Akathisia induced by concurrent use of mirogabalin and sulfamethoxazole-trimethoprim: a case report

Mirogabalin and trimethoprim-sulfamethoxazole (TMP/SMX) are frequently used as supportive purpose during and/or after chemotherapy. Mirogabalin is used to treat neuropathic pain, whereas TMP/SMX is used to prevent pneumocystis pneumonia (PCP) in patients who are immunocompromised. The interaction between mirogabalin and TMP/SMX has not been reported. Here, we report a case of akathisia that developed after concurrent administration of mirogabalin and TMP/SMX. We report the case of a 69-year-old male patient who experienced akathisia twice. The patient was diagnosed with diffuse large B-cell lymphoma and treated with the polatuzumab vedotin combined with rituximab, cyclophosphamide, doxorubicin, and prednisolone (Pola-R-CHP) regimen. On the fifth day of treatment, TMP/SMX at a dosage of 80 mg/400 mg once daily was initiated to prevent PCP. On day 20 of treatment, mirogabalin treatment was initiated for neuropathic pain probably due to polatuzumab vedotin. Akathisia first manifested on the day following the initiation of mirogabalin treatment, occurring 30 min after the administration of TMP/SMX. The patient experienced pruritus and dyspnea. Discontinuation of TMP/SMX resulted in the amelioration of symptoms. Akathisia occurred a second time, when TMP/SMX was resumed, resulting in itching of the upper body, symptoms of restlessness, and an inability to remain still. Based on these symptoms, the patient was diagnosed with akathisia. Following discontinuation of both TMP/SMX and mirogabalin, the symptoms improved. These episodes suggested the possibility that the concurrent use of mirogabalin and TMP/SMX caused akathisia. Blood concentration measurements obtained at symptom onset did not reveal a significant increase in mirogabalin levels, suggesting that the adverse event was unlikely to be explained solely by an increase in mirogabalin concentration. Concurrent use of mirogabalin and TMP/SMX may have been associated with the development of akathisia in the present case. Based on the potential for similar interactions, caution should be exercised when administering this drug to patients undergoing chemotherapy. To the best of our knowledge, this is the first case report describing akathisia associated with the concomitant use of mirogabalin and TMP/SMX, highlighting the need for careful monitoring of patients receiving both drugs.