What are the common side effects of ED medicines?

Headache, flushing, a blocked or stuffy nose, and indigestion or reflux. healthdirect lists these as the common side effects of the PDE5 inhibitors available in Australia — sildenafil (Viagra), tadalafil (Cialis), vardenafil and avanafil (Spedra) — and adds: "Usually, these side effects are mild and temporary" (healthdirect). What each label adds:

MedicineMost common on its labelAlso common
Viagra (sildenafil)Headache — 1 man in 10 or moreDizziness, flushing, a blocked nose, nausea, indigestion, colour-tinged or blurred vision
Cialis (tadalafil)Headache, indigestion, back pain, muscle aches — more often at higher dosesFlushing, a blocked nose, pain in the arms or legs
VardenafilHeadache — 1 man in 10 or moreDizziness, flushing, a blocked or runny nose, indigestion

"Common" means between 1 man in 100 and 1 in 10. Sources: sildenafil label, tadalafil label, vardenafil leaflet.

Each medicine's list in full: what are the side effects and health risks of taking Viagra?, the side effects of sildenafil and the side effects and risks of taking Cialis. Vardenafil is on the Australian Register of Therapeutic Goods (ARTG) as generic tablets — the Levitra brand is not — and its label allows a lower 5 mg dose (EMA); what else can help is in how can I reduce Levitra's side effects?

Which side effects are serious, and when do you need help?

An erection lasting more than 4 hours, a sudden change in vision or hearing, chest pain, fainting, and signs of an allergic reaction. "If you have an erection that lasts for more than 4 hours, you should go to the nearest hospital emergency department" (healthdirect): if priapism is not treated straight away, "penile tissue damage and permanent loss of potency could result" (sildenafil label). The Australian Viagra leaflet adds chest pain, a faster heartbeat, seizures, wheezing and swelling of the face, lips or tongue to the list that means calling a doctor straight away or going to the nearest Emergency Department (Viagra consumer medicine information).

How often priapism happens, and who is more prone to it — the labels name sickle cell anaemia, leukaemia, multiple myeloma and a curved or scarred penis — is in what is the likelihood of priapism with Viagra and Cialis?

Can you reduce headache, flushing, a stuffy nose or indigestion?

They usually pass within hours, and they depend on the dose. With tadalafil the most common side effects "increase with increasing dose", and on the daily tablet most headaches come in the first 10 to 30 days (tadalafil label), so a lower dose or another medicine is the usual lever (who decides). Symptom by symptom:

Can ED medicines affect your eyesight?

A short-lived colour tinge or blurring is common with sildenafil; loss of sight is rare, and an emergency. In testing, some men had mild, temporary trouble telling blue from green one hour after 100 mg of sildenafil, gone two hours after the dose — put down to its effect on PDE6, an enzyme in the retina (sildenafil label). Why it happens and how long it lasts: what causes a blue tinge to vision after taking Viagra?

"Rarely, men have lost eyesight after taking drugs to treat erectile dysfunction" (Viagra consumer medicine information). The condition named on the labels is NAION, which "causes sudden vision loss in one eye or both eyes. Vision loss may be partial, temporary or permanent" (Cialis consumer medicine information). At any sudden change in sight, stop the medicine and get urgent help; a man who has lost vision in one eye from NAION must not take sildenafil or tadalafil (sildenafil and tadalafil labels). More in can Cialis and other ED drugs cause vision problems or blindness?

Can Viagra or Cialis cause hearing loss?

Rarely, yes — and sudden hearing loss means stopping the medicine. healthdirect lists sudden hearing loss among the more severe side effects of ED medicines. On the sildenafil label, ringing in the ears and vertigo are uncommon and deafness is rare; the tadalafil label advises men "to stop taking tadalafil and seek prompt medical attention in the event of sudden decrease or loss of hearing", noting that other risk factors — age, diabetes, high blood pressure, earlier hearing loss — were present in some cases. The evidence behind it: can Viagra cause hearing loss or damage?

