Buy Viagra Without Prescription, Viagra Prescription Canada, Generic Viagra Availability

VIAGRA (sildenafil citrate – tablet; oral)

  • Manufacturer: PFIZER IRELAND
    Approval date: March 27, 1998
    Strength(s): EQ 100MG BASE [RLD], EQ 25MG BASE, EQ 50MG BASE

Includes a generic version of Viagra been approved?


No. There is currently no therapeutically equivalent version of Viagra available.

Note: Fraudulent online pharmacies may attempt to sell an illegal generic version of Viagra. These medications could possibly be counterfeit and potentially unsafe. If you purchase medications online, be sure you are buying from a reputable and valid online pharmacy. Ask your medical provider for advice if you’re unsure around the online buying any medication.

See also: About generic drugs.

Related Patents

Patents are granted from the U.S. Patent and Trademark Office at any time within a drug’s development and may include a wide range of claims.

  • Pyrazolopyrimidinone antianginal agents
    Patent 5,250,534
    Issued: October 5, 1993
    Inventor(s): Bell; Andrew S. & Brown; David & Terrett; Nicholas K.
    Assignee(s): Pfizer Inc.
    Compounds of the formula: ##STR1## wherein R.sup.1 is H, C.sub.1 -C.sub.3 alkyl, C.sub.3 -C.sub.5 cycloalkyl or C.sub.1 -C.sub.3 perfluoroalkyl; R.sup.2 is H, C.sub.1 -C.sub.6 alkyl optionally substituted by OH, C.sub.1 -C.sub.3 alkoxy or C.sub.3 -C.sub.6 cycloalkyl, or C.sub.1 -C.sub.3 perfluoroalkyl; R.sup.3 is C.sub.1 -C.sub.6 alkyl, C.sub.3 -C.sub.6 alkenyl, C.sub.3 -C.sub.6 alkynyl, C.sub.3 -C.sub.7 cycloalkyl, C.sub.1 -C.sub.6 perfluoroalkyl or (C.sub.3 -C.sub.6 cycloalkyl)C.sub.1 -C.sub.6 alkyl; R.sup.4 taken alongside the nitrogen atom to which it truly is attached completes a pyrrolidinyl, piperidino, morpholino, or 4-N-(R.sup.6)-piperazinyl group; R.sup.5 is H, C.sub.1 -C.sub.4 alkyl, C.sub.1 -C.sub.3 alkoxy, NR.sup.7 R.sup.8, or CONR.sup.7 R.sup.8 ; R.sup.6 is H, C.sub.1 -C.sub.6 alkyl, (C.sub.1 -C.sub.3 alkoxy) C.sub.2 – C.sub.6 alkyl, hydroxy C.sub.2 -C.sub.6 alkyl, (R.sup.7 R.sup.8 N)C.sub.2 -C.sub.6 alkyl, (R.sup.7 R.sup.8 NCO)C.sub.1 -C.sub.6 alkyl, CONR.sup.7 R.sup.8, CSNR.sup.7 R.sup.8 or C(NH)NR.sup.7 R.sup.8 ; R.sup.7 and R.sup.8 are each independently H, C.sub.1 -C.sub.4 alkyl, (C.sub.1 -C.sub.3 alkoxy)C.sub.2 -C.sub.4 alkyl or hydroxy C.sub.2 -C.sub.4 alkyl; and pharmaceutically acceptable salts thereof, are selective cGMP PDE inhibitors valuable in the management of cardiovascular disorders for example angina, hypertension, heart failure and atherosclerosis.

    Patent expiration dates:
    • September 27, 2012
      Pediatric exclusivity
  • Pyrazolopyrimidinones for any treatment of impotence
    Patent 6,469,012
    Issued: October 22, 2002
    Inventor(s): Peter; Ellis & Nicholas Kenneth; Terrett
    Assignee(s): Pfizer Inc
    Using compound of formula (I) wherein R1 is H; C1-C3 alkyl; C1-C3 perfluoroalkyl; or C3-C5 cycloalkyl; R2 is H; optionally substituted C1-C6 alkyl; C1-C3 perfluoroalkyl; or C3-C6 cycloalkyl; R3 is optionally substituted C1-C6 alkyl; C1-C6 perfluoroalkyl; C3-C5 cycloalkyl; C3-C6 alkenyl; or C3-C6 alkynyl; R4 is optionally substituted C1-C4 alkyl, C2-C4 alkenyl, C2-C4 alkanoyl, (hydroxy)C2-C4 alkyl or (C2-C3 alkoxy)C1-C2 alkyl; CONR5R6; CO2R7; halo; NR5R6; NHSO2NR5R6; NHSO2R8; SO2NR9R10; or phenyl, pyridyl, pyrimidinyl, imidazolyl, oxazolyl, thiazolyl, thienyl or triazolyl any kind of which can be optionally substituted with methyl; R5 and R6 are each independently H or C1-C4 alkyl, or alongside the nitrogen atom that there’re attached form an optionally substituted pyrrolidinyl, piperidino, morpholino, 4-N(R11)-piperazinyl or imidazolyl group; R7 is H or C1-C4 alkyl; R8 is optionally substituted C1-C3 alkyl; R9 and R10 together with the nitrogen atom that these are attached form an optionally substituted pyrrolidinyl, piperidino, morpholino or 4-N(R12)-piperazinyl group; R11 is H; optionally substituted C1-C3 alkyl; (hydroxy)C2-C3 alkyl; or C1-C4 alkanoyl; R12 is H; optionally substituted C1-C6 alkyl; CONR13R14; CSNR13R14; or C(NH)NR13R14; and R?13? and R14 are each independently H; C1-C4 alkyl; or substituted C2-C4 alkyl; or perhaps pharmaceutically acceptable salt thereof, or perhaps a pharmaceutical composition containing either entity, for the output of a medicament for any curative or prophylactic treating erection dysfunction inside of a male animal, including man; a pharmaceutical composition for said treatment; plus a way of said treatment of said male animal with said pharmaceutical composition or with said either entity.

    Patent expiration dates:
    • October 22, 2019
    • April 22, 2020
      Pediatric exclusivity