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Efficacy of Preoperative Administration of Acetaminophen and Melatonin on Retrobulbar Block Associated Pain in Cataract Surgery: A Letter to Editor


Reza Aminnejad 1 , * , Seyed Mehdi Sabouri 1 , **


1 Department of Anesthesiology and Critical Care, Qom University of Medical Sciences, Qom, Iran

Corresponding Authors:


Anesthesiology and Pain Medicine: 9 (1); e84957
Published Online: February 24, 2019
Article Type: Letter
Received: October 4, 2018
Revised: October 26, 2018
Accepted: November 11, 2018





Acetaminophen Melatonin Retrobulbar Block Pain Cataract, Surgery

Copyright © 2019, Author(s). This is an open-access article distributed under the terms of the Creative Commons Attribution-NonCommercial 4.0 International License ( which permits copy and redistribute the material just in noncommercial usages, provided the original work is properly cited.

Dear Editor,

I read the paper entitled “efficacy of preoperative administration of acetaminophen and melatonin on retrobulbar block associated pain in cataract surgery” in your valuable journal (1) Actually, the preemptive analgesic effect of melatonin is well established (2-6). Therefore, pain score reduction during a retrobulbar block by the preventive use of melatonin is self-explaining. On the other hand, cataract surgery patients are old enough to be more sensitive to the sedative effects of melatonin (7). In general, cataract surgeries are performed under MAC (monitored anesthesia care) or light intravenous sedation with the aim of rapid recovery and early discharge of the patients. The use of short-acting sedative drugs for this purpose is highly recommended. Up to eight hours after the ingestion of a usual dose of oral melatonin, its concentration exceeds the basal rates (8). Then, by the use of melatonin as a preemptive analgesic drug in short-time surgeries such as cataract surgery (that is usually performed by Phacoemulsification) in elderly patients, the prolonged recovery and delayed discharge are inevitable and this method will not be very fortunate in routine daily practice, especially in daycare surgery centers with high enough daily turnover. It is prudent to think more about a proper anesthesia regimen for elderly patients in outpatient settings.

  • 1. Haddadi S, Shahrokhirad R, Ansar MM, Marzban S, Akbari M, Parvizi A. Efficacy of preoperative administration of acetaminophen and melatonin on retrobulbar block associated pain in cataract surgery. Anesth Pain Med. 2018;8(5). e61041. doi: 10.5812/aapm.61041. [PubMed: 30533388]. [PubMed Central: PMC6240829].
  • 2. Kuriyama A, Urushidani S, Sato M. Melatonin and postoperative pain: Can the heterogeneous be pooled? Anaesthesia. 2015;70(1):113-4. doi: 10.1111/anae.12959. [PubMed: 25489621].
  • 3. Andersen LP, Werner MU, Rosenberg J, Gogenur I. A systematic review of peri-operative melatonin. Anaesthesia. 2014;69(10):1163-71. doi: 10.1111/anae.12717. [PubMed: 24835540].
  • 4. Maitra S, Baidya DK, Khanna P. Melatonin in perioperative medicine: Current perspective. Saudi J Anaesth. 2013;7(3):315-21. doi: 10.4103/1658-354X.115316. [PubMed: 24015137]. [PubMed Central: PMC3757807].
  • 5. Javaherforooshzadeh F, Amirpour I, Janatmakan F, Soltanzadeh M. Comparison of effects of melatonin and gabapentin on post operative anxiety and pain in lumbar spine surgery: A randomized clinical trial. Anesth Pain Med. 2018;8(3). e68763. doi: 10.5812/aapm.68763. [PubMed: 30214884]. [PubMed Central: PMC6119980].
  • 6. Faghihian R, Eshghi A, Faghihian H, Kaviani N. Comparison of oral melatonin and midazolam as premedication in children undergoing general anesthesia for dental treatment. Anesth Pain Med. 2018;8(2). e64236. doi: 10.5812/aapm.64236. [PubMed: 30009151]. [PubMed Central: PMC6035375].
  • 7. Schroeck JL, Ford J, Conway EL, Kurtzhalts KE, Gee ME, Vollmer KA, et al. Review of safety and efficacy of sleep medicines in older adults. Clin Ther. 2016;38(11):2340-72. doi: 10.1016/j.clinthera.2016.09.010. [PubMed: 27751669].
  • 8. Tordjman S, Chokron S, Delorme R, Charrier A, Bellissant E, Jaafari N, et al. Melatonin: Pharmacology, functions and therapeutic benefits. Curr Neuropharmacol. 2017;15(3):434-43. doi: 10.2174/1570159X14666161228122115. [PubMed: 28503116]. [PubMed Central: PMC5405617].