Viagra®

Viagra is an approved medication for the treatment of erectile dysfunction and is manufactured by Pfizer. Its active ingredient, sildenafil, was originally developed as a heart medication; its potency-enhancing effect was discovered during the clinical trials.

The medication makes an erection possible during sexual stimulation by improving blood flow to the penis. The characteristic blue, diamond-shaped tablets are known around the world.

Since 2013, the active ingredient sildenafil has also been available as a generic. These alternatives contain the identical active ingredient.

Viagra contains the active ingredient sildenafil, a so-called PDE-5 inhibitor. Its mechanism of action is elegant and well researched:

During sexual arousal, the body releases nitric oxide (NO) in the penis. This activates an enzyme that produces the messenger substance cGMP. cGMP relaxes the muscles in the blood vessels of the penis, allowing more blood to flow in so that an erection develops.

Normally, cGMP is broken down by the enzyme phosphodiesterase-5 (PDE-5). Viagra inhibits this enzyme so that cGMP remains active for longer. As a result, an erection can develop more easily and be maintained better.

Important to understand:

• Viagra does not trigger an automatic erection
• Sexual stimulation is still required
• The effect begins after about 30-60 minutes
• The duration of action is 4-6 hours

Viagra is approved for adult men with erectile dysfunction. It is suitable for various causes of erectile dysfunction:

Organic causes:

• Circulatory disorders (e.g., in arteriosclerosis)
• Diabetes mellitus with vascular or nerve damage
• After prostate surgery (if the nerve pathways have been preserved)
• High blood pressure and its consequences

Psychological causes:

• Fear of failure
• Performance pressure
• Stress and exhaustion
• Relationship problems

Mixed forms: In most cases, both physical and psychological factors are present. Viagra can be effective regardless of the cause.

Particularly suitable for men who:

• Prefer a proven, well-studied treatment
• Value the original
• Find a duration of action of 4-6 hours sufficient

Viagra is available in three strengths:

25 mg:

• Lowest dose
• In impaired liver function (e.g., liver cirrhosis) or severely impaired kidney function
• When taking certain other medications

50 mg:

• Standard starting dose
• The ideal starting point for most men
• Can be adjusted depending on response

100 mg:

• Highest available dose
• If 50 mg is not sufficiently effective
• Maximum daily dose

Dosage recommendation: Start with 50 mg. If the effect is not sufficient and the medication is well tolerated, the dose can be increased to 100 mg. In case of severe side effects, a reduction to 25 mg may be advisable.

When to take it: Take Viagra about 30 to 60 minutes before planned sexual intercourse. In some men, the effect may begin after as little as 30 minutes.

With or without food: Viagra can generally be taken regardless of meals. However, a high-fat meal can delay absorption and prolong the time until the effect begins. For best results, it is recommended to take it on an empty stomach or after a light meal.

The tablet:

• Take with a glass of water
• Do not chew or split (unless there is a score line)
• A maximum of one tablet per day

Duration of action: The effect lasts about 4 to 6 hours. During this time, erections are possible with sexual stimulation. After this period has passed, another tablet can be taken the next day.

Alcohol: Small amounts of alcohol are acceptable. Larger amounts can reduce effectiveness and intensify side effects.

Viagra must not be taken in case of:

Nitrate therapy: If you take nitrates (e.g., nitroglycerin spray, isosorbide dinitrate) or use amyl nitrite (poppers). The combination can cause a life-threatening drop in blood pressure.

Severe heart disease:

• Recent heart attack
• Recent stroke
• Unstable angina pectoris
• Severe heart failure
• Uncontrolled cardiac arrhythmias

Other contraindications:

• Low blood pressure (below 90/50 mmHg)
• Hereditary eye diseases such as retinitis pigmentosa
• Severe liver disease
• Loss of vision in one eye due to NAION (a circulatory disorder of the optic nerve), regardless of whether it was related to previous use of a PDE-5 inhibitor
• Allergy to sildenafil or other ingredients

Caution in case of:

• Blood clotting disorders
• Active stomach ulcer
• Anatomical deformities of the penis
• Sickle cell anemia, leukemia, or plasmacytoma

Very common side effects (more than 10%):

• Headache

Common side effects (1-10%):

• Facial redness (flushing)
• Nausea
• Stuffy nose
• Indigestion
• Visual disturbances (e.g., bluish tinge, increased sensitivity to light)
• Dizziness

Uncommon side effects (0.1-1%):

• Vomiting
• Skin rash
• Watery eyes
• Racing heart
• Muscle pain

Rare but serious side effects:

• Priapism: A painful erection that lasts longer than 4 hours. Seek medical help immediately!
• Sudden loss of vision: Rare, but requires immediate medical evaluation
• Sudden hearing loss: Very rare, see a doctor right away

Most side effects are mild and go away on their own after a few hours.

Absolutely contraindicated combinations:

• Nitrates and NO donors: nitroglycerin, isosorbide, molsidomine, amyl nitrite (poppers) – risk of a life-threatening drop in blood pressure

Important interactions:

• Alpha blockers (e.g., tamsulosin, doxazosin): Increased lowering of blood pressure possible. Only start Viagra once alpha-blocker treatment is stable.

• CYP3A4 inhibitors (e.g., ritonavir, ketoconazole, erythromycin): Increase the sildenafil concentration. Dose reduction required.

• Blood pressure medications: Additive blood pressure-lowering effect possible.

• Other PDE-5 inhibitors: Do not combine with tadalafil, vardenafil, or avanafil.

• Grapefruit juice: May slightly increase the sildenafil concentration.