For psychiatric prescribers

Stop guessing what
your patient is
actually getting.

See the real drug exposure your patient experiences — not just the prescribed dose. CYPnosis models how psychiatric medications interact in the body so you can make confident dosing decisions in complex regimens.

Regimen analysis — 4 drugs · illustrative output
Fluoxetine 20 mg HIGH · HIGH EXPOSURE TIER
190% ≈ 38 mg
Risperidone 3 mg MODERATE · MED. EXPOSURE TIER
133% ≈ 4.0 mg
Nortriptyline 50 mg HIGH · HIGH EXPOSURE TIER
214% ≈ 107 mg
Alprazolam 1 mg LOW · NEAR-BASELINE
148% ≈ 1.5 mg
MODEL SCORE: 47
SERT5-HT2ARelease
Fluoxetine
Nortriptyline
D2 occupancy
52%
QT potential
44
Complexity index
High
Engine v2.3.1 · V13.1 · Values are illustrative. Actual outputs depend on patient-specific inputs.
PRESCRIBED DOSE
3 mg
ACTUAL EXPOSURE
4.0 mg

The prescription didn't change. The exposure did. CYP2D6 inhibition from fluoxetine raises risperidone exposure by 33% — without any visible warning in the chart.

Engine v2.3.1 · V13.1 constraint set · Values are illustrative

Build a regimen.
Watch the exposure shift.

Add drugs one by one and see what happens to each drug's exposure — and the cumulative burden indices — in real time.

Drug library
SSRIs / NDRI
Antipsychotics
TCAs / Other
ADHD / CV
Patient modifiers
← Add drugs from the library
to see exposure analysis
This demo uses a simplified model across 13 curated drugs. The full tool models 213 drugs across 8+ CYP pathways with PGx integration, renal adjustment, active moiety correction, and Monte Carlo stability analysis.
Request access →

If you're not a
psychopharmacologist,
start here.

CYPnosis outputs exposure-equivalent doses and burden indices. Here's what those mean in plain terms — one drug, one interaction, walked through.

Walk me through it
Fluoxetine 20 mg + risperidone 3 mg · verified engine output · 4 steps

The regimens where
this actually matters.

Four situations psychiatric prescribers encounter regularly — where conventional DDI checkers return a flag but CYPnosis returns a number.

Regimen · illustrative
Fluoxetine 20 mg HIGH EXPOSURE TIER
190%≈ 38 mg
Risperidone 3 mg MED. EXPOSURE TIER
133%≈ 4.0 mg
Alprazolam 1 mg NEAR-BASELINE
148%≈ 1.5 mg
Serotonergic load
74
D2 occupancy
52%
Complexity index
High
What's happening
Fluoxetine is a strong CYP2D6 inhibitor with mechanism-based inactivation. Risperidone is primarily CYP2D6-metabolized (fm ≈ 0.70). The prescribed 3 mg is producing exposure closer to 4.0 mg equivalent — a shift the medication list doesn't surface.
What a flag misses
Lexicomp flags this pair. What it doesn't tell you is by how much, that D2 occupancy at 4.0 mg equivalent exposure is materially different from 3 mg, or that the three drugs together produce elevated serotonergic stacking — none of which appears in a pairwise flag.
What CYPnosis adds
A concrete exposure-equivalent for each drug. D2 occupancy recalculated at the actual risperidone exposure — not the prescribed dose. Serotonergic burden quantified across all three agents simultaneously. Complexity index reflecting regimen structural fragility.
Regimen · illustrative
Fluoxetine 40 mg PERPETRATOR · CYP2D6
Nortriptyline 50 mg HIGH EXPOSURE TIER
214%≈ 107 mg
Quetiapine 200 mg MED. EXPOSURE TIER
120%≈ 240 mg
QT potential
68
Anticholinergic
6
Serotonergic load
60
What's happening
Nortriptyline is heavily CYP2D6-dependent (fm ≈ 0.85). Fluoxetine at 40 mg is a strong mechanism-based inactivator. The TCA exposure roughly doubles — a prescribed 50 mg behaves closer to 107 mg equivalent exposure.
Why QT matters here
TCAs and quetiapine both carry QT liability. The QT burden index is scaled by actual exposure — not prescribed dose. Nortriptyline at 107 mg equivalent drives a meaningfully different QT contribution than 50 mg. The cumulative QT index reflects this. No pairwise checker surfaces this arithmetic.
What CYPnosis adds
Exposure-equivalent dose quantifies the TCA shift. QT burden integrates both nortriptyline and quetiapine at their actual — not nominal — exposure levels. Anticholinergic load stacks both drugs. TDI kinact/KI parameters for fluoxetine drive the inhibition estimate mechanistically.
Regimen · illustrative · CYP2D6 PM
Aripiprazole 15 mg HIGH EXPOSURE TIER
320%≈ 48 mg
Paroxetine 20 mg HIGH EXPOSURE TIER
280%≈ 56 mg
Ziprasidone 80 mg NEAR-BASELINE
108%≈ 86 mg
QT potential
74
D2 occupancy
79%
Complexity index
High
What's happening
A CYP2D6 PM has intrinsically reduced pathway capacity. Aripiprazole is predominantly CYP2D6-metabolized (fm ≈ 0.80). The PM phenotype alone drives a 3.2× exposure shift — before any drug inhibition. Paroxetine, a potent CYP2D6 inactivator, is handled via a Math.min ceiling to prevent double-suppression.
Why QT matters here too
Ziprasidone carries meaningful intrinsic QT liability, largely independent of CYP2D6. But aripiprazole at 48 mg equivalent exposure — not 15 mg — drives a much higher QT contribution than the label-based number implies. The QT index is built on exposure equivalents, not prescribed doses. The cumulative picture across both antipsychotics is what matters.
What CYPnosis adds
The PGx modifier enters at the pathway level before clearance reconstruction. D2 occupancy recalculated at the actual aripiprazole exposure via BBB transport modeling and PET calibration. QT burden reflects the exposure-adjusted contribution of each drug — and their sum — not categorical flags per agent.
Regimen · illustrative · QT focus
Citalopram 40 mg
≈ 40 mg
×1.0
Quetiapine 400 mg
≈ 400 mg
×1.0
Fluconazole 200 mg
perpetrator
CYP3A4
Quetiapine (adjusted)
≈ 700 mg
×1.75
QT index (baseline)
42
QT index (+fluconazole)
74
Complexity index
Mod–High
No dose change. No genotype change. QT burden driven entirely by the PK shift.
What's happening
Citalopram has dose-dependent QT liability — the FDA limits it to 40 mg partly for this reason. Quetiapine is a moderate QT-prolonging agent metabolized primarily by CYP3A4. Fluconazole is a strong CYP3A4 inhibitor commonly co-prescribed for a fungal infection. No psychiatric dose has changed. No genotype is involved.
The invisible QT shift
Fluconazole raises quetiapine exposure by approximately 1.75× via CYP3A4 inhibition. The QT burden index — built on actual AUCR per drug, not prescribed doses — rises from 42 to 74. The prescribing physician sees the same two psychiatric doses they've always prescribed. CYPnosis sees a materially different QT picture. A standard QT checklist flags citalopram and quetiapine as before — unchanged.
What CYPnosis adds
The QT burden index recalculates dynamically when any perpetrator is added — including non-psychiatric drugs. Fluconazole's CYP3A4 inhibition propagates through the quetiapine exposure estimate, which then propagates into the QT burden calculation. The clinician sees the before/after delta, not just a flag on fluconazole.

