Un Guide Complet Des Effets Secondaires Du Viagra (Sildénafil)

Un Guide Complet Des Effets Secondaires Du Viagra (Sildénafil)
20 May, 2019

La dysfonction érectile, ou DE, est une affection courante qui touche jusqu'à 40 % des hommes âgés de 40 ans. Plusieurs médicaments sont disponibles pour traiter la dysfonction érectile. Parmi ceux-ci, le Viagra (ou, sous sa forme générique, le sildénafil) est le plus connu et le plus utilisé.  

Le Viagra agit en augmentant le flux sanguin vers le pénis, ce qui vous permet d'obtenir et de maintenir plus facilement une érection lorsque vous êtes sexuellement excité. Utilisé par des millions d’hommes, c’est un médicament sûr, éprouvé et efficace.

Cependant, comme presque tous les médicaments, le Viagra peut provoquer des effets secondaires. La plupart de ces effets secondaires sont mineurs et temporaires (ils disparaissent généralement à mesure que le médicament quitte votre corps), bien que certains puissent devenir graves si vous utilisez d'autres médicaments sur ordonnance.

Ci-dessous, nous avons répertorié les effets secondaires courants et rares du sildénafil, l'ingrédient actif du Viagra. Nous avons également examiné les données derrière bon nombre de ces effets secondaires pour expliquer comment et pourquoi ils surviennent, ainsi que ce que vous pouvez faire pour les gérer.

Les effets secondaires les plus courants du Viagra

Le Viagra a plusieurs effets secondaires courants. Ces effets secondaires surviennent généralement au même moment où le médicament est actif dans votre corps (généralement trois à cinq heures), bien que certains puissent persister plusieurs heures après la disparition des effets actifs du Viagra.

Maux de tête

Les maux de tête sont de loin l’effet secondaire le plus courant du Viagra, touchant environ 25 pour cent des hommes qui utilisent ce médicament. Les maux de tête provoqués par le Viagra sont généralement légers et disparaissent généralement à mesure que le médicament devient moins concentré dans votre circulation sanguine.

D'autres médicaments contre la dysfonction érectile, tels que le Cialis (tadalafil) et le Levitra, sont également liés aux maux de tête. Ces médicaments agissent tous en élargissant vos vaisseaux sanguins, ce qui contribue à améliorer le flux sanguin vers le tissu érectile de votre pénis.

Cela a pour effet secondaire d’augmenter également le flux sanguin vers d’autres zones de votre corps. À mesure que le diamètre de vos vaisseaux sanguins augmente, cela peut contribuer aux maux de tête en étirant les nerfs sur le côté de votre tête.

À mesure que les effets du Viagra s'estompent et que vos vaisseaux sanguins se contractent, il est normal que les maux de tête que vous ressentez à cause du médicament deviennent moins intenses.

Notre guide sur le traitement des maux de tête dus aux médicaments contre la dysfonction érectile explique ce que vous pouvez faire si vous remarquez souvent des maux de tête après avoir utilisé du Viagra. La plupart du temps, les maux de tête induits par le Viagra peuvent être traités soit en réduisant la dose du médicament, soit en utilisant un analgésique en vente libre.

Douleurs musculaires

Some Viagra users experience muscle aches after taking the medication. This can range from a mild level of muscular pain to pain in a specific area, such as the lower back. Muscle aches and pain after using Viagra can be treated using over-the-counter pain relief medications.

If you have recurring, uncomfortable muscle aches after using Viagra, make sure to discuss this with your doctor. Your doctor might recommend a suitable form of pain relief or suggest using a lower dose of Viagra for ED treatment.

Nasal Congestion

Viagra can cause you to get a stuffy, partially blocked nose. Like most other side effects, this is a temporary issue that is most common while the medication is still in your system, although in some cases it can persist for several hours after the main effects of Viagra wear off.

This side effect is the result of Viagra’s effects on blood flow. By causing your blood vessels to widen, Viagra can contribute to nasal obstruction. This makes it more difficult to breathe through your nostrils.

Studies of sildenafil citrate and nasal obstruction show that this side effect can occur at a 50mg dose of Viagra. Like other side effects, it might be possible to limit the effects of Viagra on your ability to breathe through your nose by reducing your dosage of the medication.

