Methodology for AACT evidence-based recommendations on the use of intravenous lipid emulsion therapy in poisoning

Intravenous lipid emulsion (ILE) therapy is a novel treatment that was discovered in the last decade. Despite unclear understanding of its mechanisms of action, numerous and diverse publications attested to its clinical use. However, current evidence supporting its use is unclear and recommendations are inconsistent. To assist clinicians in decision-making, the American Academy of Clinical Toxicology created a workgroup composed of international experts from various clinical specialties, which includes representatives of major clinical toxicology associations. Rigorous methodology using the Appraisal of Guidelines for Research and Evaluation or AGREE II instrument was developed to provide a framework for the systematic reviews for this project and to formulate evidence-based recommendations on the use of ILE in poisoning. Systematic reviews on the efficacy of ILE in local anesthetic toxicity and non-local anesthetic poisonings as well as adverse effects of ILE are planned. A comprehensive review of lipid analytical interferences and a survey of ILE costs will be developed. The evidence will be appraised using the GRADE system. A thorough and transparent process for consensus statements will be performed to provide recommendations, using a modified Delphi method with two rounds of voting. This process will allow for the production of useful practice recommendations for this therapy.(AU)

Life-threatening systemic toxicity and airway compromise from a common European adder bite to the tongue.

A 24-year-old man was bit on the tongue by a European common adder. Within 15 min following envenomation, he experienced tongue swelling, hypotension and impaired consciousness. Antihistamine, corticosteroid and crystalloids were administered. Within 105 min of envenomation, increasing oral, pharyngeal and facial oedema compromised the airway, leading to respiratory failure, concomitant with circulatory failure related to hypoxaemia and systemic toxic effects. Acute tracheotomy secured the airway, and two doses of antivenom successfully treated the systemic, toxic effects. The reaction was severe due to rapid and suspected high-dose uptake of venom, underlining the need for early advanced symptomatic treatment with airway control and early and eventually repeated dosing of antivenom.

The effect of activated charcoal on drug exposure in healthy volunteers: a meta-analysis.

The objective of the study was to estimate the effect of activated charcoal (AC) administered during the first 6 h after drug intake and the effect of drug properties on drug exposure. Sixty-four controlled studies were integrated in a meta-analysis. AC administered 0-5 min after administration of a drug reduced median drug exposure by 88.4% (25-75 percentile: 65.0-96.8) (P < 0.00001). The effect of AC continued to be statistically significant when administered up to 4 h after drug intake (median reduction in drug exposure 27.4% (range 21.3-31.5%, P = 0.0006). The reduction in drug exposure was correlated with the AC/drug ratio (rho = 0.69, P < 0.0001), the volume of distribution (Vd) (rho = 0.46, P = 0.0001), and time to peak concentration (rho = 0.40, P = 0.02). We found that AC is most effective when given immediately after drug ingestion but has statistically significant effects even when given as long as 4 h after drug intake. AC appears to be most effective when given in a large dose.

Amodiaquine-associated adverse effects after inadvertent overdose and after a standard therapeutic dose.

A case of an acute dystonic reaction in a child presumptively treated for malaria with amodiaquine, and a case of persistent asymptomatic bradycardia in another child with mild pulmonary stenosis treated with a standard dose of amodiaquine for parasitologically confirmed uncomplicated malaria, is reported. Both subjects were homozygous for the wild type allele of cytochrome P450 2C8, the main enzyme responsible for amodiaquine metabolism. In both subjects, plasma concentrations of N-desethylamodiaquine and N-bis-desethylamodiaquine, the main metabolites of amodiaquine, were normal. No other drugs were detectable in the plasma of these two subjects after further toxicological screening. These observations, which suggest altered metabolism in the subject with an acute dystonic reaction, support the assertion that amodiaquine-associated dystonia is an idiosyncratic reaction. However, the occurrence of bradycardia after a standard dose of amodiaquine, which coincided with the time of expected peak concentrations of the active metabolite of amodiaquine, suggests a direct drug effect. These less reported adverse effects are likely to increase in parallel with the increased use of amodiaquine as a partner drug for combination therapy of malaria in Ghana. Further studies aimed at elucidating the mechanisms underlying these effects are, therefore, required.

Activated charcoal alone or after gastric lavage: a simulated large paracetamol intoxication.

AIMS: Activated charcoal is now being recommended for patients who have ingested potentially toxic amounts of a poison, where the ingested substance adsorbs to charcoal. Combination therapy with gastric lavage and activated charcoal is widely used, although clinical studies to date have not provided evidence of additional efficacy compared with the use of activated charcoal alone. There are also doubts regarding the efficacy of activated charcoal, when administered more than 1 h after the overdose. The aim of this study was to examine if there was a difference in the effect of the two interventions 1 h post ingestion, and to determine if activated charcoal was effective in reducing the systemic absorption of a drug, when administered 2 h post ingestion. METHODS: We performed a four-limbed randomized cross-over study in 12 volunteers, who 1 h after a standard meal ingested paracetamol 50 mg kg(-1) in 125 mg tablets to mimic real-life, where several factors, such as food, interfere with gastric emptying and thus treatment. The interventions were activated charcoal after 1 h, combination therapy of gastric lavage followed by activated charcoal after 1 h, or activated charcoal after 2 h. Serum paracetamol concentrations were determined by h.p.l.c. Percentage reductions in the area under the curve (AUC) were used to estimate the efficacy of each intervention (paired observations). RESULTS: There was a significant (P<0.005) reduction in the paracetamol AUC with activated charcoal at 1 h (median reduction 66%, 95% confidence intervals 49, 76) compared with controls, and a significant (P<0.01) reduction for gastric lavage followed by activated charcoal at 1 h (median reduction 48.2%, 95% confidence interval 32.4, 63.7) compared with controls. There was no significant difference between the two interventions (95% confidence interval for the difference -3.8, 34.0). Furthermore, we found a significant (P<0.01) reduction in the paracetamol AUC when activated charcoal was administered 2 h after tablet ingestion when compared with controls (median 22.7%, 95% confidence intervals 13.6--34.4). CONCLUSIONS: These results suggest that combination treatment may be no better than activated charcoal alone in patients presenting early after large overdoses. The effect of activated charcoal given 2 h post ingestion is substantially less than at 1 h, emphasizing the importance of early intervention.