Not another
contraindication flag.

Conventional DDI tools + PGx reports
Pairwise flags — each drug pair or drug-genotype pair in isolation
Static severity buckets: major / moderate / minor, or red / yellow / green
No exposure translation — the prescribed dose is the assumed exposure
PGx phenotype applied without accounting for concurrent drug inhibitors
QT assessed per drug label, not at actual regimen-adjusted exposure
No cumulative burden model across the full regimen
CYPnosis
All drugs modeled simultaneously — stacking captured across the regimen
Continuous AUCR with plausibility-bounded output, displayed in mg
Prescribed dose → exposure-equivalent dose, accounting for the full regimen
PGx enters at the pathway layer, composited with drug inhibition — not applied separately
QT burden scaled by actual AUCR per drug, cumulated with patient modifiers
Serotonergic, D2, QT, and anticholinergic burden modeled cumulatively

Turn PGx reports into
actionable dosing decisions.

Pharmacogenomic reports tell you how a patient metabolizes drugs. They don't tell you what to do with that information.

CYPnosis does.

Instead of displaying genotype as a separate flag, CYPnosis integrates PGx data directly into the clearance calculation, combining it with the patient's full medication regimen. The output is a single exposure estimate you can use to guide dosing—no manual translation required.

CYPnosis turns PGx results from informational into actionable.

CYP2D6 Poor Metabolizer — same patient, two views
What the PGx report shows vs. what CYPnosis models
illustrative · not patient data
PGx report output
Aripiprazole (Abilify®)Significant gene-drug interaction
Risperidone (Risperdal®)Significant gene-drug interaction
Fluoxetine (Prozac®)Significant gene-drug interaction
Nortriptyline (Pamelor®)Significant gene-drug interaction
Paroxetine (Paxil®)Significant gene-drug interaction
Alprazolam (Xanax®)Use as directed
Clinical note: "Serum level may be too high, lower doses may be required." No quantification of how much. No interaction between flags. Each drug considered in isolation against genotype only.
CYPnosis output — same patient, same regimen
Aripiprazole MODERATE · MED. EXPOSURE TIER
Modeled Exposure
200%
of baseline
Prescribed: 5 mg
Direction: ↑ inhibition-dominant
Exposure-Equivalent Dose
≈ 9.99 mg
Mechanistic Contributors
CYP2D6 inhibitor via
Paroxetine, Bupropion
Affected by: Paroxetine,
Bupropion
Management: Dose evaluation may be appropriate under current modeled exposure parameters.
Risperidone 3 mg
Exposure-equivalent ≈ 4.0 mg · 133% of baseline. D2 occupancy recalculated at actual exposure. Fluoxetine co-inhibition stacked onto PM baseline.
Nortriptyline 50 mg
Exposure-equivalent ≈ 107 mg · 214% of baseline. QT contribution scaled at actual exposure. Narrow therapeutic index flagged.
The PGx report answers: "Does this patient's genotype affect this drug?" CYPnosis answers: "Given this patient's genotype and everything else they're taking, what exposure is each drug actually producing — and what does that mean for D2 occupancy, QT burden, and regimen complexity?" These are complementary questions. CYPnosis is designed to sit downstream of a PGx result, not to replace it.

