Does repeated IV antibiotics for UTIs cause memory loss

The evidence you retrieved does not directly test whether repeated IV antibiotics for UTIs cause memory loss. No study in this set measured cognitive outcomes after IV antibiotic courses.

What the evidence does show is that certain IV antibiotics, especially cephalosporins, can cause serious central nervous system side effects. A nationwide French pharmacovigilance analysis of 511 serious cephalosporin-associated CNS reactions found that encephalopathy occurred in 34% of cases, convulsions in 27%, and confusional states in 19% [25]. The drugs most often implicated were cefepime (33% of reports) and ceftriaxone (30%). The average patient was 67 years old, and 88% of those with measured kidney function had renal impairment, which can cause drug levels to build up and cross into the brain [25].

These are serious neurological events, not subtle memory loss. But the mechanism is relevant: if a drug can cause encephalopathy and confusion, repeated courses in someone with marginal kidney function could plausibly contribute to cognitive decline that might be mistaken for memory loss. The study did not follow patients long enough to test whether these episodes had lasting effects.

The rest of the retrieved evidence covers antibiotic effectiveness for UTIs, not cognitive harm. One rat study showed that UTI antibiotics disrupt the gut microbiome and metabolism [16], and a melanoma meta-analysis found that antibiotics before immunotherapy worsened survival [26], but neither addresses memory.

My call: the evidence does not answer whether repeated IV antibiotics for UTIs cause memory loss. It does show that IV cephalosporins can cause serious CNS toxicity, especially in older adults with kidney impairment, and that this class of drugs is commonly used for UTIs. If you or someone you know is experiencing cognitive changes after IV antibiotics, the mechanism is plausible enough to investigate, but the specific question has not been studied.

Confidence: not clear — the direct question has not been tested, but the known CNS toxicity of these drugs makes the hypothesis worth taking seriously.