What Is the Best ED Medication for Men With Diabetes?
No trial ranks the four tablets in men with diabetes. What the trials and labels do show is who benefits, where blood sugar fits in and which safety checks matter most.
The short version
- A Cochrane review of eight randomized trials found men with diabetes were about 3.8 times as likely to report improved erections on a PDE5 inhibitor as on placebo.1
- Sildenafil, tadalafil, vardenafil and avanafil each have a placebo-controlled trial in men with type 1 or type 2 diabetes, and no trial compared all four.2345
- Benefit was reported at every level of HbA1c in the sildenafil, tadalafil and vardenafil trials, and tadalafil did not change average HbA1c.678
- Nitrates, heart condition and severely impaired autonomic blood pressure control decide safe choices more than diabetes does.235
No ED tablet is the best for every man with diabetes. Sildenafil, tadalafil, vardenafil and avanafil each have a placebo-controlled trial in men with type 1 or type 2 diabetes, and all four improved erectile function in them.6785 A Cochrane review of eight randomized trials found men on a PDE5 inhibitor were about 3.8 times as likely as men on placebo to say their erections had improved.1 The choice among the four usually turns on timing, other medicines and complications such as nerve, eye or heart disease rather than on diabetes itself.
This guide sets out what the diabetes-specific trials found, what the FDA labels add, and what to ask a prescriber. It does not rank the drugs, because no trial compared all four in men with diabetes.
Do ED tablets help men with diabetes?
Yes, in the trials, although men with diabetes often have ED that is more severe and starts earlier. The National Institute of Diabetes and Digestive and Kidney Diseases says men with diabetes may develop ED 10 to 15 years earlier than men without diabetes, and that high blood glucose that is not well controlled and nerve damage raise the likelihood.9
The Cochrane review pooled eight randomized trials, with 976 men given a PDE5 inhibitor and 741 given a control. About 80% had type 2 diabetes. The erectile function domain of the International Index of Erectile Function (IIEF) was 6.6 points higher on treatment (95% CI 5.2 to 7.9), and the average difference in successful attempts was 26.7 percentage points.1 Adverse reactions were more common on the drugs than on placebo (risk ratio 4.8), led by headache and flushing.1 The review dates from 2007, so it covers sildenafil, tadalafil and vardenafil but not avanafil.
What did each drug show in men with diabetes?
Each manufacturer ran its own trial, with different doses and different outcome questions. The table lists what each FDA label and paper reports. The numbers describe separate trials and should not be read across.
| Medicine | Diabetes-specific trial | Reported result |
|---|---|---|
| Sildenafil | Label trial of 268 men with ED attributed to diabetes complications; a separate trial of 219 men with type 2 diabetes (mean age 59), 12 weeks26 | 57% on sildenafil reported improved erections against 10% on placebo (label); 64.6% against 10.5% in the published trial26 |
| Tadalafil, as needed | 216 men with type 1 or type 2 diabetes given 10 mg, 20 mg or placebo for 12 weeks7 | IIEF erectile function score rose 6.4 and 7.3 points against 0.1 on placebo3 |
| Tadalafil, once daily | 298 men with diabetes given 2.5 mg, 5 mg or placebo3 | Score change of 4.8 and 4.5 points against 1.3 on placebo3 |
| Vardenafil | 452 men with type 1 or type 2 diabetes given 10 mg, 20 mg or placebo for 12 weeks8 | 57% (10 mg) and 72% (20 mg) reported improved erections against 13% on placebo8 |
| Avanafil | 390 men with type 1 or type 2 diabetes given 100 mg, 200 mg or placebo for 3 months5 | Score change of 4.5 and 5.4 points against 1.8 on placebo5 |
The sildenafil, tadalafil and avanafil results come from labels and trials sponsored by the manufacturers. The vardenafil label cites the same trial program and reports 439 men, against 452 randomized in the paper, so small differences in counts between sources are expected.84
Does blood sugar control change how well ED tablets perform?
It changes the starting point more than the verdict. The sildenafil trial in type 2 diabetes found men improved both with HbA1c at or below 8.3% and above it, and both with and without chronic diabetes complications.6 The tadalafil trial reported significant improvement in all primary outcomes regardless of baseline HbA1c, and tadalafil did not change average HbA1c.7 The vardenafil trial likewise reported benefit at every level of HbA1c and in both type 1 and type 2 diabetes.8
One practical point from the tadalafil label: after a 10 mg dose, drug exposure in men with diabetes was about 19% lower than in healthy men, a difference the label does not translate into a dose change.3
Which ED medication is safest with diabetes?
The main safety limits are the same as for men without diabetes, with a few that matter more because diabetes travels with other conditions.
- Nitrates. Nitroglycerin and other nitrates cannot be combined with any of the four tablets, because blood pressure can fall dangerously.2345 Many men with diabetes also have heart disease, so this check comes first.
