Issues for surgery
For treatment of hypertension – loss of blood pressure (BP) control if omitted.
For benign prostatic hyperplasia – risk of acute urinary retention if omitted.
Risk of hypotension when continued, particularly with alfuzosin (see Interactions with common anaesthetic agents)
Risk of Intraoperative Floppy Iris Syndrome (IFIS) in patients undergoing cataract surgery when continued (see Further information).
Advice in the perioperative period
Elective and emergency surgery
Continue, including combination product – monitor BP.
Patients undergoing cataract surgery
Ensure the ophthalmologist / cataract surgeon is aware the patient is taking an alpha-adrenoceptor blocker (see Further information).
Post-operative advice
Patients undergoing transurethral resection of prostate (TURP)
If indicated for the treatment of benign prostatic hyperplasia (BPH), alpha-adrenoceptor blockers may be stopped following an effectual TURP, subject to a successful trial without catheter (TWOC).
Interactions with common anaesthetic agents
Hypotension
Alpha-adrenoceptor blockers can increase the risk of hypotension when used concomitantly with inhalational or intravenous anaesthetics.
Interactions with other common medicines used in the perioperative period
Hypotension
Alpha-adrenoceptor blockers can increase the risk of hypotension when used concomitantly with droperidol or prochlorperazine.
Further information
Intraoperative Floppy Iris Syndrome (IFIS)
Isolated reports of IFIS have been received with some alpha-adrenoceptor blockers and the possibility of a class effect cannot be excluded. As IFIS may lead to increased procedural complications during the cataract operation current or past use of alpha-adrenoceptor blockers should be made known to the Ophthalmic Surgeon in advance of surgery.
References
Baxter K, Preston CL (eds), Stockley’s Drug Interactions (online) London: Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 18th March 2019]
Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 18th March 2019]
Summary of Product Characteristics - Hypovase® (prazosin) 1mg Tablets. Bayer plc. Accessed via www.medicines.org.uk 18/03/2019 [date of revision of the text August 2018]