Sildenafil citrate ingestion and prolonged priapism and tachycardia in a pediatric patient*

Clinical Toxicology (2007) 45, 798–800
Copyright Informa Healthcare USA, Inc.
ISSN: 1556-3650 print / 1556-9519 online
DOI: 10.1080/15563650701664483
Sildenafil citrate ingestion and prolonged priapism and tachycardia in a pediatric patient Sildenafil Citrate Ingestion and Prolonged Priapism and Tachycardia BRANDON K. WILLS, D.O., M.S.1,2, CHARLOTTE ALBINSON, M.D.3, MICHAEL WAHL, M.D.4,5, and JACK CLIFTON, M.D.1 1Toxikon Consortium, Chicago, Illinois, USA2Department of Emergency Medicine, Madigan Army Medical Center, Tacoma, Washington, USA3Department of Emergency Medicine, University of Illinois, Chicago, Illinois, USA4Illinois Poison Center, Chicago, Illinois, USA5Department of Emergency Medicine, Evanston Northwestern Healthcare, Evanston, Illinois, USA Introduction. Little is known about the toxicity of sildenafil overdose in the pediatric population. We present a case of prolongedpriapism and tachycardia due to unintentional sildenafil overdose in a child.
Case report. A 19-month-old male ingested up to six 50 mg Viagra tablets 45 minutes prior to presentation at the emergency department. Initial vital signs included temperature 98.2oF,blood pressure 90/58 mmHg, heart rate 140, respirations 20, and oxygen saturation of 100% on room air. The child weighed 10.4 kg.
Physical exam revealed a happy, smiling, laughing toddler who was cooperative with all aspects of his exam. He had mild facialflushing and an erect penis which was normal in color and had a capillary refill of two seconds. Precordial palpation did not showevidence of increase dynamic force, his heart sounds were regular, and no ectopy was noted. His peripheral pulses were strong andregular in all four extremities. No gastrointestinal decontamination was performed. The patient was started on maintenance IV fluidsand admitted to the pediatric floor for observation. The patient had a non-painful tumescent penis and mild tachycardia for about24 hours post-ingestion. The child never had pain from the constant erection. Sildenafil concentration drawn approximately sevenhours after ingestion was 3900 ng/ml (reporting limit 24 ng/ml) and N-desmethylsildenafil level was 1700 ng/ml (reporting limit24 ng/ml).
Conclusion. This case of pediatric sildenafil ingestion (up to 30mg/kg) initially resulted in facial flushing and priapism.
The child had asymptomatic tachycardia and prolonged priapism that persisted until hospital discharge approximately 24 hours afteringestion. The erection was non-painful and required no urologic intervention, most likely representing a high flow state. In thisingestion, only supportive care was required.
Keywords
Introduction
Case report
Clinical Toxicology Downloaded from informahealthcare.com by 79.40.187.228 In 1998, sildenafil citrate was approved by the United A 19-month-old male ingested up to six 50 mg sildenafil tab- States Food and Drug Administration as the first oral medi- lets 45 minutes prior to presentation to the emergency depart- cation indicated for the treatment of erectile dysfunction.
ment. He was found by his mother playing with a bottle Little is known about the toxicity of sildenafil in the pediat- which had contained eight tablets. She could only find two ric population. We present a case of prolonged priapism remaining tablets in the bottle. The patient had no past medi- and tachycardia due to unintentional sildenafil overdose in cal or surgical history and no known drug allergies. In the emergency department, initial vital signs were temperature98.2oF, blood pressure 90/58 mmHg, heart rate 140, respira-tions 20, and oxygen saturation of 100% on room air. Thechild weighed 10.4 kg. Physical exam revealed a happy, smil-ing, laughing toddler who was cooperative with all aspects ofhis exam. He had mild facial flushing and an erect penis Received 19 July 2006; accepted 16 November 2006.
which was normal in color and had a capillary refill of two An abstract of this article was presented at the North American seconds. Precordial palpation did not show evidence of Congress of Clinical Toxicology annual meeting, Orlando, Florida, increase dynamic force, his heart sounds were regular, and no ectopy was noted. His peripheral pulses were strong and reg- Address correspondence to Brandon K. Wills, D.O., M.S., Depart- ment of Emergency Medicine, Madigan Army Medical Center, ular in all four extremities. No gastrointestinal decontamina- MCHJ-EM, Tacoma, WA 98431, USA. E-mail: bkwills@ gmail.com tion was performed. The patient was started on maintenance Sildenafil citrate ingestion and prolonged priapism and tachycardia IV fluids and admitted to the pediatric floor for observation.
