Viagra 100 mg works by inhibiting the PDE5 enzyme, allowing for improved blood flow to the penis and facilitating an erection in response to sexual stimulation. It remains effective for 4 to 6 hours. Common side effects include headaches and hot flashes, while more serious effects may occur in rare cases, requiring medical attention.

How does Viagra 100mg work?

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Medically reviewed by Notre équipe éditoriale

Written by Anne-Sophie Laignel

Last updated 1/22/2025 - 6 min read

The mechanism of action of Viagra 100 mg

Le Viagra 100 mg agit en inhibant l’enzyme PDE5 (phosphodiestérase de type 5), qui est responsable de la dégradation du guanosine monophosphate cyclique (GMPc). Le GMPc joue un rôle essentiel dans le processus d’érection. Lors de la stimulation sexuelle, l’oxyde nitrique est libéré dans les cellules du pénis, ce qui entraîne la production de GMPc. Ce dernier provoque la relaxation des muscles lisses des artères du pénis, permettant ainsi au sang de circuler librement et de remplir les cavités des corps caverneux, ce qui entraîne une érection.

The enzyme PDE5 reduces the amount of cGMP in the penis, which decreases the ability to maintain an erection. By inhibiting this enzyme, Viagra 100 mg allows cGMP levels to remain high for longer, thus facilitating blood flow and supporting the erection.

It is important to note that Viagra 100 mg does not create an erection without sexual stimulation. The medication is effective only when the man is sexually aroused.

The dosage and frequency of administration of Viagra 100 mg

Viagra 100 mg is often prescribed when lower doses (such as 25 mg or 50 mg) are not effective enough. However, this dose should be used with caution, as it may lead to a higher risk of side effects, especially for men with underlying medical conditions.

Viagra 100 mg should be taken about 30 to 60 minutes before sexual intercourse. It can be taken with or without food, although high-fat meals slow down the absorption of the drug and delay the onset of its effects. The medication starts to work after about 30 to 60 minutes, with maximum effect observed after 1 to 2 hours.

It is essential not to take more than one 100 mg dose per day. If this dose does not provide the desired effect, it is better to consult a doctor, who can adjust the treatment or explore other therapeutic options.

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Possible side effects of Viagra 100 mg

Like any medication, Viagra 100 mg can cause side effects. Although most users tolerate this drug well, some may experience mild or moderate symptoms. The most common side effects include:

  • Headaches: A side effect frequently reported by Viagra users.
  • Hot flashes: A feeling of warmth in the face or upper body.
  • Digestive troubles: Including heartburn, nausea, or bloating.
  • Nasal congestion: A feeling of a blocked nose or nasal discharge.
  • Visual changes: For instance, increased sensitivity to light or difficulty distinguishing colors, particularly blue.

More serious side effects are possible, although rare. Among them are:

  • Priapisme : Une érection prolongée et douloureuse qui dure plus de 4 heures. Cela nécessite une intervention médicale immédiate.
  • Heart problems: Viagra can cause serious side effects in people with a history of heart disease.
  • Perte soudaine de vision : Un effet secondaire rare, mais grave, qui peut affecter un ou les deux yeux.

Il est important de consulter un médecin immédiatement si l’un de ces effets secondaires graves survient. Dans tous les cas, il est conseillé de consulter un professionnel de la santé pour discuter de tout effet secondaire ou de toute inquiétude concernant le traitement.

Les contre-indications et précautions à prendre

Le Viagra 100 mg ne doit pas être utilisé par certaines personnes, notamment celles qui :

  • Prennent des médicaments contenant des nitrates (utilisés pour traiter l’angine de poitrine), car cela peut provoquer une chute dangereuse de la pression artérielle.
  • Ont des antécédents de maladies cardiaques graves, d’hypertension non contrôlée, ou de problèmes du foie ou des reins.
  • Sont allergiques à l’un des composants du Viagra.
  • Ont des troubles graves de la vision, comme la rétinite pigmentaire, une maladie oculaire héréditaire.

Il est essentiel de consulter un médecin avant de commencer un traitement au Viagra 100 mg pour évaluer les risques et s’assurer qu’il n’y a pas de contre-indications avec d’autres médicaments ou conditions médicales.

Le Viagra 100 mg est une option de traitement efficace pour la dysfonction érectile, offrant une fenêtre d’action de 4 à 6 heures. Il agit en inhibant l’enzyme PDE5, permettant ainsi une meilleure circulation sanguine vers le pénis et facilitant l’érection en réponse à la stimulation sexuelle. Toutefois, cette dose doit être utilisée sous la supervision d’un médecin pour minimiser les risques d’effets secondaires. Bien que le Viagra 100 mg soit efficace, il est important de ne pas dépasser la dose recommandée et de consulter un médecin en cas d’effets secondaires graves.

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