Psychiatry: Known interactions given too little consideration

A psychiatric illness often requires treatment with multiple medications. Furthermore, underlying conditions such as high blood pressure frequently necessitate additional medications, especially since the risk of developing somatic comorbidities is higher in psychiatric patients than in individuals without such conditions.

Naturally, the potential for drug interactions increases with the number of medications used. A team led by Dr. Diana Dubrall from the University of Bonn has now investigated whether and how frequently known Interactions between psychotropic drugs and medications for somatic illnesses occur in everyday clinical practice in Germany. The results are published in the journal "BMC Psychiatry" .

The team analyzed 9,276 spontaneous reports of adverse drug reactions from Germany, submitted to the European database EudraVigilance between 2017 and 2021, in which antidepressants, antipsychotics, and mood stabilizers were listed as potentially problematic. Using the ABDA (Federal Union of German Associations of Pharmacists) drug database, they checked which potential interactions with somatic medications were already known. This was the case for approximately 14 percent of the spontaneous reports. 58.7 percent of these reports contained potential interactions classified as serious; 9.8 percent were even contraindicated.

Of the 1271 reports with 2655 potential interactions, 728 indicated a potential conflict between psychiatric and somatic medication. From the interactions with at least ten reports (704 reports with 1111 potential interactions), the research team identified the most frequent.

One in three of these interactions involved hyponatremia due to the combination of antidepressants and diuretics (32.6 percent). More than one in four interactions triggered bleeding events due to the combination of selective serotonin reuptake inhibitors (SSRIs) and platelet aggregation inhibitors, anticoagulants, or non-steroidal anti-inflammatory drugs (NSAIDs) (26.5 percent).

This is followed by an increased effect of beta-blockers in combination with SSRIs, hypo- or hyperglycemia when using SSRIs and antidiabetic drugs, and serotonin syndrome under serotonergic antidepressants plus opioids.