Silvasta 100mg comes in an interesting packet, which gives the impression of a “Bond 007” movie. Comment aside, the drug is yet one of the budding drugs with Sildenafil, but in this case, instead of the product being Viagra, Silvasta is a generic Viagra product. Silvasta is not a product of Pfizer, but it is a drug from Douglas, a pharmaceutical manufacturer from New Zealand. The pills of Douglas’ Silvasta are also colored in Viagra’s trademark blue color, although the shape of the pills is oval.
Silvasta is included in the generic Viagra drugs category and it is primarily because the drug contains the same active content as Viagra. Silvasta is not unique, however; there are a lot of generic Sildenafil products circulating the market, and we can expect more in the coming years, as the patent of Viagra nears its 2020 expiry. Other products classified under the generic Viagra category are Sildenafil Teva, Silagra, Suhagra, Kamagra, Avigra, Manforce, Caverta, and others. Most of these generic Viagra drugs are from Indian manufacturers, although larger companies such as Teva, and even Pfizer, are already with generic Sildenafil brands for erectile dysfunction.
The active content of the drug Silvasta (Sildenafil) belongs to the same drug family (PDE5 inhibitors) as Tadalafil or what is commonly known as Cialis, and Vardenafil, which is famous as Levitra. These drugs are the primary options for impotence management , due to their ease of administration and efficacy, compared with the archaic methods for impotence treatments, which are in part painful and arduous to comply with . Silvasta and other generic medications for impotence are exceedingly accessible and are also cheaper than the older impotence treatments, and being oral drugs, the treatment regimen for generic PDE5 inhibitors such as Silvasta is easy to follow and comply with.
In 1967, a chemist from West Auckland (New Zealand), started the company which would be known today in the pharmaceutical industry as Douglas Pharmaceuticals . Douglas Pharmaceuticals is a manufacturer of prescription medicines and consumer products , which it distributes to New Zealand and Fiji consumers and clients from various parts of the world such as Singapore and other Asian countries, the United States, and the rest of the world . It is not a large company (it is only comprised of about 450 clients) , but its reach expands to various nations across the globe.
The most significant achievement of Douglas Manufacturing is its US FDA approval and its GMP certification for its manufacturing facilities . Apart from its own manufacturing capabilities, the company is also accepting contract manufacturing orders and analytical services from other pharmaceutical companies in need of those services described .
It is also significant that Douglas Pharmaceuticals is able to manufacture pharmaceutical products even if the products are still under patent, due to the legislations/laws imposed by New Zealand and Fiji .
Scientific Studies on Sildenafil
Phosphodiesterase Type 5 inhibitor drugs are efficacious for treating impotence or erectile dysfunction in patients and the study of Setter et al in 2005 reviewed the data for the drugs’ efficacy for the management of erectile dysfunction from 1990 to 2004 (“Phosphodiesterase 5 inhibitors for erectile dysfunction”) . The data for the search terms related to PDE5 inhibitor therapy were analyzed by the authors . Based on their assessment of the available literature for Sildenafil, Tadalafil, and Vardenafil use, patients who were with erectile dysfunction were also with cardiovascular disease, patients who undergone prostatectomy, and those who were also diagnosed with diabetes . The actions of these medications were all beneficial for the patients suffering from ED and their effects only vary slightly . Apart from the efficacy of these drugs, the side effect profile of these products is also similar . Overall, the authors were able to ascertain that PDE5 inhibitors are all efficacious, well-tolerated, and innocuous for patients with erectile dysfunction .
One of the side effects of Sildenafil Citrate in patients is indigestion. To test the reports and the hypothesis of researchers regarding Sildenafil’s effect on gastric emptying, Cho et al in 2006 conducted their study, “Effect of sildenafil on gastric emptying in healthy adults”, which included 9 subjects . The patients were given either placebo or Sildenafil in 50mg and were scanned for gastric emptying in order to determine the time it takes for gastric emptying after the drug administration . It was determined by the authors, based on the results yielded by the study that Sildenafil shortened the proximal gastric emptying time as well as the proximal volume, but increased the distal volume . The authors discovered that Sildenafil does not cause gastric immobility, but rather, it changed the food distribution in the tract .
Although Sildenafil Citrate is deemed efficacious and safe, there are still cases of adverse events due to the use of the drug. Lowe and Costabile in 2012 conducted their study, “10-Year analysis of adverse event reports to the Food and Drug Administration for phosphodiesterase type-5 inhibitors”, with relation to the reports of adverse events in Sildenafil use, sought to assess the cardiovascular and death reports related to the PDE5 inhibitor drug use in 10 years prior to the study’s onset . The authors were able to request the reports for adverse events from the FDA (Center for Drug Evaluation and Research) . Based on the report data, there was a total of 14,818 reported adverse events for Sildenafil alone . For the mortality data, there were 1,824 deaths related to Sildenafil and 2,406 cardiovascular events connected with the drug . Concerning Vardenafil, the total adverse events were 6,085 and the death toll is 121; while for Tadalafil, the drug was associated with 5,548 adverse events and 236 deaths related to its use . When analyzed, the reports for mortality related to the use of the PDE5 inhibitor drugs is about 5% of all the incident reports for the adverse events .
Description and Mechanism of Action of Sildenafil
PDE5 inhibitors, although they have variance in their structures, have similar effects for erectile dysfunction. The mechanism is the same for every PDE5 inhibitor drug—Sildenafil, Tadalafil, and Vardenafil all inhibit the action of the enzyme PDE5 found in the penile tissues. This inhibition of the action of the phosphodiesterase type 5 enzyme is what leads to the accumulation of the proper amounts of the cGMP responsible for the initiation of the erectile response in men.
