XVI
SENTINELRX
XVI Health Intelligence · OTC Safety Operator
⚠️ United States Only — FDA Beers Criteria 2023 · Not valid outside the US Read full disclaimer →

What SentinelRx Does

You are caring for an elderly person who takes multiple prescription medications. Every time you reach for an over-the-counter product — a pain reliever, a cold medicine, a sleep aid, a supplement — you face a question no one has prepared you to answer: is this safe with everything they're already taking?

SentinelRx answers that question. You describe the product or share a photo of the label. It checks the ingredients against your patient's medication list and returns one clear decision — every time.

The Four Answers

SAFE TO TAKE
No known problem with their current medications. No FDA flag for their age group. OK to give at the stated dose.
⚠️
TAKE WITH CAUTION
There is a concern — but it can be managed. SentinelRx tells you exactly what to watch for or how to time the dose.
🚫
DO NOT TAKE
Clear risk. Do not give it. A safer alternative is always suggested when one exists.
📞
CALL PHARMACIST FIRST
The label is too complex or the interaction too ambiguous to decide safely. Call before giving anything.

How to Use It — Three Steps

  1. Find the active ingredients. Look at the back of the box or bottle. Find the section labeled "Active Ingredients" — it lists what the product actually contains and at what dose. That's what SentinelRx reads.
  2. Tell SentinelRx the product name and its active ingredients. Type it out or share a photo of the label in the conversation. Either works.
  3. Read the decision and act on it. SentinelRx tells you exactly what to do — and why. No medical knowledge needed to understand the answer.

Why This Matters

350K Elderly Americans hospitalized annually from OTC drug events
$14K+ Average cost per preventable hospitalization
1991 Year the FDA first published the Beers Criteria — the data has existed for decades

The assumption that "it's over-the-counter, so it's safe" is one of the leading causes of preventable drug harm in elderly patients. Products sold in every pharmacy — Tylenol PM, Benadryl, Aleve — carry serious risks for patients on common prescriptions. The risks are documented. The information exists. It just hasn't been accessible at the moment a caregiver is standing in the pharmacy aisle.

SentinelRx puts that information in your hands, before the purchase, in under 60 seconds.

3 Products That Catch Most Caregivers Off Guard

ProductThe trapDecision
Tylenol PM / Advil PM / Aleve PM Contains diphenhydramine — FDA Beers Criteria Class I flag for anyone over 65. Causes confusion, fall risk, urinary retention. The "PM" label doesn't say this. 🚫 DO NOT TAKE
Benadryl / ZzzQuil / Unisom Same active ingredient (diphenhydramine or doxylamine), same risk. Sold as "allergy" or "natural sleep" — the label doesn't change the compound. 🚫 DO NOT TAKE
Aleve (naproxen) An NSAID — dangerous with blood thinners, blood pressure medications, and diuretics. 12-hour half-life means prolonged exposure to GI and kidney risk. 🚫 DO NOT TAKE

Limitations — Know These Before You Rely on SentinelRx

United States Only

SentinelRx is built on US regulations — the FDA Beers Criteria 2023 and US drug classifications. It is not valid for patients or products outside the United States. See the Disclaimer tab for full details.

One Patient at a Time

SentinelRx operates on a single active patient profile. Managing multiple patients is not supported in this version.

Profile Accuracy Is Everything

If a prescription was changed and the profile wasn't updated, SentinelRx will use outdated data. Update the profile the same day anything changes — especially after a hospital stay.

OTC Products Only

Prescription medications, injectables, and medical devices are outside scope. SentinelRx does not adjust existing prescriptions or evaluate prescription drug combinations.

What You Need

A Claude.ai account with Projects access (Claude Pro or Team plan). No technical skills required beyond basic file management — if you can move files from a folder to a website, you can install SentinelRx.

