Viagra

Definition: Viagra

Viagra

Noun

1. Virility drug (trade name Viagra) used to treat erectile dysfunction in men.

Synonym: Viagra

Synonym: sildenafil (n). (additional references)

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Specialty Definition: Viagra

(From Wikipedia, the free Encyclopedia)

Viagra is a drug used to treat male erectile dysfunction (impotence), developed by the pharmaceutical company Pfizer. The generic name for this compound is sildenafil citrate. The pills are blue with the words "Pfizer" on one side and "VGR xx" (with xx being either 25, 50 or 100 as the miligram dose of that pill) on the other.

History

Viagra was initially developed to treat heart disease (angina). In trial studies, the erection enhancing effects were noticed. The drug was patented in 1996, approved by the FDA on March 27, 1998 (becoming the first pill approved to treat erectile disfunction in the United States) and offered for sale in the United States later that year. It soon became a smashing success. Even though Viagra is only available by prescription from a doctor, it was advertised directly to consumers on TV (famously being endorsed by Bob Dole). Numerous sites on the Internet offer Viagra for sale after an "online consultation", a mere web questionnaire. It is likely that many men (and some women) experiment with the drug to increase sexual prowess or pleasure. Annual sales of Viagra in the period 1999 - 2001 exceeded $1 billion (=1000 million).

It has been suggested that Viagra would lead to a marked drop in the demand for certain traditional remedies, such as tiger penises and rhinoceros horns and that the drug may therefore help to preserve these endangered species. However, this is unlikely in that these parts of endangered species are not only used to treat impotence. Rhinoceros horns, for example, are used as a treatment for high fever.

The "Viagra" name has become so well known that many fake aphrodisiacs now call themselves "herbal Viagra" or are presented as blue tablets imitating the shape and colour of Pfizer's product.

Pfizer's worldwide patents on sildenafil citrate will expire in 2011 - 2013. The UK patent held by Pfizer on the use of PDE5 inhibitors (see below) as treatment of impotence has been invalidated in 2000 because of obviousness; this decision was upheld on appeal in 2002.

Chemistry

Chemical name: 1-[4-ethoxy- 3-(6,7-dihydro- 1-methyl- 7-oxo- 3-propyl- 1H-pyrazolo [4,3-d]pyrimidin-5-yl) phenylsulfonyl]- 4-methylpiperazine citrate. Chemical formula: C₂₂H₃₀N₆O₄S.C₆H₈O₇. Molecular weight: 666.7

Molecular structure (citrate group not shown):

Mechanism of action

Part of the physiological process of erection involves the release of nitric oxide(NO) in the corpus cavernosum. This then activates the enzyme guanylate cyclase which results in increased levels of cyclic guanosine monophosphate (cGMP), leading to smooth muscle relaxation in the corpus cavernosum, resulting in increased inflow of blood and an erection.

Sildenafil is a potent and selective inhibitor of cGMP specific phosphodiesterase type 5 (PDE5) which is responsible for degradation of cGMP in the corpus cavernosum. This means that, with Viagra on board, normal sexual stimulation leads to increased levels of cGMP in the corpus cavernosum which leads to better erections. Without sexual stimulation and no activation of the NO/cGMP system, Viagra should not cause an erection.

Other drugs that operate by the same mechanism include Cialis and Levitra.

Viagra is metabolised by hepatic enzymes and excreted by both the liver and kidneys. If taken with a high fat meal, there may be a delay in absorption of Viagra and the net effect might be muted slightly as the plasma concentration will be lowered.

Some reports have claimed that Viagra also causes enhanced sexual pleasure for women by increasing blood flow to the sexual organs.

Contraindications and side effects

Contraindications include:

When taking other nitric oxide donors, organic nitrites and nitrates (which includes glyceryl trinitrate, sodium nitroprusside, amyl nitrite)
In men for whom sexual intercourse is inadvisable due to cardiovascular risk factors
Severe hepatic impairment
Severe impairment in renal function
Hypotension
Recent [stroke] or heart attack (myocardial infarct)
Hereditary degenerative retinal disorders (including genetic disorders of retinal phosphodiesterases)

Amongst Viagra's serious adverse effects are: priapism, severe hypotension, myocardial infarction, ventricular arrhythmias, sudden death, stroke and increased intraocular pressure.

Common side effects include headache, flushing, dyspepsia, prolonged erections, palpitations and photophobia. Visual changes including blurring of vision and a curious bluish tinge have also been reported.

Dosage and price

The dose of Viagra is 25mg to 100mg taken once per day between 0.5 to 4 hours before sexual intercourse.

It is usually recommended to start with a dosage of 50mg and then lower or raise the dosage as appropriate. The drug is sold in three dosages (25mg, 50mg, and 100mg), all three costing about USD$10 per pill. Investing in a pill cutter can therefore be advisable.

Some patients may find various degrees of discomfort at the 25 or 50mg dosage level, including flushing of the face, head pressure, headache, and tachycardia. For these patients a dosage of 10 mg to 12.5 mg may be more appropriate yet effective.

Source: adapted by the editor from Wikipedia, the free encyclopedia under a copyleft GNU Free Documentation License (GFDL) from the article "Viagra."

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Crosswords: Viagra

English words defined with "Viagra": sildenafil. (references)

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Modern Usage: Viagra

Domain	Usage
Clever	No hand signals� Driver on Viagra (references; author: unknown)
Source: compiled by the editor from various references; see credits.

