Serum concentrations in three children with unintentional tetrahydrozoline overdose
ABSTRACT Major symptoms can occur from tetrahydrozoline (THZ) overdoses in young children, requiring intensive care management. We report three cases that presented with CNS depression and cardiovascular effects where serum concentrations were performed.
Case 1 ingested an unknown amount of eye drops containing THZ, resulting in altered mental status, bradycardia, hypothermia, and hypotension. Cases 2 and 3 ingested 7.5 mL of eye drops containing THZ. Case 2 presented to the emergency department (ED) without symptoms but became lethargic and bradycardic 90 min after ingestion. By contrast, Case 3 became lethargic 15 min after ingestion and required intubation on arrival to the ED. All children were admitted to ICU for observation and improved within 24 h of ingestion. Urine obtained for drug screening was positive for THZ. Blood was obtained to assess level using gas-chromatography mass-spectrometry (GC-MS). CASE DISCUSSION: Case 1 had plasma levels of 51.4 and 23.6 ng/mL at 7 and 12 h, respectively, after ingestion, revealing a half-life of 4.4 h. Numerous case reports have been published documenting the dangers of ingesting these topical over-the-counter (OTC) products. However, human PK data are not available to help in our understanding of THZ toxicokinetics and disposition in humans after ingestion.
We report three pediatric cases after ingestion of THZ where plasma concentrations were obtained with a calculated half-life of 4.4 h in one case.
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ABSTRACT: No information exists on therapeutic or toxic concentrations of tetrahydrozoline, which has been reported to be used in drug facilitated sexual assaults. The primary aim of this investigation was to establish baseline therapeutic serum and urine concentrations in a sample of healthy volunteers. Ten healthy volunteers consented to have two drops of Original Visine® eye drops (0.05% tetrahydrozoline solution) placed directly into the conjunctival sac of each eye, 30 s apart, at times 0, 4, 8, and 12 h. Blood and urine samples were then collected at 2, 5, 9, 13, and 24 h post-application and analyzed for concentrations. Tetrahydrozoline concentrations are described using measures of central tendency and dispersion at each time point, with predictions of serum and urine concentrations over time calculated using a linear mixed effects regression model. Tetrahydrazoline concentrations were detectable in both serum and urine after therapeutic ocular administration. The mean serum half-life of tetrahydrozoline was approximately 6 h. Systemic absorption varied among subjects, with the maximum serum concentrations ranging from 0.068 to 0.380 ng/ml. At 24 h, all patients had detectable urine concentrations of tetrahydrozoline (range = 13?210 ng/ml). When used as directed by the manufacturer for therapeutic ocular administration, tetrahydrozoline concentrations were detectable in both serum and urine up to 12 h after the last administered dose. A concentration greatly exceeding the 95% confidence interval of drug present during therapeutic ocular use may be suggestive of illegal adulterant use or accidental or suicidal overdose.Clinical Toxicology 11/2011; 49(9):810-4. DOI:10.3109/15563650.2011.615064 · 3.67 Impact Factor
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ABSTRACT: We report two cases of drug-facilitated sexual assault which presented with CNS depression rendering the victims vulnerable to sexual assault and unable to recall the events surrounding the crimes. In each tetrahydrozoline (THZ) was quantified. Case #1 ingested an unknown amount of eye drops containing THZ mixed with alcoholic beverages. Case #1 presented to the emergency department (ED) approximately 7h after reportedly being sexually assaulted and was without symptoms in the ED. Earlier reports from individuals who saw her indicated the victim to be "heavily intoxicated". Case #2 also ingested an unknown amount of eye drops containing THZ mixed with alcoholic beverages. Case #2 presented to an ED without symptoms approximately 23h after reportedly being sexually assaulted. Urine obtained from both cases was assessed for THZ concentrations using gas-chromatography-mass spectrometry. CASE DISCUSSION: Case #1 had a 0.15g% (by weight by volume) urine ethanol concentration and a urinary THZ concentration of 1.481ng/ml, approximately 7h after ingestion. Case #2 was negative for ethanol but had a urine THZ concentration of 108ng/ml at 23h post-ingestion. Few case reports have been published documenting the use of THZ to facilitate sexual assault. We report two cases of drug-facilitated sexual assault involving the use of THZ where alcoholic beverages were concomitantly consumed. This is the first paper to our knowledge which discusses pharmacology of THZ ingestion and the significance of alcohol being present.Forensic science international 05/2012; 221(1-3):e12-6. DOI:10.1016/j.forsciint.2012.04.004 · 2.14 Impact Factor
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ABSTRACT: Oxymetazoline nasal spray is not FDA approved for use in children less than 6 years; however, its safety and efficacy are widely accepted, and it is in widespread use in children prior to procedures that may lead to epistaxis. We report a case of intraoperative oxymetazoline toxicity in a 4-year-old boy that led to a hypertensive crisis. While examining the possible causes for this problem, we became aware that the method of drug delivery led to an unanticipated overdose. The position in which the bottle is held causes pronounced variation in the quantity of oxymetazoline dispensed. To examine the impact that bottle position has on the volume delivered, we measured the volume of oxymetazoline dispensed with the bottle in the upright and inverted position. We also measured the volume of a drop of oxymetazoline dispensed from the bottle. Because an additional source of oxymetazoline exposure is from packing the nares with surgical pledgets, we analyzed the volume of oxymetazoline absorbed by each pledget. Squeezing the bottle in the upright position results in a fine spray of fluid that averaged 28.9 ± 6.8 μl and was largely independent of effort. This volume is nearly identical to the measured volume of a drop of oxymetazoline, which was 30 μl. However, squeezing the bottle in the inverted position resulted in a steady stream of fluid, and the volume administered was completely effort dependent. Multiple tests in the inverted position demonstrated an average volume of 1037 ± 527 μl, with a range of 473–2196 μl. Lastly, the volume of oxymetazoline absorbed by each surgical pledget was 1511 ± 184 μl. Our testing indicates that bottle position during oxymetazoline administration can cause up to a 75-fold increase in intended drug administration.Pediatric Anesthesia 05/2013; 23(10). DOI:10.1111/pan.12192 · 1.85 Impact Factor