[Different number of contraindications between summaries of product characteristics (SmPC) of drugs with the same active ingredients - an analysis of data from SmPCs of neuropsychiatric drugs].

OBJECTIVE: In the case of prescriptions of pharmaceuticals in the context of the aut-idem-regulation the physician frequently does not know, which same-substance medication is dispensed in the pharmacy; the contemplable same-substance medications may differ in numerous features which raises questions regarding the obligation to give information and medical liability for medical malpractice. Currently, systematic evaluations regarding differences between summaries of product characteristics (SmPCs) of same-substance medications are missing. To determine size and type of those differences SmPCs of most (neuro)psychiatric drugs that are approved in Germany were evaluated regarding the number of listed contraindications (CI).
METHODS: Basis for the selection of substances was the Anatomical Therapeutic Chemical (ATC) Classification System (group ATC N Nervous System). Substances that are approved in Germany for the treatment of mental disorders according to ICD-10 F were included. Brand-name medications and SmPCs were searched by means of further in- and exclusion criteria via the online services of PharmNet.Bund, Gelbe Liste, Rote Liste®/Fachinfo-Service® and communication with the manufacturer.
RESULTS: N = 941 SmPCs (=116 substances) were evaluated. Considering only the group of SmPCs with > 1 brand-name medication (n = 78; 67.2 %) differences in the number of CIs were found in more than the half of substances (N = 43; 55.1 %). Considering indication groups most groups of SmPCs of same-substance medications with differences in the numbers of CIs were found in - considering only substances with > 1 brand-name medication - hypnotics and sedatives (77.8 %), anxiolytics (75.0 %), drugs for treatment of substance use disorders (66.7 %), antidepressants (61,9 %), anticonvulsant drugs and mood stabilizers (53.8 %), followed by antipsychotics (41.2 %), antidementia-drugs (20.0 %), and psychostimulants (0 %). Largest ranges regarding the number of CIs were found in the SmPCs of morphine (14), amitriptyline (8), chlorprothixene (6), lorazepam (6) and citalopram (4). CONCLUSION(S): In numerous (neuro-)psychopharmacologic substances differences exists between the SmPCs of the associated same-substance medications regarding the number of CIs. Due to the outstanding evaluation of content aspects of these differences and legal evaluation the relevance of this result for clinical practice is not yet clear. © Georg Thieme Verlag KG Stuttgart · New York.