Sildenafil is a vasoactive medicine that is usually used for treating erectile dysfunction in males and to decrease symptoms in people with Pulmonary Arterial Hypertension. By reducing vascular opposition and reducing muscular tension, the vasoactive agent enhances blood circulation to certain body parts including the male reproductive organ. Sildenafil is normally consumed half an hour to one hour before sexual intercourse, while Sildenafil Troche can be consumed at least ten minutes before sex.
Sildenafil was invented by a group of pharmacists at Pfizer’s facility in England. The drug was originally formulated for the treatment of hypertension and chest aches brought about by insufficient blood flow to the heart. The medicine was tested on males in the Morrison Hospital, Swansea, from 1991 and 1992. The clinical trials were done under the leadership of Ian Osterloh, who insinuated that the medicine had minimal effects on curing angina, but made some very important differences in penile erections. Pfizer made a decision to sell the drug as a medication for erectile dysfunction.
The drug is being tested clinically to analyze its usage in treating sexual dysfunction in females; however, original studies revealed that Sildenafil causes outcomes that are similar to those of placebo in females. Regarding Erectile dysfunction, the drug was tried on atleast 4000 males in 21 drug trials. The average age of the participants was fifty-fiveyears, and they had suffered from the illness for an average of five years prior to being tested.
The medicine showed positive outcomes in about 70 percent of the participants. 90 percent success rates have been accomplished in tests on men suffering from psychogenic erectile dysfunction. The drug might also be successful in patients with erectile dysfunction caused by diabetes mellitus or as a result of a pelvic fracture. Sildenafil has been successful and well synthesized in patients on multiple drug antihypertensive therapies and not linked with extra safety risks.
FDA approved Sildenafil for Erectile Dysfunction treatment in March 1998. Research revealed that the drug was successful in treating pulmonary arterial hypertension sufferers. It enhanced the exercise capability, average pulmonary artery pressure and other factors of cardiovascular function in the PAH sufferers. This drug is the first oral therapy given consent to treat beginning stages of pulmonary arterial hypertension. Though a previous study involving 12 subjects suffering from sickle cell anemia revealed a reduction in PAH.
Also, a bigger trial of 134 patients studying the usage of Sildenafil for PAH in grown-ups with sickle cell anemia was halted early because of an enhanced risk of severe negative effects, particularly sickle cell pain crises, in contrast to placebo which had 38% versus 8% respectively. The cause of the enhanced pain is not known; in the original trial, however, the sufferers were administered transfusions and hydroxyurea to curb the crises. The bigger trial did not offer treatment for crises. The drug has also been successful in treating altitude sickness. The oral form of the drug called Revatio got approval for the treatment of pulmonary arterial hypertension, from the FDA in June 2005. In November 2009, the injectable version was also approved.
How Sildenafil works
Sildenafil selectively inhibits cyclic guanosine monophosphate (cGMP), and it is specific to phosphodiesterase type 5 (PDE5). The physiologic working of penile erection involves the freeing of nitric oxide in the corpus cavernosum during sex. The released chemical activates guanylate cyclase enzyme, which leads to raised amounts of cGMP. CGMP results in a reduction of muscle tension in the corpus cavernosum are therefore allowing blood circulation; the specific mechanism by which the cGMP causes muscle relaxation has not been proved.
PDE5 causes the degradation of cyclic guanosine monophosphate in the corpus cavernosum. Sildenafil improves the effect of nitric Oxide by inhibiting phosphodiesterase type 5, therefore, increasing levels of cyclic guanosine monophosphate in the corpus cavernosum.
Sildenafil is taken sublingually by mouth, or intravenously. The average Vss is 105 liters, showing tissue distribution over a large area. The drug and its main circulating N-desmethyl metabolite are both roughly 96 percent linked to plasma proteins.
The drug is mainly metabolized by the CYP enzymes. The main enzyme used for metabolizing is CYP3A4, and the minor enzyme is CYP2C9.
Sildenafil is got rid of as metabolites mainly in feces (about 80 percent of consumed oral dose) and minimally via urine (about 13 percent of consumed oral dose). Both the medication and its active metabolite are active for 4 hours before they die.
Route specific pharmacology
The drug is quickly absorbed after being administered sublingually. Its pharmacology is dose-proportional in the accepted dose amounts.
Precautions before use
Never take Sildenafil if you are under these medications:
– Methscopolamine nitrate
– Nitrates such as amyl nitrate
– Isosorbide dinitrate
– Isosorbide mononitrate
This includes other medications for Erectile Dysfunction such as tadalafil, vardenafil and other sildenafil products.
Your doctor should be notified if you have any of the following disorders:
– Bleeding disorders
– Vision problems
– Peyronie’s illness
– Heart disease
– Heartbeat problems
– Previous heart attacks
– Blood pressure irregularity
– Kidney or liver disease
– An allergic reaction to sildenafil
You should also notify the medic if you get nausea, dizziness, chest aches or arm pain when you start having sexual intercourse after consuming the drug. At that point, you should cease the activity and call your doctor immediately. Avoid alcohol while undergoing treatment with sildenafil. Using this drug does not guard you or your significant other against HIV/AIDS or STIs.
Interaction with other drugs
Probable interactions are:
– Particular high blood pressure drugs
– Some HIV/AIDS treatment drugs
– Certain fungal and yeast infection medicines (fluconazole, ketoconazole, and voriconazole
These are just a few examples. Tell your doctor about the prescription drugs, herbal medicines, non-prescription drugs, or supplements that you’re currently taking.
Fatalities have been reported in males who used sildenafil while using nitrate/nitrite treatment for angina. Also, one fatality has been witnessed in a person who was administered Sildenafil together with ritonavir and Fortovase.
Side effects of the drug
– Cardiac events (myocardial infarction, angina, hypertension, cardiac arrest, tachycardia, and others)
– Unstable diabetes mellitus
– Abdominal aches
– Accidental tripping and injury
– allergic reaction
– asthenia chills
– abnormal dreams
– increased coughing
Those are some of the side effects shown by some patients when the clinical trials were carried out. For more information on the Sildenafil drug, consult Absolute Pharmacy.