The problem


of hospitalized patients experience adverse drug reactions1


of hospital admissions are related to adverse drug reactions1


Adverse drug reactions are the 4th leading cause of death in the USA2

The response to a specific medication can differ widely between different patients

Currently, medications are prescribed in a “one-size-fits-all” approach. However, every patient is different and so is their response to certain drugs. While a certain medication might show good efficacy in one person without causing any adverse drug events, another person might experience severe adverse drug reactions when taking the same drug. These differences can partly be attributed to each patient’s individual genetic make-up.

A possible solution

The Medication Safety Code System

The Medication Safety Code system captures pharmacogenomic test results and enables the quick retrieval of relevant pharmacogenomic drug dosing guidelines

A small set of so-called pharmacogenes has an impact on the safety and efficacy of many common medications. Pharmacogenomic (PGx) tests can detect variations in these pharmacogenes based on a blood or saliva sample of the patient. The Medication Safety Code (MSC) captures these PGx test results to make them available whenever needed during medical care.

Medication Safety Codes can be printed on personalized cards that patients can carry in their wallet, or they can be incorporated in paper-based lab reports. After scanning the QR code with a standard smartphone, you are led to a website that displays drug dosing recommendations extracted from pharmacogenomic guidelines that are highly relevant for the patient based on his or her PGx test results.


  • Knowing a patient’s pharmacogenetic variants can help you individualize his or her drug therapy and thus reduce the risk for adverse drug reactions and ineffective treatments.
  • Over half of all Caucasian patients exhibit at least one pharmacogenetic variant in one of the 8 most relevant pharmacogenes with significant therapeutic implications.
  • Over 30% of all patients older than 40 receive at least one drug for which pharmacogenetic dosing guidelines are available.

Privacy and data security

  • The MSC system does not require central data storage: all pharmacogenetic data are inside the QR code and remain anonymous.
  • Patients can opt-in and opt-out at any time: Patients can choose whether or not to carry their anonymized pharmacogenomic data in their pockets and make their data available to care providers.
  • The MSC captures only PGx data that can be used to optimize a patient’s drug therapy. No other sensitive health data (e.g. current medication or diseases) are captured.


Below you can see exemplary illustrations of the MSC pocket card and corresponding website that displays the patient-tailored drug dosing recommendations for a fictional patient named “Jane Doe”. If you want to try it out for yourself, you can either scan the QR code displayed below with your smart phone, or you access the site directly by clicking on this link: Demo site.

Pocket card

Front side

  • The front side of the pocket card contains the MSC QR code, contact details of the laboratory in charge and a short description of the MSC’s purpose and functionality.
  • The MSC can be decoded with any common QR code reader app on your smartphone or tablet. In many cases, such apps come pre-installed. For example, many Android devices come pre-installed with an application called Google Goggles. Simply activate the app and point the camera of your mobile phone towards the MSC QR code.

Back side

  • The back side of the pocket card contains the patient’s indentifying information, the card number and printing date of the card, and a tabulated overview of the patient’s pharmacogenomic profile.
  • The table lists the patient’s atypical phenotypes (e.g. “CYP2C19 poor metabolizer”) and all drug substances for which essential therapy modifications are recommended based on the patient’s phenotype. These patient-specific recommendations are displayed on your smartphone after scanning the MSC code.
  • The bottom row lists all genes that were included in the PGx test but did not result in any significant therapeutic recommendations.

User interface

  • After scanning the MSC code you are led to a website that lists all drug substances for which important recommendations are available for the card owner. By clicking on the substance name the corresponding recommendation text folds out.
  • Each recommendation is also accompanied by the following information: reason for the recommendation (e.g. TPMT poor metabolizer), the publishing date of the recommendation, and a link to the Pharmacogenomics Knowledgebase (PharmGKB) website (‘Show guideline website’) for further reference.
  • The recommendations displayed by the MSC system are based on clinical guidelines authored by an expert consortium: the Dutch Pharmacogenetics Working Group (DPWG).
  • You can use the search field at the top to search for drug substances and trade names.
  • To view the patient’s raw PGx test results simply scroll down to the bottom of the page and click on ‘Show pharmacogenomic data’.


If you are interested in using the MSC system, please contact us. You can also download additional infomaterial in the download section or have a look at our FAQ section.

Frequently asked questions


What is Pharmacogenomics?
Pharmacogenomics (PGx) is the study of how genetic variations influence a person’s response to drugs. The aim of PGx is to enable patient-tailored and thus safer and more effective medical therapies in contrast to the currently applied “one size fits all” approach.
What are pharmacogenes?

The term ‘pharmacogene’ refers to all genes that play a role in drug response.

What are PGx markers?

PGx markers are indicators of an individual’s anticipated response to a certain drug. Commonly, PGx markers are single nucleotide polymorphisms (SNPs, pronounced “snips”) that affect individual pharmacogenes. SNPs are DNA variations at the nucleotide level. For example, while in most people the nucleotide cytosine (C) occurs at a certain position in the genome, in some people cytosine might be replaced with the nucleotide adenosine (A). Another example are copy-number variations (CNVs). CNVs are alterations in the number of copies of a particular gene.

How do SNPs and CNVs impact drug response?

A frequent mechanism is that SNPs and CNVs alter the activity of drug-metabolizing enzymes, such as the Cytochrome P450 (CYP) enzymes. This can lead to increased or decreased degradation or activation of drug substances respectively pro-drugs.

What are phenotypes?

Genomic alterations, such as SNPs or copy-number variations (CNVs), that change the efficacy of pharmacogenes can dictate the stratification of patients into metabolizer phenotypes for specific drugs, such as:

  • Ultrarapid metabolizer (UM)
  • Extensive metabolizer (EM)
  • Intermediate metabolizer (IM)
  • Poor metabolizer (PM)

This classification can help choosing the right dosage and avoiding potentially hazardous medication choices by providing insights into the expected response of the individual patient.

