Which SSRI is most commonly associated with the greatest anticholinergic effect?

Paroxetine is known for having the most significant anticholinergic effects among the SSRIs. This is due to its chemical structure and the way it interacts with receptors in the body. Anticholinergic effects can lead to a variety of symptoms, including dry mouth, constipation, urinary retention, and blurred vision, which arise from blocking acetylcholine, a neurotransmitter that plays a key role in many bodily functions including the regulation of smooth muscle and glandular activity.

Additionally, the pharmacological profile of paroxetine differentiates it from other SSRIs, as it not only inhibits the reuptake of serotonin but also has a higher affinity for muscarinic receptors compared to other SSRIs. This affinity is what results in the pronounced anticholinergic side effects.

In contrast, while other SSRIs like sertraline and fluoxetine may have some degree of anticholinergic activity, they are generally considered to have a lower impact in this regard. Bupropion, although an antidepressant, is not classified as an SSRI and operates through different mechanisms that do not typically involve significant anticholinergic effects. Thus, paroxetine stands out as the SSRI most commonly associated with substantial anticholinergic activity.