228 - Expressive Aphasia after Oral Trimethoprim-Sulfamethoxazole Administration

Friday, February 20, 2026

5:00 PM - 6:30 PM AST

Presenting Author(s)

KH

Kevin Huang, DO

Doctor
Inspira Health Network
Philadelphia, Pennsylvania, United States

Co-Author(s)

TP

Tejas Patel, DO

Resident Physician PGY-2
Inspira Health Network
Philadelphia, Pennsylvania, United States
AS

Arpun Shah, DO, MPH

Resident Physician
Inspira Health Network
Mullica Hill, New Jersey, United States
PY

Prateek Yadav, DO

Resident Physician
Inspira Health Network
Philadelphia, Pennsylvania, United States
DB

David Brancale, BS

OMS IV
Rowan-Virtua SOM
Somerdale, New Jersey, United States

Corresponding Author(s)

GS

Gilbert Siu, DO, PhD

Medical Director / Associate Professor
EncompassHealth/Rowan University-SOM
Mantua, New Jersey, United States

Submitter(s)

GS

Gilbert Siu, DO, PhD

EncompassHealth/Rowan University-SOM
Mantua, New Jersey, United States

Case Diagnosis: Neurotoxic effect of trimethoprim-sulfamethoxazole causing expressive aphasia

Case Description: 84-year-old female presented with urinary tract infection and was administrated oral trimethoprim-sulfamethoxazole (TMP/SMX) without history of antibiotic allergies. After 2 doses of TMP/SMX, the patient became aphasic and had diffuse weakness. CT and MRI brain imaging were all negative. In addition, laboratory studies were all negative, besides the positive Escherichia Coli urinary tract infection. The patient receptively was able to understand, but unable to express her words. Ongoing work ups were negative; however, the only new medication introduced to the patient was TMP/SMX. TMP/SMX was discontinued, and the patient was given cefuroxime. Within twenty-four hours, the patient’s expressive aphasia improved. She was transferred to acute inpatient neurologic rehabilitation and participated in intensive speech therapy. Her aphasia resolved and she was discharged home.

Discussions: Neurotoxic effects of TMP/SMX are extremely rare. Acute encephalopathy and psychosis have been reported with TMP/SMX. Aphasia is an uncommon neurotoxic effect of TMP/SMX. TMP/SMX has excellent CNS penetration with a greater penetration in the elderly population. In addition, the half-life of TMP/SMX is around 8-10 hours. The exact mechanism of neurotoxicity and aphasia is still unknown. After discontinuing the medication, symptoms generally resolved; however, some of the neurotoxic effects can persist. In our case, the patient continued to have weakness and aphasia after TMP/SMX discontinuation. The patient was admitted to acute inpatient neurologic rehabilitation and after ten days of rehabilitation, she successfully recovered and became independent.

Conclusions: Aphasia is rarely seen in people receiving TMP/SMX. This case report highlights that the acute neurotoxic effect of TMP/SMX can lead to expressive aphasia and the importance of rehabilitation.