Chisholm-Burns et al. (2022) explain that anxiety disorders are a dysfunctional response to the computation of sensory data from the fear-response system of the anthropological brain. Stimuli may be present or absent in the presence of anxiety and anxiety may even continue long after exposure to the stimuli (Chisholm-Burns et al., 2022). Per Stahl (2021) the cortico-striato-thalamo-cortical network (CSTC, a network of brain circuits) creates feedback loops and serotonin (5HT) is one neurotransmitter which modulates these circuits. Serotonin exerts an inhibitory effect in the CSTC (Chisholm-Burns et al., 2022; Stahl, 2021). Serotonin is theorized to inhibit norepinephrine (NE), another key neuromodulator in the CSTC (Chisholm-Burns et al., 2022; Stahl, 2021). A region in the brain by the name of locus ceruleus (LC) produces NE (Chisholm-Burns et al., 2022). An excess of NE because of dysregulation of the LC is thought to be the neurobiological genesis of anxiety (Chisholm-Burns et al., 2022). Fear and worry are the two core symptoms of anxiety which selective serotonin reuptake inhibitors (SSRIs) treat (Stahl, 2021).
SSRIs are first-line pharmacotherapy for anxiety due to their bearable side effect profile, lack of dependency, as well as their ability to treat cooccurring conditions (Chisholm-Burns et al., 2022). In general, the side effects of SSRIs are nausea, diarrhea, insomnia, agitation, sedation, drowsiness, sexual dysfunction, weight gain and QT prolongation (Puzantian & Carlat, 2024). These side effects vary depending on the agent used (Puzantian & Carlat, 2024). It is always advised to exercise patience to allow for acclimation to SSRIs and subsequent resolution of symptoms (Stahl, 2024). The most prominent side effect is that of sexual dysfunction and we must educate those we serve on the risks versus benefits of SSRI treatment, thus allowing them to make an informed decision. There are adjunctive treatments for sexual dysfunction secondary to SSRI treatment, but a dose reduction may also alleviate symptoms (Puzantian & Carlat, 2024). When appropriate, a dose reduction may also serve to negate other SSRI side effects (Puzantian & Carlat, 2024). QT prolongation is most notable with citalopram (Celexa) at doses over 40mg (Puzantian & Carlat, 2024). If prescribing over 40mg of Celexa, an EKG is warranted (Puzantian & Carlat, 2024).
Class warning for SSRIs also include suicidality, mania switch, serotonin syndrome, discontinuation syndrome (DS) and hyponatremia (Puzantian & Carlat, 2024). The prudent advanced practice nurse will not only equip their patients with the knowledge to address these potential concerns but will also judiciously prescribe with full consideration of the overall health and history of those they treat. This will include frequent monitoring, relevant diagnostic workups and appropriate tapering (Puzantian & Carlat, 2024). Other concerns to be aware of include the possibility of diminished release of dopamine due to the increased serotonergic action of SSRIs (Stahl, 2024) This may manifest as emotional flattening, cognitive slowing, and apathy in certain patients (Stahl, 2024). Other strategies to address side effects include taking an SSRI after a meal or a spoonful of peanut butter to address nausea (Puzantian & Carlat, 2024). Taking the SSRI in the morning if insomnia is present or at night if sedation occurs (Stahl, 2024). There are many tools in the arsenal of the psychiatric mental health nurse practitioner. When possible, adjunctive pharmacotherapy should be avoided when other methods exist that can prevent polypharmacy.
References
Chisholm-Burns, M. A., Schwinghammer, T. L., Malone, P. M., Kolesar, J. M., Lee, K. C., Bookstaver, P.B. (2022). Pharmacotherapy: Principles and practices (6th edition.). McGraw-Hill Education.
Puzantian, T., & Carlat, D. J. (2024). Medication fact book for psychiatric practice (7th ed.). Carlat Publishing, LLC.
Stahl, S. M. (2024). Prescriber’s guide: Stahl’s essential psychopharmacology (8th ed.). Cambridge University Press.
Stahl, S. M. (2021). Stahl’s essential psychopharmacology: Neuroscientific basis and practical applications (5th ed.). Cambridge University Press.
