Description
Dapoxetine hydrochloride, belonging to the class of SSRIs, was the first drug originally approved for the on-demand treatment of men with PE by seven European countries in 2008.
Premature ejaculation (PE) is the most common male sexual dysfunction. Dapoxetine is a short-acting SSRI. It is differentiated from the existing SSRI treatments for PE by the fact that it can be administered on an as-needed basis. In healthy subjects, dapoxetine is rapidly absorbed after oral administration with a peak plasma concentration (Tmax) occurring between 1.4 and 2h.
Chemical Properties
Dapoxetine hydrochloride is a white to slightly yellow powder. It is freely soluble in methanol, propylene glycol, some organic solvents (eg. N,N-dimethylformamide) , slightly soluble in ethanol and almost insoluble in water. It is a BCSI class II compound, and poor solubility is a key factor affecting the difference in clinical efficacy. Dapoxetine hydrochloride exists in various crystal forms, the solubility of different crystal forms is quite different, and there is a phenomenon of phase and transformation between crystal forms.
Uses
Dapoxetine hydrochloride is a short-acting novel selective serotonin reuptake inhibitor marketed for the treatment of premature ejaculation in men. Premature ejaculation (PE) is the most common male sexual disorder, estimated to affect up to 30% of men.
General Description
Dapoxetine ((+)-(S)-N,N-dimethyl-(α)-[2(1naphthal enyloxy)ethyl]-benzenemethanamine hydrochloride) possess a similar structure as that of fluoxetine.
Biochem/physiol Actions
Potent Selective serotonin reuptake inhibitor (SSRI); used in treatment of premature ejaculation
Synthesis
Dapoxetine can be synthesized in four chemical steps starting from R-1phenyl-
1,3-propanediol via selective tosylation of the primary hydroxy
group with p-toluenesulfonyl chloride, triethylamine and 4-(dimethylamino)
pyridine (DMAP), and subsequent condensation with 1naphthol
by means of sodium- or lithium hydroxide to yield R-3-(1naphthyloxy)-
1-phenylpropanol as the key intermediate. Conversion of
the alcohol group to the corresponding mesylate with methanesulfonyl
chloride, triethylamine, and DMAP, followed by treatment with
dimethylamine affords dapoxetine, which is then acidified to its hydrochloride
salt.
storage
room temperature (desiccate)
Mode of action
The mechanism of action of dapoxetine in premature ejaculation is presumed to be linked to the inhibition of neuronal reuptake of serotonin and the subsequent potentiation of the neurotransmitter's action at pre- and post-synaptic receptors. Dapoxetine is a centrally-acting SSRI that modulates serotonin levels in relevant areas such as the lateral paragigantocellular nucleus through inhibition of the serotonin transporter (SERT). This compound also decreases peak amplitude and accelerates the decay rate of current inactivation in a variety of voltage-gated K+ channels.
