Tadalafil

Tadalafil skeletal.svg
Tadalafil 3D 1XOZ.png
Systematic (IUPAC) name
(6R-trans)-6-(1,3-benzodioxol-5-yl)- 2,3,6,7,12,12a-hexahydro-2-methyl-pyrazino [1', 2':1,6] pyrido[3,4-b]indole-1,4-dione
Clinical data
Trade names Cialis
AHFS/Drugs.com monograph
MedlinePlus a604008
Pregnancy cat.
  • B
Legal status
  • Prescription only
Routes Oral
Pharmacokinetic data
Bioavailability varies
Protein binding 94%
Metabolism CYP3A4 (liver)
Half-life 17.5 hours
Excretion feces (> 60%), urine (> 30%)
Identifiers
CAS number 171596-29-5 Yes
ATC code G04BE08
PubChem CID 110635
DrugBank DB00820
ChemSpider 99301 Yes
UNII 742SXX0ICT Yes
KEGG D02008 Yes
ChEBI CHEBI:71940 
ChEMBL CHEMBL779 Yes
PDB ligand ID CIA (PDBe, RCSB PDB)
Chemical data
Formula C22H19N3O4 
Mol. mass 389.404 g/mol
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Tadalafil is PDE5 inhibitor marketed in pill form for treating erectile dysfunction (ED) under the name Cialis, and under the name Adcirca for the treatment of pulmonary arterial hypertension. In October 2011 the U.S. Food and Drug Administration (FDA) approved Cialis for treating the signs and symptoms of benign prostatic hyperplasia (BPH) as well as a combination of BPH and erectile dysfunction (ED) when the conditions coincide. It initially was developed by the biotechnology company ICOS, and then again developed and marketed world-wide by Lilly ICOS, LLC, the joint venture of ICOS Corporation and Eli Lilly and Company. Cialis tablets, in 2.5 mg, 5 mg, 10 mg, and 20 mg doses, are yellow, film-coated, and almond-shaped. The approved dose for pulmonary arterial hypertension is 40 mg (two 20-mg tablets) once daily.

Tadalafil is also manufactured and sold under the name of Tadacip by the Indian pharmaceutical company Cipla in doses of 10 mg and 20 mg.

On November 21, 2003 the FDA approved tadalafil (as Cialis) for sale in the United States as the third ED prescription drug pill (after sildenafil citrate (Viagra) and vardenafil (Levitra)). Like sildenafil and vardenafil, tadalafil is recommended as an 'as needed' medication. Cialis is the only one of the three that is also offered as a once-daily medication.

Moreover, tadalafil was approved in May 2009 in the United States for the treatment of pulmonary arterial hypertension and is under regulatory review in other regions for this condition. In late November 2008, Eli Lilly sold the exclusive rights to commercialize tadalafil for pulmonary arterial hypertension in the United States to United Therapeutics for an upfront payment of $150 million.