20 research outputs found
Ventricular Dysrhythmias Associated with Poisoning and Drug Overdose: A 10-Year Review of Statewide Poison Control Center Data from California
Background: Ventricular dysrhythmias are a serious consequence associated with drug overdose and chemical poisoning. The risk factors for the type of ventricular dysrhythmia and the outcomes by drug class are not well documented. Objective: The aim of this study was to determine the most common drugs and chemicals associated with ventricular dysrhythmias and their outcomes. Methods: We reviewed all human exposures reported to a statewide poison control system between 2002 and 2011 that had a documented ventricular dysrhythmia. Cases were differentiated into two groups by type of arrhythmia: (1) ventricular fibrillation and/or tachycardia (VT/VF); and (2) torsade de pointes (TdP). Results: Among the 300 potential cases identified, 148 cases met the inclusion criteria. Of these, 132 cases (89 %) experienced an episode of VT or VF, while the remaining 16 cases (11 %) had an episode of TdP. The most commonly involved therapeutic classes of drugs associated with VT/VF were antidepressants (33/132, 25 %), stimulants (33/132, 25 %), and diphenhydramine (16/132, 12.1 %). Those associated with TdP were antidepressants (4/16, 25 %), methadone (4/16, 25 %), and antiarrhythmics (3/16, 18.75 %). Drug exposures with the greatest risk of death in association with VT/VF were antidepressant exposure [odds ratio (OR) 1.71; 95 % confidence interval (CI) 0.705â4.181] and antiarrhythmic exposure (OR 1.75; 95 % CI 0.304â10.05), but neither association was statistically significant. Drug exposures with a statistically significant risk for TdP included methadone and antiarrhythmic drugs. Conclusions: Antidepressants and stimulants were the most common drugs associated with ventricular dysrhythmias. Patients with suspected poisonings by medications with a high risk of ventricular dysrhythmia warrant prompt ECG monitoring
Bioconcentration and Aquatic Toxicity of Superhydrophobic Chemicals: A Modeling Case Study of Cyclic Volatile Methyl Siloxanes
Many
chemicals in commerce are classified as âsuperhydrophobicâ,
having log octanolâwater partition coefficients (log <i>K</i><sub>OW</sub>) approaching or exceeding 7. Examples include
long-chain alkanes, halogenated aromatics, and cyclic volatile methylsiloxanes
(cVMS). We show that superhydrophobic chemicals present unique assessment
challenges because of their sparing solubility in water and difficulties
in empirical determinations of bioconcentration factors (BCFs) and
aquatic toxicity. Using cVMS as an example, BCFs are considerably
lower than expected due to biotransformation. Reviewed aquatic toxicity
test data for cVMS in a range of aquatic organisms show little or
no toxic effects up to solubility limits in water and sediment. Explanations
for this apparent lack of toxicity of cVMS, and by extension to other
superhydrophobic chemicals, are explored using a conventional one-compartment
uptake model to simulate bioconcentration and toxicity tests using
an assumed baseline narcotic critical body residue (CBR) and a range
of organism sizes. Because of the low aqueous concentrations, equilibration
times are very long and BCFs are sensitive to even very slow rates
of biotransformation. Most organisms fail to achieve the assumed CBR
during feasible test durations even at the solubility limit. Regulatory
evaluation of superhydrophobic substances requires specially designed
test protocols addressing biotransformation and dietary uptake