But, though Sildenafil is known to increase blood flow to the penis (thus mediating the erectile response in patients), the drug will not work without the presence of any form of sexual stimuli. Why? It is the fact that the cGMP is not released without the sexual stimuli. Sexual stimulation only triggers the release of the cGMP, which then leads to the initiation of the erectile response in men. Without the sexual stimulation part, the effect of Sildenafil in inhibiting PDE5 will be rendered useless.
Silvasta Effects for Erectile Dysfunction
The active pharmaceutical ingredient of the product Silvasta is Sildenafil Citrate, which gives us an overview of what the product can do for patients suffering from erectile dysfunction. Patients taking the drug can have a marked improvement in their erectile function and also can expect an ameliorated response to sexual stimuli. If before, patients are unable to have the erections or are able to have erections but have the great difficulty in sustaining them, Silvasta can help the patients to have consistently hard erections satisfactory for initiating the erectile response in patients.
Besides the function of Sildenafil for impotence, though, the drug is also useful for relieving the urinary retention symptoms brought by the enlargement of the prostate, allaying pulmonary arterial hypertension, and other off-label uses such as for fertility treatments, as counter/anti-depressants, for female sexual disorders, miscarriage deterrence, and others.
Recommended Doses and Duration of Therapy
Patients start off with 50 mg of any Sildenafil medication. Silvasta is also prescribed in an initial dose of 50mg, then the drug is increased to 100mg after some time. Usually, the length of treatment for Sildenafil is long-term; as long as the drug is afforded by the patients, they can continue with the drug’s administration. Patients usually discontinue the drug when they believed that their spontaneous erectile function has been restored, if the side effects worsen, or if they think that Sildenafil does not work for them anymore.
So, how long does it last [Sildenafil]? The drug only has a half-life of about 4 hours in the patients’ system, so the effect of the drug only lasts that long. Although this is the case, you can’t take Sildenafil thrice a day to compensate for the drug’s loss in your system; it may increase the side effects. Only a single dose is sufficient for the day, so like they say, use your time wisely when taking the product.
Side Effects and Warnings
The patients are warned about the imminent side effects as an upshot of Sildenafil use. There are side effects which are common to the patients such as heartburn indigestion, the iconic headaches and facial flushing, blurred vision, and blue vision, which are assumed to be some of the side effects of the PDE5 inhibition (or the inhibition of the other PDE enzymes). These, however, are side effects which are nothing to be concerned about if they are merely acute and evanescent. Nonetheless, if these adverse events do not seem to wane or are taking days or weeks more than they should, patients should report them to the physicians.
Patients should generally be cautious when taking PDE5 inhibitor drugs such as Silvasta with Sildenafil Citrate, as though the drug is beneficial, they also have the capacity for harm, especially when taken with wrong and high-risk medications.
Users of Sildenafil products are ill-advised towards the use of several common medications which have the potential for instigating dangerous interactions such as alpha blockers, protease blockers, nitrate-containing drugs, guanylyl cyclase stimulants, and even food supplements such as fish oil, plus herbal drugs. Also, Sildenafil shouldn’t also be taken with other PDE5 drugs, due to the likelihood of increased adverse events.
The internet seems scarce of reviews for Silvasta, but there was an available review for the product on one New Zealand-based online store:
The user did not have much explanation on his first use of Silvasta, but he commented that the product was “great”. Half his feedback, though, was directed to the appreciation of the good service the online store had. Besides this reviewer’s statement, there were no others existing for Silvasta. Nevertheless, since there were no deleterious reports for the drug, we can say that Silvasta is effective and safe for its patients to use, and mostly due to the fact that its manufacturing company is also US FDA-accredited.
Price, Available Forms, and Dosage
Silvasta is available in 100mg and 50mg forms and is also available in several online drugstores. One sample listing for the product is from the store Onlinechemist.co.nz:
The store sells the product, Silvasta, for $15.46 (converted from NZ dollar) for 4 tablets, which is more affordable than the Viagra product. The shipping rate mentioned above ($2.46) is for the intra-national shipping for the product, which patients from within the country can avail of.
Although this product has a price affordable in most buyers’ eyes (and might be tempting), there is no sale of this product outside New Zealand (from this store, anyway). However, since Douglas Pharmaceuticals is known to export to other countries, buyers can anticipate the sale of the products in other parts of the world.
Conclusion and Rating
Silvasta definitely has a cheaper cost than Viagra, although the drug is more expensive than the Indian generic drugs. Due to the affordability and the apparent good quality of Silvasta products, we can give it a rating of 4 out of 5. It is made by a company which is US FDA accredited and is known for its high-quality production, which translates to a good integrity of the product as well. Patients can consider Silvasta tablets whenever they are available in their regions albeit currently, the drug does not sell outside NZ online, so for the meantime, you can search for Silvasta in local pharmacies, or just resort to buying similar alternatives should the drug be unavailable in your area.
- Douglaspharmaceuticals.com: Our Products. Accessed from: http://www.douglaspharmaceuticals.com/en/our-products/
- https://toxnet.nlm.nih.gov/cgi-bin/sis/search2/f?./temp/~tm33VI:20:@[email protected]@/cgi-bin/sis/search2/d?./temp/~cqEiEf:[email protected]
- https://toxnet.nlm.nih.gov/cgi-bin/sis/search2/f?./temp/~tm33VI:10:@[email protected]@/cgi-bin/sis/search2/d?./temp/~cqEiEf:[email protected]
- https://toxnet.nlm.nih.gov/cgi-bin/sis/search2/f?./temp/~tm33VI:17:@[email protected]@/cgi-bin/sis/search2/d?./temp/~cqEiEf:[email protected]