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Commercial Usage: Viagra

Domain	Title
Books	The Viagra Alternative: The Complete Guide to Overcoming Erectile Dysfunction Naturally (reference) The Virility Solution: Everything You Need to Know About Viagra, the Potency Pill That Can Restore and Enhance Male Sexuality (reference) Viagra And The Quest For Potency (reference) Thanks to Viagra I Don't Roll Out of Bed Anymore (reference) The Psychology of Humor and Wit: From Banana Peels to Viagra Jokes (reference) (more book examples)
Source: compiled by the editor from various references; see credits.

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Non-Fiction Usage: Viagra

Subject	Topic	Quote
Health		In March 1998, the Food and Drug Administration approved sildenafil citrate (marketed as Viagra), the first oral pill to treat impotence. (references)
Business		However, it is illegal to provide Viagra in hospitals as part of a treatment process. (references)
		The MOH has last year allowed pharmacies to sell Viagra upon availability of doctor's prescription. (references)
		Pfizer's Viagra, for example, is very expensive, but sells successfully in Germany, even though not reimbursed. (references)
Source: compiled by the editor from ICON Group International, Inc.; see credits.

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Spoken Usage: Viagra

Speaker	Phrase(s)
Dennis Miller	But this recent intifada has hardened him like a dead guy on Viagra.
Source: compiled by the editor from various references; see credits.

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Frequency of Internet Keywords: Viagra

The following statistics estimate the number of searches per day across the major English-language search engines as identified by various trade publications. Hyperlinks lead to commercial use of the expression at Amazon.com.

Expression	Frequency per Day
viagra	20,371
generic viagra	913
viagra online	879
viagra for woman	863
buy viagra	825
viagra cheap	628
viagra prescription	537
order viagra	517
free viagra	388
viagra alternative	386
female viagra	382
purchase viagra	365
herbal viagra	303
viagra price	271
best price viagra	268
viagra best buy	261
viagra sale	245
viagra uk	242
discount viagra	213
viagra pill	201
Source: compiled by the editor from various references; see credits.

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Modern Translations: Viagra

Language		Translations for "Viagra"; alternative meanings/domain in parentheses.
Japanese Kanji		ハ長調 (bar, bar code, barbarism, barbecue, barbell, barber, barell, bargain, bargain sale, bargaining power, bartender, barter, base, Bayer, BBQ, Berkeley, berkelium, Berkley, Bermuda shorts, Bermuda Triangle, berth, bias, biathlon, bio, bio music, biochip, biocomputer, bioconversion, bioelectronics, bioethics, biofeedback, biogas, biography, biohazard, bioholonics, bioindustry, bioinfomatics, biomass, bionics, biopsy, bioreactor, biorhythm, bioscience, biosensor, biotechnology, biotelemetry, biotron, bird carving, bird sanctuary, bird watching, birdcall, birdie, Birmingham, birth, birth control, birthday, bourbon, Burberry, burger, burlesque, burner, burn-out syndrome, burst, buying power, by, bye, C major, crowbar, Farbenfabriken Bayer Aktiengesellschaft, hair combed in stripes across a bald pate, old man who takes Viagra, scale, updating a software version, Vermont, vernier, verse, version, vertical marketing, violin, violinist, virgin, Virginia, virginity, virtual, virtual circuit, virtual reality). (various references)

Japanese Katakana		バイじい (old man who takes Viagra). (various references)

Pig Latin		iagravay
Source: compiled by the editor from various translation references.

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Anagrams: Viagra

Scrabble® Enable2K-Verified Anagrams
	Words within the letters "a-a-g-i-r-v"
	-1 letter: agria, varia, virga.
	-2 letters: agar, aria, raga, ragi, raia, vagi, vair, vara, viga.
	-3 letters: aga, air, ava, gar, rag, ria, rig, var, via, vig.
	-4 letters: aa, ag, ai, ar.
	Words containing the letters "a-a-g-i-r-v"
	+1 letter: agravic, gravida.
	+2 letters: avigator, gravidae, gravidas, gravitas, ravaging, stravaig, vagaries, vicarage.
	+3 letters: averaging, avigators, gravamina, gravitate, navigator, stravaigs, vagarious, variating, variegate, vicarages, vulgarian.
	+4 letters: caravaning, galvanizer, gravitases, gravitated, gravitates, margravial, margravine, navigators, palavering, reavailing, savageries, stravaging, stravaiged, travailing, vagrancies, variegated, variegates, variegator, vegetarian, vulgarians.
	+5 letters: aggravating, aggravation, aggregative, antigravity, caravanning, cavaliering, degradative, evaporating, galvanizers, gravitating, gravitation, gravitative, laborsaving, margraviate, margravines, propagative, revaluating, stravaiging, vagariously, vanguardism, vanguardist, variegating, variegation, variegators, vegetarians.
Source: compiled by the editor from various references; see credits. SCRABBLE® is a registered trademark. All intellectual property rights in and to the game are owned in the U.S.A and Canada by Hasbro Inc., and throughout the rest of the world by J.W. Spear & Sons Limited of Maidenhead, Berkshire, England, a subsidiary of Mattel Inc. Mattel and Spear are not affiliated with Hasbro.