Significant Blood Pressure Increases During Onabotulinumtoxin A Detrusor Injection

Overview

In a study of 70 female patients undergoing Onabotulinumtoxin A detrusor injection (OnabotA-DI) for overactive bladder, significant increases in systolic, diastolic, and mean blood pressure were observed during the procedure under local anesthesia. The study identified a high-risk subgroup with elevated resting blood pressure who exhibited amplified cardiovascular stress responses during injection.

Background

Overactive bladder (OAB) is a chronic condition characterized by urinary urgency, frequency, and nocturia, often treated initially with medications such as anticholinergics. Onabotulinumtoxin A detrusor injection is an approved second-line therapy for idiopathic OAB and neurogenic detrusor overactivity, offering symptom improvement when conservative treatments fail. While efficacy has been demonstrated in clinical trials, real-world safety data, particularly regarding cardiovascular responses during awake procedures, remain limited. This study aimed to evaluate hemodynamic changes, including blood pressure and heart rate, during OnabotA-DI performed under local anesthesia.

Data Highlights

Key Findings

• OnabotA-DI performed under local anesthesia caused significant increases in systolic, diastolic, and mean blood pressure during the injection procedure.
• Heart rate and rate pressure product (RPP), indicators of cardiac workload and oxygen consumption, also increased during the procedure.
• A high-risk subgroup, defined as the 20% of patients with the highest resting blood pressure, showed amplified cardiovascular stress responses during injection.
• Patients with known hypertension were more likely to be in the high-risk group exhibiting greater hemodynamic changes.
• No patients with resting systolic blood pressure >190 mmHg or diastolic >120 mmHg underwent the procedure, ensuring safety screening prior to injection.
• The study included both first-time and repeat OnabotA-DI patients, with hemodynamic parameters analyzed across these groups.

Clinical Implications

Clinicians should monitor blood pressure and heart rate closely during OnabotA-DI, especially in patients with known hypertension or elevated resting blood pressure. Pre-procedure screening to exclude patients with severely elevated blood pressure is essential to minimize cardiovascular risk. Awareness of transient hemodynamic changes can guide patient selection and peri-procedural management to ensure safety during awake injections.

Conclusion

Onabotulinumtoxin A detrusor injection under local anesthesia induces significant acute increases in blood pressure and cardiac workload parameters in patients treated for overactive bladder. Identifying high-risk patients and monitoring cardiovascular parameters during the procedure are critical for optimizing safety in routine clinical practice.

References

1. Hamid et al. 2023 -- GRACE study on Onabotulinumtoxin A efficacy and safety
2. FDA Approvals 2011 & 2013 -- Onabotulinumtoxin A for neurogenic and idiopathic OAB
3. Clinical guidelines on OAB and Onabotulinumtoxin A treatment