Buy Generic Viagra

Just like Viagra, Sildenafil (generic Viagra) used for treatment for erectile dysfunction, when a man is unable to get or maintain an erection, and is a very common condition which will affect most men at some point in their lives. Sildenafil relaxes muscles and increases blood flow to particular areas of the body. Sildenafil under the name Viagra is used to treat erectile dysfunction (impotence) in men. There are other brands of sildenafil, which is used to treat pulmonary arterial hypertension and improve exercise capacity in men and women.

Description

Sildenafil Pharmacokinetics

Sildenafil inhibits phosphodiesterase type-5 (PDE5) which is responsible for cGMP degradation in the corpus cavernosum. Inhibition of PDE5 increases cGMP levels in the corpus cavernosum which results in smooth muscle relaxation and inflow of blood to the corpus cavernosum.

Absorption

Rapidly absorbed after oral admin. Bioavailability: about 40%.

Distribution

Widely distributed. Plasma protein binding: 96%.

Metabolism

Metabolised in the liver mainly by CYP3A4 and CYP2C9.

Excretion

Excreted as metabolites mainly in the faeces.

Side Effects

Headache, flushing, respiratory tract infection, angina pectoris, AV block, migraine, syncope, tachycardia, postural hypotension, MI, cerebral thrombosis, cardiac arrest, paraesthesia, tremor, depression, herpes simplex, skin ulcer, oesophagitis, abnormal LFT, rectal haemorrhage, hypoglycaemic reaction, arthritis, deafness, retinal vascular disease, photosensitivity, accidental fall.

Special Precautions

Caution when used in patients with anatomical deformation of penis or conditions that may predispose them to priapism (e.g. sickle cell anaemia, myeloma, or leukaemia). Mild, transient, dose-related impairment of colour discrimination (blue/green) may occur. Hepatic or severe renal impairment, bleeding disorders, active peptic ulceration, hypotension, recent history of stroke, MI, arrhythmias, unstable angina, heart failure or retinal disorders. May cause sudden loss or decrease in hearing. Overdosage: Should be managed by standard supportive care.

Interactions

Inhibitors of CYP3A4 such as cimetidine and erythromycin are likely to reduce sildenafil clearance. CYP3A4 inducers such as rifampicin may decrease the plasma concentrations of sildenafil. Plasma concentrations are increased by ritonavir. Concurrent admin with grapefruit juice may lead to increased plasma levels of sildenafil. Potentially Fatal: May potentiate hypotensive effects of of organic nitrates and nicorandil.

Pregnancy

Either animal-reproduction studies have not demonstrated a foetal risk but there are no controlled studies in pregnant women or animal-reproduction studies have shown an adverse effect (other than a decrease in fertility) that was not confirmed in controlled studies in women in the 1st trimester (and there is no evidence of a risk in later trimesters).

Dose selection

Viagra
Dose selection should be cautious, usually starting at the lower end of the dosing range, reflecting the greater frequency of decreased hepatic and renal function and comorbidity. Consider initial dose of 25 mg in patients older than 65 years of age.

Dosage

Oral
Erectile dysfunction
Adult: 50 mg about 1 hour before sexual intercourse.
May adjust dose depending on penile response. Max: 100 mg/dose and not to be taken once in 24 hours.
Elderly: 65 years: Lower initial dose at 25 mg.
30 Initially, 25 mg.
Hepatic impairment: Initially, 25 mg

Sildenafil with Food

May be taken with or without food

Tags:
  • Buy discount sildenafil online
  • Sildenafil online pharmacy
  • Purchase Generic Sildenafil USA