Anesderm

Pharmacotherapeutic group: anaesthetics, local; amides ATC code: N01B B20 Mechanism of action EMLA Cream provides dermal anaesthesia through the release of lidocaine and prilocaine from the cream into the epidermal and dermal layers of the skin and the vicinity of dermal pain receptors and nerve endings. Lidocaine and prilocaine are amide-type local anaesthetics.‍‍‍‍‍‍​​​‍​​​​​​ They both stabilise neuronal membranes by inhibiting the ionic fluxes required for the initiation and conduction of impulses, thereby producing local anaesthesia. The quality of anaesthesia depends upon the application time and the dose. Skin EMLA Cream is applied to intact skin under an occlusive dressing. The time needed to achieve reliable anaesthesia of intact skin is 1 to 2 hours, depending on the type of procedure. The local anaesthetic effect improves with longer application times from 1 to 2 hours in most parts of the body, with the exception of the skin of the face and the male genitals. Because of thin facial skin and high tissue blood flow, maximal local anaesthetic effect is obtained after 30-60 minutes on the forehead and on the cheeks. Similarly, local anaesthesia of the male genitals is achieved after 15 minutes. The duration of anaesthesia following the application of EMLA Cream for 1 to 2 hours is at least 2 hours after removal of the dressing, except in the face where the duration is shorter. EMLA Cream is equally effective and has the same anaesthetic onset time across the range of light to dark pigmented skin (skin types I to VI). In clinical studies of EMLA Cream on intact skin, no differences in safety or efficacy (including anaesthetic onset time) were observed between geriatric patients (aged 65 to 96 years) and younger patients. EMLA Cream produces a biphasic vascular response involving initial vasoconstriction followed by vasodilatation at the application site (see section 4.8). Irrespective of the vascular response, EMLA Cream facilitates the needle procedure compared to placebo cream. In patients with atopic dermatitis, a similar but shorter vascular reaction is seen, with erythema occurring after 30-60 minutes, indicating more rapid absorption through the skin (see section 4.4). EMLA Cream may cause a transient increase in skin thickness, partly caused by hydration of the skin under the occlusive dressing. The skin thickness decreases over the course of 15 minutes air exposure. The depth of cutaneous anaesthesia increases with application time. In 90% of patients the anaesthesia is sufficient for the insertion of a biopsy punch (4 mm diameter) to a depth of 2 mm after 60 minutes and 3 mm after 120 minutes EMLA Cream treatment. The use of EMLA Cream prior to measles-mumps-rubella or intramuscular diphtheria-pertussis-tetanus-inactivated poliovirus-Haemophilus influenzae b or Hepatitis B vaccines does not affect mean antibody titres, rate of seroconversion, or the proportion of patients achieving protective or positive antibody titres post immunisation, as compared to placebo treated patients. Genital mucosa Absorption from the genital mucosa is more rapid and onset time is shorter than after application to the skin. After a 5-10 minute application of EMLA Cream to female genital mucosa the average duration of effective analgesia to an argon laser stimulus, which produced a sharp, pricking pain was 15-20 minutes (individual variations in the range 5-45 minutes). Leg ulcers Reliable anaesthesia for the cleansing of leg ulcers is achieved after an application time of 30 minutes in most patients. An application time of 60 minutes may improve the anaesthesia further. The cleansing procedure should start within 10 minutes of removal of the cream. Clinical data from a longer waiting period are not available. EMLA Cream reduces the postoperative pain for up to 4 hours after debridement. EMLA Cream reduces the number of cleansing sessions required to achieve a clean ulcer compared to debridement with placebo cream. No negative effects on ulcer healing or bacterial flora have been observed. Paediatric population Clinical studies involved more than 2,300 paediatric patients of all age groups and demonstrated efficacy for needle pain (venipuncture, cannulation, s.c. and i.m. vaccinations, lumbar puncture), laser treatment of vascular lesions, and curettage of molluscum contagiosum. EMLA Cream diminished the pain of both needle insertion and injection of vaccines. Analgesic efficacy increased from 15 to 90 minutes application on normal skin but on vascular lesions 90 minutes provided no benefit over 60 min. There was no benefit of EMLA Cream versus placebo for liquid nitrogen cryotherapy of common warts. No adequate efficacy for circumcision could be demonstrated. Eleven clinical studies in newborn infants and infants showed that peak methaemoglobin concentrations occur about 8 hours after epicutaneous EMLA Cream administration, are clinically insignificant with recommended dosage, and return to normal values after about 12-13 hours. Methaemoglobin formation is related to the cumulative amount of prilocaine percutaneously absorbed, and may therefore increase with prolonged application times of EMLA Cream. The use of EMLA Cream prior to measles-mumps-rubella or intramuscular diphtheria-pertussis-tetanus-inactivated poliovirus-Haemophilus influenzae b or Hepatitis B vaccines did not affect mean antibody titres, rate of seroconversion, or the proportion of patients achieving protective or positive antibody titres post immunisation, as compared to placebo treated patients.