Sildenafil Side Effects
Some side effects of sildenafil may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.
For the Consumer
Applies to sildenafil: oral powder for suspension, oral tablet
Other dosage forms:
Along with its needed effects, sildenafil may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.
Check with your doctor immediately if any of the following side effects occur while taking sildenafil:Less common
- Bladder pain
- burning feeling in the chest or stomach
- burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
- cloudy or bloody urine
- increased frequency of urination
- pain on urination
- stomach upset
- tenderness in the stomach area
- Abnormal vision
- behavior change similar to drunkenness
- bleeding of the eye
- blurred vision
- bone pain
- breast enlargement
- chest pain
- cold sweats
- convulsions (seizures)
- cool and pale skin
- deafness or hearing loss
- decrease in amount of urine or the frequency of urination
- decreased vision
- difficulty in concentrating
- dizziness or lightheadedness, especially when getting up from a lying or sitting position suddenly
- double vision
- dry eyes
- dry mouth
- dryness, redness, scaling, or peeling of the skin
- excessive hunger
- eye pain
- fainting or faintness
- fast, irregular, or pounding heartbeat
- feeling of something in the eye
- fever or chills
- headache (severe or continuing)
- increase in the size of the pupil
- increased sweating
- increased thirst
- lower back or side pain
- migraine headache
- nausea (severe or continuing)
- numbness of the hands
- painful, swollen joints
- prolonged, painful erection of penis
- redness, burning, or swelling of the eyes
- redness, itching, or tearing of the eyes
- restless sleep
- seeing shades of colors differently than before
- sensitivity to light
- skin lesions with swelling
- skin paleness
- skin rash, hives, or itching
- skin ulcers
- slurred speech
- sore throat
- sudden weakness
- swelling of the face, hands, feet, or lower legs
- trouble breathing
- twitching of the muscles
- unusual feeling of burning or stinging of the skin
- unusual tiredness or weakness
- vision changes
- vision loss, temporary
Some side effects of sildenafil may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects. Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:More common
- Aches or pains in the muscles
- bloody nose
- difficult or labored breathing
- pain or tenderness around the eyes and cheekbones
- redness of the skin
- stomach discomfort following meals
- stuffy or runny nose
- trouble sleeping
- unusually warm skin
- Abdominal or stomach pain
- abnormal dreams
- clumsiness or unsteadiness
- diarrhea or stomach cramps (severe or continuing)
- difficulty in swallowing
- ear pain
- increased amount of saliva
- increased skin sensitivity
- lack of coordination
- loss of bladder control
- mental depression
- numbness or tingling of the hands, legs, or feet
- rectal bleeding
- redness or irritation of the tongue
- redness, soreness, swelling, or bleeding of the gums
- ringing or buzzing in the ears
- sensation of motion, usually whirling, either of one's self or of one's surroundings
- sexual problems in men (continuing), including failure to experience a sexual orgasm
- sores in the mouth and on the lips
- tense muscles
- trembling and shaking
- waking to urinate at night
- worsening of asthma
For Healthcare Professionals
Applies to sildenafil: intravenous solution, oral tablet
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 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 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. Veno-occlusive crises have been reported in patients with pulmonary hypertension (PH) secondary to sickle cell disease.
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 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 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 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.
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.
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.
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 have included anemia and leukopenia.
Metabolic side effects have included thirst, peripheral and general edema, gout, hyperglycemia, hypoglycemia (including hypoglycemia reactions), and hypernatremia.
Other side effects have included facial edema, shock, asthenia, pain, chills, and accidental falls and injuries.
Musculoskeletal side effects have included arthritis, arthrosis, myalgia, tendon rupture, tenosynovitis, bone pain, myasthenia, and synovitis.
Psychiatric side effects have included anecdotal reports and case studies of psychological disturbances and aggressive behavior.
Other side effects have included cases of sudden decrease or loss of hearing reported postmarketing 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.
More about sildenafil
- Sildenafil tablets
- Sildenafil injection
- Sildenafil (Advanced Reading)
- Sildenafil Intravenous (Advanced Reading)
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