Activated charcoal in oral ethanol absorption: lack of effect in humans

Ethanol Intoxication of Young Children

Ethanol intoxication of infants and young children can be a challenging diagnosis in the pediatric emergency department, and features of the poisoning may differ in comparison with adolescents. The sources of ethanol exposures in this age are varied and include unintentional, malicious, and iatrogenic etiologies. Young children exposed to ethanol often present with mixed clinical signs and symptoms that may not fit the traditional ethanol or sedative-hypnotic toxidrome. Pediatric ethanol intoxications are often managed supportively, and recovery is usually rapid. The purpose of this review is to describe the sources of ethanol poisoning among children 6 years and younger, highlight presenting symptoms and pharmacokinetic considerations unique to this age group, and review management strategies. In addition, published cases of ethanol poisoning due to ingestion among young infants are compiled for presentation.

Population Pharmacokinetics of Ethanol in Drinking Drivers Using Breath Measures

This study was undertaken to evaluate the population pharmacokinetic behavior of ethanol from breath ethanol measures and to see if these results could be used to establish the drinking history of our drinking drivers. The population consisted of 55 self-identified light to heavy drinkers. All had been arrested at least once for driving under the influence of alcohol. Sixteen were women, and 39 were men. Breath was analyzed for ethanol using a 3-wavelength infrared spectrophotometer. An iterative 2-stage Bayesian (IT2B) parametric modeling program was used first to obtain gamma, a measure of the relative magnitude of the intraindividual variability. The nonparametric adaptive grid (NPAG) maximum likelihood program, using gamma, was then used to obtain the full nonparametric joint parameter density. A 2-compartment Michaelis-Menten model was evaluated. The 2-compartment model gave a gamma of 1.75. Thus, the standard deviation (SD) of the nonassay sources of intraindividual variability was 1.75 times the SD of the assay itself for the 2-compartment model. The NPAG program gave the following means, medians, modes, and standard deviations for the 2-compartment model: ka (h(-1)) = 6.43, 5.46, 2.93, 4.58; Vmax (g/h) = 12.09, 11.90, 13.03, 3.73; Km (g/L) = 0.1273, 0.1367, 0.1991, 0.0528; Vc (L) = 31.32, 29.30, 24.88, 10.52; kcp (h(-1)) = 4.38, 1.30, 1.12, 6.16; and kpc (h(-1)) = 9.11, 2.47, 0.89, 8.98. These drinking drivers had a rate of metabolism of ethanol that was between that of moderate drinkers and confirmed alcoholics. Properly collected breath ethanol measures can be useful in a therapeutic drug-monitoring situation to obtain quick, accurate, and reliable measures of a patient's ethanol concentrations.

Effect of ethanol and pH on the adsorption of acetaminophen (paracetamol) to high surface activated charcoal, in vitro studies

BACKGROUND

Paracetamol (acetaminophen) intoxication often in combination with ethanol, is seen commonly in overdose cases. Doses of several grams might be close to the maximum adsorption capacity of the standard treatment dose (50g) of activated charcoal. The aim of this study was to determine the maximum adsorption capacity for paracetamol for two types of high surface-activated charcoal [Carbomix and Norit Ready-To-Use (not yet registered trademark in Denmark) both from Norit Cosmara, Amersfoort, The Netherlands] in simulated in vivo environments: At pH 1.2 (gastric environment), at pH 7.2 (intestinal environment), and with and without 10% ethanol.

METHODS

Activated charcoal, at both gastric or intestinal pHs, and paracetamol were mixed, resulting in activated charcoal-paracetamol ratios from 10:] to 1:1. In trials with ethanol, some of the gastric or intestinal fluid was replaced with an equivalent volume of ethanol, resulting in an ethanol concentration of 10% v/v. After incubation, the concentration of unabsorbed paracetamol was analyzed by high-performance liquid chromatography. The maximum adsorption capacity of paracetamol to activated charcoal was calculated as mg paracetamol adsorbed/g activated charcoal, using Langmuir's isotherm.

