Studies on cerebrospinal fluid diffusion of trimethoprim in children

: Full quantitative fluorometric analysis of TMP in serum and cerebrospinal fluid in 91 infants and children (all anyhow designed for lumbar puncture for other reasons) 1/2 - 12 hours after i. v. injection of TMP in a single dose of 4 mg/kg (73 cases, tab. 1-2, fig. 1) or 12 mg/kg (18 cases, tab. 3, fig. 2). TMP in serum and cerebrospinal fluid showed regularly high plateaus for the whole time investigated, i.e. 12 hours after i. v. injection (fig. 1-2). The c.s.f./serum ratio for TMP (2-12 hours after injection) was 30-40%(fig. 1). After a dose of 12 mg/kg the ratio was even 50% and more (fig. 2). There were - in our material - no differences of the ratio according to c.s.f. state (normal - tab. 1, or pathological-tab. 2), or age. Considerating published data on enteral resorption of trimethoprim-sulfamethoxazole and c.s.f. diffussion of SMZ together with our results, we can expect a very intensifying proportion TMP: SMZ near 1:10 in cerebrospinal fluid after intake of officinal TMP-SMZ (Co-trimoxazol). This might have diagnostic and therapeutic consequences.