Sodium Valproate induced priapism in an adult with bipolar affective disorder
A 48-year-old married male was brought by his family in the emergency department with an acute onset of elation, grandiosity, distractibility, pressured speech and hallucinatory behavior for the past 2 months. Patient had a history suggestive of two manic episodes of moderate severity, with complete inter-episodic recovery in last 4 years. There was no past history of any depressive episode or medical comorbidity. There was no family history of medical or psychiatric morbidity or substance use. A diagnosis of bipolar affective disorder was made. The current episode was diagnosed as manic with psychotic features.\nA detailed treatment history and perusal of medical records revealed that 3 years ago, he had experienced persistent painful penile erection when he had been on sodium valproate (1500 mg/day) and risperidone (6 mg/day). This was unrelated to sexual arousal or stimulation and lasted for around 20-24 hours. He had five to six such episodes over a span of 7-10 days. Despite significant distress, he did not report the problem to the clinician. This was the only adverse effect experienced by the patient. He discontinued taking the medication and got relief from the priapism after 3-4 days of the last dose, but had another manic episode 2 years ago.\nIn light of existing medical literature, priapism was attributed largely to risperidone in this instance. However, it was difficult to attribute an adverse effect due to drug combination solely to a single agent. In view of history of priapism possibly due to risperidone and valproate, lithium carbonate was started as the mood stabilizer and olanzapine as anti-psychotic during the second episode. Over the next 6 months, olanzapine was gradually tapered-off. Around 8 months ago (nearly 1½ year after initiation) lithium carbonate was stopped after lithium induced hypothyroidism was detected. Thereafter, he was prescribed sodium valproate again; suspecting that earlier episode of priapism was attributable to risperidone, as sodium valproate has not been reported to cause priapism. Sodium valproate was started and doses were increased upto 1500 mg/day, with corresponding serum levels of 100 mg/l. This time patient adhered to treatment with sodium valproate at doses of 1500 mg/day continuously for a period of 5 months, until he developed priapism. This happened around 3 months ago and attributing this condition to medication, patient discontinued treatment and got relieved of this adverse effect.