Which TCA is known for its high sedative effects?

Doxepin is recognized for its potent sedative effects due to its ability to block histamine H1 receptors, which is crucial in the mediation of sleep and sedation. This strong antihistaminergic action results in significant drowsiness, making it particularly useful in treating sleep disturbances and anxiety disorders.

While other tricyclic antidepressants (TCAs) can also have some sedative properties, they tend to vary in their sedative strength and side effect profiles. For example, nortriptyline and protriptyline tend to be more stimulating and are less commonly used primarily for their sedative effects. Amitriptyline does have sedative properties as well, but generally to a lesser degree compared to doxepin, which has a more significant impact on sedation.

In clinical practice, the choice of a TCA may be influenced by the need for sedation, particularly in patients struggling with insomnia or high levels of anxiety. Therefore, doxepin stands out due to its pronounced sedative qualities, making it the correct answer in this case.