The definitions of interactions are those of the AFSSAPS:

• The contraindications: are absolute and must not be transgressed.
• Discouraged associations: must be avoided in most cases, except after review depth of the benefit / risk and requires close monitoring of the patient.
• Precautions for use: are the most frequent case. The association is possible from there is compliance, especially in early treatment recommendations for simple avoid the occurrence of interaction (titration, strengthening clinical surveillance, biological, etc …).
• Take into account: where the potential drug interaction exists, and usually corresponds to the addition of side effects and no practical recommendation can be proposed. It is the physician to assess the appropriateness of the association.

Each interaction is represented by an icon as shown below.

Icon	Meaning
	Unrecognize drugs (interactions not available)
	Known drug without interaction
	Low level interaction : INN duplication
	Low level interaction: Precaution of use
	Interaction : Take into account
	Interaction : Unadvised association
	Interaction : contraindication
	Pure textual prescription (no interaction available)

The interactions are detailed. Are presented:

• nature of risk: Contraindication, Association recommended, see above…
• risk: Major side effects or loss of efficacy and mechanism… Action summary, when available
• management: This most often comes down to one level of risk in the case of an “contraindication” or “unadvised association”. In the case of a “precaution for use”, recommendations often simple to implement is proposed to avoid the occurrence of the interaction (dose adjustment, biological controls, etc …). Level “to take into account” has no practical recommendation primarily because it signals the addition of side effects that only the use of alternative therapies may help avoid.

All databases can use the interaction engine. They just need to include mandatory datas (links between molecular content of drugs and their ATC code).

The drugs database information dialog, available from the menu About/About databases/Information on drugs database allow you to evaluate the accurancy of the database. The percents of known molecules for the interaction engine is shown in the category Validity/Interaction engine completion.

More informations about the drugs database schema.

If you want to help this project:

• creating new drugs database (for your country)
• helping medical doctor to link molecular content to ATC codes

The interactions are calculated in real time. This means that every addition of a drug in the prescription (double click in the search / selection), interactions are automatically recalculated. No additional action on your part is required.
The search for interactions involves analysis of INN and therapeutic classes defined by AFSSAPS. The INN can belong to several classes. The INN and the classes are presented in the tooltip that appears under the name of the drug when you leave the mouse over without action.

Interactions datas are extracted from the french interaction thesaurus from the AFSSAPS (governemental) and translated by hand.

The window dosages presents the existence or non-drug interaction for the bias an icon in the upper left corner.

Interactions alerts can be:

• dynamics : a dialog shows when one or more interactions are found asking user to confirm ;
• passives : interactions are represented by icons, there are no dialog no user prompt.

Dynamic alerts shows :

• interacting drugs
• level of risk
• interacting classes and/or molecules

You can set the two types of alerts warning the minimum level to limit the number of requests for confirmation (refer to application preferences). For example, it is possible to set alerts only for dynamic interactions to unadvised associations and contraindications.

The details of interactions are available by clicking on the name of the drug in the protocol window or by activating the “interactions' synthesizer” by clicking on the ad hoc (one pair of eyes). The synthesizer shows, in a separate window, each interaction found: INN, drugs and all information interaction. The summary can be printed with your header, footer and watermark printing with a click.
The synthesizer is an indispensable tool for pharmacies or prescription's analysis consultations.

: Enable the interactions' synthesizer