All of the following are pharmacological effects of anticholinergic drugs EXCEPT:

Explanation

## Anticholinergic Drug Effects: Overview Anticholinergic drugs block muscarinic acetylcholine receptors, leading to predictable organ-system effects. Understanding which effects occur versus which are blocked is critical for NEET PG. ### Pharmacological Effects of Anticholinergics | System | Effect | Mechanism | |--------|--------|----------| | **Eye** | Mydriasis, cycloplegia | Blockade of M3 on ciliary & iris sphincter muscles | | **Heart** | Tachycardia, increased CO | Blockade of M2 on SA/AV nodes; vagal inhibition removed | | **GI** | Decreased motility, constipation | Blockade of M3 on smooth muscle | | **GU** | Urinary retention | Blockade of M3 on detrusor muscle | | **Salivary glands** | **Decreased** salivation | Blockade of M3 on acinar cells | | **Bronchial glands** | **Decreased** secretions | Blockade of M3 on mucus-secreting cells | | **Skin** | Anhidrosis | Blockade of M3 on sweat glands | ### Key Point: **Anticholinergics DECREASE secretions** — salivary, bronchial, and sweat gland secretions all fall. They do NOT increase them. ### High-Yield: The mnemonic **"Dry as a bone, blind as a bat, red as a beet, mad as a hatter"** captures anticholinergic toxicity: - **Dry**: decreased salivation, bronchial secretions, sweating - **Blind**: mydriasis and cycloplegia - **Red**: flushed skin (vasodilation from loss of sweating) - **Mad**: CNS effects (confusion, agitation) ### Clinical Pearl: Anticholinergics are used *therapeutically* to reduce bronchial secretions in anesthesia (glycopyrrolate, atropine) and to treat bronchospasm (ipratropium). The *decreased* secretion is the desired effect. ### Why Option 1 is Correct: Increased salivation and bronchial secretions is the **opposite** of what anticholinergics produce. This is a cholinergic (muscarinic agonist) effect, not an anticholinergic effect.