RESULTS

Carbomix [95% confidence limits are shown in square brackets]: 623.7 [612.8;634.5] mg paracetamol adsorbed/g activated charcoal (pH 1.2), 626.2 [611.6;640.9] mg paracetamol adsorbed/g activated charcoal (pH 7.2); Norit Ready-To-Use: 693.6 [676.8;710.5] mg paracetamol adsorbed/g activated charcoal (pH 1.2), 722.6 [687.4;757.9] mg paracetamol adsorbed/g activated charcoal (pH 7.2). For experiments with ethanol (10% v/v) the results with Carbomix were 465.7 [449.2;482.2] mg paracetamol adsorbed/g activated charcoal (pH 1.2), 498.6 [481.8;515.6] mg paracetamol adsorbed/g activated charcoal (pH 7.2); with Norit Ready-To-Use: 617.2 [606.6;627.7] mg paracetamol adsorbed/g activated charcoal (pH 1.2), 640.6 [624.9;656.4] mg paracetamol adsorbed/g activated charcoal (pH 7.2).

CONCLUSION

Under conditions simulating immediate treatment with charcoal, a standard dose of 50 g of either of the two tested activated charcoals adsorbed a sufficient amount of paracetamol to be beneficial in the treatment of the majority of overdoses of this drug. For both types of activated charcoal, with or without ethanol, there was no significant difference in the adsorption of paracetamol at pH 1.2 and 7.2. Norit Ready-To-Use had a larger maximum adsorption capacity than Carbomix, and was not as sensitive as Carbomix to environmental changes (pH and ethanol). The presence of 10% ethanol lowered the adsorption capacity of the two tested activated charcoal preparations by an amount that might be clinically relevant in cases of intoxications by high-gram doses.

Lowering of blood ethanol by activated carbon products in rats and dogs

Earlier studies on the effects of activated carbon (charcoal) on blood alcohol levels (BAL) in animals have been conflicting. The present study was designed to study the effects of a commercially available product (Charcoaid) and a new patented product (Alcosorb), in capsules and in suspension on the BAL of rats and dogs. We compared peak BAL and the regression of BAL with time during ethanol clearance in rats given 1.5 g/kg of carbon products in sorbitol intragastrically, followed 5 min later by 3.5 g/kg ethanol intragastrically. Peak BAL were significantly higher after Charcoaid 1 h after intubation, compared to Alcosorb and sorbitol (vehicle for the charcoal suspension). A study in which ethanol was given intraperitoneally instead of intragastrically showed no differences in ethanol BAL produced by the intragastric carbon treatments. In a crossover study using Beagle dogs, 780 mg capsules of carbon products ("low dose") given 5 min before ethanol had no significant effect on BAL. A "high" dose of 20 g of charcoal products suspended in water, followed by ethanol intragastrically, was also ineffective in lowering blood ethanol. However, carbon products suspended in a water/ethanol vehicle (20% w/v) did significantly lower peak BAL. We conclude that carbon products significantly lower BAL in rats and dogs, and that in rats, Alcosorb and sorbitol produce a greater BAL lowering effect than Charcoaid for a brief time after administration. The mechanisms of the BAL lowering effect by sorbitol and charcoal products are probably different.

Gastric emptying in the acutely inebriated patient

Fifty inebriated emergency department (ED) patients underwent evacuation of gastric contents via a nasogastric tube, in order to determine if a significant amount of ingested ethanol can be removed prior to absorption. Such a result could potentially reduce additional intoxicating effect. The gastric contents were assayed for total ethanol concentration, and a potential (postabsorption) additive blood alcohol level (PABAL) was projected and compared to the actual BAL on arrival. The type of beverage ingested and the time since last drink were recorded. BAL ranged from 108 to 637 mg/dL (mean +/- SD, 290 +/- 104.7). Gastric aspirate volume ranged from 50 to 700 mL (190 +/- 134), and contained alcohol in a range of 87 to 2271 mg/dL (475 +/- 479). Based on the distribution volume for alcohol calculated according to the patient's weight, this corresponded to a PABAL of 3 to 167 mg/dL (mean, 24.3 +/- 29.3). There was no significant correlation between the volume or concentration of gastric aspirate and the patient's stated drinking history. The authors conclude that a significant amount of ingested alcohol may occasionally be removed from absorption by the routine evacuation of gastric contents in intoxicated patients. These patients cannot be identified upon presentation, however, and these data cannot support routine use of gastric emptying in the detoxification of inebriated patients.

