Precautions while taking sildenafil (Viagra)

男女の医者

この記事の概要

Sildenafil (brand name Viagra, etc.) is a medication used to treat erectile dysfunction, but there are several contraindications and combinations that require caution. Some of these are listed below:

Sildenafil (brand name Viagra, etc.) is a medication used to treat erectile dysfunction, but there are several contraindications and combinations that require caution. Some of these are listed below:

  1. Nitrates: concomitant use with nitrates and nitric oxide donors used to treat chest pain can cause a sudden drop in blood pressure. These include nitroglycerin and isosorbide.
  2. Guanylate cyclase stimulants: concomitant use with riociguat can also dangerously lower blood pressure and should be avoided.
  3. Some antibiotics and antifungals: clarithromycin, erythromycin, ketoconazole, itraconazole, etc., these drugs may slow the breakdown of sildenafil in the body and may increase the risk of side effects.
  4. HIV protease inhibitors: Concomitant use with HIV medications such as ritonavir and saquinavir can increase blood levels of sildenafil and increase the risk of side effects.
  5. Alpha-blockers: Combined use with telmisartan or doxazosin, drugs used to treat hypertension and benign prostatic hypertrophy, can intensify the blood pressure lowering effect and cause dizziness or fainting spells.

What not to do

  • Heavy alcohol consumption: Alcohol is a vasodilator and when combined with sildenafil, increases the risk of blood pressure drops.
  • Driving and hazardous work: Sildenafil can sometimes affect vision or cause dizziness, so you should avoid driving or operating machinery if you experience such side effects.
  • Heavy Machinery Operation: For the above reasons, care should also be taken when operating heavy machinery.

Always follow your doctor’s instructions when using sildenafil and report any other medications you are taking to your doctor.

医師監修 監修日:2024年9月5日

畠山 聡先生 (はたやま さとし)

医師・医学博士 ヒロクリニック医師

略歴

  • 2016年 大阪市立大学(現:大阪公立大学)卒業
  • 2016年 育和会記念病院
  • 2019年 大阪鉄道病院
  • 2021年 大阪公立大学附属病院
  • 2022年 大阪鉄道病院医長
  • 2023年 ヒロクリニックなんば心斎橋院院長

資格・所属

  • 日本泌尿器科学会認定の泌尿器科専門医

この記事は、ヒロクリニックNIPTの編集・監修体制にもとづき、資格を持つ医師が内容を確認しています。