Mechanism of action: Solifenacin balliculeVisual mnemonic: Solifenacin mascot “Solar fencin’ Vesica cares” “red as a beet” → anticholinergic asterisk → no mad hatter hat → minimal CNS effects due to minimal blood-brain barrier penetration
What it isM3-preferring muscarinic antagonist; overactive bladder.
Why this oneIt is the antimuscarinic specifically labeled with mirabegron when either mechanism alone is inadequate.
What limits itStill anticholinergic, so cognition and constipation matter in the elderly. QT prolongation; CYP3A4 substrate.
Defining liabilityGenerally tolerated at therapeutic doses; clinically important risks are agent-specific and increase with interactions or organ impairment.