Gastrointestinal transit times of a charcoal/sorbitol slurry in overdose patients

Gut decontamination with a slurry of activated charcoal and sorbitol is one of the methods presently available to decrease total body burden of ingested drug. This one year retrospective audit of patients presenting with a history of recent toxic ingestion was designed to determine the time to stool of a charcoal/sorbitol slurry (CSS) when used for differing ingestants. A total of 69 patients received a CSS. 50.7% took less than 6 hours for their first charcoal stool, while 26.1% had emesis of the CSS within 30 minutes of administration. Ingestion of drugs which may increase gastrointestinal transit time (i.e. opioids, cyclic antidepressants) correlated with prolonged time to stool despite treatment with the CSS. Though a prospective, controlled study needs to be performed, variation in dosage of the CSS may be appropriate in select patient groups to offset the effects of the ingestant on bowel motility.

The effect of "superactive" charcoal and magnesium citrate solution on blood ethanol concentrations and area under the curve in humans

Eleven healthy males between 21 and 37 years of age were enrolled into a non-randomized crossover study comparing superactive charcoal (SAC) given after ethanol administration. After receiving 0.6 gm/kg ethanol orally (95% V/V diluted in orange juice), blood was sampled at 0, 0.5, 1.0, 1.5, 2.0, 3.0, and 4.0 hours. Area under the curve (AUC) was calculated and the highest ethanol level was recorded. After a minimum of 1 week washout, the volunteers ingested an identical ethanol dose but in addition received 60 grams of SAC and 300 ml of 5.8% magnesium citrate solution 1 and 3 hours post ingestion. The data was compared using the paired t-test with p less than 0.05 considered significant. Nine volunteers completed the study. Volunteers had difficulty ingesting the full second 60 gram SAC dose. The AUC (mean 1184 mcg x hr/ml) and highest ethanol concentrations (mean 46.3 mg/dl) for the control group were not significantly greater than in the SAC group (mean AUC 1167 mcg x hr/ml and highest ethanol concentration of 49.0 mg/dl). The ethanol concentration in the SAC group was significantly less than control only at 2.0 hours (31.6 mg/dl vs 36.6 mg/dl, p less than 0.01). The peak ethanol concentration in the SAC group occurred at 1.0 hours in 7 of 9 volunteers, while in the control group, peak concentration occurred randomly between 0.5 and 2.0 hours. We conclude SAC in the dose used is not effective in decreasing AUC, highest ethanol concentration, and blood ethanol levels when given 1 and 3 hours after ethanol ingestion.

Oral activated charcoal in the treatment of intoxications. Role of single and repeated doses

Activated charcoal has an ability to adsorb a wide variety of substances. This property can be applied to prevent the gastrointestinal absorption of various drugs and toxins and to increase their elimination, even after systemic absorption. Single doses of oral activated charcoal effectively prevent the gastrointestinal absorption of most drugs and toxins present in the stomach at the time of charcoal administration. Known exceptions are alcohols, cyanide, and metals such as iron and lithium. In general, activated charcoal is more effective than gastric emptying. However, if the amount of drug or poison ingested is very large or if its affinity to charcoal is poor, the adsorption capacity of activated charcoal can be saturated. In such cases properly performed gastric emptying is likely to be more effective than charcoal alone. Repeated dosing with oral activated charcoal enhances the elimination of many toxicologically significant agents, e.g. aspirin, carbamazepine, dapsone, dextropropoxyphene, cardiac glycosides, meprobamate, phenobarbitone, phenytoin and theophylline. It also accelerates the elimination of many industrial and environmental intoxicants. In acute intoxications 50 to 100g activated charcoal should be administered to adult patients (to children, about 1 g/kg) as soon as possible. The exceptions are patients poisoned with caustic alkalis or acids which will immediately cause local tissue damages. To avoid delays in charcoal administration, activated charcoal should be a part of first-aid kits both at home and at work. The 'blind' administration of charcoal neither prevents later gastric emptying nor does it cause serious adverse effects provided that pulmonary aspiration in obtunded patients is prevented. In severe acute poisonings oral activated charcoal should be administered repeatedly, e.g. 20 to 50g at intervals of 4 to 6 hours, until recovery or until plasma drug concentrations have fallen to non-toxic levels. In addition to increasing the elimination of many drugs and toxins even after their systemic absorption, repeated doses of charcoal also reduce the risk of desorbing from the charcoal-toxin complex as the complex passes through the gastrointestinal tract. Charcoal will not increase the elimination of all substances taken. However, as the drug history in acute intoxications is often unreliable, repeated doses of oral activated charcoal in severe intoxications seem to be justified unless the toxicological laboratory has identified the causative agent as not being prone to adsorption by charcoal. The role of repeated doses of oral activated charcoal in chronic intoxication has not been clearly defined.(ABSTRACT TRUNCATED AT 400 WORDS)