Currently, the treatment of refractory epilepsy (RE) in children is still a difficult point in epilepsy treatment. In China, pirenzapine (PER) is still a new drug for treating RE in children, and there is currently a lack of recommendations for adding PER to the treatment of RE in children. And in Chinese reports, the sample size of RE patients treated with PER is relatively small. Therefore, the efficacy of PER for pediatric RE, especially for young children with RE, still needs to be further studied with a large sample size.

To explore the efficacy, possible indications, adverse reactions, and tolerability of PER addition therapy for RE in children.

A self-control and retrospective analysis was conducted on children with RE aged 0-18 who were treated at the Women and Children's Hospital, Qingdao University from January 2022 to January 2023. The frequency of seizures at different observation points before and after the addition of PER treatment was compared, and the effective rate of PER was evaluated. Adverse drug reactions and drug retention rates were recorded, and the clinical characteristics of the effective and ineffective groups of PER were analyzed.

A total of 192 study subjects were included. After adding PER treatment, the effective rates at 12, 24, and 36 weeks were 56.3% (108/192), 62.1% (113/182), and 69.7% (122/175), respectively, and the seizure free rates were 19.3% (37/192), 21.4% (39/182), and 24.6% (43/175). The incidence of adverse reactions was 16.1% (31/192), mainly including dizziness, irritability, weakness, and drowsiness. The last follow-up drug retention rate was 91.1% (175/192). There was a statistically significant difference in the onset age, duration of anti-epileptic treatment, type of origin, seizure form, frequency of seizures before the addition of PER, number of combined anti-epileptic drugs (ASMs), and ketogenic diet/surgical treatment between patients with RE who received continuous medication for 12 weeks (P<0.05). In addition, 178 children underwent EEG examination, and 167 children underwent cranial magnetic resonance imaging examination. There was a statistically significant difference in the electroencephalogram (EEG) and head magnetic resonance imaging (MRI) results between patients who received effective and ineffective treatment. In the results of electroencephalogram examination, the effective rate of discharge in the anterior (anterior, middle, temporal anterior, and middle) part of the brain was higher (P<0.05) ; In the results of cranial imaging examination, the normal group had a higher effective rate, followed by children with mainly white matter damage.

The overall effective rate and retention rate of PER addition therapy for RE in children are high, with mild adverse reactions and good drug tolerance. It is more effective for children with RE who have a late onset age, seizures in the form of motor seizures, focal origin, short course of anti-epileptic treatment, fewer combination medications, and less frequency of seizures. In electroencephalography, patients with normal discharge in the anterior (anterior, middle, anterior temporal, and middle temporal) of the brain and normal results in cranial magnetic resonance imaging have a higher effective rate.