Can you take Viagra with other medicines? Usually yes — but never with nitrates, "poppers" (amyl nitrite) or riociguat: with sildenafil, the medicine in Viagra, they can cause a severe drop in blood pressure that may be difficult to treat. The Australian Viagra leaflet then names a short list — cimetidine, some antifungals and antibiotics, HIV medicines, alpha-blockers and bosentan — that may call for a different dose or medicine. Most everyday medicines are not on it, but the doctor who prescribes sildenafil should still see your full list.
What must never be taken with Viagra?
Nitrates, poppers and riociguat. Nitrates are angina and heart medicines — glyceryl trinitrate (nitroglycerin), isosorbide mononitrate and dinitrate, nicorandil and sodium nitroprusside — as tablets, patches, sprays or injections; riociguat treats high blood pressure in the lungs (Viagra CMI). The Australian product information rules nitrates out "either regularly or intermittently", and no sildenafil label gives a safe gap between the two (Viagra PI (Australia)). If you get angina after Viagra, the leaflet says not to take a nitrate for the pain and to tell your doctor immediately (Viagra CMI). The detail: nitroglycerin and Viagra.
Which medicines does the Viagra label list?
Class by class: raising sildenafil may make side effects likelier; lowering it may make Viagra work less well (EMA — Viagra).
| Medicine | Examples | What the labels say | In detail |
|---|---|---|---|
| Nitrates, poppers | glyceryl trinitrate, isosorbide mononitrate, nicorandil; amyl nitrite | Never together | Nitroglycerin |
| Riociguat | riociguat | Never together | — |
| Antibiotics | erythromycin; rifampicin | Erythromycin raised exposure by 182%; rifampicin is expected to lower it; azithromycin had no effect | Antibiotics |
| Antifungals | ketoconazole, itraconazole | Expected to raise it more than erythromycin | Same page |
| HIV medicines | ritonavir, saquinavir | Ritonavir raised exposure 11-fold: not advised, and never more than 25 mg in 48 hours; saquinavir: +210% | Same page |
| Cimetidine | cimetidine (for ulcers) | Raised levels by 56% | — |
| Alpha-blockers | doxazosin (the one studied), tamsulosin, alfuzosin | Low blood pressure with symptoms in a few men, mostly within 4 hours | Alfuzosin |
| Bosentan | bosentan (for lung blood pressure) | Cut sildenafil exposure by 62.6% | — |
| Other blood-pressure medicines | amlodipine; ACE inhibitors, beta-blockers, sartans, diuretics | Amlodipine: a further 8/7 mmHg, about what sildenafil does alone; side effects no different from placebo across the classes | Amlodipine, ramipril, beta-blockers |
| Other ED medicines, Revatio | tadalafil, vardenafil; Revatio (sildenafil) | Not studied together, so not recommended | Cialis, Levitra |
| Grapefruit juice | — | "Modest increases" in sildenafil | Grapefruit |
| Alcohol | — | Little or no added fall in blood pressure at a blood alcohol of 80 mg/dL; it can weaken erections | Alcohol |
Sources: Viagra CMI; Viagra PI (Australia), sections 4.2–4.5; EMA — Viagra, sections 4.4–4.5.
Which medicines change the Viagra dose?
Mostly the ones that slow its breakdown. With erythromycin, saquinavir, ketoconazole or itraconazole, the Australian product information says a 25 mg starting dose should be considered, and with ritonavir no more than a single 25 mg dose in 48 hours; the same first dose is considered for men over 65 and for men with severe kidney disease or liver impairment (Viagra PI (Australia)). Medicines that speed it up work the other way: bosentan cut sildenafil exposure by 62.6%, and rifampicin is expected to lower it too (EMA — Viagra).
Can you take Viagra with blood-pressure or prostate medicines?
Usually, with care. Sildenafil lowers blood pressure a little, and healthdirect lists blood pressure medicines among its interactions (healthdirect — Sildenafil). Alpha-blockers, used for high blood pressure or prostate problems, can cause blood pressure to drop on standing in a few men: be stable on the alpha-blocker first and start sildenafil low. Adding sildenafil to sacubitril/valsartan lowered blood pressure significantly more than sacubitril/valsartan alone, so caution applies there too (EMA — Viagra). ACE inhibitors such as ramipril and lisinopril, and beta-blockers, did not change sildenafil levels. More: beta-blockers, carvedilol and minoxidil.
Which common medicines are not on the list?
Most everyday ones. In the label studies sildenafil did not add to aspirin's effect on bleeding time, had no significant interaction with warfarin or the diabetes tablet tolbutamide, and antidepressants of the SSRI and tricyclic groups did not change its levels (EMA — Viagra). The common questions each have a page: aspirin, warfarin, Xarelto, statins, metformin, antidepressants, Xanax, tramadol and Priligy (ruled out by its own label).
Can you take supplements with Viagra?
Tell the prescriber about them: the Viagra leaflet asks about "vitamins or supplements that you buy without a prescription from your pharmacy, supermarket or health food shop" (Viagra CMI). L-arginine and caffeine are not listed: L-arginine with Viagra and coffee and caffeine. Some sex supplements are sildenafil in disguise: in June 2026 the TGA found undeclared sildenafil in 5 of 11 products "that claimed to be dietary supplements or natural formulas" (TGA safety advisory), and one sildenafil tablet in 24 hours is the limit (healthdirect — Sildenafil): can you take more than one Viagra?
The short answer
Never take Viagra with nitrates, poppers, riociguat or another erectile dysfunction medicine. For the rest of the list the dose may change, often to a 25 mg start, so remind any doctor, dentist or pharmacist you see that you take Viagra (Viagra CMI). The same list for tadalafil is in what interacts with Cialis?, and both medicines side by side in our guide to taking Viagra or Cialis with other medicines.
