Viagra Side Effects

Generic name: sildenafil

Please note - some side effects for Viagra may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA at http://www.fda.gov/medwatch/ or 1-800-FDA-1088 (1-800-332-1088).

Side Effects of Viagra - for the consumer

Viagra

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Viagra:

Diarrhea; dizziness; flushing; headache; heartburn; mild, temporary vision changes (eg, blue/green color tint to vision, blurred vision, sensitivity to light); stuffy nose; upset stomach.

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue); chest pain; fainting; fast or irregular heartbeat; memory loss; painful or prolonged erection; ringing in the ears; seizure; severe or persistent dizziness; severe or persistent vision changes; sudden decrease or loss of vision in one or both eyes; sudden hearing loss.

For the professional

Viagra

CLINICAL TRIALS

Viagra was administered to over 3700 patients (aged 19–87 years) during pre-marketing clinical trials worldwide. Over 550 patients were treated for longer than one year.

In placebo-controlled clinical studies, the discontinuation rate due to adverse events for Viagra (2.5%) was not significantly different from placebo (2.3%). The adverse events were generally transient and mild to moderate in nature.

In trials of all designs, adverse events reported by patients receiving Viagra were generally similar. In fixed-dose studies, the incidence of some adverse events increased with dose. The nature of the adverse events in flexible-dose studies, which more closely reflect the recommended dosage regimen, was similar to that for fixed-dose studies.

When Viagra was taken as recommended (on an as-needed basis) in flexible-dose, placebo-controlled clinical trials, the following adverse events were reported:

Other adverse reactions occurred at a rate of >2%, but equally common on placebo: respiratory tract infection, back pain, flu syndrome, and arthralgia.

In fixed-dose studies, dyspepsia (17%) and abnormal vision (11%) were more common at 100 mg than at lower doses. At doses above the recommended dose range, adverse events were similar to those detailed above but generally were reported more frequently.

The following events occurred in <2% of patients in controlled clinical trials; a causal relationship to Viagra is uncertain. Reported events include those with a plausible relation to drug use; omitted are minor events and reports too imprecise to be meaningful:

Body as a whole: face edema, photosensitivity reaction, shock, asthenia, pain, chills, accidental fall, abdominal pain, allergic reaction, chest pain, accidental injury.

Cardiovascular: angina pectoris, AV block, migraine, syncope, tachycardia, palpitation, hypotension, postural hypotension, myocardial ischemia, cerebral thrombosis, cardiac arrest, heart failure, abnormal electrocardiogram, cardiomyopathy.

Digestive: vomiting, glossitis, colitis, dysphagia, gastritis, gastroenteritis, esophagitis, stomatitis, dry mouth, liver function tests abnormal, rectal hemorrhage, gingivitis.

Hemic and Lymphatic: anemia and leukopenia.

Metabolic and Nutritional: thirst, edema, gout, unstable diabetes, hyperglycemia, peripheral edema, hyperuricemia, hypoglycemic reaction, hypernatremia.

Musculoskeletal: arthritis, arthrosis, myalgia, tendon rupture, tenosynovitis, bone pain, myasthenia, synovitis.

Nervous: ataxia, hypertonia, neuralgia, neuropathy, paresthesia, tremor, vertigo, depression, insomnia, somnolence, abnormal dreams, reflexes decreased, hypesthesia.

Respiratory: asthma, dyspnea, laryngitis, pharyngitis, sinusitis, bronchitis, sputum increased, cough increased.

Skin and Appendages: urticaria, herpes simplex, pruritus, sweating, skin ulcer, contact dermatitis, exfoliative dermatitis.

Special Senses: sudden decrease or loss of hearing, mydriasis, conjunctivitis, photophobia, tinnitus, eye pain, ear pain, eye hemorrhage, cataract, dry eyes.

Urogenital: cystitis, nocturia, urinary frequency, breast enlargement, urinary incontinence, abnormal ejaculation, genital edema and anorgasmia.