Can ED medicines make your heart race, or cause blood clots?

A fast heartbeat or palpitations are uncommon side effects; blood clots are not listed. Both labels list a fast heartbeat and palpitations as uncommon, and the Viagra leaflet counts an "unusual heartbeat" among the serious side effects to call a doctor about. The question in full: can Viagra cause palpitations or a rapid heartbeat?; what sildenafil does to heart rate and blood pressure, in numbers, is on Viagra's own side-effects page.

The sildenafil label does not list blood clots as a side effect. Heart attack, bleeding in the brain and mini-strokes have been reported since it came onto the market, mostly in men who already had cardiovascular risk factors, and the label says it is not possible to determine what caused them (sildenafil label). See can Viagra cause or worsen blood clots? The opposite question is answered in does Viagra thin the blood?

Chest pain is the one to act on at once. The Cialis leaflet: "If you experience chest pain during or after sexual activity: stop what you are doing, sit up and sit forward. Call an ambulance if the pain does not resolve. Do not use nitrates" (Cialis consumer medicine information) — in Australia, triple zero (000). Taken with nitrates, sildenafil can cause "a sudden drop in your blood pressure that is hard to treat" (healthdirect).

Can ED medicines affect your skin, muscles, kidneys or hair?

Rash and muscle pain are on the labels; kidney damage and hair loss are not. On the sildenafil label, rash, muscle pain, pain in the arms or legs, chest pain and blood in the urine are uncommon, while back pain and muscle aches are among tadalafil's most common side effects; joint pain as such is on neither label. The question as asked: can Viagra cause skin problems, joint pain or chest pains?

Kidneys: neither label lists kidney damage. With severe kidney disease sildenafil is cleared more slowly, so its label suggests starting at 25 mg; tadalafil is capped at 10 mg and not taken daily (sildenafil label; Cialis consumer medicine information). See does Viagra have any negative effects on kidney function?

Hair: neither label lists hair loss or hair growth. The Cialis leaflet mentions hair once — finasteride, "used to treat prostate and hair loss problems", is on its list of medicines that may interfere with Cialis: do erectile dysfunction drugs affect hair growth or loss?

What if you take too much, or take it for years?

Too much brings more side effects, not a better erection. "Doses of 200 mg did not result in increased efficacy but the incidence of adverse reactions (headache, flushing, dizziness, dyspepsia, nasal congestion, altered vision) was increased" (sildenafil label). If you — or anyone else — may have taken too much, phone the Poisons Information Centre on 13 11 26, call your doctor or go to the nearest hospital emergency department, "even if there are no signs of discomfort or poisoning" (Viagra consumer medicine information). More in what happens if you take too much Viagra or sildenafil? and can you overdose on Viagra?

Over years: "The safety and efficacy of sildenafil was maintained in long-term studies" (sildenafil label), and men on daily tadalafil should have it "reassessed periodically" (tadalafil label). What is and is not known: what are the long-term side effects of using Viagra?

What are the side effects of ED injections?

Pain or bruising where you inject, and priapism. When tablets do not suit, healthdirect names alprostadil, "a medicine you take via injection" that can be self-administered 15 minutes before sex (healthdirect); among the complications of ED treatments it lists "painful erections (priapism)" and "local pain or bruising" (healthdirect). The injectable medicines by name: what are the names and side effects of injectable ED medications?

Who decides what to do about a side effect?

The doctor who prescribes your ED medicine — a lower dose, a different medicine or another treatment. healthdirect: "If you are concerned by any side effects or have underlying health conditions, ask your doctor or pharmacist for advice." After getting medical advice, you can also report a side effect to the Therapeutic Goods Administration (TGA) online (Viagra and Cialis consumer medicine information). Who should not take these medicines at all is on our health conditions and ED medicines page, and what not to mix with them on Viagra and Cialis with other medicines.

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