Clozapine is the first option for treatment-resistant schizophrenia, affecting about 20–30% of all patients. Weight gain, sedation, hypotension and hypersalivation are common and well-known adverse effects associated with clozapine. However, it is also important to be aware of uncommon adverse effects, like parotitis.

We report a case of clozapine-induced parotitis.

Literature was accessed through Pudmed, using the search terms parotitis and clozapine.

A 36-year-old male with paranoid schizophrenia, whose psychotic symptoms have responded only slightly to two antipsychotic trial, with both haloperidol and olanzapine. Therefore, he began treatment with clozapine with the dose titrated to 400 mg/day. At first, the only registered adverse effect was hypersalivation. Eventually, after 3 months of treatment, he developed a unilateral swelling of the left parotid gland. Bacterial and viral parotitis were ruled out and the diagnosis of clozapine-induced parotitis was evoked. Patient scored 5 in the Parotitis-Specific Criteria Modified Naranjo Probability Scale. Symptomatic medication was initiated with paracetamol and a non-steroidal anti-inflammatory with a favorable outcome.

There are few reports of clozapine-induced parotitis, a very rare and poorly known adverse effect with an unknown pathophysiology. Early recognition and proper management are essential to reduce morbidity associated with the treatment. There is no consensus how to manage these adverse effect, however, generally it is not necessary to discontinue the treatment.

The authors have not supplied their declaration of competing interest.