Dizziness

Some men report feeling dizzy after using ED medication such as Viagra. This is typically due to the increase in nitric oxide Viagra can trigger. Most of the time, any dizziness from Viagra is light and passes quickly as your body gets used to the effects of the medication.

If you frequently experience dizziness after using Viagra, let your doctor know. Like many other common side effects of Viagra, you can often limit or avoid dizziness by adjusting your dosage of the medication.

Facial Flushing

Sildenafil, the active ingredient in Viagra, causes your blood vessels to widen, improving blood flow to your penis and making it easier to get an erection.

This can also cause blood vessels in other parts of your body to widen. When the blood vessels in your skin dilate, your skin can take on a red, flushed appearance. Some men who use Viagra notice this effect around their nose, cheeks and forehead.

Just like headaches, facial flushing fades away on its own as the dose of sildenafil that’s active in your body decreases. If you’re prone to facial flushing from Viagra, using a lower dose of the medication might cause this side effect to become less intense and visible.

Facial flushing is a common side effect of all ED medications, meaning that switching to Cialis or Levitra might not prevent this from occurring.

Indigestion/Heartburn

Indigestion, or heartburn, is a common side effect of Viagra. This occurs because of the effects of Viagra on smooth muscle tissue in your body.

After you take Viagra, the smooth muscle tissue in your penis starts to relax, leading to higher levels of blood flow. This effect also occurs in other smooth muscle tissue, including the lower esophageal sphincter (LES), a group of muscles that separate your stomach and esophagus.

This can result in small quantities of stomach acid making its way from your stomach into your esophagus.

Heartburn from Viagra can be treated using over-the-counter antacids such as Gaviscon, which creates a protective layer on the top of your stomach contents. If you experience mild heartburn from Viagra, drinking several glasses of water can also help to prevent discomfort.

If you frequently get indigestion/heartburn after using Viagra, consider discussing switching to a lower dose of the medication with your doctor. It’s also important to avoid drinking alcohol after using Viagra, as alcohol can further relax the LES and worsen heartburn symptoms.

Nausea

Sildenafil, the active ingredient in Viagra, can cause a small percentage of users to experience nausea shortly after it’s taken. Of the common side effects of Viagra, this is one of the rarest — in a four-year study, only one out of 979 participants reported nausea as a side effect.

Nausea from sildenafil is generally mild. Like other side effects, it most frequently occurs while the medication is active, with nausea and stomach discomfort typically fading away as Viagra’s effects wear off.

If you feel nauseous after using Viagra, consider talking to your doctor about using a lower dose of the medication.

Visual Disturbances

Viagra is linked to several visual disturbances, including blurred vision, increased brightness of lights and cyanopsia, a form of chromatopsia in which your vision becomes overly blue.

Studies state that these effects are transient and mild, with vision issues typically occurring as the sildenafil in Viagra is at its peak concentration in the body. Long-term studies of Viagra do not show any lasting, permanent side effects related to vision or the structure of the eye.

Reduced Blood Pressure

Viagra is a vasodilator that can affect your blood pressure. On average, people’s blood pressure drops by 8.4/5.5 mmHg after taking a typical dose of Viagra. This reduction is small and doesn’t lead to any negative health effects in people with healthy, non-hypertensive blood pressure.

In short, if you’re healthy and don’t have any blood pressure issues, Viagra will affect your blood pressure, but not in a dangerous way.

If you have cardiovascular disease or hypertension, Viagra could have a more significant effect on your blood pressure and general health. It’s important to discuss this with your doctor before considering Viagra, especially if you use medication to treat a cardiovascular health issue.

Less Common, More Serious Side Effects of Viagra

Although serious side effects from Viagra are highly uncommon, they can still happen. Viagra has several uncommon side effects, including interactions with certain medicines used to treat  hypertension and a small risk of priapism.

Priapism

Priapism is a serious condition in which you experience a painful, persistent erection that lasts for several hours without sexual stimulation. This can lead to permanent damage to the erectile tissue of the penis.

