What is a common anti-cholinergic side effect of phenothiazines?

The correct answer identifies dry mouth as a common anti-cholinergic side effect of phenothiazines. Phenothiazines, which are primarily used as antipsychotic medications and antiemetics, block dopamine receptors in the brain. However, in doing so, they also exhibit anticholinergic properties by blocking acetylcholine, a neurotransmitter responsible for various bodily functions.

One of the major effects of anticholinergic activity is a reduction in secretions throughout the body, including saliva. This leads to the sensation of dry mouth, also known as xerostomia. Patients on phenothiazines often report this side effect, which can be uncomfortable and may necessitate strategies to manage oral hygiene and comfort.

While other options may have varying levels of connection to phenothiazines, dry mouth distinctly reflects the anticholinergic mechanism of action associated with these medications. Blurred vision is also a recognized side effect, but it is less directly linked to the classic anticholinergic symptoms. Weight gain is a common side effect of many psychotropic drugs but does not fall under the usual anticholinergic effects. Increased salivation is contrary to the effects of anticholinergic drugs, making dry mouth the most appropriate answer.