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| Indications |
Sexual impotence(erectile dysfunction)
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| Pharmacological Class |
Derivative of pyrimidine-methyl piperazine.
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| Pharmacological Properties |
Inhibitor of phosphodiesterase (type V).
Treatment of Erectile dysfunction.
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| Mechanism of Action |
Today, nitric oxide (NO) is considered to be the principal neurotransmitter involved in the bringing about an erection. Sexual stimulation induces its release via the nerve endings and vascular endothelium. Nitric oxide activates a guanyl-cyclase responsible for the production of cyclic GMP, its second intracellular messenger. It is cyclic GMP that induces relaxation of the smooth cavernous muscle responsible for the erection, before being destroyed by type V phosphodiesterase, which thus limits the effect of NO on the erection. Sildenafil specifically inhibits this phosphodiesterase and therefore potentiates the effects of sexual stimulation. It cannot thus induce an erection by itself and only acts provided there is mental and sensory stimulation.
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| Side Effects |
Moderate and transient (headache, skin vasodilation, dyspepsia, nasal congestion, visual disorders)
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| Contradictions |
• Hypersensitivity to one of the components
• Patients receiving nitrates (potentiation of hypotensive effect)
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| Observations |
Sildenafil must be used with caution in patients suffering from cardiac insufficiency, unstable angina, renal and hepatic insufficiency and in patients taking several hypotensive drugs
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