- Heart condition. The labels tell prescribers to weigh cardiovascular status before treating ED, because sexual activity carries some cardiac strain.24
- Autonomic nerve damage. Each label lists men with severely impaired autonomic control of blood pressure as particularly sensitive to the blood-pressure-lowering effect of PDE5 inhibitors.235 The labels do not name diabetic neuropathy in that warning, but NIDDK links nerve damage with diabetes-related sexual problems, so it is worth raising.9
- Eyes. Rare cases of sudden vision loss from non-arteritic anterior ischemic optic neuropathy (NAION) have been reported with all PDE5 inhibitors. Diabetes appears among the risk factors in the label description of reported cases, and anyone with sudden loss of vision in one or both eyes should stop the medicine and seek care at once.2345
- Erection lasting more than four hours. This is an emergency on every label.23
Headache, flushing and rhinitis were the most common side effects in the diabetes trials, with headache and dyspepsia leading for tadalafil.87 For a side-effect comparison across the four drugs, see our guide to ED medication with the least side effects.
How do the choices differ in daily life?
Because the trials all show benefit, the practical differences decide. Tadalafil is the only one of the four with a labelled once-daily regimen, and it has a diabetes trial for that use.3 A man who wants predictable planning around a single dose may prefer an as-needed tablet instead. Older men and those with kidney or liver disease may need a lower starting dose, which our over-60 guide covers. The labels also differ on interactions with alpha-blockers, so the full medicine list matters more than the diabetes diagnosis.234
Some men with diabetes also take medicines for blood pressure and cholesterol. None of that rules out an ED tablet, but each of them needs to be on the list a prescriber reviews.
What should you ask before getting a prescription?
- Is my heart healthy enough for sexual activity, and do I take any nitrate?24
- Could diabetic nerve damage, low blood pressure on standing or an alpha-blocker change which tablet or dose I start with?
- Do I have any history of sudden vision loss, or eye disease I should mention?23
- Is my diabetes care plan part of the problem? NIDDK notes a doctor can treat ED with medicine or with a change to the diabetes care plan.9
- What should I do if an erection lasts more than four hours?23
A telehealth service can answer these only if its screening asks them. Our guide to online prescriptions lists what a proper check includes.
What this article does not cover
This guide covers approved oral tablets. Compounded versions are not FDA-approved.10 The trials are 12 weeks or 3 months long and mostly industry-sponsored, so they say little about long-term results. They also enrolled men who could take the studied drugs, so men with advanced heart, kidney or eye disease need an individual assessment from a licensed clinician.
Frequently asked questions
What is the best ED medication for men with diabetes?
No label or trial names one best drug. Sildenafil, tadalafil, vardenafil and avanafil each improved erectile function in placebo-controlled trials in men with diabetes, so the choice depends on timing, other medicines and complications.
Do ED pills work for type 1 diabetes as well as type 2?
The vardenafil, tadalafil and avanafil trials enrolled men with type 1 or type 2 diabetes. About 80% of men in the Cochrane review had type 2, so evidence is stronger for type 2.
Does poor blood sugar control stop ED tablets helping?
In the trials, men improved at every HbA1c level studied, though a prescriber may still look at the diabetes care plan. NIDDK notes ED can be treated with medicine or a change to the diabetes care plan.
Can ED tablets affect blood sugar?
The tadalafil diabetes trial found no change in average HbA1c. The other trials cited here did not report HbA1c effects, so this guide cannot say.
Is tadalafil daily or as-needed better for diabetes?
Both regimens have a diabetes-specific trial in the Cialis label. No trial compared them in men with diabetes, so the choice rests on timing preference and a prescriber's review.
Related reading
Sources
- Vardi M, Nini A. Phosphodiesterase inhibitors for erectile dysfunction in patients with diabetes mellitus. Cochrane Database Syst Rev. 2007. PubMed 17253475.
- Pfizer. VIAGRA (sildenafil citrate) prescribing information. DailyMed, U.S. National Library of Medicine.
- Eli Lilly. CIALIS (tadalafil) prescribing information. DailyMed, U.S. National Library of Medicine.
- Teva Pharmaceuticals USA. Vardenafil hydrochloride tablets prescribing information. DailyMed, U.S. National Library of Medicine.
- Metuchen Pharmaceuticals. STENDRA (avanafil) prescribing information. DailyMed, U.S. National Library of Medicine.
- Boulton AJ, et al. Sildenafil citrate for the treatment of erectile dysfunction in men with Type II diabetes mellitus. Diabetologia. 2001. PubMed 11692178.
- Sáenz de Tejada I, et al. Effects of tadalafil on erectile dysfunction in men with diabetes. Diabetes Care. 2002. PubMed 12453954.
- Goldstein I, et al. Vardenafil, a new phosphodiesterase type 5 inhibitor, in the treatment of erectile dysfunction in men with diabetes: a multicenter double-blind placebo-controlled fixed-dose study. Diabetes Care. 2003. PubMed 12610037.
- National Institute of Diabetes and Digestive and Kidney Diseases. Diabetes, Sexual, & Bladder Problems. National Institutes of Health.
- U.S. Food and Drug Administration. Compounding and the FDA: Questions and Answers.