Pharmacology may be the basis of Causation

Pharmacology is the study of how substances affect a living organisms. 

How does the substance change the normal function.  (Nagle 2005 ).  

Clinical Pharmacology

Medication effects specifically in humans

Example of Pharmacology or Pharmacodynamics - Ethyl Alcohol

Alcohol is a drug that produce a depressant effect and agitation.   The depressant effect is considerably short effect than the depressant effect.

Alcohol is though to disturb the synaptic activity of various neurotransmitters.  It may also disturb various intracellular transduction pathways.

Glutamate Receptors

Alcohol is an inhibitor of the function of the glutamate receptor.  It depresses the responsiveness of NMDA receptors to release glutamate.  With continued alcohol use, the NMDA receptors become more active.  When the alcohol is suddenly stopped, this increased activity in the receptors can lead to tremors and seizures. 

GABA Receptors

Alcohol triggers a response from GABA induced chloride ion flow which causes neuronal stopping. 

This causes sedation, muscle relaxation, and cognitive/motor skill decreases.

My Experience

I have worked with attorneys in developing their case.  First, to show how a drug works in the body and its' effect at a cellular level.   Then providing a pharmacologic explanation that the drug was the cause of the clients adverse experience.