216 GENERAL ANESTHESIA Controlled-release codeine is equivalent to aceta- minophen plus codeine for post-cholecystectomy analgesia [La codéine à libération contrôlée est équivalente à de l’acétaminophène plus de la codéine pour l’analgésie postcholécystectomie] Frances Chung MD,* Doris Tong MD,* Paula C. Miceli MSc,† Joseph Reiz BSc,† Zoltan Harsanyi MBA,† Andrew C. Darke PhD,† Lance W. Payne PHARMD† Purpose: Following ambulatory surgery, long-acting analgesics may Objectif : En chirurgie ambulatoire, les analgésiques postopératoires provide advantages over short-acting analgesics. This study com- d’action prolongée peuvent avoir des avantages sur les analgésiques pared controlled-release codeine (CC) and acetaminophen plus d’action brève. Nous comparons la codéine à libération contrôlée (CC) codeine (A/C; 300 mg/30 mg) for pain control in the 48-hr period et une combinaison d’acétaminophène et de codéine (A/C ; 300 following laparoscopic cholecystectomy. mg/30 mg) comme analgésique pendant 48 h après une cholécystec- Methods: Eligible patients were randomized to CC or A/C in a tomie laparoscopique. double-blind, double-dummy parallel group study. Unrelieved pain Méthode : Des patients admissibles à l’expérimentation ont reçu de in hospital was treated with fentanyl iv bolus. Pain [100 mm visual la CC ou de l’A/C lors d’une étude à double insu, à double placebo en analogue scale (VAS)] was assessed before the first dose of medica- contrôle parallèle. À l’hôpital, la douleur tenace a été traitée avec des tion; at 0.5, one, two, three, and four hours post-dose; at dis- bolus iv de fentanyl. La douleur [échelle visuelle analogique (EVA) de charge; and three times a day for 48 hr. Adverse events were 100 mm] a été évaluée avant la première dose de médicament ; à recorded and measures of patient satisfaction were assessed at the 0,5, une, deux, trois et quatre heures après la dose ; au moment du end of the study. départ et trois fois par jour pendant 48 h. Les événements indésirables ont été notés et des mesures de la satisfaction du patient ont été Results: Eighty-four patients were enrolled in the study; 42 faites à la fin de l’étude. patients in each group. There were no statistically significant differ- ences between CC and A/C treatment. Mean VAS baseline pain Résultats : L’étude a été réalisée auprès de 84 patients : 42 dans chaque groupe. Il n’y a pas eu de différence statistiquement significa- was similar in both groups (P = 0.49) and there was no significant tive entre les traitements à la CC ou à l’A/C. La douleur initiale difference in the time to onset of analgesia (P = 0.17). At 0.5 hr, moyenne a été similaire dans les deux groupes (P = 0,49) et il n’y a the mean VAS pain score was significantly reduced from baseline in pas eu de différence significative de temps précédant le début de both groups (P = 0.0001). The VAS pain scores at discharge were l’analgésie (P = 0,17). À 0,5 h, le score de douleur moyen à l’EVA reduced 59% and 56% from baseline, respectively (P = 0.61). était significativement réduit dans les deux groupes (P = 0,0001). Les There was no difference between treatments in the incidence of scores à l’EVA au départ de l’hôpital ont été respectivement réduits de adverse events and patients reported similar levels of satisfaction. 59 % et de 56 % par rapport aux mesures initiales de la douleur (P Conclusions: Controlled-release codeine provides an equivalent = 0,61). Aucune différence intergroupe dans l’incidence d’événe- onset of analgesia, reduction in postoperative pain, and level of ments indésirables n’a été notée et la satisfaction des patients était patient satisfaction, to acetaminophen plus codeine, over 48 hr fol- comparable d’un groupe à l’autre. lowing cholecystectomy, with the advantage of less frequent dosing. Conclusion : La codéine à libération contrôlée offre un délai d’in- stallation de l’analgésie, une réduction de la douleur postopératoire et un niveau de satisfaction équivalents à une combinaison d’acéta- minophène et de codéine pendant 48 h après une cholécystectomie, et ce, avec l’avantage d’un dosage moins fréquent. From the Department of Anesthesia,* Toronto Western Hospital, University of Toronto, Toronto; and Purdue Pharma,† Pickering, Ontario, Canada. Address correspondence to: Dr. Frances Chung, Department of Anesthesia, Toronto Western Hospital, 399 Bathurst Street, Toronto, Ontario M5T 2S8, Canada. Phone: 416-603-5118; Fax: 416-603-6494; E-mail: [email protected] This study was partially supported by a grant from Purdue Pharma (Canada) Inc. Accepted for publication May 29, 2003. Revision accepted December 1, 2003. CAN J ANESTH 2004 / 51: 3 / pp 216–221 Chung et al.: CONTROLLED RELEASE CODEINE 217 APAROSCOPIC cholecystectomy is the available as 50, 100, 150 and 200 mg controlled- surgical treatment of choice for symptomatic release tablets, which is designed to provide controlled cholecystolithiasis