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What Are Tadalafil Effects On Kidneys?

red cartoon kidneys holding pill

Tadalafil (Cialis) is commonly prescribed to treat erectile dysfunction in men. This article will talk about some of the common side effects of tadalafil treatment as well as more serious complications associated with its use. We will specifically look at whether tadalafil has an effect on the kidneys and if it is safe for use by patients with kidney disease.

PDE5 Inhibitors: Drugs used to treat erectile dysfunction, BPH (benign prostatic hyperplasia), and PAH (pulmonary arterial hypertension)

Erectile Dysfunction

Tadalafil (Cialis) and sildenafil (Viagra) belong to the group of medications called phosphodiesterase 5 (PDE5) inhibitors. They are commonly prescribed to men with erectile dysfunction (sexual impotence). PDE5 inhibitors work by blocking the action of the enzyme PDE5. By doing so,  this drug class improves blood flow to the penis, thus, helping maintain an erection during sexual stimulation. It is worth noting that PDE5 inhibitors like tadalafil and sildenafil need physical stimulation for the medication to work. 

Benign Prostatic Hyperplasia

Other uses of tadalafil include treating lower urinary tract symptoms of benign prostatic hyperplasia (BPH) or enlarged prostate in men. Tadalafil helps to reduce the severity of symptoms such as urinary frequency and urgency, decreased urine flow, and nocturia (getting up at night to urinate). 

Pulmonary Arterial Hypertension

Adcirca, a specific brand name of tadalafil, is used in both men and women with pulmonary arterial hypertension (high blood pressure in the main artery that takes blood from the heart to the lungs); thus, Adcirca can improve the ability to exercise. Tadalafil helps to relax the blood vessels, increase blood flow to the lungs, and reduce the heart's workload.

What are the side effects of tadalafil?

Taking tadalafil tablets can cause side effects such as heartburn, belching, indigestion, stomach pain, upset stomach, diarrhea, headache, back pain, muscle aches, stuffy nose, and reddish skin (flushing). These side effects are typically mild and go away after taking tadalafil for some time. If they are severe or do not go away, you should talk to your doctor or pharmacist.

More serious side effects of tadalafil include:

  • Priapism (a painful erection that does not go away)
  • Vision changes 
  • Hearing loss
  • Low blood pressure

You should call your doctor immediately or seek emergency medical care if you experience these serious adverse effects. 

Can sildenafil damage kidneys?

Sildenafil (Viagra) is considered safe for the kidneys and may be prescribed to people with renal failure, including men with advanced kidney failure and severely reduced renal function who receive dialysis. Research has shown that 75% of men on dialysis can develop erections with sildenafil treatment. The success rate is slightly lower in men who have diabetes in addition to renal failure. 

With that said, sildenafil should be used with extra caution in patients who have existing kidney disease, as inappropriate dosing of sildenafil in these patients can cause serious complications. There have been reports of acute tubular necrosis (ATN) in men with kidney disease who took large doses of sildenafil. The risk is even higher if there are drug interactions, such as nitrates (medications used to treat chest pain). Drinking plenty of fluids while taking sildenafil can help decrease the severity of kidney injury and acute renal failure. 

Can you take Cialis with kidney disease?

Studies indicate that phosphodiesterase 5 (PDE5) inhibitors like tadalafil (Cialis) protect the kidneys. 

Can CKD patients take tadalafil?

Various studies on rats in the laboratory have looked at the effects of tadalafil on renal tissue. Here are some of the findings in brief: 

After 8 weeks of tadalafil use, serum creatinine and urine protein levels were significantly lower in rats compared to controls. High-dose tadalafil had a positive effect on renal blood flow and blood pressure as well. The study authors concluded that both low-dose and high-dose tadalafil helps prevent injury to renal tissue in rats with chronic kidney disease. 

Tadalafil has shown promising effects in rats with chronic kidney disease and hypertension induced by high salt intake. The findings suggest that PDE5 inhibitors may help preserve kidney function and prevent the progression of CKD with hypertension into end-stage renal disease. 

In rats with sepsis, tadalafil caused a significant difference in acute inflammation and kidney injury. Rats that received tadalafil had significantly less kidney tissue injury caused by inflammation, and the difference was considered statistically significant. In other words, tadalafil was found to suppress inflammation and prevent sepsis-related damage in rat kidney tissues.

Studies have shown that administering tadalafil to rats before inducing renal ischemia-reperfusion injury helped lessen the effects of the renal ischemia-reperfusion injury. Tadalafil also helps prevent renal dysfunction and renal injury due to tubular necrosis.

 Though these studies in rats are very promising, there is significant work needed to have a clearer understanding of the reno-protective properties of PDE5 inhibitors in CKD patients. As far as the treatment of ED, PDE5 inhibitors such as tadalafil (Cialis) or sildenafil (Viagra) are commonly used in men with CKD with efficacy under the supervision of physicians.

Safe use of tadalafil

This medication is generally safe for use by men with kidney disease. However, it is important to follow your doctor’s advice when taking tadalafil (Cialis) or other drugs used to treat erectile dysfunction. Here are some tips on the safe use of tadalafil:

  • Tell your doctor if you have ever had an allergic reaction to tadalafil or other PDE5 inhibitors.
  • Tadalafil and other PDE5 inhibitors may not be safe for some people, for example, those with heart disease. Discuss alternative treatment options for erectile dysfunction with your health care professional if you have risk factors related to tadalafil use.
  • If you are taking a nitrate medicine (isosorbide mononitrate or isosorbide dinitrate), you should not use Viagra or any PDE5 inhibitors within 7 days of these nitrate medicines. Other forms of nitrates are sublingual tablets and oral spray. You should not use Viagra within 24 hours of these specific dosage forms of nitrate. The drug interaction of nitrates and PDE5 inhibitors can lead to a dangerous drop in blood pressure. 
  • Give your doctor a complete list of medications, including prescription, over-the-counter, and supplements. This can help avoid serious drug interactions.
  • Do not take more than one dose of tadalafil in 24 hours. An overdose can lead to serious health complications. If the medication is not working, talk to your doctor before increasing the dose.
  • If you are on a regular dosing schedule of tadalafil, do not take two doses of the medicine to make up for a missed dose.
  • Drinking grapefruit juice while taking tadalafil can lead to higher amounts of the drug in your body and cause complications. Avoid eating grapefruit or drinking grapefruit juice while on tadalafil.
  • Tadalafil treatment helps erectile dysfunction (ED) but does not protect against sexually transmitted diseases. You should practice safe sex and take appropriate precautions, such as using condoms.
  • Tadalafil therapy works only in the presence of sexual stimulation. 
  • Tadalafil is not meant for use by children. The safety and efficacy of this drug in children have not been established.
  • There are no specific precautions for the use of tadalafil by older men. However, older patients are at higher risk for side effects in general. Talk to your health care professional if this is a concern for you.


  1. https://www.mayoclinic.org/drugs-supplements/tadalafil-oral-route/side-effects/drg-20067204?p=1
  2. https://physoc.onlinelibrary.wiley.com/doi/full/10.14814/phy2.14556
  3. https://www.kidney.org.uk/sexual-relationship-in-kidney-failure-for-men
  4. https://physoc.onlinelibrary.wiley.com/doi/full/10.14814/phy2.14556
  5. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC5433375/
  6. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6248710/
  7. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4362549/
  8. https://www.ahajournals.org/doi/10.1161/hypertensionaha.113.01774