POST-MARKETING EXPERIENCE

Serious cardiovascular, cerebrovascular, and vascular events, including myocardial infarction, sudden cardiac death, ventricular arrhythmia, cerebrovascular hemorrhage, transient ischemic attack, hypertension, subarachnoid and intracerebral hemorrhages, and pulmonary hemorrhage have been reported post-marketing in temporal association with the use of Viagra. Most, but not all, of these patients had preexisting cardiovascular risk factors. Many of these events were reported to occur during or shortly after sexual activity, and a few were reported to occur shortly after the use of Viagra without sexual activity. Others were reported to have occurred hours to days after the use of Viagra and sexual activity. It is not possible to determine whether these events are related directly to Viagra, to sexual activity, to the patient's underlying cardiovascular disease, to a combination of these factors, or to other factors.

Cases of sudden decrease or loss of hearing have been reported postmarketing in temporal association with the use of PDE5 inhibitors, including Viagra. In some of the cases, medical conditions and other factors were reported that may have also played a role in the otologic adverse events. In many cases, medical follow-up information was limited. It is not possible to determine whether these reported events are related directly to the use of Viagra, to the patient’s underlying risk factors for hearing loss, a combination of these factors, or to other factors.

Other events reported post-marketing to have been observed in temporal association with Viagra and not listed in the clinical trial adverse reactions section above include:

Nervous: seizure, seizure recurrence, anxiety, and transient global amnesia.

Urogenital: prolonged erection, priapism, and hematuria.

Special Senses: diplopia, temporary vision loss/decreased vision, ocular redness or bloodshot appearance, ocular burning, ocular swelling/pressure, increased intraocular pressure, retinal vascular disease or bleeding, vitreous detachment/traction, paramacular edema and epistaxis.

Non-arteritic anterior ischemic optic neuropathy (NAION), a cause of decreased vision including permanent loss of vision, has been reported rarely post-marketing in temporal association with the use of phosphodiesterase type 5 (PDE5) inhibitors, including Viagra. Most, but not all, of these patients had underlying anatomic or vascular risk factors for developing NAION, including but not necessarily limited to: low cup to disc ratio ("crowded disc"), age over 50, diabetes, hypertension, coronary artery disease, hyperlipidemia and smoking. It is not possible to determine whether these events are related directly to the use of PDE5 inhibitors, to the patient's underlying vascular risk factors or anatomical defects, to a combination of these factors, or to other factors.

By body system

General side effects

Prior to approval by the FDA, use of sildenafil was evaluated in over 3,700 patients who ranged from 19 to 87 years of age. Over 550 patients were treated for at least 1 year. In placebo-controlled trials, the rate of discontinuation of therapy due to adverse events associated with sildenafil averaged 2.5%, which was not significantly different compared with placebo (2.3%). The incidence of side effects has been dose-dependent.

Nervous system side effects

Nervous system side effects have included headache, observed in up to 16% of patients. Other nervous system side effects have included dizziness in 2%, and, in less than 2%: ataxia, hypertonia, neuralgia, neuropathy, paresthesias, tremor, vertigo, depression, insomnia, somnolence, abnormal dreams, decreased reflexes, and hypesthesia. There have been case reports of transient global amnesia and tonic-clonic seizures. Post marketing experience has included reports of anxiety, seizure and seizure recurrence.

Cardiovascular side effects

Cardiovascular side effects have included flushing (vasodilation) in 10% and dizziness in 2% of patients. Consistent with its known effects on the nitric oxide/cGMP pathway, use of sildenafil has been shown to potentiate the hypotensive effects of nitrates, and its administration to patients who are concurrently taking organic nitrates is considered contraindicated. The following cardiovascular side effects have been associated with the use of sildenafil in less than 2% of patients: angina pectoris, AV block, migraine, syncope, tachycardia, palpitation, hypotension, postural hypotension, myocardial ischemia, cerebral thrombosis, cardiac arrest, heart failure, abnormal electrocardiogram, chest pain, and cardiomyopathy.

Postmarketing studies have reported serious cardiovascular events, including myocardial infarction, sudden cardiac death, ventricular arrhythmia, cerebrovascular hemorrhage, transient ischemic attack, and hypertension in temporal association with the use of sildenafil. Most patients had preexisting cardiovascular risk factors. Many of these events were reported to occur during or shortly after sexual activity, and a few were reported to occur shortly after the use of sildenafil without sexual activity. Others were reported to have occurred hours to days after the use of sildenafil and sexual activity. It has not been determined whether these events are related directly to sildenafil, to sexual activity, to the patient's underlying cardiovascular disease, to a combination of these factors, or to other factors.

