Which of the following is NOT an adverse effect of LAMAs?

Long-acting muscarinic antagonists (LAMAs) primarily work by blocking the action of acetylcholine on muscarinic receptors in the airways, leading to bronchodilation. However, because these medications can also affect muscarinic receptors in other tissues, they can lead to several side effects.

Dry mouth is a well-known adverse effect of LAMAs due to reduced saliva secretion caused by the inhibition of muscarinic receptors in the salivary glands. Similarly, urinary retention can occur because LAMAs can also inhibit detrusor muscle contraction in the bladder, leading to difficulty in urination. Headache can occur as an adverse effect as well, likely due to changes in blood flow or neural activity related to the medication's action.

Weight gain, on the other hand, is not typically associated with LAMAs. These medications are intended to help improve lung function and overall respiratory conditions, and they do not have a pharmacological profile that generally leads to weight gain. Therefore, identifying weight gain as NOT an adverse effect of LAMAs is accurate.