Table 1.

Topical anaesthetics before needle procedures on intact skin

Active ingredient (trade name)	Amide anaesthetics		Ester anaesthetic	Pentafluoropropane Tetrafluoroethane
	Lidocaine - prilocaine 5% (EMLA)	Liposomal lidocaine 4% (Maxilene)	Amethocaine 4% / Tetracaine (Ametop)	Vapocoolant spray (Pain Ease)
Onset	60 min (increased dermal analgesia with up to 2 h of occlusion)	30 min	30 min	Immediate
Maximal application time	Max 4 h in children Max 1 h in ≤3 months (Max application area of 10 cm2)	Max 2 h (Max application area 100 cm2 in <10 kg)	Studied up to 60 min (Max dose 50 mg)	Spray 10 s or until blanching (Max use twice at the same site)
Duration of efficacy after removal	Up to 1–2 h (efficacy increases up to 15–60 min after removal)	Longer than EMLA (efficacy increases up to 30 min after removal)	4 h	45–60 s
Advantages	No cross-sensitivity with Ametop	Rapid action Occlusion not required No cross-sensitivity with Ametop	Rapid action Superior to EMLA No cross-sensitivity with lidocaine	Immediate
Side effects	Vasoconstriction Methemoglobinemia (increased if <1-year-old) Hypersensitivity (rare)	Methemoglobinemia (rare)	Hypersensitivity	Burning sensationFrostbite
Contraindications	Allergy, application on mucosae or an open wound or in eyes, methemoglobinemia, G6PD. Use cautiously with heart block or severe hepatic disorder	Allergy, application on mucosae or an open wound or in eyes. Use cautiously with heart block or severe hepatic disorder	Allergy (including PABA and sulfonamides), application on mucosae or an open wound or in eyes	<3 years of age, hypersensitivity, application on mucosae or an open wound

Data drawn from references (59–64).

G6PD Glucose-6-phosphate dehydrogenase deficiency; PABA Para-aminobenzoic acid.