What is the cause of nausea, diarrhea, dizziness, and throat pruritus in a 74-year-old patient with a UTI taking Bactrim (trimethoprim/sulfamethoxazole)?

From the Guidelines

The patient should discontinue Bactrim immediately and switch to an alternative antibiotic, such as nitrofurantoin or a fluoroquinolone, due to the adverse reaction symptoms, including nausea, diarrhea, dizziness, and throat itchiness, which may indicate an allergic reaction. The symptoms experienced by the patient, including nausea, diarrhea, dizziness, and throat itchiness, are consistent with an adverse reaction to Bactrim (trimethoprim-sulfamethoxazole) 1. The throat itchiness is particularly concerning as it may indicate an allergic reaction that could potentially progress to a more serious condition like anaphylaxis.

Alternative Treatment Options

Alternative antibiotics for treating E. coli UTIs include:

• Fluoroquinolones (such as ciprofloxacin 500mg twice daily for 7 days), which have an estimated clinical efficacy of 90% and microbiological efficacy of 91% 1
• Nitrofurantoin (100mg twice daily for 5-7 days), which has an estimated clinical efficacy of 93% and microbiological efficacy of 88% 1
• Cephalosporins (such as cefuroxime 250mg twice daily for 7 days), which have an estimated clinical efficacy of 89% and microbiological efficacy of 82% 1 The choice of alternative antibiotic depends on the antibiotic sensitivity of the E. coli strain and the patient's medical history.

Considerations for Elderly Patients

Elderly patients, like the 74-year-old patient in this case, are more susceptible to medication side effects due to age-related changes in drug metabolism and elimination.

Documentation and Future Precautions

The healthcare provider should document this reaction in the patient's medical record to avoid future Bactrim prescriptions, as subsequent exposures could trigger more severe reactions.

From the FDA Drug Label

Fatalities and serious adverse reactions including severe cutaneous adverse reactions (SCARs) including Stevens-Johnson syndrome, toxic epidermal necrolysis, drug reaction with eosinophilia and systemic symptoms (DRESS), acute febrile neutrophilic dermatosis (AFND), acute generalized erythematous pustulosis (AGEP); fulminant hepatic necrosis; agranulocytosis, aplastic anemia and other blood dyscrasias; acute and delayed lung injury; anaphylaxis and circulatory shock have occurred with the administration of sulfamethoxazole and trimethoprim products, including sulfamethoxazole and trimethoprim Sulfamethoxazole and trimethoprim should be discontinued at the first appearance of skin rash or any sign of a serious adverse reaction. Clinical signs, such as rash, pharyngitis, fever, arthralgia, cough, chest pain, dyspnea, pallor, purpura or jaundice may be early indications of serious reactions.

The patient's symptoms of nausea, diarrhea, dizziness, and throat itchiness while taking Bactrim (sulfamethoxazole and trimethoprim) may be indicative of a serious adverse reaction.

• The presence of these symptoms warrants immediate discontinuation of the medication.
• The patient should be closely monitored for signs of a serious reaction, such as a skin rash or other clinical signs.
• Alternative treatment options should be considered for the patient's UTI. 2

From the Research

Patient Symptoms and Treatment

• The patient, a 74-year-old individual, is experiencing symptoms of nausea, diarrhea, dizziness, and throat itchiness after being treated with Bactrim (trimethoprim-sulfamethoxazole) for a urinary tract infection (UTI) caused by E. coli.
• These symptoms may be related to the treatment, as Bactrim can cause adverse effects such as gastrointestinal disturbances and allergic reactions 3.

Resistance to Trimethoprim-Sulfamethoxazole

• Studies have shown that there is a significant prevalence of resistance to trimethoprim-sulfamethoxazole among E. coli isolates, with rates ranging from 13% to 45% 4 and 24% 5.
• The use of trimethoprim-sulfamethoxazole may be compromised by the increasing resistance rates, making it essential to consider alternative treatment options 5.

Alternative Treatment Options

• Fluoroquinolones may be considered as an alternative treatment option, but resistance rates to these antibiotics are also increasing, with rates ranging from 1% to 6% 4 and 16.4% 3.
• Oral β-lactam antibiotics may be a viable option for step-down treatment, especially when other options are limited by resistance or adverse effects 6.

Considerations for Treatment

• The choice of antibiotic treatment should be based on the susceptibility of the E. coli isolate and the patient's clinical condition 4, 5, 6, 3.
• It is essential to monitor the patient's response to treatment and adjust the antibiotic regimen as needed to ensure effective treatment and minimize the risk of adverse effects 6, 3.