tardive

Tardive is a Latin-derived term meaning late or delayed. In medical use, it describes conditions that arise after long-standing treatment, most notably tardive dyskinesia, a movement disorder that can develop after extended exposure to dopamine D2 receptor blocking agents such as antipsychotics. The term tardive can also appear in the broader phrase tardive syndrome, which encompasses a range of late-onset, medication-related movement disorders.

Tardive dyskinesia (TD) is the best-known manifestation, but tardive syndrome may include orofacial dyskinesia, limb chorea, dystonia, and other involuntary movements. TD and related conditions typically emerge after months or years of dopamine receptor blockade and can persist even after the offending drug is reduced or stopped.

Pathophysiology is not fully understood but involves dopamine receptor sensitization in the striatum due to chronic D2 blockade, with alterations in basal ganglia circuits. Neurochemical changes beyond dopamine also contribute to the syndrome's development and variability.

Risk factors include older age, female sex, longer duration of antipsychotic exposure, higher cumulative dose or potency of typical antipsychotics, and concomitant use of multiple psychotropic medications. The risk remains with certain newer antipsychotics, though shapes of risk differ among drugs.

Clinical features are characterized by involuntary, repetitive movements of the face, mouth, and tongue (lip smacking, tongue protrusion), as well as choreiform or dystonic movements of the limbs and trunk. Symptoms can be persistent and may become disabling or irreversible in some cases.

Diagnosis relies on history of exposure to dopamine-blocking medications and careful observation, often using standardized scales such as the Abnormal Involuntary Movement Scale (AIMS). Management focuses on reducing or replacing the offending agent when possible, and treating TD with VMAT2 inhibitors (such as valbenazine and deutetrabenazine) to reduce symptoms; preventive strategies emphasize using the lowest effective dose and regular monitoring.