PubMed Health⌕ Search

SEARCH · PubMed Health

Results for “Cephalexin”

Explore indexed PubMed citations for clinical trials, systematic reviews and public health research. Read source abstracts and follow each citation to its original PubMed record.

Quote a phrase for an exact phrase match. Source license links do not imply unrestricted reuse.

At least 19 recordsLinked to original sources
PubMed1988

Comparative study of cephalexin hydrochloride and cephalexin monohydrate in the treatment of skin and soft tissue infections.

In two prospective, randomized multicenter double-blind studies with a dosage of either 250 mg given four times a day (study A) or 500 mg given two times a day (study B), the comparative efficacy and safety of cephalexin hydrochloride (LY061188; Keftab) and cephalexin monohydrate (Keflex) for treatment of skin and soft tissue infections were determined. In study A, 97 patients received cephalexin hydrochloride and 101 patients received cephalexin monohydrate. In study B, 75 patients received cephalexin hydrochloride and 70 patients received cephalexin monohydrate. Diagnoses included abscesses, cellulitis, wound infections, and infected dermatitis, and were comparable in the different treatment groups. Pathogens were isolated from 82% of patients enrolled; the majority of isolates were of Staphylococcus aureus, Streptococcus pyogenes, other staphylococcal species, and a few gram-negative bacteria. In study A, 68 of 71 (95.7%) evaluable patients who received cephalexin hydrochloride responded satisfactorily; 73 of 81 (90%) patients who received cephalexin monohydrate also responded satisfactorily. In study B, 56 of 58 (96.5%) evaluable patients who received cephalexin hydrochloride responded satisfactorily; 47 of 50 (94%) patients who received cephalexin monohydrate also responded satisfactorily. An adverse clinical event leading to discontinuation of the treatment drug developed in 17 of 343 (4.95%) patients in both studies. No differences were noted between the two drugs. Skin eruptions, pruritus, and mild gastrointestinal symptoms were the common adverse effects. These data suggest that cephalexin hydrochloride, a new formulation of cephalexin, is a safe and effective antimicrobial agent for treatment of a variety of skin and subcutaneous infections in a dosage of either 250 mg four times a day or 500 mg twice a day.

Adult↗
PubMed1994

Cephalexin concentrations in radicular granuloma following a single oral administration of 250- or 500-mg cephalexin.

1. Cephalexin concentrations in radicular granuloma and serum following a single oral administration of 250- or 500-mg cephalexin were measured by a paper disk method. 2. The highest concentration of cephalexin in radicular granuloma following administration of 250-mg cephalexin to nonfasting patients was observed at 2 hr, and was 1.62 micrograms/g. The mean cephalexin concentration ratio of radicular granuloma/serum at 2 hr was 0.35. 3. The highest concentrations of cephalexin in radicular granuloma following administration of 500-mg cephalexin to nonfasting and fasting patients occurred at 2 and 1.5 hr, and was 3.35 and 3.42 micrograms/g, respectively. Mean cephalexin concentration ratios of radicular granuloma/serum at 2 and 1.5 hr were 0.32 and 0.30, respectively. 4. All mean cephalexin concentrations in radicular granuloma following administration of 500-mg cephalexin to both fasting and nonfasting patients exceeded MIC for 90% (2 micrograms/ml) of clinically isolated strains of alpha-hemolytic streptococci. However, those concentrations obtained by 250-mg cephalexin did not exceed it.

Adult↗
PubMed1983

Ineffectiveness of cephalexin in treatment of cephalexin-resistant bacteriuria in patients with chronic indwelling urethral catheters.

Catheterized patients not only are subject to risks of bacteriuria but the catheter also may act as reservoirs for nosocomial infections. Antibiotics that are concentrated in the urine, even those to which the organisms are nominally resistant, have been advocated as a means of treatment and infection control. During a randomized study of repetitive 10-day courses of cephalexin in chronically catheterized patients we observed the impact of such treatment upon susceptible, moderately resistant and highly resistant strains of bacteria. Cephalexin diminished the persistence of cephalexin-susceptible strains. However, its effect upon moderately resistant (inhibited by 200 micrograms per ml.) was not different than its effect upon highly resistant (not inhibited by 200 micrograms per ml.) strains. Indeed, the persistence of strains of moderately and highly resistant organisms during cephalexin courses was similar to that of such organisms during comparable periods in patients not receiving cephalexin. The administration of cephalexin to chronically catheterized patients with moderately or highly resistant organisms causing bacteriuria does not clear these organisms from the urine.

