UK Clinical Pharmacy Association


Issues for surgery

For pulmonary arterial hypertension (PAH) – loss of pulmonary arterial pressure control and worsening of symptoms if omitted.

For benign prostatic hyperplasia (BPH) – risk of acute urinary retention if omitted.

Risk of hypotension if continued.

Advice in the perioperative period

Elective surgery 



  • For erectile dysfunction (ED) – advise patient not to take the day prior to and the day of procedure.

Patients with PAH

Planning for elective surgery should involve a discussion with the patient's Specialist Centre.

Emergency surgery 

Follow the advice as for elective surgery. If dose(s) taken due to indication, or prior to admission, monitor BP.

Patients with PAH

A discussion with the patient’s specialist centre should be considered if there is time prior to emergency surgery.

Post-operative advice


Restart post-operatively once enteral intake resumes and ensure to correct any volume depletion. If a long nil by mouth (NBM) period is anticipated, or there are concerns with enteral absorption, advice should be sought from a specialist, especially for PAH.

Monitor BP (see Further information).

For ED

Hold whilst inpatient.

Interactions with common anaesthetic agents


PDE5 inhibitors can increase the risk of hypotension when used concomitantly with inhalational or intravenous anaesthetics.

Interactions with other common medicines used in the perioperative period


PDE5 inhibitors can increase the risk of hypotension when used concomitantly with the antiemetics droperidol and prochlorperazine.


Clarithromycin and erythromycin are predicted to increase the exposure to PDE5 inhibitors due to inhibition of CYP3A4.

Whilst single surgical prophylactic doses should not pose a problem, consult product literature for recommendations regarding dose adjustments and monitor closely should continued post-operative treatment be required.

Further information


Due to their vasodilatory effects, PDE5 inhibitors can cause hypotension. Where tadalafil is being used for PAH, it should be avoided if systolic blood pressure (SBP) falls below 90 mmHg (diastolic blood pressure < 50 mmHg) and caution should be exercised where there is intravascular volume depletion.

Treatment discontinuation

It is recommended that abrupt discontinuation of PDE5 inhibitors for PAH should be avoided due to possible clinical deterioration. There is no published data on how to manage omission of more than one dose of PDE5 inhibitors and where omission cannot be avoided, advice should be sought from a Specialist before re-introducing the medication.


Joint Formulary Committee. British National Formulary (online) London: BMJ Group and Pharmaceutical Press. (Accessed on 20th September 2023)

Baxter K, Preston CL (eds), Stockley’s Drug interactions (online) London: Pharmaceutical Press. (Accessed on 20th September 2023)

Summary of Product Characteristics – Adcirca® (tadalafil). Eli Lilly and Company Limited. Accessed via 20th September 2023 [date of revision of the text September 2023]

Narenchania S, Torbic H, Tonelli A. Treatment Discontinuation or Interruption in Pulmonary Hypertension. Journal of Cardiovascular Pharmacology and Therapeutics, 2020; 25(2): 131 – 141