Alfuzosin
Alfuzosin, sold under the brand name Uroxatral among others, is a medication of the α1 blocker class. It is used to treat benign prostatic hyperplasia.
As an antagonist of the α1-adrenergic receptor, it works by relaxing the muscles in the prostate and bladder neck, making urination easier.
Clinical information
Side effects
The most common side effects are dizziness, upper [respiratory tract infection], headache, fatigue, and abdominal disturbances. Side effects include stomach pain, heartburn, and congested nose. Adverse effects of alfuzosin are similar to that of tamsulosin, but with 70% lower rate of retrograde ejaculation.Indications for use
The drug is indicated for the treatment of symptoms associated with benign prostatic hyperplasia. It has no effect on prostate size.Contraindications
Administration is contraindicated in patients with severe hepatic impairment or arterial hypotension, as well as in those undergoing treatment with other alpha blockers.Pharmacological properties
As an antagonist, alfuzosin selectively binds to postsynaptic Α1-adrenoceptors, leading to relaxation of the smooth muscle in the prostate and urethra. This increases uroflowmetry and facilitates micturition. The bioavailability is 64%, and the plasma half-life is 4 to 6 hours. The maximum plasma concentration is reached after approximately 90 minutes.Chemistry
Alfuzosin contains a stereocenter, so is chiral, with two enantiomeric forms, - and -alfuzosin. The drug is used as a racemate, -alfuzosin, a 1:1 mixture of the - and - forms.It is provided as the hydrochloride salt.
Society and culture
History
Alfuzosin was patented in 1979 and first developed as an antihypertensive agent in 1982 by Sanofi-Synthélabo. It was approved for medical use in 1988. It was approved in the US for benign prostatic hyperplasia in 2003. In 2020, it was the 336th-most commonly prescribed medication in the United States, with more than 700,000 prescriptions.Brand names
It is sold under the brand names Alfosoft, Uroxatral, Xatral, Prostetrol, and Alfural.Synthesis
The nitration of veratraldehyde gives 6-Nitroveratraldehyde . Oxidation of the aldehyde to the acid, halogenation with thionyl chloride and amide formation with ammonia gives 4,5-dimethoxy-2-nitrobenzamide . Béchamp reduction of the nitro group gives 2-amino-4,5-dimethoxybenzamide . Reaction with urea leads to 6,7-Dimethoxyquinazoline-2,4-dione . Halogenation with phosphoryl chloride gives 2,4-Dichloro-6,7-dimethoxyquinazoline . Treatment with one equivalent of ammonia yields 4-Amino-2-chloro-6,7-dimethoxyquinazoline .File:Alfuzosin synthesis.svg|thumb|center|500px| Synthesis: Patent: New patent: Radiolabelled:
The reaction of 2-tetrahydrofuroic acid with ethyl chloroformate gives ethoxycarbonyl oxolane-2-carboxylate, PC10997775. Treatment of the mixed anhydride with 3-Methylaminopropionitrile gives N-tetrahydro-N-methyl-2-furancarboxamide . Catalytic hydrogenation gives N-tetrahydro-N-methyl-2-furancarboxamide . Migration of the amide methyl group to the terminal position gives N-oxolane-2-carboxamide . Convergent synthesis between the two counterparts completed the synthesis of Alfuzosin.