Pharmacokinetic analysis of a phenobarbital overdose treated with urinary alkalinization alone.
Toxicol Rep
; 12: 574-577, 2024 Jun.
Article
em En
| MEDLINE
| ID: mdl-38798988
ABSTRACT
Phenobarbital is a long-acting barbiturate used to treat alcohol withdrawal and epilepsy. Acute overdoses present with varying levels of central nervous system depression and large overdoses can be life threatening. Phenobarbital is an attractive candidate for enhanced elimination using urinary alkalinization given it is a weak acid with a long half-life and extensive urinary elimination. Limited human data exist regarding use of urine alkalinization for the treatment of phenobarbital overdose. We present a fourteen-year-old female who was treated with urinary alkalinization alone following an intentional ingestion of 3800â¯mg (84.4â¯mg/kg) of phenobarbital tablets. Urine drugs of abuse screening was preliminary positive for barbiturates and confirmed to be phenobarbital only. The initial serum phenobarbital concentration, drawn nine hours post-ingestion, was 97.4â¯mcg/ml (normal range 15-40â¯mcg/ml). Urinary alkalinization with sodium bicarbonate was started approximately 12â¯h post-ingestion and stopped at 72â¯h post-ingestion; clinical toxicity resolved by hospital day 5. The infusion was titrated to a urinary pH of greater than 7.5. Serial serum and urine phenobarbital measurements were obtained to determine elimination half-life and urinary excretion. The elimination half-life while undergoing urinary alkalinization was 81.3â¯h. Prior to initiation of urinary alkalinization, the urine phenobarbital concentration was 37â¯mcg/ml. Approximately 8.75â¯h after initiation, it was greater than 200â¯mcg/ml at a urine pH of 8.5. Urinary alkalinization appeared to augment urinary phenobarbital excretion, though with no discernible effect on elimination half-life and unclear clinical benefit. Further research is needed to better characterize the clinical effects of urinary alkalinization for phenobarbital overdose.
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Bases de dados:
MEDLINE
Idioma:
En
Revista:
Toxicol Rep
Ano de publicação:
2024
Tipo de documento:
Article
País de afiliação:
Estados Unidos