Vizarsin 50 mg and 100 mg film-coated tablets – sildenafil for erectile dysfunction

Vizarsin film-coated tablets contain the active substance sildenafil, which belongs to a group of medicines called phosphodiesterase type 5 (PDE5) inhibitors. The medicine helps the blood vessels in the penis to relax and allows blood to flow into the penis when you are sexually excited – it only helps you get an erection if you are sexually stimulated.

Vizarsin is a treatment for men with erectile dysfunction (impotence), a condition in which a man cannot get or keep an erection hard enough for sexual activity. In Serbia it is authorised in 50 mg and 100 mg strengths (KRKA), in packs of 4 film-coated tablets.

What is Vizarsin used for and how should it be taken correctly?

Key facts about the medicine

What is Vizarsin used for?

Vizarsin is used to treat erectile dysfunction in adult men – a condition in which a man cannot get or keep a hard, erect penis suitable for sexual activity.

• The medicine only works with sexual stimulation – it does not cause an erection by itself.
• It should not be used if you do not have erectile dysfunction.
• Vizarsin is not intended for women or for people under 18 years of age.

How is it taken and dosed?

The recommended starting dose is 50 mg, taken as needed approximately one hour before sexual activity. Based on efficacy and tolerability, the doctor may increase the dose to 100 mg. According to the SmPC, other manufacturers’ products are used to start treatment with 25 mg, as Vizarsin is not authorised in that strength.

• Swallow the tablet whole with a glass of water.
• Do not take the medicine more than once a day. Doses above 100 mg do not increase the effect but increase the number and severity of side effects.
• The time to onset varies from person to person, usually between half an hour and one hour; after a heavy meal it may take longer.
• If you feel the medicine is too strong or too weak, or the erection does not last long enough, talk to your doctor.

Special patient groups

• Elderly (65 years and over): according to the SmPC no dose adjustment is required.
• Kidney impairment: in mild to moderate impairment the usual dosing applies; in severe impairment a 25 mg starting dose is considered.
• Liver impairment: a 25 mg starting dose is considered; the medicine must not be taken in severe liver problems.
• People under 18 years and women: the medicine is not intended for these groups.

Contraindications – when the medicine must not be used

Vizarsin must not be taken:

• if you are allergic to sildenafil or to any of the excipients;
• if you are taking nitrates (medicines often given to relieve the symptoms of angina pectoris – “chest pain”);
• if you are using nitric oxide donors such as amyl nitrite (“poppers”);
• if you are taking riociguat (a medicine for pulmonary arterial hypertension and chronic thromboembolic pulmonary hypertension);
• if you have severe heart or liver problems;
• if you have recently had a stroke or heart attack, or if you have low blood pressure;
• if you have a rare inherited eye disease such as retinitis pigmentosa;
• if you have ever had loss of vision in one eye due to non-arteritic anterior ischaemic optic neuropathy (NAION).

Warnings and precautions

Tell your doctor before taking the medicine:

• if you have sickle cell anaemia, leukaemia or multiple myeloma;
• if you have a deformity of the penis or Peyronie’s disease;
• if you have heart problems – the doctor should check whether your heart can cope with the extra strain of sexual intercourse;
• if you currently have a stomach ulcer or a bleeding disorder (e.g. haemophilia);
• if you have kidney or liver problems.

If you experience a sudden decrease or loss of vision, stop taking the medicine and contact your doctor immediately. Vizarsin should not be used with other treatments for erectile dysfunction (oral or topical) or with medicines for pulmonary arterial hypertension containing sildenafil or another PDE5 inhibitor. The medicine contains lactose monohydrate; it contains less than 1 mmol (23 mg) sodium per tablet, i.e. it is essentially “sodium-free”.

Interactions with other medicines, food and drink

Tell your doctor or pharmacist about all medicines you are taking. It is particularly important:

• nitrates and nitric oxide donors (amyl nitrite) – contraindicated because of a dangerous fall in blood pressure; if you need emergency medical help, tell the healthcare professional that you have taken Vizarsin and when;
• riociguat – contraindicated;
• alpha-blockers (for high blood pressure or enlarged prostate) – dizziness or light-headedness may occur on sitting or standing up quickly, most likely within 4 hours of taking the medicine; the doctor may start with a lower dose (25 mg);
• HIV protease inhibitors and other CYP3A4 inhibitors – the doctor may start with the lowest dose (25 mg); according to the SmPC co-administration with ritonavir is not recommended.

Vizarsin can be taken with or without food, but after a heavy meal the effect may start later. Alcohol can temporarily impair the ability to get an erection – do not drink large amounts of alcohol before taking the medicine. According to the SmPC, grapefruit juice (a weak CYP3A4 inhibitor) may modestly increase sildenafil blood levels.

