Very rarely, Viagra can lead to temporary memory loss, heart attack, seizures, chest pain, shortness of breath, irregular heartbeat, low blood pressure accompanied with dizziness, fainting and light-headedness, stroke and pulmonary hemorrhage. Alcohol: Consumption of alcohol in large amounts may decrease the ability to get an erection and may also temporarily decrease blood pressure, causing dizziness and fainting. You should also let your doctor know if you have or have had low blood pressure. Always seek the advice of your physician or other qualified health providers with any questions you may have regarding a medical condition. Viagra Warnings Before you begin using a medication, be sure to inform your doctor of any medical conditions or Allergies you may have, any medications you are taking, whether you are pregnant or breast-feeding, and any other significant facts about your health. The medication Viagra belongs to the class of drugs called as phosphodiesterase type 5 PDE5 inhibitors.Brand Name Viagra Common Name sildenafil In this drug factsheet: How does this medication work? What will it do for me? How should I use this medication? What form (s) does this medication come in? Who should NOT take this medication? What side effects are possible with this medication? Home Health Medication dictionary Viagra tablet 50mg Viagra tablet 50mg Description This medication is typically used for erectile problems in men. Its effects can be felt within 1 hour. Find a Pharmacy Print this card Instructions Certain heart medication (nitrates) must be avoided while taking this product. If in doubt, consult your pharmacist. These sites tell you they will save you the “embarrassment” of talking to your doctor about certain prescription drugs, such as Viagra, or drugs to prevent hair loss, or promote weight loss. What they do not tell you is that it is dangerous to take a prescription drug without being examined in person and monitored by a health care practitioner.