Final answer:
Risperidone (Risperdal) is considered to have a lower risk of causing or exacerbating tardive dyskinesia due to its antagonism of D2 and serotonin type 2 receptors, in addition to other receptor activities. Antipsychotics work by blocking overactive dopamine transmission in schizophrenia.
Step-by-step explanation:
The antipsychotic that is least likely to cause or exacerbate tardive dyskinesia is generally considered to be risperidone (Risperdal). Risperidone is known to antagonize D2 (a subtype of the dopamine receptor) and serotonin type 2 receptors. In the context of tardive dyskinesia, this is significant because the condition is often associated with the long-term use of antipsychotics that block dopamine's effects too strongly. By also acting on serotonin receptors and having a slightly lower affinity for dopamine receptors compared to typical antipsychotics, risperidone tends to have a lower risk of causing tardive dyskinesia. However, it's important to note that no antipsychotic is completely risk-free.
The reduction of symptoms such as hallucinations, delusions, and agitation by antipsychotics can be attributed to their antagonistic effects on dopamine neurotransmission, which is overactive in conditions like schizophrenia. Using drug treatments that avoid or reduce glutamate-mediated excitotoxicity can also be beneficial, as this process is implicated in movement disorders, like tardive dyskinesia. Some treatments in experimental stages focus on drugs that specifically target subunits of the NMDA receptor involved in this excitotoxic process.
Side effects on motor control, which could be symptomatic of haloperidol use, are likely to affect regions of the nervous system responsible for fine movement control. It is critical for healthcare providers to consider the potential side effects of antipsychotics, such as haloperidol, which can impact motor function.