Identification of Possible Causative Agents in a Polymedicated Patient Presenting With Toxic Epidermal Necrolysis

Abstract

Purpose: To present the pharmacological evaluation process in a case of a polymedicated patient presenting with toxic epidermal necrolysis (TEN). Summary: A 75-year-old Caucasian polymedicated woman had been treated for hip pain with nonsteroidal anti-inflammatory drugs and pregabalin in the months preceding the apparition of an expanding papulo-erythematous rash. She had also started using new medicated eye drops for glaucoma. She presented to the emergency department of a regional hospital where all of her medications were stopped. The patient was transferred and admitted to a tertiary-care teaching hospital’s specialized burn unit for significant cutaneous detachment. It was estimated that 70% to 80% of the body surface area was affected. Skin biopsy showed keratinocyte necrosis with a partial detachment of the epidermis leading to a diagnosis of TEN. The reaction ceased to progress 2 days after the discontinuation of her medications. A complete reepithelialization was objectified after 10 days. A series of steps were followed by the hospital pharmacist to determine which drugs were the most probable culprits. A complete pharmacological history was obtained and a timeline for medication use in the 3 months preceding rash apparition was established. A review of the literature was done to determine the drugs’ relationships to Steven-Johnson syndrome or TEN. Using the algorithm of drug causality for epidermal necrolysis (ALDEN) score, it was determined that naproxen, pregabalin, and brinzolamide–timolol drops were all possible culprits. Conclusion: A systematic method for pharmacological evaluation of a polymedicated patient with TEN is presented. Naproxen, pregabalin, and brinzolamide–timolol drops were all retained as possible culprits.

Pregabalin-induced delayed cutaneous hypersensitivity reaction occurring after 40 days of use: a case report

“…Our case had the longest time interval between initiating pregabalin and the onset of the hypersensitivity reaction, and the largest skin area of involvement compared with other cases. [5][6][7][8][9][10][11][12] These findings in our case were attributed to pregabalin and confirmed by a drug provocation test. Gabapentinoids are first-line drugs for treating HZ neuralgia.…”

“…4 Reported cases of cutaneous hypersensitivity reactions caused by pregabalin generally occur within 2 weeks of initiating medication. [5][6][7][8][9][10][11][12] We report a rare case of a delayed cutaneous hypersensitivity reaction caused by pregabalin, which was confirmed by a drug provocation test. An elderly patient with severe herpes zoster (HZ) neuralgia developed maculopapular drug eruption covering 80% to 90% of the total body surface area after 40 days of combined multidrug analgesia.…”

“…To the best of our knowledge, eight cases of cutaneous hypersensitivity reactions caused by pregabalin have been reported. 5–12 Three of these cases occurred within 1 week, 5,6,12 three within 2 weeks, 7,9,10 and one within 4 weeks after initiating medication, 8 and the time interval was not reported in one case. 11 In patients who are not previously sensitized, the onset of maculopapular drug eruption occurs within 4 to 14 days after the start of exposure, but rarely occurs at weeks to months.…”

“…To the best of our knowledge, eight cases of cutaneous hypersensitivity reactions caused by pregabalin have been reported. [5][6][7][8][9][10][11][12] Three of Figure 3. Timeline of the patient's medications.…”

“…4 Reported cases of cutaneous hypersensitivity reactions caused by pregabalin generally occur within 2 weeks of initiating medication. 5–12…”