Managing antidepression overdoses.

Depression is a physiological disorder that is medically treated by increasing the bodily amount of one or all of the following neurotransmitters: serotonin, dopamine and norepinephrine. Although there are seven distinct classes of antidepressants, prehospital care professionals should at minimum be able to distinguish the monoamine oxidase inhibitors (MAOIs), tricyclic antidepressants (TCAs), selective serotonin reuptake inhibitors (SSRIs), and newer antidepressants that are none of these. Monoamine oxidase inhibitors have severe, potentially life-threatening interactions with a variety of medications, including the paramedic drug meperidine, as well as with many common foods. An overdose of tricyclic antidepressants can cause lethal cardiac irregularities. Tricyclics are toxic to children in very small doses. A patient who has overdosed on TCAs may be walking and talking when you first arrive, then quickly deteriorate and die before your eyes. The treatment for TCA overdose is sodium bicarbonate; refer to your medical direction for dosages and indications. A common indication of TCA overdose, secondary to the patient's having access to the drugs, is widening of the QRS complex to greater than 0.12 seconds. Serotonin syndrome is often the result of taking a new generation antidepressant, such as an SSRI, while there is still TCA or MAOI in the bloodstream.