Setup — One Time Only

  1. Create a new Claude Project.
    Go to claude.ai → Projects → New Project. Name it after your patient or call it "SentinelRx."
  2. Upload the SentinelRx folder contents to the Project.
    In Project Settings → Project Knowledge, upload all files: CLAUDE.md, identity.md, rules.md, examples.md, and everything inside reference/, templates/, and patients/.
  3. Set up the patient profile.
    Open templates/patient-profile-template.md. Fill it in completely — name, age, all current prescriptions, known conditions, allergies. Save it as patients/[patient-name].md and upload it to the Project.
  4. Test it.
    Start a conversation in the Project. Type: "Active ingredients: Acetaminophen 500mg, Diphenhydramine HCl 25mg. Product: Tylenol PM."
    You should get 🚫 DO NOT TAKE with a Beers Criteria citation. If you do, the operator is working.

Keeping It Current

Update the patient profile immediately after:
  • Any prescription is added, changed in dose, or stopped
  • Any doctor, specialist, or pharmacist visit
  • Any ER visit or hospital stay
  • Quarterly lab results that lead to a medication adjustment

Edit patients/[patient-name].md, update the LAST_UPDATED date at the top, and re-upload it to the Project. SentinelRx checks this date on every scan and warns you if it's stale.

Patient Profile Fields

The patient profile is the only thing that makes SentinelRx specific to your patient. Every field below feeds the decision logic directly — incomplete profiles produce less reliable decisions.

FieldWhy it mattersRequired
LAST_UPDATEDSentinelRx shows a staleness warning when this date exceeds the threshold. Update every time anything changes.Required
STALENESS_THRESHOLD_DAYSDefault 14 days. How many days before SentinelRx flags the profile as potentially outdated. Reduce to 7 for patients with frequent prescription changes.Optional
AgeFDA Beers Criteria applies at 65+. Age also triggers dosing adjustments for patients over 80.Required
Current prescriptionsEvery drug, dose, and frequency — this is the primary interaction check. Missing a drug means missing a potential conflict.Required
Known conditionsEnables condition-specific rules: CKD → NSAID risk; heart failure → NSAID/fluid risk; hypertension → decongestant risk.Required
Known allergiesCross-referenced on every scan.Required
OTC products already in regular useRequired to calculate total daily acetaminophen — hidden in many combination products.Required
Kidney / liver functionActivates drug clearance rules critical for metformin, NSAIDs, and digoxin.Recommended
Fall riskAdds a warning to any medication that increases sedation or dizziness.Recommended
Recent hospitalizationsContext for the staleness warning — any hospitalization is a high-risk change window.Recommended

Staleness Threshold — How Often to Update

The STALENESS_THRESHOLD_DAYS value tells SentinelRx how long to trust the profile before flagging it as potentially outdated. The default is 14 days.

SituationRecommended setting
Stable medications, changes are infrequent14 days (default)
On warfarin — INR checked every 2–4 weeks with dose adjustments7 days
Within 30 days of a hospitalization3–7 days
Multiple active conditions, frequent lab reviews7 days
The Gap No Setting Can Cover

A staleness threshold catches calendar-based drift. It cannot catch a prescription change that happened today. This is why SentinelRx appends a hospitalization reminder to every scan — because the most dangerous moment is right after a hospital discharge, when medications often change significantly and caregivers are most exhausted.

Audit Trail — Keeping a Scan History

After every scan, SentinelRx automatically writes a log entry to audit/scan-log.md. No action required — the file is updated before the response is complete.

━━━ SCAN LOG ENTRY ━━━ Date : 2026-06-12 14:33 Patient : Margaret Chen Product : Tylenol PM Ingredients: Acetaminophen 500mg, Diphenhydramine HCl 25mg Decision : 🚫 DO NOT TAKE Reason : Diphenhydramine — Beers Criteria Class I for 65+ Profile updated : 2026-05-29 ━━━━━━━━━━━━━━━━━━━━━

This builds a human-readable history of every check — what was scanned, what was decided, and what the profile looked like at the time. The log can be shown to a doctor, pharmacist, or other caregiver at any time.

