it is one of the most severe adverse drug reactions and can be fatal , if not identified early and treated promptly . almost any drug can cause anaphylaxis ; however , antibiotics like penicillin group of drugs are the most commonly implicated . other medications which are implicated are nondepolarizing neuromuscular blockers such as rocuronium , nonsteroidal anti - inflammatory agents , and ionic radiocontrast media . ranitidine is a commonly used h2 ( histamine type 2 ) receptor blocker and is considered to be a safe drug with few side effects . a 24-year - old male , with no known comorbidities , presented with complaints of pain left flank of 1-day duration . pain was colicky , severe , associated with vomiting and radiating from the loin to the groin . there was no history of hematuria , graveluria , or any other significant past or family history . ultrasound of the kidney , ureter , and bladder revealed left distal ureteric calculus with hydroureteronephrosis and right renal calculus with right hydroureteronephrosis . he was planned for ureteroscopic lithotripsy ( left ) with placement of double j stent under general anesthesia . he was accepted for surgery in american society of anesthesiologist grade i. patient was given premedication with injection ranitidine 50 mg , injection fentanyl 30 mg , and injection glycopyrrolate 2 mg intravenous ( iv ) . immediately after induction patient developed severe hypotension ( 80/40 mm hg ) , bronchospasm , and tachycardia . surgery was abandoned , and patient managed with mechanical ventilation and adrenaline infusion initiated at the rate of 0.3 mg / kg / min , increased to 1 mg / kg / min and tapered after 12 h and patient recovered . patient was again taken up for surgery after 1 month with similar protocol , and he again developed anaphylactic reaction . in view of repeated , severe anaphylactic reactions - the patient was referred to dermatology department for further evaluation . we reviewed his entire drug history and elicited that 1 year ago he developed abdomen pain for which he was given iv injection ranitidine 50 mg , and immediately thereafter he developed urticaria which was treated with iv injection hydrocortisone and promethazine . during his hospital stay , he developed flushing of the face along with chest tightness on administration of iv ranitidine . in view of his repeated reaction to ranitidine , reaction had a score of 7 in naranjo probability scale and certain cause in the who  umc causality category [ table 1 ] . he successfully underwent ureteroscopic lithotripsy under subarachnoid spinal block using 2.5 ml bupivacaine and was discharged with caution of avoiding ranitidine in future . it is difficult to establish the exact cause of anaphylaxis in these patients as multiple drugs , which are known to cause anaphylaxis , are administered simultaneously in a short period of time . drugs such as muscle relaxants , latex , antibiotics , hypnotics , and induction agents are the most common causes of perioperative anaphylaxis . it is used in acid peptic disease , as a preoperative premedication and for the prophylaxis of stress ulcers . common adverse effects of ranitidine are headache , drowsiness , decreased sex drive , nausea , and vomiting . anaphylaxis to ranitidine can occur at the first exposure , or it can occur after previous minor reactions leading to sensitization . presence of raised specific ige to ranitidine has been reported in many of these patients who developed anaphylaxis . we presented a case in which a commonly used drug such as ranitidine was presumably a cause of repeated perioperative anaphylaxis , and the patient underwent successful surgery when ranitidine was avoided . it is imperative to keep a high index of suspicion in perioperative anaphylaxis and in our setting , good history taking even in the absence of definitive tests , can result in successful outcome and prevention of a potentially fatal event .
perioperative anaphylaxis is a rare and catastrophic event . 
 anaphylaxis during perioperative period changes the entire management plan for the patient . since a large number of drugs 
 are administered to the patient during the short span of time , it becomes difficult to identify the culprit drug . 
 this has an impact on the management of the patients who have to undergo surgery . 
 ranitidine is considered a safe drug used in perioperative period ; however , rarely it can lead to perioperative anaphylaxis . 
 we present one such case of ranitidine - induced perioperative anaphylaxis which was successfully managed by early diagnosis and avoidance of drug .