Sildenafil is a phosphodiesterase-5 (PDE5) inhibitor that is predominantly employed in the treatment of erectile dysfunction and pulmonary hypertension.
Sildenafil is a specific and effective cyclic guanosine monophosphate inhibitor (cGMP)-specific phosphodiesterase type 5 (PDE5) enzyme in the corpus cavernosum that leads to pulmonary vascular smooth muscle cell relaxation. It replenishes impaired erectile function by increasing the blood flow to the penis; hence, Sildenafil needs sexual stimulation to produce its pharmacological effects.
Drug = Sildenafil
Strength = 100 mg
Manufacturer = Pfizer
Quantity per sleeve = 2 Tablet (for the price quoted)
How To Take Sildenafil (Viagra) 100 mg Tablet
This medicine may be taken with or without food. The tablet must be swallowed whole with a glassful of water.
Try to take it at the same time each day. It must be taken regularly for it to be effective.
Take exactly as directed by your doctor or according to the instructions on the label. Do not take more or less than instructed by your doctor. Do not stop taking it unless instructed by the doctor.
Dosage of Sildenafil (Viagra) 100 mg Tablet
Adult: Erectile dysfunction: 50 mg approximately 1 hour before sexual intercourse. Maximum dose of 100 mg/day.
Pulmonary arterial hypertension: 5 mg or 20 mg three times a day.
Missed Dose of Sildenafil (Viagra) 100 mg Tablet
If you often forget to take your medicine, let your doctor and pharmacist know.
Take the missed dose as soon as you remember. If it is almost time for your next dose, skip the missed dose and return to your usual dosing schedule.
Do not double a dose under any circumstances.
Overdose
If you think you may have used Sildenafil more than the usual dose, please seek medical help immediately.
Symptoms of overdose may include the following:
- Hypotension
- Syncope
- Prolonged erection
Contraindications
People with the following medical conditions should not take Sildenafil:
- Unstable angina
- Cardiac failure
- Loss of vision in 1 eye because of non-arteritic anterior ischemic optic neuropathy (NAION)
- Hypotension (BP <90/50 mmHg)
- Recent history of stroke or myocardial infarction
- Known hereditary degenerative retinal disorders
- Severe hepatic impairment
Side Effects
Sildenafil may have the following side effects:
- Headache
- Flushing
- Dyspepsia
- Blurred vision
- Photophobia
- Chromatopsia
- Cyanopsia
- Eye irritation, pain and redness
- Dizziness
- Insomnia
- Anxiety
- Vertigo
- Epistaxis
- Nasal congestion
- Pyrexia
- Diarrhea
- Vomiting
- Priapism
- Skin rashes
- Erythema
- Alopecia
- Limb/back pain
- Myalgia
- Facial edema
- Fluid retention
- Paresthesia
- Urinary tract infection
- Dyspnea
- Cough
- Rhinitis
- Sinusitis
- Bronchitis
- Cellulitis
- Sudden decrease or loss of hearing
- Anemia
- Leucopenia
- Gynecomastia
- Urinary frequency or incontinence
- Hematuria
- Seizures
- Cerebrovascular hemorrhage
- Transient ischemic attack
- Palpitations
- Syncope
- Hypertension
- Hypotension
- Hypersensitivity reactions
- NAION causing permanent loss of vision
- Retinal hemorrhage
Potentially Fatal:
- Myocardial infarction
- Arrhythmias
- Tachycardia
- Unstable angina
Warnings
Do not take Sildenafil with the following medicines:
- Alpha-blockers
- Cimetidine
- Delavirdine
- Erythromycin
- Itraconazole
- Ketoconazole
- HIV-protease inhibitors
- Rifampicin
- Bosentan
Potentially Fatal:
- Nitrates
- Nicorandil
Always notify your doctor and pharmacist if you are taking any other medicines, including herbal tonics such as traditional Chinese medicine, supplements and medicines that you buy without a prescription.
This list does not include all medicines that may interact with Sildenafil.
How Does It Work?
Sildenafil is a potent and selective inhibitor of cyclic guanosine monophosphate (cGMP) specific phosphodiesterase type 5 (PDE5) enzyme in the corpus cavernosum, which results in the relaxation of pulmonary vascular smooth muscle cells. It restores impaired erectile function by increasing the blood flow to the penis; therefore, sexual stimulation is required for Sildenafil to produce its pharmacological effects.
Uses
Sildenafil is used to treat the following conditions:
- Erectile dysfunction
- Pulmonary arterial hypertension
Special Precautions and Connected Warnings
Take special precautions if you have the following conditions:
- Patient with anatomical deformation of the penis
- Hematological disorders that may predispose to priapism
- Not indicated for pulmonary hypertension secondary to sickle-cell disease
- Mild to moderate hepatic and severe renal impairment
- Children (chronic use)
- Pregnancy
- Lactation
Storage Conditions
- Store between 15-30°C.
- Store in a cool, dry place away from the reach of children.
- Do not use Sildenafil that is expired or out of date.