and can be used in more delivery of codeine over a 12-hr period. It is current- L than 90% of cases.1,2 Over 37,000 laparo- ly the only controlled-release opioid marketed in scopic cholecystectomy procedures were performed in Canada for the treatment of mild to moderate pain. Canadian facilities during the fiscal year 2000–2001.3 The controlled-release formulation has demonstrated The laparoscopic approach to cholecystectomy has equivalent bioavailability to immediate-release tablet shortened the in-hospital recovery period following or liquid codeine formulations in single dose and surgery from one to three days to same-day dis- steady-state studies.21 In acute pain models, the medi- charge.4,5 Discharge time is dependent, in part, on the an time to onset of analgesia with controlled-release rate of recovery from anesthesia and the provision of codeine was 30 to 40 min, similar to immediate- appropriate postoperative analgesia.6,7 Unanticipated release preparations. admissions due to inadequate pain have enormous Following ambulatory surgery, long-acting anal- medical, social and cost implications.7 Therefore, the gesics may have advantages compared to short-acting aim of an analgesic technique should be not only to analgesics. The study was designed to evaluate the reduce post-laparoscopic pain, but also to facilitate ear- efficacy, safety and benefits of controlled-release lier mobilization, reduce perioperative complications, codeine compared with acetaminophen plus codeine and increase patient satisfaction.7 in the control of postoperative pain following laparo- Following laparoscopic cholecystectomy, patients scopic cholecystectomy. tend to report parietal,8 visceral9 and shoulder pain.10,11 Visceral pain is predominant during the first few post- Methods operative hours. The major groups of drugs used in the The study was conducted at the day surgery unit treatment of postoperative pain are opioid anal- (DSU), Toronto Western Hospital. Male and female gesics,12–15 and non-steroidal anti-inflammatory drugs.7 patients ($ 18 yr) scheduled to undergo laparoscopic Moderate to severe pain may follow laparoscopic chole- cholecystectomy were eligible for enrollment. Both cystectomy and often necessitates the use of opioid the general and local anesthesia during the procedure analgesics.7 Opioids may be administered by a variety of were standardized for all patients. routes; oral dosing is usually the most convenient and Study patients were admitted to the postanesthetic least expensive. It is appropriate as soon as the patient care unit (PACU) following surgery and later trans- can tolerate oral intake and is the mainstay of pain man- ferred to the DSU for complete recovery before being agement in the ambulatory surgical population.16 discharged home. When patients reported a visual Since the most severe pain following laparoscopic analogue scale (VAS) pain intensity > 40 mm, but cholecystectomy occurs during the first two to three were still unable to tolerate oral analgesics, fentanyl hours,17,18 an oral opioid analgesic with an onset of (12.5–50 µg) iv boluses were given to titrate to a VAS less than one hour would offer an effective method of # 40 mm. Patients who satisfied the PACU discharge analgesia. Although oral administration is associated criteria (Aldrete score $ 9),22,23 were discharged to the with a slower onset of analgesia, the duration of pain DSU, where they were monitored for a short time and relief is significantly longer than with an equi-analgesic subsequently, discharged from hospital. dose of parenteral opioid.7 Postoperative oral analgesics were initiated when the Codeine plus acetaminophen combination prepara- patient was able to tolerate oral medication and when tions are the most commonly used opioid analgesics for VAS $ 40 mm was reported. Patients were randomized ambulatory surgery procedures.19 With fixed-dose com- to receive either active controlled-release codeine (CC) binations of acetaminophen plus codeine there is a rela- every 12 hr or active acetaminophen plus codeine tively flat dose-response curve and a clear ceiling effect (A/C; 300 mg/30 mg) every six hours during the 48- and the analgesic potential of fixed-dose combinations is hr study period. Study blinding was maintained using generally limited by unacceptable side effects associated the double-dummy technique, with matching placebo. with the acetaminophen component. Fixed-dose combi- All patients were administered study medication nation preparations must be given every four to six hours according to a structured dose de-escalation schedule: and a delay in administration, especially when ordered on day one: CC 150 mg every 12 hr or A/C two tablets a “as needed (prn)” basis, may result in lower plasma opi- every six hours and day two: CC 100 mg every 12 hr or oid concentrations and, thus, the re-emergence of pain.20 A/C 1 tablet every six hours.