ED Medicine and Blood Pressure Medication: What to Check

High blood pressure and erectile dysfunction turn up together often enough that the combination is almost expected. Both involve blood vessels, both become more common with age, and some blood pressure medicines can themselves affect erectile function. So the question of how the two treatments interact is one of the most common in this area — and one where the details genuinely matter.

Why the two conditions travel together

The arteries supplying the penis are narrow. Damage from sustained high blood pressure affects them earlier and more visibly than it affects larger vessels, which is why erectile difficulty is sometimes the first noticeable consequence of untreated hypertension.

The important implication is that ED here is a symptom of a wider vascular picture, and treating the blood pressure is part of managing it — not a side issue.

The absolute limit: nitrates

The rule that overrides everything else. Nitrate medicines are an absolute contraindication with erectile dysfunction medicines of this class. That includes:

• Glyceryl trinitrate in any form — spray, patch, or tablet under the tongue.
• Isosorbide mononitrate and isosorbide dinitrate.
• Nicorandil, which has nitrate-like activity.
• Recreational nitrites, known as poppers.

Both nitrates and this class of medicine lower blood pressure through related pathways, and together they can cause a severe, sudden and dangerous fall. This applies even to a nitrate spray used only occasionally for angina — including one carried in a pocket for emergencies. Tell your prescriber if you have any nitrate anywhere in the house, not just one you take daily.

Alpha-blockers need care

Alpha-blockers such as prazosin, and the prostate-related ones such as tamsulosin, silodosin and alfuzosin, also lower blood pressure. Combined with an ED medicine, the effect on blood pressure can add up, with a risk of dizziness or fainting on standing.

This is not an absolute contraindication, but it is a combination that requires the prescriber to make deliberate decisions about how the two are used together. Many men take both safely under supervision. What is not safe is adding one to the other without telling anyone, or borrowing a tablet from a friend while on an alpha-blocker.

Tell your prescriber if you are on an alpha-blocker for prostate symptoms — men often think of these as urinary medicines rather than blood pressure ones and forget to mention them.

Other blood pressure medicines

ACE inhibitors, angiotensin receptor blockers, calcium channel blockers and thiazide diuretics are commonly used alongside ED medicines under medical supervision. There can still be an additive blood pressure effect, so your prescriber will consider your overall blood pressure control, how many agents you take, and whether you have symptoms of low blood pressure.

Beta-blockers and thiazide diuretics have themselves been associated with erectile difficulty in some men. If your symptoms began after a change in blood pressure medicine, that is a specific and useful thing to report — sometimes there is an alternative. Never stop a blood pressure medicine on your own; uncontrolled hypertension carries far greater risk than the symptom that prompted the thought.

Very low or uncontrolled blood pressure

Prescribers will also consider whether your blood pressure is too low to start with, or too high and unstable. Both situations may mean addressing blood pressure first. Recent stroke or heart attack, unstable angina and significant cardiovascular disease all need assessment before ED treatment is considered.

Practical things to raise

• Every antihypertensive you take, with strengths, plus how long you have been on each.
• Any nitrate, however occasional, including a spray you carry but rarely use.
• Any alpha-blocker, including those prescribed for prostate symptoms.
• Whether you get dizzy or lightheaded on standing.
• Home blood pressure readings, if you take them.
• Any supplements or over-the-counter products, some of which affect blood pressure.
• Whether you drink alcohol around sexual activity, as alcohol lowers blood pressure too.

Warning signs to act on

Seek urgent medical care for:

• Chest pain, pressure or breathlessness during or after sexual activity. Do not take a nitrate to relieve it if you have used an ED medicine — tell the ambulance or emergency staff what you have taken and when.
• Fainting, or dizziness severe enough that you cannot stand.
• An erection lasting more than four hours.
• Sudden loss of vision in one or both eyes, or sudden hearing loss.

The regulated route exists for this reason

Sildenafil, tadalafil, vardenafil and dapoxetine are Schedule 4 prescription-only medicines in Australia requiring a valid prescription from a registered Australian prescriber. The interaction picture above is exactly why. A seller that supplies without a prescription never asks about your nitrate spray, and a product of unverified content makes the interaction unpredictable on top of everything else.

Bring your full medicine list to your GP or pharmacist and ask them to check it against anything being considered. The Australian Commission on Safety and Quality in Health Care and Healthdirect Australia publish independent information on medicine interactions if you want to read further.

This article is general health information, not medical advice. Never start, stop or change a prescribed medicine without speaking to your doctor or pharmacist.