Neurotoxicity in dental anaesthesia may be related to the high (4%) concentration of articaine used.3 8 Admittedly, in the two studies published on ophthalmic anaesthesia, only articaine 2% was used,1 2 which may prove to be safer. However, the consequence of neurotoxicity in ophthalmic anaesthesia is arguably more serious than in dental anaesthesia, with possible loss of vision, diplopia and ptosis. Pedlar felt that there was sufficient evidence to urge caution in the widespread use of articaine as a local anaesthetic alternative to lidocaine.6 Despite the apparent superiority of articaine for ophthalmic anaesthesia, we too would urge caution with the introduction of articaine into ophthalmic anaesthesia.
Eastbourne, UK
Kahramanmaras, Turkey
Prolonged paraesthesiae, as reported by Haas and Lennon, occurred at an estimated incidence of 1:785 000.3 Of the 143 cases reported over a 21 yr period (49% involving the use of articaine and 42% the use of prilocaine), 31 cases had documented stabbing or electric shock type pain on injection of the local anaesthetic. This low frequency and typical history would seem to suggest a mechanism of nerve damage caused by inadvertent intraneural injection.
Randall describes the submission of 72 yellow cards to the Committee on Safety of Medicines concerning articaine.4 I am uncertain as to the number which would be considered as excessive for a newly released drug, but Randall describes this number as relatively small.
Finally, we should be careful before ascribing too much weight to anecdotal descriptions of drug reactions.57 In such reports, it is impossible to distinguish between true drug related events, those caused by adjuncts (e.g. vasoconstrictors), or those attributable to the technique used. However, a recent multicentre, randomized, double-blind study of 1325 dental subjects comparing articaine 4% with lidocaine 2% (both with epinephrine 1:100 000), found no difference in adverse outcomes.12
I would whole-heartedly agree that caution should be exercised when using any new agent, and the risks/benefits carefully assessed. The main purpose of our trials using articaine has been to search for a more effective agent for use in sub-Tenon's anaesthesia. Increased acceptance of this technique might help to reduce the risks associated with sharp needle ophthalmic anaesthetic practicerisks that include a neuro/myotoxicity rate of 0.5% when using standard agents such as lidocaine and bupivacaine.13 I would like to thank the authors for bringing this literature to our attention.
Exeter, UK
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