Sildenafil is a widely used agent for management of erectile dysfunction which is one of the most frequently diagnosed sexual disorders in men. It is a selective inhibitor of phosphodiesterase type 5 (PDE5) and enhances vasodilation in penis. Although sildenafil is often used to treat antipsychotic induced erectile dysfunction, it can cause unusual side effects. Here we report a 32-year-old patient with sildenafil induced psychotic symptoms.
A 32-year-old Iranian married male was referred to hospital because of psychotic symptoms such as delusional jealousy, delusion of reference and auditory hallucination. The psychotic symptoms had become apparent about one week before referral. He also suffered from insomnia, irritability and had outbursts of aggressive behavior. He did not have any previous episodes of psychotic or mood symptoms. The patient had been taking sildenafil because of erectile dysfunction over the past two months. His physical examination including a thorough neurological assessment was unremarkable. He smoked tobacco for the past four years and he did not report any other recreational substance use. He didn`t have positive family history for psychiatric disorders. He was admitted to the hospital and oral form of risperidone was initiated. Surprisingly, all of the psychotic symptoms remitted only 2 weeks after the initiation of risperidone and was discharged from hospital. In the first follow-up visit within two weeks of discharge, he complained of akathisia. Propranolol 10 three times a day was started, nevertheless he discontinued medication because of annoying side effects. After 2 months, he came to clinic because of recurrence of similar psychotic symptoms which occurred after taking sildenafil only once. Fortunately, he remitted by prescribing of olanzapine 5mg daily without any problematic side-effects.
To the best of our knowledge this is the first report on sildenafil induced psychotic symptoms. We can conclude that psychotic symptoms of our patient are due to the use of sildenafil because of closed temporal relationship between the use of medication and emergence of symptoms as well as full remission and dramatic response to treatment after discontinuation of suspected agent. This is in contrast to the expected course of primary psychotic disorders such as schizophrenia or delusional disorder.

May psychosis be a rare side-effect of sildenafil? A case-report