An Appraisal of Cephalexin Monohydrate Levels in Semen and Prostatic Tissue

Abstract

Studies were carried out on a series of patients with chronic bacterial prostatitis and on a series of patients who had undergone vasectomy or prostatectomy, to determine whether cephalexin monohydrate could be found at a bacteriocidal level in semen and prostatic tissue. 500-mg and 1-g tablets were given prior to collecting semen samples or prostatectomy. Semen levels were obtained in 38 samples. The mean values obtained were 1.7 μg/ml after 500 mg of cephalexin and 2.76 μg/ ml after 1 g. Prostatic tissue levels were obtained in 21 samples. The mean values obtained were 0.88 and 3.91 μg/g, respectively. These low semen and prostatic tissue levels fall short of the MIC values of the flora that can be isolated from cases of chronic bacterial prostatitis, and it would seem likely that this antibiotic will be of little value in the treatment of this condition.

Penetration of Antimicrobial Agents into the Prostate

“…These features probably are responsible for the low but measurable level of cephalexin found in prostatic tissue [14]. In two studies on human prostatic tissue, the concentration of cephalexin after oral administration was invariably less than 10 Ìg/ml and was less than 5 Ìg/ml in the majority of patients [15,16].…”

Male Fertility

“…Improvement only followed long-term intensive treatment of the infection. This need for long-term therapy correlates with work done at The London Hospital which showed a lower concentration of antibiotic in the prostate than in the blood serum (Symes et al 1974). For such cases it is best to avoid nitrofurantoin because of possible interference with the maturation of the spermatocytes (Nelson & Bunge 1957).…”

Pharmacokinetics of β-Lactam Antibiotics

“…Drug concentration in fetal urine, placenta, amniotic fluid, umbilical cord, and fallopian tube was 8%-25% of the concentration in maternal serum. SYMES et al (1974) found cephalexin levels in semen and prostatic tissue to be low after 0.5-g or 1.0-g oral doses. KOERNER and JAESCHKE (1974) found that cephalexin must be dosed at 3 g per day for at least 3 days before significant drug levels could be found in epididymis, fat tissue, and muscle tissue.…”