Treatment of Lip Smacking Movements in Tardive Dyskinesia
The first-line treatment for lip smacking movements associated with tardive dyskinesia is to discontinue or reduce the dose of the offending dopamine receptor blocking agent, and if continued antipsychotic therapy is necessary, switch to an atypical antipsychotic with lower TD risk. 1, 2
Immediate Management Steps
Discontinue the causative medication if clinically feasible, as this is the primary treatment approach recommended by the American Academy of Child and Adolescent Psychiatry 1, 2. If the patient requires ongoing antipsychotic treatment:
- Switch to an atypical antipsychotic (such as clozapine, quetiapine, or olanzapine) which have significantly lower risk of causing tardive dyskinesia compared to typical antipsychotics 1, 3
- Reduce the dose of the current medication if complete discontinuation is not possible 1
- Withdraw gradually rather than abruptly, as some patients experience exacerbation of tardive symptoms with sudden cessation 3
FDA-Approved Pharmacologic Treatment
If moderate to severe or disabling tardive dyskinesia persists after medication adjustment, VMAT2 inhibitors are the recommended treatment 2, 4:
- Valbenazine and deutetrabenazine are FDA-approved specifically for tardive dyskinesia 2, 4
- These represent the first FDA-approved medications specifically targeting TD and have demonstrated efficacy in class 1 studies 2
Critical Diagnostic Considerations
Lip smacking is a characteristic feature of orofacial tardive dyskinesia, occurring in repetitive patterns that interrupt speech 5, 6. When evaluating these movements:
- Distinguish from drug-induced parkinsonism, which presents with tremor, bradykinesia, and rigidity rather than choreiform movements 7
- Avoid anticholinergic medications (like benztropine) as they can worsen TD, though they are appropriate for drug-induced parkinsonism 7, 4
- Use the Abnormal Involuntary Movement Scale (AIMS) for baseline assessment and ongoing monitoring every 3-6 months 1, 2, 4
Important Clinical Pitfalls
TD can develop rapidly - there is no minimal safe duration of exposure to dopamine receptor blocking agents 3. Common mistakes include:
- Failing to recognize that anti-emetics (prochlorperazine, promethazine, metoclopramide) can cause tardive dyskinesia 3
- The European Medicines Agency specifically warns against long-term metoclopramide use due to potentially irreversible TD risk 2
- Up to 50% of youth receiving neuroleptics may experience some form of tardive or withdrawal dyskinesia 1, 2
Prognosis and Monitoring
TD may persist permanently even after medication discontinuation, making prevention and early detection critical 1, 2, 3. In documented cases:
- One patient developed lip smacking that persisted for more than 2 years after haloperidol discontinuation 5
- Another patient had persistent tongue movements causing speech difficulty 7 years after stopping treatment 5
- Regular AIMS monitoring facilitates measurement-based care and early intervention 4
Special Populations
Elderly patients are at particularly high risk for potentially irreversible tardive dyskinesia 2. The concern over TD should not outweigh potential benefits for patients who genuinely need antipsychotics, but adequate informed consent regarding TD risk is necessary 2.