Premedication with buccal midazolam in children and in adults with learning disabilities

Abstract

The routine use of premedication for both children and patients with learning disabilities has been questioned [1]. The drugs routinely used for premedication help to calm the patient but may cause problems in the postoperative period. Oral midazolam 0.5 mg.kg−1 remains the most commonly used drug, but can be associated with unpleasant sequelae. Abnormal postoperative behaviour (negativism, food rejection, nightmares, night terrors and anxiety) have been seen after oral midazolam premedication in children [2]. The injectable preparation is normally used, which has a bitter taste and, despite adding a sweetening agent to the mixture, the drug may be refused. The absorption rate is not standard and effects are unpredictable after oral administration. Oral transmucosal delivery of midazolam was reported in 1988 [3]. Transmucosal application avoids first-pass metabolism in the liver and increases bioavailability from 36% to 78%[3–5]. Different routes for transmucosal application – sublingual, intranasal, buccal – have been tested since then [4, 5]. The fastest onset of action is after intranasal application, but this route is poorly tolerated [4, 5]. Nasal administration is associated with intense burning or stinging [1]. Buccal administration of midazolam is recommended but is limited by both the low concentration (1, 2 or 5 mg.ml−1) of available midazolam preparations and the bitter taste of the drug [4, 5]. An unlicensed liquid preparation containing midazolam 10 mg.ml−1 for buccal administration (Epistatus®, Special Products Ltd, Woking, UK) was introduced into clinical practice in the UK in 2002. A similar preparation specifically indicated for sedation prior to surgical and diagnostic procedures (Consed®, Special Products Ltd) was introduced in May 2006. No relevant data regarding the use of buccal midazolam in the UK as a premedication agent has been published before. However, buccal midazolam has been used in the emergency treatment of epileptic seizures and status epilepticus [6]. McIntyre et al. compared buccal midazolam with rectal diazepam used for treatment of seizures in children and concluded that buccal midazolam was more effective and was not associated with an increased incidence of respiratory depression. We have used buccal midazolam since June 2006 in approximately 30 patients. The patients were children above 2 years of age scheduled for ENT or dental procedures (n = 22) and eight adult patients with learning disabilities undergoing dental treatment under general anaesthesia. Buccal midazolam was usually given in the anaesthetic room to patients who did not co-operate sufficiently. The total dose given was in accordance with manufacturer's recommendations of up to 0.2 mg.kg−1. The drug was prepared in the syringe supplied as part of the commercially prepared solution. An anaesthetist, or a parent or carer inserted their index finger into the patient's mouth and the tip of syringe was placed on the mucosa between patient's gum and cheek and the half the dose applied on each side. The first signs of sedation appeared usually within 5 min and within 10 min all patients were able to undergo either inhalational or intravenous induction. One child refused to take buccal midazolam on the first attempt and two patients reported the taste as unpleasant. Recovery appeared smoother than after oral midazolam and no patient was discharged later than were the unpremedicated patients. We found that the application of buccal midazolam is technically easy, takes up to 10 s, and is very well tolerated by patients. Prospective, randomised studies are needed to assess all aspects of buccal midazolam premedication (onset, co-operation, retrograde amnesia, emergence, acute postoperative behaviour and frequency of sleep disturbance in the first week after surgery).