Compared to other Viagra side effects, priapism is very rare. Most cases of priapism related to Viagra involve people taking overly large doses of the medication (in one case, 200mg at once), as well as men who use sildenafil in combination with penile injection therapy.

In the entire year of 2007, there were only 93 reported cases of this side effect from Viagra and other ED medication. Considering millions of men in the US use Viagra without issue, it’s safe to say that priapism is very uncommon.

If you do experience priapism after using Viagra or any other ED medication, you should seek emergency medical care. Priapism is a serious medical emergency that needs to be treated by a qualified professional in order to avoid damaging your penile tissue.

Damage to the Optic Nerve

Although it’s extremely rare, erectile dysfunction drugs such as Viagra are linked to damage to the optic nerve, or nonarteritic anterior ischemic optic neuropathy, in a very small percentage of users.

Nonarteritic anterior ischemic optic neuropathy can cause loss of vision as a result of insufficient blood supply to the optic nerve. In severe cases, this condition can lead to the loss of the upper or lower hemifield of the visual field (for example, loss of half of one eye’s field of vision).

In a 2006 review of clinical trial data, researchers found that approximately 2.8 cases of NAION (nonarteritic anterior ischemic optic neuropathy) occur per 100,000 patient-years of Viagra use, making this an extremely rare potential side effect.

It’s worth noting that most of the cases of optic nerve damage associated with Viagra reported in the US involved men who were already at risk of vision complications due to a small cup-to-disc ratio that’s associated with this condition.

Hearing Issues

Viagra and other commonly used ED medications are linked to several cases of hearing loss, some of which occurred within 24 hours of using the drugs.

An extremely small percentage of men who’ve used Viagra have experienced a condition that’s known as sudden sensorineural hearing loss (SSHL). This involves damage to the inner ear that can cause permanent loss of hearing.  

Although researchers are unsure of why this happens, it’s believed to be linked to the effects of Viagra on the nitrous oxide-cyclic GMP (No/cGMP) pathway. On average, the men affected by this side effect were 56.6 year of age, with 88 percent losing their hearing in only one ear.

Comme les problèmes de vision évoqués ci-dessus, les problèmes d’audition dus au Viagra sont extrêmement rares. Un guide du NHS  note qu'il n'y a eu que 47 cas de perte auditive liés aux inhibiteurs de la PDE5 comme le Viagra depuis l'introduction des médicaments à la fin des années 1990 jusqu'en 2011, année de publication du guide.

Interaction avec les médicaments contre la tension artérielle

Le sildénafil, l'ingrédient actif du Viagra, peut interagir avec certains médicaments utilisés pour traiter l'hypertension artérielle. Utilisés ensemble, ces médicaments peuvent provoquer une chute soudaine de la tension artérielle pouvant nuire gravement à votre santé.

Vous ne devez pas utiliser le Viagra si vous utilisez également des nitrates, tels que la nitroglycérine, le dinitrate d'isosorbide, le mononitrate d'isosorbide ou le nitrate d'amyle, pour traiter l'hypertension. Le Viagra ne doit pas être pris avec des « poppers », qui contiennent souvent des ingrédients tels que le nitrate d'amyle.

Ces médicaments peuvent interagir avec le Viagra et provoquer une chute soudaine et sévère de la tension artérielle pouvant entraîner une perte de conscience ou un arrêt cardiaque. En plus du Viagra, ces effets secondaires peuvent potentiellement survenir si le Cialis ou le Levitra sont utilisés en association avec des nitrates.

Si vous souffrez de problèmes de santé cardiovasculaire, tels que l'hypertension ou une maladie cardiaque, vous devez informer votre médecin de ces problèmes et de tout médicament que vous prenez pour ceux-ci avant de discuter de l'utilisation du Viagra ou de tout autre médicament contre la dysfonction érectile.

En savoir plus sur le Viagra et la dysfonction érectile

Dans l’ensemble, le Viagra est un médicament sûr et très efficace. Il est utilisé régulièrement par des millions d’hommes rien qu’aux États-Unis, ainsi que par des dizaines de millions dans le monde. Bien que certains effets secondaires, tels que des rougeurs au visage et des maux de tête, soient fréquents, les effets secondaires graves sont extrêmement rares.