Issues for surgery
For benign prostatic hyperplasia – risk of acute urinary retention if omitted.
Combination products containing tamsulosin – risk of hypotension if continued.
Combination products containing tamsulosin – risk of Intraoperative Floppy Iris Syndrome (IFIS) if continued prior to cataract surgery.
Advice in the perioperative period
Elective and emergency surgery
Continue – including the following combination product (see below).
Combination product:
- Tamsulosin with dutasteride (also see Tamsulosin drug monograph)
Patients undergoing cataract surgery
Ensure the ophthalmologist or cataract surgeon is aware if patient is taking combination product containing tamsulosin (see Further information).
Post-operative advice
Patients undergoing transurethral resection of prostate (TURP)
Dutasteride may be stopped following an effectual TURP, subject to a successful Trial Without Catheter (TWOC).
Interactions with common anaesthetic agents
None for dutasteride alone.
Hypotension
For combination products containing tamsulosin see Tamsulosin drug monograph.
Interactions with other common medicines used in the perioperative period
Macrolides antibiotics
Clarithromycin and erythromycin are predicted to increase the exposure to dutasteride.
Whilst single surgical prophylactic doses should not pose a problem, monitor for an increase in dutasteride side effects if a prolonged course is required.
Further information
Administration
During normal handling the coating on the intact dutasteride capsule prevents contact with the active ingredient. However leaking dutasteride capsules should not be handled by women who may be pregnant as transdermal absorption would pose a risk to a male foetus.
Intraoperative Floppy Iris Syndrome (IFIS)
For combination products containing tamsulosin see Tamsulosin drug monograph.
References
Baxter K, Preston CL (eds), Stockley’s Drug Interactions (online) London: Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 18th July 2019]
Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press. http://www.medicinescomplete.com [Accessed on 18th July 2019]
Summary of Product Characteristics – Avodart® (dutasteride) 0.5mg soft capsules. GlaxoSmithKline UK. Accessed via www.medicines.org.uk 18/07/2019 [date of revision of the text December 2017]