Sildenafil interactions
Overview
Sildenafil (Viagra) is a PDE5 inhibitor for erectile dysfunction. In our database it has 16 known interactions with common medicines and substances: 1 serious, 3 that need caution and 12 minor.
Avoid / serious 1 interaction
Use caution 3 interactions
Heavy drinking can drop blood pressureTadalafil
Do not combine two ED medicinesTamsulosin
Blood pressure can drop too low
Minor 12 interactions
Small extra drop in blood pressureAtenolol
Small extra drop in blood pressureCarvedilol
Small extra drop in blood pressureClonidine
Small extra drop in blood pressureFurosemide
Small extra drop in blood pressureHydrochlorothiazide
Small extra drop in blood pressureLisinopril
Small extra drop in blood pressureLosartan
Small extra drop in blood pressureMetoprolol
Small extra drop in blood pressurePropranolol
Small extra drop in blood pressureSpironolactone
Small extra drop in blood pressureTizanidine
Small extra drop in blood pressure
In-depth guides
No known interaction found
Our rules found no interaction between Sildenafil and: Acetaminophen, Acyclovir, Albuterol, Allopurinol, Alprazolam, Amitriptyline, Amoxicillin, Amoxicillin-clavulanate, Amphetamine salts, Apixaban, Aripiprazole, Ashwagandha, Aspirin, Atorvastatin, Azithromycin, Baclofen, Birth control pills, Bismuth subsalicylate, Buprenorphine-naloxone, Bupropion, Buspirone, Caffeine, Calcium carbonate, Cannabis, Celecoxib, Cephalexin, Cetirizine, Ciprofloxacin, Citalopram, Clindamycin, Clonazepam, Clopidogrel, Codeine, Colchicine, Creatine, Cyclobenzaprine, DayQuil, Dextromethorphan, Diazepam, Diclofenac, Digoxin, Diphenhydramine, Doxycycline, Doxylamine, Duloxetine, Empagliflozin, Escitalopram, Esomeprazole, Estradiol, Excedrin, Famotidine, Fexofenadine, Finasteride, Fish oil, Fluconazole, Fluoxetine, Gabapentin, Glipizide, Grapefruit juice, Guaifenesin, Hydrocodone, Hydroxychloroquine, Hydroxyzine, Ibuprofen, Insulin, Iron supplements, Isotretinoin, Kratom, Lamotrigine, Levetiracetam, Levofloxacin, Levothyroxine, Lisdexamfetamine, Lithium, Loperamide, Loratadine, Lorazepam, Magnesium, Meclizine, Melatonin, Meloxicam, Metformin, Methocarbamol, Methotrexate, Methylphenidate, Methylprednisolone, Metronidazole, Mirtazapine, Montelukast, Morphine, Naltrexone, Naproxen, Nicotine, Nitrofurantoin, NyQuil, Omeprazole, Ondansetron, Oseltamivir, Oxycodone, Pantoprazole, Paroxetine, Phentermine, Phenylephrine, Potassium supplements, Pravastatin, Prednisone, Pregabalin, Probiotics, Promethazine, Pseudoephedrine, Quetiapine, Rivaroxaban, Rosuvastatin, Semaglutide, Sertraline, Simvastatin, St. John's wort, Sulfamethoxazole-trimethoprim, Sumatriptan, Tirzepatide, Topiramate, Tramadol, Trazodone, Turmeric, Valacyclovir, Venlafaxine, Vitamin D, Warfarin, Zinc, Zolpidem.
Add at least two medicines, supplements or alcohol.
Sources
Source: FDA label for Sildenafil on DailyMed (effective 2026-08), plus the labels of each interacting medicine.
This list covers the 147 medicines and substances in our database. It is not a complete list of every possible interaction. Always tell your doctor and pharmacist about every medicine, supplement and herbal product you take.