mented however, there were no effects on heart rate or blood The patient had a non-painful tumescent penis and mild pressure (8). A large overdose of 2000 mg in a 42-year-old tachycardia for approximately 24 hours post-ingestion. The female patient was well tolerated with the only abnormalities child never appeared to have pain from the erection. The being flushing, headache and mild tachycardia (9). One patient was discharged the following afternoon after com- review of national poison center data on sildenafil exposures plete resolution of symptoms. Serum sildenafil concentration recorded 129 sildenafil-only cases. Of these, five resulted in obtained approximately 7 hours after ingestion was 3900 ng/ serious outcomes or death (10). Common adverse effects ml (reporting limit 24 ng/ml) and N-desmethylsildenafil level included flushing (14%), dizziness (8%), headache (8%), was 1700 ng/ml (reporting limit 24 ng/ml).
tachycardia (8%), chest pain (6%), drowsiness (6%),hypotension (4%), nausea (4%), and syncope (4%) (10).
Little is known about the relationship between sildenafil Discussion
concentrations and clinical toxicity. Peak sildenafil concen-trations from oral “therapeutic” doses of 50mg, 100 mg, and Sildenafil citrate was originally investigated as an antihyper- 0.68 mg/kg were 260, 450, and 212 ng/ml, respectively (11).
tensive agent and is currently used for the treatment of erec- Pharmacogenetic differences may exist between ethnic popu- tile dysfunction and pulmonary hypertension. The primary lations. Substantially higher peak sildenafil concentrations of mechanism of action of sildenafil is inhibition of phosphodi- 1044 ng/ml were found after an oral dose of 100mg in Mexi- esterase type 5 (PDE ) which results in increased nitric can volunteers (12). One paper documenting a fatality from oxide-stimulated release of cyclic guanosine monophosphate sildenafil overdose reported a concentration of 6270 ng/ml (cGMP) and subsequent smooth muscle relaxation, vasodila- (13). In our case report, the sildenafil and N-desmethyl- tion, and engorgement of penile tissues (1). Modest decreases sildenafil concentrations were 3900 and 1700 ng/ml, respec- in blood pressure are noted with therapeutic doses (1).
tively, representing the highest non-fatal levels reported in Sildenafil is metabolized by cytochrome 3A4 which could potentially result in multiple drug interactions and could havevarying responses between ethnic groups. A well known druginteraction is with nitrates which can potentiate hypotension Conclusion
Priapism is defined as a prolonged erection, not associated This case of pediatric sildenafil ingestion (up to 30mg/kg) with sexual stimulation. Low-flow priapism is generally a initially resulted in facial flushing and priapism. The child painful erection due to obstruction of venous outflow and had asymptomatic tachycardia and prolonged erection that subsequent ischemia. Corporal damage can begin within 12 persisted for approximately 24 hours. The erection was non- hours of onset resulting in fibrosis and permanent erectile painful and required no urologic intervention, most likely dysfunction (3). High-flow priapism is due to increased arte- representing a high flow priapism. No hypotension was rial inflow with preserved venous outflow (4). High-flow pri- observed and only supportive care was required.
apism is generally not painful and less likely to result inerectile dysfunction. Initially all types of priapism start in ahigh flow state (3). This patient had a prolonged painless Clinical Toxicology Downloaded from informahealthcare.com by 79.40.187.228 erection. Given the lack of symptoms and the pharmaceutical Acknowledgment
effect of the drug, it is postulated that the priapism was ahigh-flow state.
The opinion and assertions contained herein are the views Priapism with therapeutic use of sildenafil has been docu- of the author and are not to be construed as official or as mented (5). In patients with sickle cell disease, sildenafil has reflecting the views of the United States Department of been reported to cause a low-flow priapism yet has also suc- cessfully treated priapism due to vasoocclusive crisis (6,7).
Decreased expression of PDE in sickle cell patients may be a contributor of stuttering priapism (characterized by repeated References
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Post-mortem detection and identification of sildenafil (Viagra) and its 7. Bialecki ES, Bridges KR. Sildenafil relieves priapism in patients with metabolites by LC/MS and LC/MS/MS. Int J Legal Med 2001; sickle cell disease. Am J Med 2002; 113:252.
8. Cantrell FL. Sildenafil citrate ingestion in a pediatric patient. Pediatr 12. Flores-Murrieta FJ, Castaneda-Hernandez G, Granados-Soto V, Herrera JE. Increased bioavailability of sildenafil in Mexican men. Jama 2000; 9. Hung DZ, Yang DY. Sildenafil overdose in a female patient. J Toxicol 13. Tracqui A, Miras A, Tabib A, Raul JS, Ludes B, Malicier D. Fatal over- 10. Krenzelok EP. Sildenafil: clinical toxicology profile. J Toxicol Clin dosage with sildenafil citrate (Viagra): First report and review of the lit- erature. Hum Exp Toxicol 2002; 21:623–629.
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