Guidance based on BOT-PLUS and the AEMPS Summaries of Product Characteristics.
It does NOT replace the pharmacist's professional judgement or a medical consultation.
Before changing any medicine, check the official Summary of Product Characteristics — in Spain,
CIMA; elsewhere, your national
medicines agency. See our clinical content policy.
Add the medication
Type a name and press Enter or the + button. Active ingredient or brand (warfarin, Coumadin, Advil, Ventolin, Synthroid…). Supplements and herbal products count too.
How to read the result
The tool cross-checks every drug against every other one and grades each pair. Severity tells you what to do, not how alarmed to be: most real interactions are managed by spacing doses or monitoring, not by stopping treatment.
Major
The risk can be clinically serious and usually needs a prescriber's decision: a change of drug, a dose adjustment or blood monitoring. That is not settled at the counter. What the pharmacy can do is spot it, document it and refer, telling the patient not to stop anything on their own before speaking to their doctor — stopping an anticoagulant or an antiepileptic out of fear of an interaction is usually more dangerous than the interaction itself.
Moderate
The commonest category, and where pharmacist input adds the most. Many are resolved with concrete measures: space the doses by a few hours, take with or without food, split the daily dose, or watch for one specific sign over the first few days. Record the advice on the patient's record so it is not lost at the next dispensing.
Minor
Low clinical relevance in most patients. It deserves attention when several stack up, when the patient is elderly or frail, or when there is renal or hepatic impairment: in those cases, individually minor interactions can add up.
No alert does not mean no risk. A pair that does not appear is a pair not described in the sources consulted, not a pair proven safe. The Summary of Product Characteristics for each medicine remains the reference that prevails.
A note on where this data comes from
The reviewed dataset behind this page was built in Spain, against BOT-PLUS and the Summaries of Product Characteristics published by the Spanish Medicines Agency (AEMPS). That matters in two ways, and neither is hidden here:
- The pharmacology travels; the packaging does not. A CYP3A4 inhibition or a chelation is the same in Manchester, Mexico City and Madrid. Brand names, available strengths and licensed indications are not.
- Some drugs are regional. Acenocoumarol is the vitamin K antagonist used in Spain, warfarin the one used in the UK and the US; both are recognised here and the class rules apply to both. Metamizole (dipyrone) is widely used in Spain and Latin America and is not marketed in the UK or the US.
Confirm anything you act on against your own national medicines agency — the MHRA, the FDA, the EMA or your local equivalent.
What to ask before you screen
The result is only as good as the list you put in, and the list a patient gives you is almost never complete. Four questions cover most of the gaps:
- Are you taking anything the doctor did not prescribe? Patients do not count the ibuprofen, the omeprazole or the paracetamol they keep at home as "medication" — and those are exactly the ones that accumulate the most interactions.
- Any herbal products or supplements? Herbal medicine is perceived as harmless because it is "natural". Some plants are potent enzyme inducers and can cut a long-term treatment's efficacy until it fails outright.
- Have you started or stopped anything in the last few weeks? Interactions driven by enzyme induction or inhibition take days to show, so the problem appears once the patient no longer connects the symptom with the change.
- Are you taking it as prescribed? A real-world "when it hurts" schedule changes the risk completely compared with the one written on the label.
If the patient is on more than five or six medicines, it is more practical to review it in blocks than to try to settle everything in a single dispensing.
Common mistakes when screening
- Screening by brand instead of active ingredient. One active ingredient appears under dozens of brand names, and the patient may be duplicating without knowing it — two different painkillers with the same active, for instance. This tool translates the commonest brands, but when in doubt, type the active ingredient.
- Forgetting what is not swallowed. Eye drops, patches, inhalers and creams are absorbed too. A beta-blocker eye drop is a beta-blocker.
- Stopping at the pair and not looking at the patient. The same interaction does not weigh the same in a healthy 40-year-old and in an 85-year-old with reduced renal function. Age, weight and renal and hepatic function modulate nearly everything.
- Alarming without offering a way out. Flagging a risk with no concrete alternative pushes patients to abandon treatment. Better to explain the practical measure — space the doses, watch for one sign — and refer when needed.
Sources
- CIMA — AEMPS. Official Summaries of Product Characteristics and patient leaflets. This is the source that prevails over any result from this tool.
- BOT PLUS — General Council of Official Colleges of Pharmacists (Spain).
- Our clinical content policy (in Spanish): how the clinical information on this site is generated, reviewed and limited.
Guidance intended to support professional practice. It does not replace the pharmacist's judgement or a medical assessment.
Frequently asked questions
How does the checker work?
Add the medicines one at a time (active ingredient or brand). Press check and you get every pair with its severity (Major/Moderate/Minor), the mechanism and what to do. Results come from a reviewed clinical dataset, with an AI lookup for pairs that are not in it.
Which sources do you use?
BOT-PLUS from the Spanish General Council of Pharmacists and the official Summaries of Product Characteristics held by the AEMPS (CIMA). When an answer is generated by AI it is labelled as such and you are reminded to verify it against the SmPC.
Does it replace a pharmacist or a doctor?
No. The information is for guidance. Any clinical decision must be discussed with a pharmacist or a doctor. The official source is always the Summary of Product Characteristics.
Can I type brand names?
Yes. Common brands from the UK, the US and Spain (Coumadin, Advil, Tylenol, Plavix, Synthroid, Ventolin, Lipitor, Nexium, Zoloft…) are translated to the active ingredient automatically. If a brand is not recognised, type the active ingredient.
Are the products the same as in my country?
The active ingredients and the interactions are international; availability, brand names and licensed indications are not. The dataset was built against Spanish sources — see the note above — so confirm anything you act on against your own national medicines agency.
How many drugs can I add?
Up to 10 at a time — the number of pairs grows fast when everything is crossed against everything. If your patient is on more, review them in blocks. Each unknown pair triggers one cached AI lookup, so the same pair is never asked twice.