[The interactions of antidepressant drugs].

An overview is presented of interactions of currently frequently used antidepressants with various other drugs. The effects of interactions of tricyclic antidepressants, tetracyclics, monoamine oxidase (MAO) inhibitors, lithium and carbamazepine are comparatively well documented, their pharmcodynamic and pharmacokinetic characteristics extensively researched and well known to the practitioner. These interactions concern synergic effects, enzyme inhibition, enzyme induction in the liver, competitive inhibition of absorption and reciprocal effects on the receptor. With regard to lithium, problems of renal clearance and circulation are also important. On the other hand, interactions of reversible and selective MAO-A inhibitors (RI-MA) and selective serotonin reuptake inhibitors (SSRI) with various other drugs are in the process of elucidation. Very threatening interactions are known to be caused by a combination of SSRI and MAO inhibitors (serotonergic syndrome). SSRI and tricyclic antidepressants dispensed concurrently cause an increase in the plasma level of the tricyclic antidepressant. Hence, the practitioner must become aware of this high responsibility towards the patient when prescribing even on single drug, which must be selected with the utmost care.