Choose medicines
Search generic, brand, or common names. Add food or supplements the same way when they are in the formulary. Free tier: up to five items.
For licensed healthcare professionals & supervised students
See how medicines may interact — starting in plain English.
FirstPass is a learning desk for medicine, supplement, and food combinations. You add names (generic, brand, or common street/clinic names). The desk shows mapped findings: first a short everyday summary, then optional clinical detail and sources. It does not replace a clinician, a pharmacist, or the official drug label. The free checker supports up to five items.
- Free up to five medicines
- Search by everyday names
- Plain summary, then detail
A few ways to explore
Try ready-made examples.
Pick a card to open the live desk with that combination already loaded. Search by medicine name or topic. These are learning examples — not treatment recommendations and not a personal risk score.
EXAMPLE 01 · FOOD & ROUTE
Grapefruit + oral ketamine
Why drinking grapefruit juice can matter more when ketamine is swallowed than when it is given by IV.
Open this example EXAMPLE 02 · FOOD & MEDICINETacrolimus + grapefruit
A transplant medicine where food can change blood levels — a classic “small change, big stakes” teaching case.
Open this example EXAMPLE 03 · SUPPLEMENT & ROUTEPiperine + oral ketamine
Black-pepper extract is a common supplement; see how it shows up next to an oral medicine on the map.
Open this example EXAMPLE 04 · MEDICINE & ROUTEOral ketamine + clarithromycin
An antibiotic that can slow a gut enzyme — useful for seeing why “route matters” on the map.
Open this example EXAMPLE 05 · CNS & SEDATIONKetamine + alprazolam
Two medicines that can both affect alertness and breathing — how the desk stacks those notes for review.
Open this example EXAMPLE 06 · SEROTONINMDMA + phenelzine
A high-stakes serotonin teaching pair: open the desk for the plain summary, then the clinical notes and sources.
Open this example EXAMPLE 07 · CYP & SEROTONINDXM + sertraline
Cough medicine plus a common antidepressant — see enzyme and serotonin notes side by side.
Open this example EXAMPLE 08 · CNS & SEDATIONAlcohol + opioid + benzodiazepine
Three items that each add sedation risk — see how the desk ranks pairs when more than two names are on the list.
Open this example EXAMPLE 09 · SUPPLEMENT & CYPCBD + clobazam
A cannabinoid product next to a seizure medicine — how the checker surfaces enzyme pathway notes.
Open this exampleA simple review flow
From names to context in three steps.
Think of FirstPass as a structured study sheet: it surfaces mapped findings so you can discuss them — it does not decide care.
Read the summary
Start with the everyday-language line. Severity badges help you scan the list; they are teaching labels, not a personal risk score.
Open the detail
Expand a row for pathway notes, clinical teaching text, and sources. Always check current prescribing information and a qualified clinician.
What's on the desk
Tools that show why, not just what.
Free for up to five drugs. The founding license is $79 once. Educational only, not FDA-cleared, and the prescribing information governs.
Gut vs vein
See how much of a swallowed dose the gut and liver clear before it reaches the blood, compared with an IV dose.
Same drugs, different person
Flip smoking, a slow CYP2D6, age, kidneys, or pregnancy and see exactly what changes on the list.
Phenoconversion
Run the same tray with a blocking drug off and on, and watch a normal metabolizer act like a poor one.
Watch and study
Track recent OpenFDA label changes, and work through lab-book assignments you can export.
A short or empty list is not a green light. It only means nothing in the mapped set matched.
A short glossary
What the words mean.
You do not need a pharmacology degree to start. Here are the labels you will see most often, in everyday language.
Interaction
One medicine (or food or supplement) changing how another works — more effect, less effect, or a new side-effect pattern.
CYP / enzyme pathway
“CYP” names are liver and gut enzymes that break down many medicines. If two items share a pathway, levels can rise or fall. FirstPass maps those pathways; it does not measure your personal enzymes.
Pharmacodynamic (PD)
Effects that stack in the body even when levels look “normal” — for example two sedating medicines, or two that raise serotonin.
Severity label
A teaching category on a mapped finding (how the desk sorts the card). It is not a personal prediction of harm for any one patient.
First-pass / route
Swallowed medicines often meet gut enzymes before the bloodstream. IV and some other routes skip that step — so the same names can look different by route.
Regimen vs pair
Two names make one pair. Three or more names make a regimen. The desk ranks every pair and leads with the sharpest mapped row, not the order you typed.
When you add more than two names
How FirstPass ranks a full list.
Real clinic lists are rarely two drugs. The checker compares each pair, ranks by the strongest mapped finding, and opens with a plain-English line for that lead row. You can still open every other pair below.