Reference Files — Pre-Loaded, Rarely Changed

FileWhat it containsWhen to update
beers-criteria-summary.mdFDA Beers Criteria 2023 — OTC-relevant drug classes and disease interactionsWhen AGS publishes an updated Beers Criteria (every ~3 years)
risk-reference.mdOTC × prescription interaction matrix; products commonly assumed safe but flaggedIf a new confirmed interaction is identified
brand-ingredient-map.mdActive ingredients for common OTC brands — Tylenol PM, NyQuil, Excedrin, etc.When manufacturers change formulations — verify against current packaging

Five real-world edge cases — each one shows a moment where the common assumption was wrong and SentinelRx caught it.

Example 1 — The PM Suffix Trap

Situation: Caregiver picks up Tylenol PM for nighttime pain. Assumes it's just regular Tylenol with a sleep component added. Patient is 86, on digoxin and furosemide.

Tylenol PM label — Acetaminophen 500mg, Diphenhydramine HCl 25mg
Tylenol PM · Acetaminophen 500mg · Diphenhydramine HCl 25mg
DECISION: 🚫 DO NOT TAKE PRODUCT: Tylenol PM ACTIVE INGREDIENTS: Acetaminophen 500mg, Diphenhydramine HCl 25mg REASON: Diphenhydramine (the "PM" sleep component) is a Beers Criteria Class I risk for all patients 65+. Causes confusion, fall risk, and urinary retention. No dose is safe for this age group. ACTION: The pain component (acetaminophen 500mg) is safe on its own. Use regular Tylenol instead. For sleep issues, speak with the physician. ━━━ SCAN LOG ENTRY ━━━ Date : 2026-06-12 09:41 Patient : Margaret Chen Product : Tylenol PM Ingredients: Acetaminophen 500mg, Diphenhydramine HCl 25mg Decision : 🚫 DO NOT TAKE Reason : Diphenhydramine — Beers Criteria Class I for 65+ Profile updated : 2026-05-29 ━━━━━━━━━━━━━━━━━━━━━

Example 2 — The Natural Supplement Trap

Situation: Caregiver buys high-dose fish oil (1200mg), marketed as heart-healthy. Patient is on warfarin. The fish oil label says nothing about drug interactions.

Fish oil supplement label — Omega-3 Fatty Acids 1200mg
Fish Oil 1200mg · Omega-3 Fatty Acids (EPA 360mg · DHA 240mg)
DECISION: 🚫 DO NOT TAKE PRODUCT: Fish Oil 1200mg ACTIVE INGREDIENTS: Omega-3 fatty acids 1200mg (EPA + DHA) REASON: Fish oil at this dose has blood-thinning properties. Patient is on warfarin. Combining them raises bleeding risk and can raise INR unpredictably — which warfarin monitoring is designed to prevent. ACTION: Do not give without physician or pharmacist approval first. ━━━ SCAN LOG ENTRY ━━━ Date : 2026-06-12 10:15 Patient : Margaret Chen Product : Fish Oil 1200mg Ingredients: Omega-3 fatty acids 1200mg Decision : 🚫 DO NOT TAKE Reason : Anticoagulant effect — warfarin + high-dose omega-3 = bleeding risk Profile updated : 2026-05-29 ━━━━━━━━━━━━━━━━━━━━━

Example 3 — Safe, But Only at the Right Time

Situation: Caregiver asks about Tums for heartburn. Patient takes levothyroxine every morning. Not a hard stop — but timing matters.

Tums Extra Strength label — Calcium carbonate 750mg
Tums Extra Strength · Calcium carbonate 750mg
DECISION: ⚠️ TAKE WITH CAUTION PRODUCT: Tums Extra Strength ACTIVE INGREDIENTS: Calcium carbonate 750mg REASON: Patient takes levothyroxine every morning. Calcium carbonate binds to the thyroid medication in the stomach and reduces how much is absorbed. This is a timing issue, not a prohibition. ACTION: Do not take Tums within 4 hours of the morning levothyroxine dose. Afternoon or evening is safe. 1–2 tablets at standard dose. ━━━ SCAN LOG ENTRY ━━━ Date : 2026-06-12 11:02 Patient : Margaret Chen Product : Tums Extra Strength Ingredients: Calcium carbonate 750mg Decision : ⚠️ TAKE WITH CAUTION Reason : Timing — calcium impairs levothyroxine absorption within 4h Profile updated : 2026-05-29 ━━━━━━━━━━━━━━━━━━━━━

Example 4 — Hidden Acetaminophen Buildup

Situation: Patient already takes Excedrin Extra Strength for headaches. Caregiver considers adding regular Tylenol for back pain the same afternoon — not realizing Excedrin already contains acetaminophen.

