Chlorpromazine is considered a second-line treatment due to which of its associated risks?

Chlorpromazine, while historically one of the first antipsychotic medications, has been categorized as a second-line treatment due to its association with significant cardiovascular risks, particularly related to QTc prolongation. QTc prolongation is a concerning side effect as it can lead to torsades de pointes, a potentially life-threatening arrhythmia. This risk necessitates careful monitoring of the heart's electrical activity in patients taking chlorpromazine, especially in those with pre-existing cardiac conditions or those who are on other medications that can also prolong the QT interval.

Although chlorpromazine does pose other risks, such as metabolic syndrome and potential for immediate allergic reactions, these issues typically do not account for its current standing as a second-line treatment. The potential for QTc issues is particularly pertinent in populations that may already be at increased risk for cardiac events, highlighting the need for close monitoring and consideration of alternative treatments in those cases. This focus on cardiac safety makes the association with QTc prolongation a pivotal factor in the clinical decision-making process regarding the use of chlorpromazine.