TETRACAINE VERSUS LIDOCAINE-PRILOCAINE FOR PREVENTING VENIPUNCTURE INDUCED PAIN IN CHILDREN

The efficacy of tetracaine cream versus that of lidocaine-prilocaine c ream for the prevention of pain in children undergoing venipuncture wa s studied. Hospital inpatients 1-15 years of age received, on the back of each hand, a 30-minute application of tetracaine 4% cream or a 60- minute application of lidocaine-prilocaine cream (EMLA, Astra) before undergoing scheduled venipuncture. The phlebotomists in this open, ran domized trial evaluated the efficacy of the cream at the moment of ven ipuncture as adequate, inadequate, or inconclusive. Blood samples were taken immediately after venipuncture from 10 patients one to five yea rs of age to measure the serum concentrations of tetracaine and its me tabolite, N-butyl-p-aminobenzoic acid. Lidocaine-prilocaine cream was significantly more efficacious in preventing pain than tetracaine 4% c ream (97% of the former group [n = 32] had adequate pain relief, compa red with 76% of the latter [n = 34]. The only adverse effects observed were mild local erythema in the tetracaine group and local skin blanc hing in the lidocaine-prilocaine group. No tetracaine could be detecte d in serum, and the serum concentrations of N-butyl-p-aminobenzoic aci d ranged from 0 to 1.8 mg/L. Statistically, lidocaine-prilocaine cream was more efficacious than tetracaine 4% cream, but the difference is of minor clinical significance and is outweighed by the practical adva ntages of tetracaine 4% cream, namely the shorter application time, va sodilation and lower cost.