Psychopharmacology

CYP450 Interactions for Psychiatric Medications

See which psychiatric drugs are substrates, inhibitors or inducers of CYP1A2, 2B6, 2C9, 2C19, 2D6 and 3A4, with strong, moderate and weak ratings.

Open the P450 Interactions table

Runs free in your browser. Open any drug to see its P450 profile; nothing you search is sent to a server.

What it shows

PsychoPharmRef records cytochrome P450 metabolism for each medication in its Drug Database, which covers antidepressants, antipsychotics, mood stabilizers, sleep medications, anxiolytics, stimulants, non-stimulant ADHD drugs and VMAT2 inhibitors. For six enzymes (CYP1A2, CYP2B6, CYP2C9, CYP2C19, CYP2D6 and CYP3A4), plus UGT glucuronidation where relevant, it marks whether a drug is a substrate, an inhibitor, or an inducer.

Reading the P450 profile

Open any drug from the Drug Database and its detail view shows a P450 fingerprint: one row per enzyme the drug touches, with columns for substrate, inhibitor and inducer.

MarkMeaning
Check markSubstrate of that enzyme
S / M / W (inhibitor column)Strong, moderate or weak inhibitor
S / M / W (inducer column)Strong, moderate or weak inducer
DashNo listed effect

Drugs with no entries show "No significant P450 interactions." Hovering a drug card gives a one-line summary, for example which enzymes a drug strongly or moderately inhibits. The P450 Interactions table lays out every medication against the six CYP enzymes, filterable by category.

Checking a combination

To check a specific regimen, add the drugs to Med Comparison and open its P450 tab. It matches each drug's substrates against the others' inhibitors and inducers, ranks the interactions as strong, moderate or weak, and states the expected direction (higher or lower exposure) with suggested action text. It also flags additive QT prolongation when two or more selected agents prolong QT, and adds label-based notes for interactions the CYP model cannot express.

Limitations

The substrate, inhibitor and inducer listings are a summary model. They do not capture dose, genotype, the size of each enzyme's contribution to clearance, or non-CYP transporter effects beyond the curated notes. Confirm clinically important interactions against current prescribing information and an interaction reference.

About PsychoPharmRef

PsychoPharmRef is a free clinical psychopharmacology reference built by Jerad Shoemaker, MD for psychiatrists, residents, and medical students. All tools are evidence-based and designed for point-of-care clinical decision support.

  • 101 psychiatric medications with receptor binding, P450, dosing, and monitoring data
  • 65 interactive clinical tools, rating scales, and therapy-course modules
  • Receptor binding profiles with bar chart, heatmap, and treemap views
  • PK curve comparison, P450 interaction checking, and a QTc calculator with Tisdale risk scoring
  • Medication taper and cross-taper planners
  • 124 evidence-based clinical chapters

PsychoPharmRef Clinical Reference | A resource for medical professionals | Page updated October 23, 2026

This tool is intended for educational purposes for healthcare professionals. Clinical decision-making should incorporate individual patient assessment and current guidelines.

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