Sir, how many of us take the time to read the information leaflets provided with everyday drugs and medicaments used in dentistry? It may be of interest, and even entertaining, to read the product and patient information leaflet provided by Septodont in their packs of Lignospan Special (2% lidocaine with 1:80,000 adrenaline). The leaflets contain inaccurate information that could be quite alarming to patients. For example, the following side effects are stated as 'common', reportedly affecting between 1-10 of every 100 patients treated: cardiovascular collapse which may lead to cardiac arrest, arrhythmia, conduction disorders, hypotension and convulsions. Assuming these side effects occur in different patients, we could apparently be looking at up to 50% of the population having a life-threatening medical event every time they receive a local anaesthetic. Perhaps the GDC's minimum CPD requirements on basic life support should be revisited?

We note the highly conservative information sheet has led to a widespread misconception that the number of local anaesthetic cartridges should be limited to three in a healthy adult. To the contrary, the BNF suggests a maximum dose of 25 ml of 2% lidocaine with 1:80,000 adrenaline or 500 mg, which equates to approximately 7 mg per kg for an adult weighing 70 kg. The 7 mg per kg limit is consistent with that quoted in many authoritative texts, and equates to 11 cartridges in a 70 kg adult – this limit clearly exceeds a sensible dose in almost all dental applications, although puts the 'three cartridge' ceiling into perspective; Septodont's recommendation equates to a dose of less than 2 mg per kg for the very same 70 kg adult.

In what appears to be a complete contradiction, the maximum dose recommended for a child is stated in the same information leaflet as 'no more than 5 mg per kg'. To suggest that a 30 kg child can receive a higher dose than a 70 kg adult seems most peculiar.

Millions of local anaesthetic injections are delivered without incident in dental practice each year, although anyone reading the above would be forgiven for believing that lidocaine should be withdrawn with immediate effect. C. F. took the liberty of contacting Septodont in January 2015 to express concerns over the information provided, and was advised that changes would be made to the leaflets – to date this has not happened. To offer BDJ readers reassurance, C. F. went on to contact Dental Protection in order to seek advice on how to proceed if a manufacturer provides information that conflicts with other published guidance and current clinical practice, and was informed that if the manufacturer has acknowledged that errors exist, then following guidance in the BNF is sensible practice. Whilst caution does indeed have to be exercised to ensure patients with low BMI or hepatic impairment receive appropriate amounts of a drug which when used in excess is highly toxic, we do hope BDJ readers will continue to deliver appropriate amounts of local anaesthetic to their patients so as to ensure their dentistry remains pain-free.

Michael G. Cann, Managing Director of Septodont Ltd, responds: Septodont are world leaders in dental pain management with products licensed in many countries.

Patient safety is at the heart of everything that we do, so accordingly, advice to practitioner and patient evolves, with documentation being revised on a regular basis, in line with regulatory requirements and updated clinical best practice.

All documentation included within the Lignospan 2% Special 1/80 000 2.2 ml carton is necessarily approved by the MHRA (Medicinal Health Regulatory Agency) in the UK, forming a part of the licensed product presentation.

Septodont submitted its most recently updated documentation at the end of last year and the patient information leaflet is currently under review by the MHRA and is expected to be approved imminently.

Irrespective of the included documentation, the safety profile of Lignospan 2% Special 1/80 000 2.2 ml stands as our key priority and continues to reassure the many users of the drug, both in the UK and around the world.