1. Build the list
Add up to five medicines free (more on licensed plans). Brand names, generics, and many common aliases all search.
2. Read the lead summary
Start with the everyday sentence for the sharpest pair. That is a map highlight, not a dose or a next clinical step.
3. Open any row
Expand for mechanism notes, clinical teaching text, and source links — then verify against current labeling and a qualified clinician.
A finding has more than a label
Follow the signal, then check the context.
FirstPass separates a readable starting point from the details you may want to examine next.
Plain-language summary
A quick explanation of the possible direction of an interaction, without treating a category as an individual outcome.
Mechanism & clinical notes
Expand a finding to see pathway details and the clinical note attached to that map entry.
Sources to review
Follow available citations and references, then verify against current labeling and the full clinical context.
The map is selective and can be incomplete. Source links are a starting point for review—not a guarantee that every finding has been captured.
Designed for learning and review
A desk for curious clinicians and learners.
Clinical teams
Use the desk as one input during professional review — plain summary first, then mapped pathway detail.
Pharmacy learners
Practice reading interaction language with ready examples, without treating the map as a charting system.
Educators
Load a teaching pair in class, then walk from the everyday sentence into mechanism and sources.
Curious clinicians
Explore combinations you already think about (ketamine clinics, MAT, primary care stacks) on a selective teaching map.
Free teaching packs
Send a clinic a link that already opens.
These three sets load on the live desk today. They stay inside the free five-drug cap. They are teaching maps, not a treatment plan and not a chart note. Open today's free case: a new teaching pair each day.
PACK · KETAMINE CLINIC
Clinic onboard
Oral first-pass, a benzo airway stack, and induction loss. Three free maps for an infusion or KAP desk.
Open clinic pack PACK · MAT / OTPMAT / street cup
Xylazine, naltrexone with a leftover opioid, loperamide, and a designer benzo. Still within five items.
Open MAT pack PACK · STUDENTSPharmD lab
Swallowed ketamine, a benzo stack, transplant food, and a street sedative. A class set, not an exam key.
Open student packStart free · expand when useful
Five-drug checks stay free. Founding is $79 once.
Try the main workflow at no cost. Founding lifetime unlocks host factors, the enzyme atlas, metabolite maps, and export — yours for life on the desk. Pay on this page; paste the key under Redeem inside the checker.
Free desk · no card
Check up to five medicines.
- Interaction cards (enzyme pathways and stacked body effects)
- Search by common, generic, and brand names
- Plain-language summary before clinical detail
- Citation and source links when available
Optional license · founding $79 once
Add more context and tools.
- More medicines on the list (up to eight)
- Host factors: metabolizer phenotype, smoking, alcohol, and route
- Enzyme atlas and metabolite teaching views
- Full report plus JSON/CSV export
Pay $79 once. After it clears, you get a signed key by email or text. Paste it under Redeem on Plans. Nothing unlocks by itself. You can still start a 7-day preview inside the checker.
Questions or a missing key: FirstPassInteractions@gmail.com
Good to know
A few important questions.
How do I pay for the $79 founding license?
Send $79 once on Venmo @kaleblovingier, Cash App $kaleblovingier7, or PayPal to FirstPassInteractions@gmail.com. After it clears, a signed key arrives by email or text. Paste that key under Redeem on Plans in the checker. The free five-drug desk does not need a payment. Write FirstPassInteractions@gmail.com if the key does not show up.
Does “no mapped interaction” mean a combination is safe?
No. The checker can miss interactions and its map is not exhaustive. Review current prescribing information and use qualified clinical judgment.
Does FirstPass provide treatment or dosing advice?
No. It is an educational and clinical-review aid, not a dose calculator, personal treatment guide, or substitute for a clinician.
Who is this for if I am not a specialist?
You can still explore the examples and read the plain-English summaries. Decisions about medicines belong with a licensed clinician or pharmacist. Students should use FirstPass under supervision when it is part of coursework.
What does “sharpest pair” mean on a longer list?
When three or more names are on the desk, FirstPass compares each two-item pair, ranks them by the strongest mapped finding, and leads with that pair’s everyday summary. Other pairs stay available below. Ranking is for navigation, not a personal risk score.
Is FirstPass a government-approved medical device?
No. It is not FDA-cleared or FDA-approved. The official Prescribing Information for each product still governs.
What should I do in an urgent situation?
Do not wait for an online checker. Contact local emergency services or a poison center for urgent illness, possible overdose, or immediate safety concerns.
Important limits
FirstPass is an educational and clinical-review aid. It is not FDA-cleared or FDA-approved, does not provide dosing instructions, and does not replace clinical judgment or current prescribing information. It can miss interactions; no finding does not mean a combination is safe. It is not intended to guide personal treatment decisions.
Explore at your own pace