Main Research Findings

For over 40 years, antipsychotic drugs have been used to manage symptoms and reduce relapse rates in patients with schizophrenia. First-generation oral medications such as haloperidol and chlorpromazine are associated with high levels of unwanted neurological effects and poor patient adherence. 2

Second-generation antipsychotic agents (also known as atypical antipsychotics) were introduced into clinical practice over 16 years ago. Although these agents have a lower tendency to cause extrapyramidal side effects, they are associated with a range of other unwanted effects (e.g. weight gain and its consequences). 2

Three long-acting injectable formulations of second-generation antipsychotics are now available in the UK: olanzapine embonate injection (ZypAdhera), paliperidone injection (Xeplion), and risperidone injection (Risperdal Consta). 2

A 64-year-old female experienced rhabdomyolysis after a monthly injection of long-acting injectable (LAI) paliperidone palmitate (Invega Sustenna). 1

Reasons for side effects

Antipsychotic medications are known to potentially cause extrapyramidal side effects (EPS). 1

Common side effects

Extrapyramidal side effects

A patient who received paliperidone palmitate injection experienced acute dystonia. 1

Rhabdomyolysis

A patient who received paliperidone palmitate injection experienced rhabdomyolysis. 1

Countermeasures for side effects

Dystonia

The symptoms were resolved after the administration of benztropine and cyclobenzaprine. 1

Rhabdomyolysis

The symptoms were resolved after IV hydration. 1

Comparison between studies

Common points

Both studies are about the side effects of long-acting injectable antipsychotics.

Differences

2 provides an overview of long-acting injectable formulations of second-generation antipsychotics. On the other hand, 1 reports acute dystonia and rhabdomyolysis as side effects of paliperidone palmitate injection.

Precautions for application in real life

When using long-acting injectable antipsychotics, it is necessary to be aware of the risk of side effects such as extrapyramidal symptoms and rhabdomyolysis. 1

Limitations of the current study

The number of reports of side effects of paliperidone palmitate injection is still small, so further research is needed. 1

Future research directions

Further research is needed on the incidence and severity of side effects from paliperidone palmitate injection.

Conclusion

Long-acting injectable antipsychotics can help improve medication adherence, but it is important to be aware of the risk of side effects such as extrapyramidal symptoms and rhabdomyolysis. 2 1