We know that people with schizophrenia who adhere to their treatment are more likely to experience sustained periods of time without psychotic symptoms. However, lots of patients find it hard to stick to the prescribed medication, so doctors sometimes recommend alternative treatments to try and encourage adherence.
Long-acting intramuscular injections are one option available to people who take antipsychotic drugs. A risperidone injection (which must be refrigerated) has been available for some time, which patients need to take every 2 weeks. A new systematic review from the Cochrane Schizophrenia Group looks at a different injection of paliperidone palmitate (a metabolite of risperidone), which patients take once a month and does not require refrigeration.
The reviewers carried out a gold standard search for randomised controlled trials that compare the effects of paliperidone palmitate with any other treatment for people with schizophrenia and schizophrenia-like illnesses. They found 5 trials (involving a total of 2,215 patients) to include in their meta-analysis.
Here’s what they found:
- Short term trials showed that paliperidone palmitate is more effective than placebo
- The side effects of paliperidone palmitate were similar to other antipsychotics with extrapyramidal movement disorders, weight gain, and tachycardia all more common than with placebo
- Paliperidone palmitate is associated with substantial increases in serum prolactin, but the review found no increase in the reported incidence of sexual side effects
- The review did not find any data about use of services, quality of life, behaviour, patient satisfaction, cognitive functioning or cost
The authors concluded:
When flexibly dosed with a mean doses of approximately 70 to 110 mg every four weeks, paliperidone palmitate appears comparable in efficacy and tolerability to risperidone long-acting injection flexibly dosed with mean doses of approximately 35 mg every two weeks.
Nussbaum AM, Stroup TS. Paliperidone palmitate for schizophrenia. Cochrane Database of Systematic Reviews 2012, Issue 6. Art. No.: CD008296. DOI: 10.1002/14651858.CD008296.pub2.