Can you take ED medicines before surgery? Tell your surgeon and your anaesthetist that you take them, and when you took the last one: they decide what you take before the operation. No Australian label or healthdirect page sets a time to stop sildenafil (Viagra) or tadalafil (Cialis) before surgery, so there is no fixed number of hours to count. What the labels do make clear is why the team needs to know: nitrates must never be combined with these medicines.
Do you have to stop ED tablets before an operation?
Only if your surgical team tells you to. healthdirect asks you to tell your doctor about all the medicines you take, "including over-the-counter and complementary or alternative medicines", because you may need to stop some before surgery; its examples are anti-inflammatory medicines, medicine for diabetes and blood thinners such as aspirin (healthdirect — Preparing for surgery). Before a general anaesthetic, a member of your health team may also tell you which medicines not to take before and on the day of surgery (healthdirect — General anaesthetic). The erectile dysfunction (ED) medicines are not among healthdirect's examples, and neither the Viagra nor the Cialis label sets a time to stop them before an operation (Viagra PI (Australia); Cialis PI (Australia)). Stop times such as 24 hours or a week, which some websites give, are not in the Australian labels or on healthdirect's surgery pages. Your own team's instructions are the ones to follow.
What should you tell the surgeon and anaesthetist?
Which medicine you take, the dose, and when you took the last tablet. healthdirect's advice is to "Tell your anaesthetist about your health, allergies, all your medicines and any past problems with anaesthetics" (healthdirect — General anaesthetic), and both Australian leaflets say to remind any doctor, dentist or pharmacist you visit that you use the medicine (Viagra CMI; Cialis CMI). The timing matters most for tadalafil: the leaflet says Cialis "has been proven to be effective for up to 36 hours" (Cialis CMI), so a tablet taken the day before still counts. If you took one shortly before you came in, tell the anaesthetist or the nurse who admits you, with the time.
Why do nitrates matter in hospital?
Because the combination is never allowed. The Australian Viagra label rules out nitrates "either regularly or intermittently", and its list includes glyceryl trinitrate "(injection, tablets, sprays or patches)", isosorbide salts, sodium nitroprusside, amyl nitrite and nicorandil (Viagra PI (Australia)). Together they may lead to a severe drop in blood pressure that may be difficult to treat (Viagra CMI), and no sildenafil label states a safe gap. For tadalafil, the Australian label tells doctors that when a nitrate is needed in a life-threatening situation, at least 48 hours in most patients, and 4–5 days in the elderly, should have passed since the last Cialis dose, and then only under close medical supervision (Cialis PI (Australia)). That is why the time of your last tablet matters to the people treating you. Chest pain after taking Viagra means calling 000, never a nitrate spray. More: nitroglycerin and Viagra.
Do ED tablets interact with anaesthetics?
Neither Australian label names an anaesthetic among the medicines that interact with it (Viagra PI (Australia); Cialis PI (Australia)). What the Viagra label does describe is a small fall in blood pressure: after a 100 mg dose, the average largest drop in systolic pressure, lying down, was 8.4 mmHg (Viagra PI (Australia)). During the operation the anaesthetist monitors your heart rate and blood pressure, along with your breathing and oxygen level (healthdirect — General anaesthetic). The leaflets also list alpha-blockers, and the Cialis leaflet other blood-pressure medicines, among the medicines that interact (Viagra CMI; Cialis CMI): Viagra with blood-pressure tablets, class by class. The Viagra leaflet's warning about sudden vision problems (stop the medicine and get medical attention urgently) applies at any time; the label does not tie it to surgery or anaesthesia (Viagra CMI).
What about after the operation?
The same nitrate rule applies, and the medicines you go home with need checking. That is covered on its own page: can you take Viagra after surgery? If you leave hospital on a blood thinner, see Viagra and blood thinners; after prostate surgery, see Viagra after prostate surgery or a biopsy.
The short answer
There is no Australian rule for how long before surgery to stop an ED tablet. Tell your surgeon and anaesthetist what you take and when you took the last dose, never combine it with a nitrate, and follow what your team decides. Other operations and their effect on erections are in our guide to erection problems after surgery.