Pregnancy and breast-feeding

Vizarsin is not indicated for use in women, so pregnancy and breast-feeding data are not applicable.

Driving and using machines

Vizarsin can cause dizziness and visual disturbances. You should know how the medicine affects you before driving or using machines.

Possible side effects

Side effects are usually mild to moderate and short-lived.

• Very common (more than 1 in 10 patients): headache.
• Common (up to 1 in 10): nausea, facial flushing and hot flushes, indigestion, changes in colour vision, blurred vision, visual disturbance, stuffy nose, dizziness.
• Uncommon (up to 1 in 100): vomiting, skin rash, eye irritation and bloodshot eyes, eye pain, seeing flashes or sparkles of light, sensitivity to light, watery eyes, pounding and rapid heartbeat, high or low blood pressure, muscle pain, sleepiness, reduced sense of touch, vertigo, ringing in the ears, dry mouth, blocked sinuses, inflammation of the nasal lining, upper abdominal pain, heartburn (reflux), blood in urine, pain in arms or legs, nosebleed, feeling hot and tired; allergic reaction and chest pain.
• Rare (up to 1 in 1,000): fainting, stroke, heart attack, irregular heartbeat, temporary decreased blood flow to parts of the brain, tight throat, numb mouth, bleeding at the back of the eye, double vision, reduced sharpness of vision, swelling of the eye or eyelid, halos around lights, dilated pupils, bleeding from the penis, blood in semen, prolonged and sometimes painful erection, sudden decrease or loss of vision, serious skin reactions, seizures, sudden decrease or loss of hearing.

Unstable angina and sudden death have rarely been reported after marketing, mostly in men who had heart problems before taking the medicine.

Overdose, missed dose and stopping treatment

• Overdose: doses above 100 mg do not increase the effect but increase the number and severity of side effects. Do not take more tablets than your doctor prescribed; if you have taken more, tell your doctor.
• Missed dose: the medicine is taken as needed before sexual activity – there is no regular dosing schedule; do not take more than one dose a day.
• Stopping: the medicine is not taken regularly, so there are no special instructions for stopping; if it does not help, talk to your doctor instead of changing the dose yourself.

Related information

For products for protection during sexual intercourse, see also the Condoms category – products in this category do not replace the medicine prescribed to you.

Composition, pack and manufacturer

• Active substance: sildenafil (as sildenafil citrate) – 50 mg or 100 mg per film-coated tablet.
• Tablet core: microcrystalline cellulose; calcium hydrogen phosphate; croscarmellose sodium; hypromellose (E464); magnesium stearate (E470b).
• Film coating (Opadry II 31K58875 White): lactose monohydrate; hypromellose (E464); titanium dioxide (E171); triacetin (E1518).
• Pack: perforated PVC/Alu unit-dose blister with 4 film-coated tablets in a carton.
• Marketing authorisation holder: KRKA-FARMA D.O.O. Belgrade, Jurija Gagarina 26/V/II. Manufacturers: KRKA d.d., Novo Mesto, Slovenia; TAD Pharma GmbH, Cuxhaven, Germany.

Storage

• The medicine does not require any special storage conditions.
• Keep out of the sight and reach of children.
• Do not use after the expiry date; return unused medicine to a pharmacy that collects unused medicines.

Frequently asked questions

How long before intercourse should Vizarsin be taken?

According to the leaflet, the tablet should be taken approximately one hour before sexual activity. The effect usually starts within half an hour to one hour, and later after a heavy meal.

Does Vizarsin work without sexual arousal?

No. Vizarsin only helps you get an erection when there is sexual stimulation.

Is there a 25 mg Vizarsin?

In Serbia, Vizarsin is authorised only in 50 mg and 100 mg strengths (the 25 mg authorisation ended in 2021). If your doctor decides you need a 25 mg starting dose, they will prescribe sildenafil from another manufacturer.

Can I take Vizarsin if I use heart or blood pressure medicines?

Vizarsin must not be taken with nitrates, nitric oxide donors (amyl nitrite) or riociguat. With alpha-blockers and other blood pressure medicines always consult your doctor – a lower starting dose may be needed.

Sources

• ALIMS – Summary of Product Characteristics, Vizarsin® 50 mg film-coated tablets (SmPC, Serbian)
• ALIMS – Package leaflet, Vizarsin® 50 mg and 100 mg film-coated tablets (PIL, Serbian)
• ALIMS – Summary of Product Characteristics, Vizarsin® 100 mg film-coated tablets (SmPC, Serbian)
• ALIMS – Package leaflet, Vizarsin® 100 mg film-coated tablets (PIL, Serbian)

Sources checked on: 25 October 2026.