Adult↗
PubMed1998

Analysis of the pharmacokinetic interaction between cephalexin and quinapril by a nonlinear mixed-effect model.

Oligopeptidic drugs such as beta-lactams and angiotensin-converting enzyme inhibitors share the same carriers in humans and animals, which results in possible pharmacokinetic interactions. To model such interactions, the effects of quinapril on cephalexin pharmacokinetics were investigated in rats. Blood cephalexin concentrations were measured by liquid chromatography, and the data were analyzed by a noncompartmental method and by fitting a bicompartmental model by a nonlinear mixed-effect modeling approach. Five groups of eight rats were examined. In the first three groups, cephalexin elimination kinetics after intra-arterial administration alone or in combination with quinapril given by the parenteral or the oral route were studied, and the occurrence of a pharmacokinetic interaction was not revealed. The absence of an effect of quinapril on cephalexin elimination after parenteral administration might be explained either by the higher affinity of cephalexin for the renal anionic transport system than that of quinapril or by the much higher concentrations of cephalexin than those of quinapril. In the last two groups, cephalexin was administered by the oral route alone or in combination with quinapril. The mean area under the concentration-time curve (AUC) for cephalexin was increased by ca. 30% by coadministration of quinapril (40.1 versus 31.4 mg.h/liter; P = 0.04). The mean elimination clearance of cephalexin was significantly decreased by quinapril, from 0.81 to 0.64 liter/h/kg of body weight (P < 0.05), probably by competitive inhibition of cephalexin secretion at the tubular level. The mean absorption rate constant of cephalexin was significantly lowered by quinapril (from 0.249 to 0.177 h-1; P < 0.01), without modification of the extent of absorption (89%). This pharmacokinetic interaction could be explained by competitive inhibition of cephalexin active transport by quinapril at the intestinal level.

Angiotensin-Converting Enzyme Inhibitors↗
PubMed2004

Effects of progesterone and norethisterone on cephalexin uptake in the human intestinal cell line Caco-2.

Little is known about the regulatory effects of steroid hormones on the intestinal H(+)/oligopeptide transporter PEPT1. In the present study, we investigated the effects of progesterone and its related compounds on the uptake of cephalexin, a typical PEPT1 substrate, using the human intestinal cell line Caco-2. Caco-2 cell monolayers were cultured on plastic cell culture plates coated with rat tail collagen type I. The determination of cephalexin uptake was performed with HPLC. To investigate the effect of progesterone treatment on cephalexin uptake, the monolayers were incubated with cephalexin after progesterone treatment. Progesterone decreased cephalexin uptake in a concentration-dependent manner, and the IC(50) value was calculated to be 2.3 microM. A significant decrease in cephalexin uptake was observed after progesterone treatment for 12 h, and the decrease was maximal when the monolayers were treated for 24-72 h. Cephalexin uptake was significantly inhibited by treatments with 17alpha-hydroxyprogesterone, norethisterone, and chlormadinone. By contrast, treatment with dehydroepiandrosterone, pregnenolone, estradiol, testosterone, hydrocortisone, and dexamethasone did not affect cephalexin uptake. The effects of progesterone and norethisterone treatment on the kinetic parameters of cephalexin uptake were investigated. The saturable component of cephalexin uptake was markedly inhibited by progesterone and norethisterone treatments. The J(max) of cephalexin uptake with progesterone and norethisterone treatments was significantly decreased compared with the control, whereas K(m) and K(d) values were not affected. Therefore the quantitative decrease in PEPT1 density is considered to be one cause of the decrease in cephalexin uptake with progesterone and norethisterone treatments.

Biological Transport↗
PubMed2002

Integrated reactor concepts for the enzymatic kinetic synthesis of cephalexin.

