Patterns of presentation and clinical toxicity after reported use of alpha methyltryptamine in the United Kingdom. A report from the UK National Poisons Information Service.

OBJECTIVE: To characterise the patterns of presentation, clinical effects and possible harms of acute toxicity following recreational use of alpha methyltryptamine (AMT) in the United Kingdom, as reported by health professionals to the National Poisons Information Service (NPIS) and to compare clinical effects with those reported after mephedrone use. METHODS: NPIS telephone enquiries and TOXBASE user sessions, the NPIS online information database, related to AMT were reviewed from March 2009 to September 2013. Telephone enquiry data were compared with those for mephedrone, the recreational substance most frequently reported to the NPIS, collected over the same period. RESULTS: There were 63 telephone enquiries regarding AMT during the period of study, with no telephone enquiries in 2009 or 2010, 19 in 2011, 35 in 2012 and 9 in 2013 (up to September). Most patients were male (68%) with a median age of 20 years. The route of exposure was ingestion in 55, insufflation in 4 and unknown in 4 cases. Excluding those reporting co-exposures, clinical effects recorded more frequently in AMT (n = 55) compared with those of mephedrone (n = 488) users including acute mental health disturbances (66% vs. 32%; Odds Ratio [OR], 4.00; 95% Confidence Intervals [CI], 2.22-7.19), stimulant effects (66% vs. 40%; OR, 2.82; 95% CI 1.57-5.06) and seizures (14% vs. 2%; OR, 9.35; 95% CI 3.26-24.18). CONCLUSIONS: Although still infrequent, toxicity following reported exposure to AMT has been encountered in the United Kingdom since January 2011. Stimulant features, acute mental health disturbances and seizures are more frequently reported than in those presenting following reported use of mephedrone.

Guidelines for laboratory analyses for poisoned patients in the United Kingdom.

To enable consistency of investigation and the establishment of best practice standards, consensus guidelines were formulated previously by the UK National Poisons Information Service and the Association for Clinical Biochemistry. These joint guidelines have now been updated to reflect current best practice. The types of laboratory investigation required for poisoned patients are categorized as either (a) essential common laboratory investigations or (b) specific toxicological assays, and also as either (i) common or (ii) specialist or infrequent. Tests in categories (a) and (bi) should be available 24 hours per day, with a maximum turnaround time of 2 h. For the specialist assays, i.e. category (bii), availability and turnaround times have been specified individually. The basis for selection of these times has been clinical utility. The adoption of these guidelines, along with the use of the National Poisons Information Service (0844 8920111) and its online poisons information resource TOXBASE(®) (www.toxbase.org) enable the poisoned patient to receive appropriate, 'best practice' investigations according to their clinical needs and will avoid unnecessary investigations.

Chronic valproic acid intoxication: reversal by naloxone.

A 76-year-old woman being treated with sodium valproate for bipolar depression presented with a 4-day history of acute confusion and tremulousness. She had apnoeic episodes, a reduced conscious level and generalised myoclonic movements. Her plasma valproate concentration was 848 µmol/litre (normal range 300-600 µmol/litre). Administration of naloxone 0.8 mg led to rapid clinical improvement. Naloxone may be useful in reversing the features of chronic valproate toxicity.

Survey of cases of paracetamol overdose in the UK referred to National Poisons Information Service (NPIS) consultants.

BACKGROUND: Paracetamol is the most common means of drug overdose in the UK. Guidance on management is available to junior doctors through TOXBASE, the online resource managed by the UK National Poisons Information Service (NPIS) and in poster form. TOXBASE is supported by NPIS units and further by a UK national rota of clinical toxicologists. A study was undertaken to examine reasons why calls about paracetamol are referred to consultants to better understand issues in managing this common poisoning. METHODS: Calls relating to paracetamol overdose referred by a poisons information specialist to the duty NPIS consultant between 1 May 2005 and 30 April 2006 were identified from the database and the number of TOXBASE accesses during the same time period was determined. Enquiries that resulted in consultant referral were classified into six categories. RESULTS: Calls referred to NPIS consultants pertain mainly to patients who present late, staggered overdoses, adverse reactions to N-acetylcysteine, and interpretation of blood results. This information has been used to inform the development of TOXBASE so that comprehensive advice is readily available to end users. CONCLUSIONS: The operation of a national consultant rota enables information on difficult or unusual cases of poisoning to be pooled so that treatment guidelines can be developed to optimise treatment throughout the UK.

Thioridazine: resurrection as an antimicrobial agent?

The emergence of multiresistant bacterial strains and the continuing burden of infectious disease globally point to the urgent need for novel affordable antimicrobial drugs. Thioridazine is a phenothiazine antipsychotic drug with well-recognized antimicrobial activity, but this property has not been harnessed for clinical use as a result of its central nervous system and cardiac side-effects. The cardiotoxicity of thioridazine has recently been shown to be structurally specific at a molecular level, whereas its antimicrobial properties are shared by a number of phenothiazine analogues. This raises the possibility that its enantiomers or its inactive metabolite, the ring sulphoxide, may act as a lead compound in the future development of antimicrobial drugs to face the new challenges in infectious disease.

Chronic valproic acid intoxication: reversal by naloxone.

A 76-year-old woman being treated with sodium valproate for bipolar depression presented with a 4 day history of acute confusion and tremulousness. She had apnoeic episodes, reduced conscious level and generalised myoclonic movements. Her plasma valproate concentration was 848 micromol/l (normal 300-600 micromol/l). Administration of naloxone 0.8 mg led to rapid clinical improvement. Naloxone may be useful in reversing the features of chronic valproate toxicity.