What are some examples of drugs and associated adverse drug reactions that can potentially be prevented with PGx-guided drug dosing?
Drug class Drugs Examples of adverse reactions
Antidepressants Amitriptyline, Citalopram, Clomipramine, Imipramine Cardiotoxicity, therapy failure
Antiplatelet drugs Clopidogrel Therapy failure
Antipsychotics Aripiprazole, Risperidone Extrapyramidal symptoms
Analgesics Codeine Decreased pain relief, respiratory depression
Thiopurines Azathioprine, Thioguanine, Mercaptopurine Myelosuppression
How do PGx tests work?

There are two main methods of obtaining information about an individual’s pharmacogenomic profile: genotyping tests and sequencing tests. Sequencing tests are used to read the exact nucleotide sequence of the whole genome or parts of it. In contrast, genotyping tests are used to determine the presence of certain previously defined variants. Usually, PGx tests are performed by using saliva or blood samples.

What is the difference between PGx and predictive genetic tests?

Predictive genetic tests are used to determine predispositions for certain diseases whereas PGx tests focus solely on drug response.

What are the costs of PGx tests?

Currently, the costs for standard PGx tests that analyse the most important pharmacogenes are less than 300€.

Are PGx tests currently covered by health insurances?

Unfortunately, the costs for PGx tests are currently not covered by European health insurances.

Where can my patients get tested?

If you are interested in using the MSC system to make your patients’ therapies safer and more effective please contact us via the contact form on this website.

Medication Safety Code System

What is a QR code?

A QR (quick response) code is a two-dimensional barcode that consists of black square dots arranged in a square grid on a white background. QR codes can be scanned with QR code readers (e.g. with an app on your smartphone) that convert the code into a useful form, in case of the MSC into a web address.

What does the MSC contain?

The MSC contains PGx test results in a compressed form, i.e. encoded in digits and letters. This sequence of digits and letters double-act as a web address that leads to a service for decoding and interpreting these data. The MSC itself does not contain any identifying information (e.g. name or birth date).

Is the MSC system for free?

Use of the MSC system itself to retrieve the patient-specific drug dosing recommendations is for free. The only costs to be considered are those that arise from the one-time PGx test.

Where do the recommendations displayed by the MSC system come from?

The recommendations displayed by the MSC system are authored by the Dutch Pharmacogenetics Working Group (DPWG), a consortium that develops PGx guidelines based on extensive literature review.

How many guidelines are currently available?

Currently, the MSC system’s knowledge base encompasses guidelines for 54 different drug substances. A complete list of all drug substances can be found here.

Can I access the recommendations without a QR code scanner?

Accessing the mobile site that displays all relevant patient-specific recommendations is only possible by scanning the QR code. Nevertheless, there are two alternative ways to access the recommendations if you don’t have a QR code scanner available: Besides generating a pocket card, the PGx test results and corresponding patient-specific recommendations can also be incorporated into a lab report sheet (digital or paper). Furthermore, the back side of the pocket card lists all of the patient’s relevant phenotypes. You can use this information to look up the drug dosing recommendations at a trusted source, e.g.

Where can I get a QR code reader?

In many cases, QR code reader app come pre-installed on mobile devices. For example, many Android devices come pre-installed with an application called Google Goggles. Another Android app would be QR Droid. iPhone/iPad users can try the QR Reader app.

Can the PGx data in the QR code become outdated?

PGx test results have lifelong validity. Therefore, testing of the most relevant pharmacogenes that are responsible for the largest part of variance in drug metabolism and drug response has significant clinical implications throughout an individual’s lifespan. In the future, additional drug dosing guidelines may become available. However, this does not affect the validity of the PGx data in the QR code.

Does the MSC system perform any calculations to display the drug dosing recommendations?

No, the MSC operates without using any complex algorithms or calculations. It uses a simple search to match the patient’s phenotypes (as printed on the MSC card) with recommendations for these phenotypes extracted from pharmacogenomic drug dosing guidelines.

What about data privacy if a patient loses the card?

The pocket card and QR code only contain data on specific PGx markers that can be used to anticipate a patient’s response to certain drugs. The MSC code does not contain any sensitive data on the owner’s health status, risk to develop certain diseases or current medication.

Where can I get infomaterial for my patients?

You can download infomaterial including an information leaflet for your patients in our download section.

If you have any other questions please feel free to contact us.

Downloads & References


Brochures, documentations and other infomaterials Link
MSC info folder for healthcare providers
MSC info folder for your patients
Overview of drugs covered by the MSC system (standard version, DPWG guidelines)

Selected peer-reviewed scientific papers

Blagec K, Romagnoli KM, Boyce RD, Samwald M. (2016) „Examining perceptions of the usefulness and usability of a mobile-based system for pharmacogenomics clinical decision support: a mixed methods study.” PeerJ 4:e1671

Matthias Samwald and Robert R Freimuth. „Making data on essential pharmacogenes available for every patient everywhere: the Medication Safety Code initiative“. Pharmacogenomics 14. Nr. 13 (October 2013)

Matthias Samwald, Klaus-Peter Adlassnig. „Pharmacogenomics in the pocket of every patient? A prototype based on Quick Response (QR) codes“ J Am Med Inform Assoc,Published Online First: 23 Jan 2013


[1] Bouvy, J. C., De Bruin, M. L. & Koopmanschap, M. A. Epidemiology of adverse drug reactions in europe: a review of recent observational studies. Drug Saf. 38, 437–453 (2015).
[2] US Food and Drug Administration (FDA);