Regulatory DDI math,
applied to psychiatry.

The same mechanistic framework used in FDA DDI guidance — fm decomposition, well-stirred hepatic clearance, TDI stacking — applied to the drugs psychiatric prescribers actually use.

Full CYP pathway decomposition
Every drug characterized across CYP1A2, CYP2B6, CYP2C8, CYP2C9, CYP2C19, CYP2D6, CYP3A4, CYP3A5, and five UGT isoforms. CYP3A4 hepatic and intestinal first-pass modeled separately. Clearance reconstructed from first principles.
Multi-drug stacking logic
Competitive inhibition (Ki-based), mechanism-based inactivation (kinact/KI), and induction composited per pathway into a single net modifier — never applied sequentially. Monotonicity enforced throughout.
Exposure-equivalent dose
Prescribed dose translated into the exposure-equivalent it represents given the full regimen. Displayed in mg — a number that can be reasoned about. Prodrug and active moiety modeling included for relevant drugs.
~
Serotonergic burden (STRiC)
SERT inhibition stacking, 5-HT receptor load, and additive serotonergic mechanisms quantified as a mechanistic burden index. Most informative when multiple moderate agents are combined — the scenario where pairwise flags are least useful.
Exposure-adjusted QT burden
Per-drug QT weights scaled by actual AUCR — not prescribed doses. Cumulative across all agents. Patient modifiers (electrolytes, sex, structural heart disease) integrated as multipliers. Identifies regimens where PK inhibition amplifies QT liability invisibly.
D2 receptor occupancy
Full PD sub-engine: plasma Css estimation, BBB transport modeling, PET calibration data, competitive D2 occupancy across all antipsychotics simultaneously. EPS burden from peak occupancy. Recalculates at actual — not nominal — drug exposure.
Pharmacogenomic integration
Phenotypes for CYP2D6, CYP2C19, CYP2C9, CYP3A4, CYP1A2, and CYP2B6. Modifiers enter at the pathway layer before clearance reconstruction. Math.min ceiling prevents double-suppression when genotype and drug inhibitor affect the same enzyme simultaneously.
Renal clearance adjustment
Cockcroft-Gault CrCl mapped to FDA renal impairment categories. Renal and hepatic clearance fractions modeled independently — relevant for renally-eliminated drugs common in psychiatric practice (lithium, gabapentin, paliperidone).
σ
Monte Carlo stability analysis
Parameter uncertainty modeled across 1,000 seeded iterations — deterministic and reproducible. Outputs include mean AUCR, 5th/95th percentile bounds, and boundary violation counts. Confirms model numerical stability, not clinical probability.

Built for prescribers
managing psychiatric complexity.

CYPnosis surfaces mechanistic information that takes hours to extract manually — if it can be extracted at all from the tools currently available.

Outpatient Psychiatry
Complex medication management
The patient on five psychotropics who isn't responding as expected. CYPnosis makes visible what CYP inhibition stacking is doing to each drug's effective exposure — and gives you a concrete number to reason about rather than a flag to acknowledge and override.
Inpatient / Consult-Liaison
Rapid regimen audit
A patient with movement symptoms or altered mental status whose medication list has three antipsychotics and an SSRI. CYPnosis surfaces D2 occupancy at actual exposure, QT burden across the full regimen, and complexity index — quickly.
Clinical Pharmacy — Behavioral Health
Mechanistic reconciliation
Move beyond pairwise flags and PGx color codes into regimen architecture. Understand which drugs carry the metabolic load, how a PGx result interacts with concurrent inhibitors, and what happens to QT burden when exposure shifts.
Receptor binding systems — clinical rationale
D2 · H1 · M1 · α1 · Serotonin subtypes · what each contributes and why it matters in polypharmacy

Explicit about
scope and method.

Clinical tools that overclaim lose the clinicians who most need them. CYPnosis is precise about what its outputs represent — and what they don't.

What the engine models — and what it doesn't
Scope, limits, and modeling governance
Early access

See what your next
complex regimen
actually looks like.

Before you prescribe it.

CYPnosis is currently in limited access for psychiatric prescribers and clinical pharmacists in behavioral health. Request an invite below.

For clinical education and decision support only. Not a substitute for clinical judgment,
laboratory monitoring, or therapeutic drug monitoring. Not FDA-cleared.
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