What is a key side effect associated with tricyclic antidepressants (TCAs)?

Tricyclic antidepressants (TCAs) are known for a range of side effects, and one of the most notable is their anticholinergic effects. These effects arise due to the blockade of acetylcholine receptors, which can lead to symptoms such as dry mouth, constipation, urinary retention, blurred vision, and confusion. This is particularly significant given that acetylcholine plays a critical role in various bodily functions, including those related to the autonomic nervous system.

While weight gain, increased libido, and insomnia may occur with certain antidepressants, they are not as characteristic of TCAs as the anticholinergic effects. Weight gain can be a side effect but is more frequently associated with other classes of antidepressants, such as SSRIs or certain atypical antipsychotics. Increased libido is typically not associated with TCAs, as these medications can sometimes cause sexual dysfunction. Insomnia can occur with TCAs, especially if taken later in the day since some can be sedating; however, this isn't as commonly recognized as a significant side effect.

Overall, understanding the prominent anticholinergic effects of TCAs is essential, as these can significantly impact patient compliance and overall treatment.