Before taking Viagra When first deciding to take Viagra, you should speak with your doctor about your general health condition in order to determine whether you are in proper health to engage in rigorous sexual activity. If you ever experience unusual discomfort during sex, including chest pain and nausea, you should seek immediate medical attention.You should also discuss any pre-existing health problems related to: blood pressure, liver and kidneys, stomach and heart. Men over 65, and those with kidney or liver problems, should take special heed to the safety information regarding the use of Viagra. In these cases, your doctor will probably recommend a lower dosage at the beginning. Recommended dosageViagra pills should be taken in doses as prescribed by a physician. For men under 65, usually a 50 mg tablet is consumed once daily, 30 minutes to 4 hours before intercourse. For men 65 and older, usually 25 mg is the recommended intake, also consumed between 30 minutes and four hours prior to intercourse.Viagra should not be taken more than once a day. And, you must always consult a doctor before increasing your dosage.Your dosage may also be lowered to 25 mg if you are already taking a protease inhibitor, such as that used to treat HIV. And in this case, your doctor may only permit you to take one tablet every two days.Signs of overdose include: swollen limbs, heartbeat irregularities, chest pain, and a persisting, painful erection that lasts for over four hours. For your safety, do not overdose on Viagra. If this occurs, call emergency.Unsafe drug combinationsViagra should never be taken in conjunction with nitrate medications, generally used to treat heart disease and cardiac-related conditions like chest pain and angina. This can result in a severe and sudden drop in blood pressure and may land you in an emergency room.Why does this happen? When Viagra (Sildenafil) is combined with a nitrate drug (NO), it affects the circulation of NO, enabling it to dilate arterial blood vessels. This relaxation of the smooth muscle in blood vessels then leads to a decrease in blood pressure.Drinking alcohol may also produce adverse affects if taken in combination with Viagra.Side effectsThere are certain rare but serious side effects that may be spurred by taking Viagra, like sudden vision or hearing loss. For your safety, you must stop taking the drug if these occur and speak to a doctor right away.More common side effects include headache, upset stomach and flushing. Less common are thing like blurred vision and sensitivity to light. Always consult a physician if you are uncertain about any conditions arising after taking Viagra.Side effects in general are more likely to occur in men over 65 who are taking Viagra.Use of the drug by women is not known to be harmful, though it is designed to be used by men for the treatment of erectile dysfunction. There is a chance that Viagra could pass into the breast milk of women, but this is not clear.