Gastrointestinal side effects

Gastrointestinal side effects have included dyspepsia (7%) and diarrhea (3%). Less common gastrointestinal side effects have included abdominal pain, vomiting, glossitis, colitis, dysphagia, gastritis, gastroenteritis, esophagitis, stomatitis, dry mouth, abnormal liver function tests, rectal hemorrhage, and gingivitis. Inhibition of contractile activity of the esophagus has been reported in patients receiving sildenafil who have idiopathic achalasia.

Results from a study of patients with idiopathic achalasia given sildenafil therapy showed inhibition of contractile activity of the esophageal musculature resulting in decreased lower esophageal sphincter tone and residual pressure as well as contraction amplitude.

Respiratory side effects

Respiratory system side effects have included nasal congestion (4%). Other respiratory system side effects have included wheezing, dyspnea, laryngitis, pharyngitis, sinusitis, bronchitis, increased sputum production, and cough.

Genitourinary side effects

Genitourinary side effects have included urinary tract infection in 3% of patients. Less commonly, occurring in less than 2% of patients, cystitis, nocturia, urinary frequency, breast enlargement, urinary incontinence, abnormal ejaculation, genital edema, and anorgasmia have been reported. Prolonged erection greater than 4 hours and priapism (painful erections greater than 6 hours in duration) have been reported infrequently since market approval of sildenafil. In the event of an erection that persists longer than 4 hours, the patient should seek immediate medical assistance. If priapism is not treated immediately, penile tissue damage and permanent loss of potency could result. Acute priapism associated with the use of sildenafil in a patient with sickle cell trait has been reported.

Ocular side effects

Ocular side effects have included mild and transient blue or colored-tinged vision, sometimes associated with photosensitivity or blurred vision. Less common ocular side effects (less than 2% of patients) have included mydriasis, conjunctivitis, photophobia, tinnitus, eye pain, deafness, ear pain, eye hemorrhage, cataract, and dry eyes. Several cases of optic neuropathy have been associated with sildenafil use.

Sildenafil is selective for phosphodiesterase-5 (PDE5). It has lesser affinity for other PDE isoenzymes, one of which is PDE6, an enzyme found in the retina. This lower selectivity is thought to be the basis for abnormalities related to color vision observed with higher doses or plasma levels.

Nonarteritic anterior ischemic optic neuropathy developed in one eye within minutes to hours after ingestion of sildenafil. Four of the five patients had no vascular risk factors for ischemic optic neuropathy.

Dermatologic side effects

Dermatologic side effect have included rash which was reported in at least 2% of patients. Other dermatologic side effects have included urticaria, herpes simplex, pruritus, sweating, skin ulcer, contact dermatitis, and exfoliative dermatitis.

Hematologic side effects

Hematologic side effects have included anemia and leukopenia.

Metabolic side effects

Metabolic side effects have included thirst, peripheral and general edema, gout, hyperglycemia, hypoglycemia (including hypoglycemia reactions), and hypernatremia.

Other side effects

Other side effects have included facial edema, shock, asthenia, pain, chills, and accidental falls and injuries.

Musculoskeletal side effects

Musculoskeletal side effects have included arthritis, arthrosis, myalgia, tendon rupture, tenosynovitis, bone pain, myasthenia, and synovitis.

Psychiatric side effects

Psychiatric side effects have included anecdotal reports and case studies of psychological disturbances and aggressive behavior.

Other side effects

Other side effects have included cases of sudden decrease or loss of hearing reported post-marketing in temporal association with the use of PDE5 inhibitors, including sildenafil. In some cases, medical conditions and other factors were reported that may have also played a role in the otologic adverse events. In many cases, medical follow-up information was limited. It is not possible to determine whether these reported events are related directly to the use of sildenafil, to the patient's underlying risk factors for hearing loss, a combination of these factors, or to other factors.

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