Excedrin Extra Strength and Tylenol Regular Strength labels side by side
Excedrin Extra Strength · Acetaminophen 250mg + Aspirin 250mg + Caffeine 65mg  |  Tylenol Regular Strength · Acetaminophen 325mg
DECISION: 🚫 DO NOT TAKE PRODUCT: Tylenol Regular Strength (added to existing Excedrin) ACTIVE INGREDIENTS: Acetaminophen 325mg REASON: Excedrin Extra Strength already contains 250mg of acetaminophen per tablet. Adding Tylenol risks exceeding 3,000mg/day — the safe daily limit for patients over 65. Excedrin also contains aspirin (an NSAID), which carries separate bleeding risk for patients on anticoagulants. ACTION: Do not add Tylenol to an Excedrin dose. Ask the physician to prescribe a single pain reliever with a defined daily limit. ━━━ SCAN LOG ENTRY ━━━ Date : 2026-06-12 13:47 Patient : Margaret Chen Product : Tylenol added to existing Excedrin Ingredients: Acetaminophen 325mg (added) + 250mg from Excedrin = overlap Decision : 🚫 DO NOT TAKE Reason : Total acetaminophen risk — daily 3,000mg limit for 65+ Profile updated : 2026-05-29 ━━━━━━━━━━━━━━━━━━━━━

Example 5 — Stale Profile After Hospitalization

Situation: Patient was hospitalized 3 days ago. Her doctor switched her from warfarin to apixaban and increased her furosemide. The caregiver hasn't updated the profile yet. Profile is 22 days old. Caregiver photographs Advil.

Advil label — Ibuprofen 200mg
Advil · Ibuprofen 200mg (NSAID)
DECISION: 🚫 DO NOT TAKE PRODUCT: Advil ACTIVE INGREDIENTS: Ibuprofen 200mg REASON: Profile lists warfarin. NSAIDs with anticoagulants carry major bleeding risk and can destabilize INR. ACTION: Use regular Tylenol for pain instead. No NSAID while on anticoagulant therapy. ⚠️ PROFILE STATUS: Last updated 22 days ago — exceeds the 14-day check interval. Verify all medications are still current. If the patient had a hospital stay or doctor visit since this profile was last updated, confirm prescriptions before acting on this decision. ━━━ SCAN LOG ENTRY ━━━ Date : 2026-06-12 16:08 Patient : Margaret Chen Product : Advil Ingredients: Ibuprofen 200mg Decision : 🚫 DO NOT TAKE Reason : NSAID + anticoagulant (warfarin per profile) — bleeding risk Profile updated : 2026-05-29 ⚠️ STALE — 22 days ━━━━━━━━━━━━━━━━━━━━━
Why This Is the Most Dangerous Scenario

The decision (DO NOT TAKE) is correct — apixaban, the new drug, carries the same NSAID interaction as warfarin. But the profile didn't know about the switch. If the hospitalization had added a new drug that creates an interaction not in the old profile, SentinelRx would have missed it. The staleness warning is the only safety net here. Update the profile the same day your patient is discharged.

United States Only — Do Not Use Outside the US

SentinelRx is built exclusively on United States regulatory standards. It is not valid for any other country.

SentinelRx's decision logic is grounded in the American Geriatrics Society (AGS) Beers Criteria® 2023 — a US-specific clinical guideline for potentially inappropriate medication use in older adults. All drug classifications, interaction risks, dosing thresholds, and escalation rules in this operator are derived from US regulatory sources.

