*3.2.4 Off-target effects*

Hypertension and hypertensive crisis have been reported among patients who were treated with niraparib. Grade ≥ 3 hypertension occurred in 5–9% of patients across treatment settings. Niraparib's pharmacological inhibition of the dopamine transporter, norepinephrine transporter, and serotonin transporter, demonstrated in an *in vitro* pharmacology screen may explain its unique effects on pulse rate and blood pressure. As such, blood pressure and heart rate monitoring weekly for the first 2 months, then monthly for the first year of treatment, and periodically thereafter is recommended [47, 48].

Posterior reversible encephalopathy syndrome (PRES) is a rare, reversible, neurological disorder that presents with symptoms including seizure, headache, altered mental status, visual disturbance, or cortical blindness, with or without associated hypertension. PRES was observed in 0.1% of 2165 patients treated with niraparib in clinical trials and post-marketing reports. If PRES is suspected, discontinue niraparib and specific symptoms associated with PRES shall be treated [47, 48].
