What we advise on

NPIS provides information, advice and statistics on a wide range of poisonings, involving substances from pharmaceuticals and complementary medicines to drugs of abuse, and household and industrial chemicals.

General trends and changes

Poisons change with the times. Recent examples of new agents NPIS has dealt with range from antiviral treatments for H1N1 pandemic flu to alcohol-based hygiene hand gels, and from new legal drugs of abuse such as mephedrone to washing sachets ('liquitabs').

Over the past decade, there has been a small reduction in poison-related patient admissions, due in part to national strategies to reduce suicide and self-harm. At the same time, new and unfamiliar agents appear on the scene, and the patterns of drugs involved and approaches to therapy continue to change.

More than half of enquiries to NPIS involve pharmaceuticals, with paracetamol and ibuprofen the products about which most enquiries are made.

Across the board, the cases seen most often seen are as a result of drug overdose, either intentional in the context of self harm, or poisoning associated with drugs of misuse. Many other poisoning cases involve accidental exposure to household or occupational chemicals, environmental poisons and medication errors.

Methanol and glycols are the second most common reason for cases to be referred to a NPIS consultant. In children under ten, concern about poisoning with household products is the most frequently encountered.

Drugs of misuse

Drugs of misuse constitute a considerable public health issue in the UK. Data provided by NPIS is extremely useful in monitoring shifting trends.

In 2009/10, for example, NPIS experienced a surge in enquiries relating to synthetic cathinones such as mephedrone. In this year, there were 4,500 online and 292 telephone enquiries relating to mephedrone - up from none in the previous year. NPIS enquiry data helped to inform government policy on the control of these drugs. Cathinones were classified as Class B controlled drugs in April 2010.

As new recreational drugs and 'legal highs' emerge, NPIS develops the detailed TOXBASE data needed to support frontline professional colleagues when they encounter them. In addition, NPIS analysis of enquiries relating to drugs of misuse plays an important part in helping to assess the public health implications associated with the very serious toxic effects of these agents.

Strong opiates such as heroin or methadone are often implicated in deaths associated with drugs of misuse. In recent years, NPIS has experienced an overall increase in enquires relating to the toxic effects of cocaine, though latterly these reduced slightly as users switched to newer stimulants. Cocaine is currently the second most cited drug of misuse in telephone enquiries, after mephedrone.  

Other stimulants generating increasing TOXBASE and telephone activity include ketamine, gamma-butyrolactone (GBL) and benzylpiperazines, although enquiries about these substances remain relatively rare.

By monitoring fluctuating levels of enquiry, NPIS is able to contribute to information on national trends in drugs of misuse. It has, for example, noted a downward trend in TOXBASE accesses and telephone enquiries relating to cannabis and ecstasy (MDMA), while the statistics relating to LSD or hallucinogenic ('magic') mushrooms remain constant.

Proportion of TOXBASE sessions relating to Class A drugs of misuse*

 

TOXBASE sessions relating to selected drugs of misuse other than Class A drugs*

*Data for 2002-2003 by calendar year: subsequent data by financial year

 

Medication errors

The majority of medication errors happen at home (89%) and most (98%) cause little harm, although the potential dangers should not be underestimated.

In 2008/09 NPIS received more than 9,000 enquiries from NHS health professionals concerning medication errors, over a third of them involving either children under 5 or adults over 70 years. However, medicines information services are the main source of advice on prescribed medicines.

Pharmaceutical products

Pharmaceutical products remain the most frequent reason for making an enquiry to NPIS.

Widely used pharmaceutical products such as paracetamol, ibuprofen, co-codamol and diazepam continue to pose very serious problems.

In addition, NPIS has highlighted changes in the pattern of enquiries about antidepressant overdoses and increasing incidents of quinine poisoning

Household products

Many poisonings occur from exposure to consumer products. Enquires about these are the subject of many enquiries to NPIS. The majority relate to children under five and most involve accidental incidents in the home.

A recent NPIS study highlighted the potential hazards to young children of many of the everyday cleaning products to be found in kitchen cupboards - items such as fabric cleaning liquid tablets, bleach, multipurpose cleaners, descalers and alcohol-based hygiene hand gels.

Type of product involved in phone enquiries related to household products, 2009-2010

Product	Number of enquiries
Fabric cleaning liquid tablets	647
Bleach	473
Multipurpose cleaner	408
Descaler	397
Disinfectant/antiseptic/sanitiser liquid	270
Plug ins liquid	206
Dishwasher tablet	201
Toilet cleaner/freshener liquid	156
Washing up liquid	130
Prewash stain remover	116
Rinse aid	112
Biocidal hand cleanser (domestic use)	104
Fabric cleaning powder tablet	102
Floor cleaner	101
Bathroom/bath cleaner	100
Toilet cleaner/freshener solid/powder	99
Fabric cleaning powder	95
Fabric cleaning liquid	94
Toilet rim block	80
Insect control powder (domestic use)	79

Co-proxamol

Following concerns from NPIS, among others, over the number of deaths associated with co-proxamol overdose, a phased withdrawal was initiated by the UK Medicines and Healthcare Products Regulatory Agency in 2005.

This has resulted in a considerable fall in enquiries relating to this product, with co-proxamol related telephone enquiries down 85% and TOXBASE product accesses down 68%.

Other published work confirms the impact of this change on mortality in England and Wales, and Scotland. The European Medicines Evaluation Agency has indicated it would like the ban extended Europe-wide.

Carbon monoxide

Incidents of carbon monoxide poisoning are particularly concerning. They are a major cause of preventable deaths and may involve multiple exposures and be under-diagnosed, due to non-specific symptoms.

Despite public awareness campaigns, enquiries about confirmed or suspected carbon monoxide poisonings continue to rise. During 2009/10, 386 telephone enquiries were received on the subject, 290 involving incidents. In one event alone, 17 people were exposed.

Lead exposure in pregnancy

By analysing the data it holds on the outcome of pregnancy following exposure to lead, the UK Teratology Information Service (UKTIS) has been able to add to the evidence available on the impact on the developing fetus.

To date its findings, in line with other published data, do not demonstrate an increased risk of major malformations, although other adverse health effects are recognised. Work in this area continues.

Pesticides

Enquiries about pesticide poisonings account for only a small percentage (1.9%) of NPIS's work. Most exposures are accidental and result in mild or no symptoms. Pyrethroids are the most usual source of exposure. The withdrawal from sale of paraquat in the UK in 2008 has resulted in a sharp reduction in enquiries about this substance, although it may remain in garden sheds for many years yet.

Last reviewed: 23 February 2011