CoursePsychopharmacology Introduction

The drug-action atlas

Enter through a molecule, a synapse, or a brain circuit. Change the conditions and trace what happens next.

All learning models

Explore the system

Repeated doses accumulate

Vary interval and half-life. See each dose add to what remains, producing peaks, troughs, and a repeating plateau.

Repeated doses accumulate

Diagram zoom

Repeated dosesAmount remaining (model units)

Mechanism and exceptions

Dose interval (hours)
Time (hours)	Repeated doses	Amount remaining (model units)
0	60	60
5.3	71.43	23.81
10.7	66.15	9.45
16	116.25	3.75
21.3	93.76	1.49
26.7	75	0.59
32	119.77	0.23

Amount remaining (model units): 90

Julien: approach to steady state in about five to six half-lives. Course: approximately six. A plateau still has peaks and troughs; it is not a perfectly flat concentration.

Starting amount / amount per dose60Half-life (hours)4Elapsed time (hours)4Dose interval (hours)4

Model units; no clinical dose or treatment prediction.

Animate the diagram

On a small screen, pan the diagram or increase zoom. Named controls provide the same exploration by keyboard.

Sources and model limits

Original schematic. Positions show relationships; structures and concentrations are not to scale.

Julien's Primer of Drug Action · 15 · 1 · Repeated doses accumulate · PDF 19 · 1.11

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The drug-action atlas

Enter through a molecule, a synapse, or a brain circuit. Change the conditions and trace what happens next.

All learning models

Explore the system

Repeated doses accumulate

Vary interval and half-life. See each dose add to what remains, producing peaks, troughs, and a repeating plateau.

Repeated doses accumulate

Diagram zoom

Repeated dosesAmount remaining (model units)

Mechanism and exceptions

Dose interval (hours)
Time (hours)	Repeated doses	Amount remaining (model units)
0	60	60
5.3	71.43	23.81
10.7	66.15	9.45
16	116.25	3.75
21.3	93.76	1.49
26.7	75	0.59
32	119.77	0.23

Amount remaining (model units): 90

Julien: approach to steady state in about five to six half-lives. Course: approximately six. A plateau still has peaks and troughs; it is not a perfectly flat concentration.

Starting amount / amount per dose60Half-life (hours)4Elapsed time (hours)4Dose interval (hours)4

Model units; no clinical dose or treatment prediction.

Animate the diagram

On a small screen, pan the diagram or increase zoom. Named controls provide the same exploration by keyboard.

Sources and model limits

Original schematic. Positions show relationships; structures and concentrations are not to scale.

Julien's Primer of Drug Action · 15 · 1 · Repeated doses accumulate · PDF 19 · 1.11