The following vary significantly between countries and are not accounted for in SentinelRx:

  • Drug approval status — medications available OTC in the US may be prescription-only elsewhere, and vice versa
  • Active ingredient formulations — brand names may contain different compounds or doses in different markets
  • Approved dosing ranges — what is a standard adult dose in the US may differ in other countries
  • Regulatory classification of risk — a drug classified as high-risk by the US FDA may be classified differently by EMA, Health Canada, TGA, or other agencies
  • Available alternatives — safe substitutes recommended by SentinelRx may not be available in other countries
Specific Risk for Non-US Users

Using SentinelRx for patients outside the United States may produce decisions that are incorrect, inapplicable, or actively misleading for that patient's actual medication context. A DO NOT TAKE decision may be based on an interaction that does not apply to the version of the drug available in your country. A SAFE TO TAKE decision may miss a risk that exists in your country's formulation. Do not use SentinelRx outside the United States.

Medical Disclaimer

SentinelRx is a decision-support tool, not a licensed medical or pharmacy service. It applies encoded rules derived from published clinical guidelines to a stored patient profile. It does not replace the judgment of a licensed pharmacist or physician.

SentinelRx always recommends consulting a pharmacist or physician when:

  • The product label is incomplete, illegible, or unusually complex
  • The interaction is novel or outside the encoded rule set
  • The patient's condition has recently changed
  • Any doubt exists about the correctness of the stored patient profile

When SentinelRx returns 📞 CALL PHARMACIST FIRST, that instruction is not a hedge — it is the decision. Do not override it.

Known Failure Modes

SentinelRx is designed to escalate rather than guess in these situations. These are not bugs — they are explicit design choices:

SituationWhat SentinelRx doesWhy
Active ingredient list is incomplete or illegible📞 CALL PHARMACIST FIRSTA partial assessment is worse than no assessment
Combination product with more than 4 active ingredients📞 CALL PHARMACIST FIRSTInteraction complexity exceeds reliable rule coverage
Unrecognized ingredient not in the rule set📞 CALL PHARMACIST FIRSTCannot assess what it cannot identify
Patient profile not updated after hospitalizationStaleness warning appended to outputThe profile may not reflect current prescriptions — caregiver must verify

In all four cases: a wrong confident answer is more dangerous than a correct escalation to a professional.

Regulatory Source

All decision logic in SentinelRx is grounded in:

American Geriatrics Society 2023 updated AGS Beers Criteria® for Potentially Inappropriate Medication Use in Older Adults. J Am Geriatr Soc. 2023. Published by the American Geriatrics Society. Available at americangeriatrics.org.

The Beers Criteria is updated approximately every 3 years. SentinelRx should be reviewed and updated when a new version is published. The current version encoded in this operator is the 2023 update.

Prototype Disclaimer — EU AI Act

SentinelRx is a competition prototype. It is not a deployed product and must not be used for real clinical decisions.

SentinelRx was created as a submission for Jake Van Clief's Operator Challenge #7 on Skool.com and is shared publicly for educational and demonstration purposes only.

This system has not been placed on the market, put into service, or validated for clinical use. It is a pre-market prototype and falls within the research and development exclusion of Article 2(8) of EU Regulation (EU) 2024/1689 (EU AI Act), which exempts AI development activity prior to market placement. Outputs produced by this system are illustrative only and carry no clinical authority.

This system does not constitute a medical device under EU Regulation (EU) 2017/745 (EU MDR) or under US FDA definitions. It does not replace a licensed pharmacist or physician, and has undergone no clinical validation.

EU and Non-US Users

SentinelRx is built exclusively on US regulatory frameworks (FDA Beers Criteria 2023) and is not designed, validated, or intended for use in the European Union or any jurisdiction outside the United States. The Article 2(8) EU AI Act exemption applies to this prototype in its current pre-market, non-deployed state.

Notice to Future Deployers

Any person seeking to deploy a comparable system in a real-world context must conduct a full EU AI Act compliance assessment prior to market placement or operational use. Health-related AI advisory systems may qualify as high-risk AI under Annex III of Regulation (EU) 2024/1689 and would be subject to the obligations applicable to high-risk AI providers and deployers under that regulation.