Drug Uses

Viagra is used for treating erectile dysfunction (e.g. male impotence). It works by helping the blood flow into the penis to achieve and maintain an erection during sexual stimulation.

Cialis is to treate male impotence (eg, men's erectile dysfunction). It is supposed to be used for other purposes.

Cialis' Benefits:

comparing to Viagra and Levitra, Cialis' effect lasts much longer - up to 48 hours. Besides, Cialis has fewer side effects;
Cialis is to be taken from 30 minutes to 12 hours before sex;
66% clients prefer Cialis to Viagra.

Cialis is to be used for daily use, so you can be ready anytime.

How to use

Viagra is to be taken 30 minutes to 1 hour before sexual activity. You may take it up to 4 hours before sexual activity. Viagra is not supposed to be taken more often than once per day.

Cialis should be taken as directed by your doctor. Please check the label to detemine an exact dosing instructions.
Cialis is to be taken oral, with or without food.

For using as needed: Cialis is to be taken at least 30 minutes before sexual activity, as directed by your doctor. Cialis' effects can last for up to 48 hours after taking.

For daily use: Take Cialis regularly at about the same time each day.

Talk to your doctor, if you have questions about the way of taking Cialis. Consult your physician before eating grapefruit or drinking grapefruit juice while using Cialis.

Drug Class and Mechanism

Viagra is a phosphodiesterase type 5 inhibitor and it works by helping the blood flow into the penis to achieve and maintain an erection during sexual stimulation.

Cialis is a phosphodiesterase inhibitor type 5. It works by helping the blood flow into a penis to achieve and maintain an erection.

Missed Dose

Viagra is to be used as necessary, so you are not supposed to take it according to a schedule.

If you miss a dose of Cialis and you still intend to engage in sexual activity, take it as soon as you remember. Continue to take it as directed by your doctor.

Storage

Viagra is to be kept in its original container. It is to be stored at room temperature between 59 and 86 degrees F (15-30 degrees C) away from moisture, heat and light and out of the reach of children.

Keep Cialis at room temperature away from moisture, heat and light (between 59 and 86 degrees F (15-30 degrees C)). Store this medication out of the reach of children.

Warnings/Precautions

Do not take Viagra, if you are also using a nitrate drug for chest pain or heart problems, including nitroglycerin (Nitrostat, Nitrolingual, Nitro-Dur, Nitro-Bid, Minitran, Deponit, Transderm-Nitro), isosorbide dinitrate (Dilatrate-SR, Isordil, Sorbitrate), and isosorbide mononitrate (Imdur, ISMO, Monoket), or recreational drugs such as amyl nitrate or nitrite ("poppers").

Before taking Viagra, tell your doctor about all other medications you use for erectile dysfunction, or if you are using any of the following medications:

bosentan (Tracleer);
a blood thinner such as warfarin (Coumadin);
cimetidine (Tagamet, Tagamet HB);
an antibiotic such as erythromycin (E-Mycin, Eryc, Ery-Tab) or clarithromycin (Biaxin);
doxazosin (Cardura), prazosin (Minipress), Terazosin (Hytrin);
HIV medicines such as amprenavir (Agenerase), tipranavir (Aptivus), darunavir (Prezista), efavirenz (Sustiva), nevirapine (Viramune), indinavir (Crixivan), saquinavir (Invirase, Fortovase), lopinavir/ritonavir (Kaletra), fosamprenavir (Lexiva), ritonavir (Norvir), atazanavir (Reyataz), or nelfinavir (Viracept);
an antifungal medication such as itraconazole (Sporanox) or ketoconazole (Nizoral);
carbamazepine (Tegretol), phenobarbital (Luminal), or phenytoin (Dilantin); or
rifampin (Rifadin, Rimactane) or rifabutin (Mycobutin).
Tell your doctor about all the prescriptions and over-the-counter medications you use. This includes vitamins, minerals, herbal products, and drugs prescribed by other doctors. Do not start using a new medication without telling your doctor.

If you have heart problems severe enough to make sexual activity a dangerous, you should avoid using Viagra. Use it cautiously, if you've had a heart attack, stroke, or life-threatening heart irregularities within the past 6 months. Be equally cautious, if you have severe high or low blood pressure, heart failure or unstable angina.

In case of cardiac symptoms developing (for example, dizziness, nausea, and chest pain) during sexual activity, do not continue. Tell your doctor about the problem as soon as possible.

If you have a condition that might result in long-lasting erections, such as sickle cell anemia, multiple myeloma (a disease of the bone marrow), or leukemia, use Viagra with caution. Also use cautiously if you have a genital problem or deformity such as Peyronie's disease. If an erection lasts more than 4 hours, seek treatment immediately. Permanent damage and impotence could result.

If you have a bleeding disorder, a stomach ulcer, or the inherited eye condition known as retinitis pigmentosa, use Viagra with caution. Its safety under these circumstances has not been studied yet.

Do not take Cialis, if you are also using a nitrate drug for chest pain or heart problems, including

nitroglycerin (Nitrostat, Nitrolingual, Nitro-Dur, Nitro-Bid, Minitran, Deponit, Transderm-Nitro),
isosorbide dinitrate (Dilatrate-SR, Isordil, Sorbitrate),
isosorbide mononitrate (Imdur, ISMO, Monoket), or recreational drugs such as amyl nitrate or nitrite ("poppers").
Taking Cialis with a nitrate medicine can cause a serious decrease in blood pressure, leading to fainting, stroke or heart attack. Before taking tadalafil, tell your doctor, if you have:
heart disease or heart rhythm problems;
a recent history a heart attack (within the past 90 days);
a recent history of stroke or congestive heart failure (within the past 6 months);
angina (chest pain);
high or low blood pressure;
liver disease;
kidney disease (or if you are on dialysis);
a blood cell disorder such as sickle cell anemia, multiple myeloma, or leukemia;
a bleeding disorder such as hemophilia;
a stomach ulcer;
retinitis pigmentosa (an inherited condition of the eye);
a physical deformity of the penis (such as Peyronie's disease); or
if you have been told you should not have sexual intercourse for health reasons.

Possible Side Effects

If you experience any of the following serious side effects, stop taking Viagra and seek emergency medical attention or notify your doctor immediately:

sudden vision loss;
ringing in your ears, or sudden hearing loss;
chest pain or heavy feeling, pain spreading to the arm or shoulder, nausea, sweating, general ill feeling;
irregular heartbeat;
swelling in your hands, ankles, or feet;
shortness of breath;
vision changes;
feeling light-headed, fainting; or
penis erection that is painful or lasts 4 hours or longer.
Less serious side effects may include:
warmth or redness in your face, neck, or chest;
stuffy nose;
headache;
upset stomach; or
back pain.
This is not a complete list of side effects and others may occur. Tell your doctor about any unusual or bothersome side effect.

The most common side effects with Cialis are headache, indigestion, back pain, muscle aches, flushing, and stuffy or runny nose. These side effects usually go away after a few hours.

Patients who get back pain and muscle aches usually get it 12 to 24 hours after taking Cialis. Back pain and muscle aches usually go away by themselves within 48 hours. Call your doctor, if you get a side effect that bothers you or one that will not go away.

More Information

If you are older than 65 years, you can suffer Viagra side effects. However, your physician may prescribe you a lower dose of this medication.

Sexual stimulation is required for Cialis effect. Without sexual stimulation you can't get erection just by taking Cialis.