Integrated process concepts for enzymatic cephalexin synthesis were investigated by our group, and this article focuses on the integration of reactions and product removal during the reactions. The last step in cephalexin production is the enzymatic kinetic coupling of activated phenylglycine (phenylglycine amide or phenylglycine methyl ester) and 7-aminodeacetoxycephalosporanic acid (7-ADCA). The traditional production of 7-ADCA takes place via a chemical ring expansion step and an enzymatic hydrolysis step starting from penicillin G. However, 7-ADCA can also be produced by the enzymatic hydrolysis of adipyl-7-ADCA. In this work, this reaction was combined with the enzymatic synthesis reaction and performed simultaneously (i.e., one-pot synthesis). Furthermore, in situ product removal by adsorption and complexation were investigated as means of preventing enzymatic hydrolysis of cephalexin. We found that adipyl-7-ADCA hydrolysis and cephalexin synthesis could be performed simultaneously. The maximum yield on conversion (reaction) of the combined process was very similar to the yield of the separate processes performed under the same reaction conditions with the enzyme concentrations adjusted correctly. This implied that the number of reaction steps in the cephalexin process could be reduced significantly. The removal of cephalexin by adsorption was not specific enough to be applied in situ. The adsorbents also bound the substrates and therewith caused lower yields. Complexation with beta-naphthol proved to be an effective removal technique; however, it also showed a drawback in that the activity of the cephalexin-synthesizing enzyme was influenced negatively. Complexation with beta-naphthol rendered a 50% higher cephalexin yield and considerably less byproduct formation (reduction of 40%) as compared to cephalexin synthesis only. If adipyl-7-ADCA hydrolysis and cephalexin synthesis were performed simultaneously and in combination with complexation with beta-naphthol, higher cephalexin concentrations also were found. In conclusion, a highly integrated process (two reactions simultaneously combined with in situ product removal) was shown possible, although further optimization is necessary.

Adsorption↗
PubMed1984

Cephalexin pharmacokinetics in patients with cystic fibrosis.

Pharmacokinetics of cephalexin were studied in 7 pediatric and 4 adult patients with cystic fibrosis (CF) and 4 normal adult volunteers. Cephalexin, 250-500 mg, was given as a single dose in suspension. The area under the cephalexin serum concentration-time curve normalized for dose per kilogram averaged 0.185, 0.242, and 0.272 ml/min/kg-1 in pediatric CF patients, adult CF patients, and normal adults, respectively (p greater than 0.05). A threefold interindividual variation was observed in cephalexin renal clearance in CF patients. Renal clearance of cephalexin averaged 5.85 ml/min/kg in pediatric and 4.61 ml/min/kg in adult CF patients (p greater than 0.05). Elimination half-life of cephalexin averaged 0.74, 0.76, and 1.04 h in pediatric patients, adult patients, and normal adults (p greater than 0.05). Cephalexin was well absorbed based on a mean 24-hour urinary recovery of 89 and 93% in pediatric and adult patients. A trend for higher renal clearance of cephalexin was observed among pediatric compared to adult patients. These results indicate that clearance of cephalexin may not increase in patients with CF of minimal severity characterized by an excellent Shwachman score.

Adult↗
PubMedDate not supplied

Efficacy of cephalexin two vs. three times daily vs. cefadroxil once daily for streptococcal tonsillopharyngitis.

