Which of the following are rare but serious adverse reactions to Escitalopram (Lexapro) therapy?

A. QTc prolongation: Escitalopram can rarely prolong the QT interval, increasing the risk of torsades de pointes, particularly in patients with pre-existing cardiac conditions or when combined with other QT-prolonging drugs. ECG monitoring may be warranted in high-risk individuals. B. Serotonin syndrome: Excess serotonergic activity from escitalopram, especially when combined with other serotonergic agents, can lead to serotonin syndrome. Symptoms include agitation, hyperreflexia, autonomic instability, and gastrointestinal upset, requiring prompt recognition and intervention. C. Suicidal thoughts: SSRIs, including escitalopram, carry a boxed warning for increased risk of suicidal ideation in children, adolescents, and young adults. Close monitoring for behavioral changes is essential during the initiation and dose-adjustment periods. D. All of the above: Each of the listed adverse effects—QTc prolongation, serotonin syndrome, and suicidal thoughts—are rare but clinically significant risks associated with escitalopram therapy. Vigilant assessment and patient education are necessary to detect and manage these reactions promptly.