Viagra, Erectile Dysfunction And Blood Pressure

Viagra for erectile dysfunction

Viagra, Levitra, Cialis, Staxyn and Spedra are medicines used to treat male erectile dysfunction (impotence). They are available to buy from online clinics whose doctors will assess your request, issue a prescription, and send the medicine to you in a plain wrapping. A new version of Viagra, known as Viagra Connect (sildenafil citrate 50mg) is now also available from UK pharmacies without the need for a prescription.

Viagra was originally developed to treat cardiovascular diseases, including high blood pressure, and men with poorly controlled hypertension are more likely to develop hardening and furring up of the arteries which can lead to erectile dysfunction.

Here’s what you need to know if you have high blood pressure and are thinking about using Viagra Connect or related medicines.

Treatment for erectile dysfunction

Viagra (sildenafil citrate), Cialis (tadalafil), Levitra (vardenafil), Staxyn (mouth dispersible vardenafil) and Spedra (avanafil) work by blocking an enzyme called PDE5 (phosphodiesterase type 5). This stops the breakdown of a chemical (cyclic GMP) that enhances the effects of nitric oxide. Nitric oxide relaxes smooth muscle fibres in arteries throughout the body, including those that supply blood to the penis so they dilate to bring in more blood. Nitric oxide also relaxes the sponge-like, erectile tissues of the penis (so they expand and trap more blood). This results in an erection once sexual stimulation starts.

You can buy these drugs from an online pharmacy such as Boots Erectile Dysfunction Clinic where a doctor will assess your answers to a questionnaire that takes around 10 minutes to complete. When buying Viagra Connect (sildenafil citrate 50mg) however, you don’t need a prescription and a pharmacist will assess if you are suitable for treatment.

Four out of 5 men taking erectile dysfunction drugs report an improvement in the quality of their erections. The time each of these drugs takes to start working, and how long their effects last vary.

Viagra  

Viagra (sildenafil citrate) is available 25mg, 50mg, 100mg doses. The pharmacy version is called Viagra Connect and supplies a 50mg dose (in packs of 4 or 8 tablets).

Viagra starts working in 15 to 30 minutes and its effects last around two to four hours.  Its action may be delayed after eating. Viagra and generic sildenafil are usually taken around one hour before sexual activity.

Cialis

buy viagra connect onlineCialis (tadalafil) is available in 2.5mg, 5mg, 10mg and 20mg doses

Cialis starts working in 30 to 60 minutes but its effects last for as long as 36 hours. Its action is not affected by food. Cialis is taken at least 30 minutes before sexual activity.

Levitra

Levitra (vardenafil hydrochloride) is available in doses of 5mg, 10mg and 20mg.

Levitra starts working in 30 to 60 minutes and its effects last four to five hours. Its action is less affected by food. Levitra is taken 25 to 60 minutes before sexual activity.

Orodispersible Levitra (Staxyn in some countries)

Orodispersible Levitra (vardenafil hydrochloride plus aspartame and sorbitol sweeteners) is placed on the tongue and rapidly dissolves for easy swallowing (must be taken without liquid). It is available in a 10mg dose and is used approximately 25 to 60 minutes before sexual activity.

Spedra

Spedra (avanafil) is available from online clinics in doses of 50mg, 100mg and 200mg.

Spedra starts working in 15 to 30 minutes, and its effects last from 4 to 6 hours. Its action may be delayed after eating. Spedra is usually taken 15 to 30 minutes before sexual activity.

You can also buy a starter bundle from Boots Erectile Dysfunction Online Clinic which includes Sildenafil, Spedra and Tadalafil to see which treatment suits you best.

How Viagra, Cialis, Levitra and Staxyn affect blood pressure

When you buy Cialis online, or Viagra, Levitra, Staxyn or Spedra, a doctor (or pharmacist in the case of Viagra Connect) will check your medical history and current medication to ensure you are suitable for treatment.

Viagra and related drugs work via nitric oxide, a substance that dilates arteries throughout the body so blood pressure falls. This is the same effect as can occur with beetroot juice and L-arginine supplements.

Taking Viagra (sildenafil citrate) causes a mild and transient decrease in blood pressure – after taking Viagra 100mg, blood pressure falls, on average, by 8.4/5.5 mmHg due to its blood vessel dilating effects.

As these erectile dysfunction drugs dilate blood vessels, their effects may be additive to those of other blood pressure treatments and may cause low blood pressure with symptoms of dizziness, light-headedness, or feeling faint. For example, in one interaction study, sildenafil (100 mg) was given together with a calcium channel blocker (amlodipine) in people with hypertension, and there was an additional reduction in blood pressure on lying down of 8/7 mmHg. However, this was a similar reduction to that seen when sildenafil was given alone to healthy volunteers.

Men whose blood pressure is very low (less than 90/50 mmHg), or whose blood pressure is very high (for example greater than 170/100 mmHg) should not take these medicines until their blood pressure is well controlled at acceptable levels.

Treatments for erectile dysfunction should not be used by men using certain medicines (eg nitrates) or those for whom sexual activity is inadvisable, such as men who have recently experienced a stroke or heart attack, or who have unstable angina or severe heart failure.

Viagra and alpha blockers

There is a particularly high chance of low blood pressure when one of these erectile dysfunction drugs is taken together with an alpha-blocker drug (eg alfuzosin, doxazosin, prazosin, tamsulosin, terazosin, silodosin) which are prescribed to treat either high blood pressure or prostate problems. If you are on an alpha blocker, then your blood pressure must be stable and you will usually be started on the lowest dose of erectile dysfunction treatment (eg sildenafil citrate 25mg). This will help to reduce the chance of your blood pressure dropping too low.

Viagra and alcohol

If you have high blood pressure, it’s best to avoid alcohol when using some of these drugs – check the Patient Information Leaflet provided. The combination of alcohol plus a PDE5 inhibitor may increase your heart rate and lower your blood pressure, and may lead to dizziness, headache or palpitations. However some erectile dysfunction drugs, such as vardenafil, did not appear to increase the effects of alcohol in clinical studies.

Side effects of viagra

Erectile dysfunction drugs are generally well tolerated. The most common side effects reported in various trials include headache, nasal congestion (because the nose also contains erectile tissues), indigestion, facial flushing, dizziness, stuffy nose and pelvic muscle pain. These side effects are usually mild and short lasting.

Potentially serious side effects which need urgent medical treatment include an erection that won’t go away (priapism), blurred vision, sudden decrease or loss of vision and sudden decrease or loss of hearing.

Image credits: pixabay tim.reckmann/wikimedia;   


About DrSarahBrewer

Dr Sarah Brewer qualified from Cambridge University with degrees in Natural Sciences, Medicine and Surgery. After working in general practice, she gained a master's degree in nutritional medicine from the University of Surrey. Sarah is a registered Medical Doctor, a registered Nutritionist and a registered Nutritional Therapist. She is an award winning author of over 60 popular self-help books and a columnist for Prima magazine.

Please leave any comments or ask me a question ...