimens. The active slot determines which medication the surrounding controls currently edit.

Slots included in combined calculations can be selected under Include Slots in Totals.

Snapshots

Open Snapshots and select Save Snapshot (Active) to store the currently displayed regimen simulation.

Saved snapshots can be:

• shown or hidden on the chart
• applied to restore their saved state
• renamed
• deleted

Up to 20 snapshots may be stored. Snapshots persist after changing models or refreshing the page.

Snapshots are stored in this browser’s local storage. They are not saved to an account or shared profile.

A newly saved snapshot may need to be enabled using its visibility checkbox before its curve appears on the chart.

System overlays

Open System Overlays to display combined information from the medication slots selected under Include Slots in Totals.

Available overlays include:

• Show Total Concentration
• Show Combined D2 Occupancy

Combined D2 occupancy is available only when the included models provide compatible receptor-occupancy information.

System overlays use Regimen A from the included slots. Their chart labels therefore include “(A)”.

These overlays are modelling aids and do not establish a therapeutic target or recommended treatment.

Exporting results

Choose the required High-res step, then select Export CSV.

CSV export contains simulated model output for the currently displayed regimen, not measured patient concentration data. It does not export Regimen A and Regimen B together, snapshots, receptor-occupancy curves or system overlays.

A step of 24 h produces one row per day. Smaller steps produce more detailed output using an hourly time scale.

The exported duration includes the regimen and its selected Tail after last dose.

Sources and Help

Select Sources to view references for the active model.

Dialogs can be closed using their close control or the standard keyboard controls supported by the browser.

Important limitations

Predictions depend on the selected population model, its assumptions and the entered model inputs. Available controls and outputs differ between models.

See Disclaimer for clinical-use limitations.

PeaK provides model-based pharmacokinetic and pharmacodynamic simulations for education and exploratory review of model-based simulations. Outputs are predictions derived from published models (where possible) and depend on the assumptions, parameter estimates and user-entered values applied by each model. These outputs are simulated model outputs, not measured patient concentrations.

Although reasonable care has been taken in preparing and implementing the information and models presented, no guarantee is made regarding their completeness, accuracy, currency or suitability for any particular purpose.

PeaK does not provide prescribing advice and must not replace clinical assessment, therapeutic drug monitoring, current approved product information, relevant guidelines or consultation with an appropriately qualified health professional.

Users should independently verify medication doses, administration instructions, contraindications, warnings and precautions using current authoritative sources before applying any information in clinical practice.

To the extent permitted by law, the developer accepts no responsibility for loss, injury or damage arising from use of, or reliance on, the viewer or its outputs.