Pharmacology

A pharmacology expert can examine whether one medication may alter the concentration or effect of another, whether an interaction is pharmacokinetic or pharmacodynamic, and whether dose, timing, metabolic pathways, or concurrent medications affect the interpretation. FDA notes that drug-drug interactions can alter systemic exposure and potentially reduce efficacy or increase adverse reactions. Interaction studies and labeling information can therefore be important evidence when the effect of combined medications is disputed.

An alleged prescription drug overdose may involve questions about dose-response relationships, absorption, distribution, metabolism, elimination, drug interactions, tolerance, and the expected effects of a medication at a particular exposure. Those issues can fall within pharmacology when the dispute centers on how the drug behaves and produces effects. Questions about measured concentrations in biological specimens, fatal toxicity, cause of death, or poisoning may instead require Toxicology or medical expertise. The specific scientific opinion being requested should determine which specialty is appropriate.

Polypharmacy can complicate interpretation because several medications may interact through pharmacokinetic or pharmacodynamic mechanisms, produce overlapping effects, or alter a patient's response to treatment. Medication lists, prescribing histories, dose changes, timing, metabolic pathways, and known interaction information may therefore require comparison. Published medical literature also recognizes that increasing numbers of medications can increase the opportunity for drug-drug interactions and adverse drug effects, particularly when patient-specific factors alter drug disposition or response.