Indications and Usage
Kamagra is dispensed as a pill and ingested orally. Within approximately 30-60 minutes the drug is absorbed into the bloodstream. Kamagra then functions as an inhibitor to an enzyme called phosphodiesterase type (PDE5) which is found primarily in the penis. By inhibiting PDE5, smooth muscle in the penis remains relaxed for a longer period. This allows for increased blood flow into the cavernous tissue of the penis thereby generating an erection.

Contraindications
Men who are taking medicines that contain nitrates (Nitroglycerin) of any kind must NEVER use Kamagra. Patients should not take Kamagra even if you only take nitroglycerin medication occasionally.

There is also a potential for cardiac risk during sexual activity in patients with pre-existing cardiovascular disease. Therefore, Kamagra should NOT be used in men where sexual activity is inadvisable because of their underlying cardiovascular status.

Several medications are known to interact with Kamagra. Therefore, you should inform your physician concerning all medications you are taking, including those medications acquired by a prescription as well as over the counter medicines.

The use of Kamagra offers no protection against sexually transmitted diseases, including HIV. Patients should continue to use protective measures necessary to guard against these diseases. In case of an overdose, call your physician immediately.

Dosage and Administration
Take sildenafil exactly as directed by your doctor. If you do not understand these directions, ask your pharmacist, nurse, or doctor to explain them to you. Take each dose with a full glass of water. Sildenafil is usually taken when needed. It can be taken anywhere from 4 hours to one-half hour before sexual activity. Generally, it is taken 1 hour before sexual activity. The medication can help achieve an erection when sexual stimulation occurs. An erection will not occur just by taking a pill. Follow your doctor's instructions. Taking sildenafil after eating a high-fat meal (such as a cheeseburger and french fries) may cause the medication to take a little longer to start working. Do not take sildenafil more than once a day. If you develop dizziness, nausea, or angina (pain, tightness, discomfort, numbness, or tingling in the chest, arms, neck, or jaw) during sexual activity, refrain from further sexual activity and notify your doctor. Contact your doctor or seek emergency medical attention for any erection that lasts longer than 4 hours. A sustained erection can damage the penis. Grapefruit and grapefruit juice may interact with sildenafil. The interaction could lead to potentially adverse effects. You should discuss the use of grapefruit and grapefruit juice with your doctor. Do not increase or decrease the amount of grapefruit products in your diet without first talking to your doctor.

Possible Side Effects
The side effects of Kamagra are relatively few and if they do occur, they are usually short lived. However, some patients have reported the following side effects: congestion, diorrhea, facial flushing, headaches, urinary tract infections, and visual changes (mild and temporary changes in blue/green colours or increased sensitivity to light).

Miss a Dose
Sildenafil is used as needed, so you are not likely to miss a dose.

Overdosage
Seek emergency medical attention. Symptoms of a sildenafil overdose are not known, but are likely to include chest pain, dizziness, an irregular heartbeat, and swelling of the ankles or legs.

Drug Interaction
Do not take sildenafil if you are using a nitrate drug for chest pain or heart problems. Nitrates include nitroglycerin (Nitrostat, Nitrolingual, Nitro-Dur, Nitro-Bid, Minitran, Deponit, Transderm-Nitro, others), isosorbide dinitrate (Dilatrate-SR, Isordil, Sorbitrate), and isosorbide mononitrate (Imdur, ISMO, Monoket). Nitrates are also found in some recreational drugs such as amyl nitrate or nitrite ("poppers"). Before taking sildenafil, tell your doctor if you are taking any of the following medications:
- any other drug used to treat impotence, such as alprostadil (Caverject, Muse, Edex) or yohimbine (Yocon, Yodoxin, others);
- the antibiotic drugs clarithromycin (Biaxin), erythromycin (E-Mycin, Eryc, Ery-Tab, others), or troleandomycin (TAO);
- an antifungal medication such as itraconazole (Sporanox) or ketoconazole (Nizoral);
- the HIV medications amprenavir (Agenerase), delavirdine (Rescriptor), indinavir (Crixivan), nelfinavir (Viracept), ritonavir (Norvir), or saquinavir (Fortovase, Invirase);
- cimetidine (Tagamet, Tagamet HB);
- phenobarbital (Luminal);
- carbamazepine (Tegretol) or phenytoin (Dilantin);
You may not be able to take sildenafil, or you may require a dosage adjustment or special monitoring during treatment if you are taking any of the medicines listed above. Drugs other than those listed here may also interact with sildenafil or affect your condition. Talk to your doctor or pharmacist before taking any prescription or over-the-counter medicines, including herbal products.

Storage
Store this medication at room temperature 15–30°C (59–86°F). Keep away from children and excess heat and moisture (not in the bathroom).