Drug typeTricyclic antidepressant (TCA)
How it worksChanges serotonin and noradrenaline signalling and also affects several other receptor systems.
Typical roleUsed selectively for depression, OCD, neuropathic pain, migraine prevention or sleep-related symptoms.
Key cautionCan cause dry mouth, constipation, sedation and heart-rhythm effects; overdose can be dangerous.