The purpose of this study was to compare the bacteriologic and clinical efficacy of oral cephalexin twice vs. three times daily vs. cefadroxil once daily as therapy for group A beta-hemolytic streptococcal (GABHS) tonsillopharyngitis. A prospective open-label, observational cohort study was conducted over 18 months (January 2000-June 2001). Children enrolled had an acute onset of symptoms and signs of a tonsillopharyngeal illness and a laboratory-documented GABHS infection. Follow-up examination and laboratory testing occurred 21 +/- 4 days following enrollment. Two hundred seventy-one patients were enrolled (intent to treat group): 63 received cephalexin twice daily, 124 received cephalexin three times daily, and 84 received cefadroxil once daily. Fifty-three children did not return for the follow-up visit, leaving 218 patients in the per-protocol group: 54 cephalexin twice-daily treated, 94 cephalexin 3-times daily treated, and 70 cefadroxil once-daily treated. In the per-protocol group, bacteriologic cure for those treated with cephalexin twice daily was 87%, for cephalexin 3 times daily, it was 81% and for cefadroxil once daily it was 81% (p = 0.61). The clinical cure rate for cephalexin twice-daily treatment was 91%; for three-times daily, it was 86%; and for cefadroxil once daily, it was 84% (p = 0.56). Because treatment allocation was not randomized, logistic regression analysis was used to adjust for treatment group differences. Younger age of patient was significantly associated with bacteriologic (p = 0.04) and clinical (p = 0.01) failure independent of treatment group but in the adjusted logistic model no differences were found among the 3 treatment regimens. Cephalexin dosed twice daily or three times daily and cefadroxil dosed once daily appear equivalent in bacteriologic and clinical cure of GABHS tonsillopharyngitis.

Administration, Oral↗
PubMed1992

Cephalexin and penicillin in the treatment of group A beta-hemolytic streptococcal throat infections.

OBJECTIVE: To determine whether cephalexin or penicillin is more effective in the treatment of group A beta-hemolytic streptococcal tonsillopharyngitis in children. DESIGN: Randomized, double-blind, crossover study conducted from 1981 to 1984. SETTING: Seven pediatric practices in the United States, including private offices and pediatric clinics. PARTICIPANTS: Of the 654 patients, 525 children and adolescents with clinical evidence of tonsillitis or pharyngitis and throat cultures positive for group A beta-hemolytic streptococcal infection were evaluable. Eighty percent of patients completed the study; none were withdrawn because of adverse reaction. SELECTION CRITERIA: Children and adolescents who had acute illness suggestive of group A beta-hemolytic streptococcal infection were enrolled in the study. Treatment was continued if the throat culture was positive for group A beta-hemolytic streptococcal infection. INTERVENTIONS: Four doses of cephalexin and penicillin (27 mg/kg per day) were prescribed to be taken on an empty stomach for 10 days. MEASUREMENTS/MAIN RESULTS: Symptomatic clinical failure occurred in 8% of penicillin-treated patients and in 3% of cephalexin-treated patients. Bacteriologic failure rates were 11% in the penicillin treatment group and 7% in the cephalexin treatment group. The combined treatment failure rate of clinical relapse plus asymptomatic bacteriologic failure was 19% in the penicillin treatment group and 10% in the cephalexin treatment group. Paired antistreptolysin-O titer increased significantly in 62.3% of penicillin-treated patients and in 64.2% of cephalexin-treated patients. Similarly, anti-DNase B titers rose 52.2% in penicillin-treated patients and 52.4% in cephalexin-treated patients. CONCLUSION: Cephalexin is a more effective drug than penicillin in the treatment of group A beta-hemolytic streptococcal throat infection in children.

Adolescent↗
PubMed1996

A pharmacokinetic comparison of cefadroxil and cephalexin after administration of 250, 500 and 1000 mg solution doses.

The pharmacokinetics of cefadroxil and cephalexin were examined following single oral doses of either 250, 500 or 1000 mg to a total of 36 healthy volunteers. The volunteers were divided into groups of 12 per dose-group and solution doses of cefadroxil or cephalexin were administered after an overnight fast according to a crossover design for the cephalosporins but not for doses. Serial blood and urine samples were collected from each individual and were analyzed for cefadroxil or cephalexin using validated HPLC assays with UV detection. The individual subject plasma concentration-time data for each cephalosporin were analyzed using noncompartmental methods. Profiles for cephalexin in plasma showed sharper and higher peaks than those for cefadroxil. Although values for the peak concentrations (Cmax) for cefadroxil were lower than that of cephalexin, the levels of cefadroxil in plasma and urine remained above the reported minimum inhibitory concentrations of susceptible organisms for longer period of time than those of cefalexin. The elimination half-life (t1/2) of cefadroxil (about 2 h) was significantly longer than that of cephalexin (about 1 h). The values for Cmax and AUC0-infinity values for both these cephalosporins showed dose-proportional increase, whereas t1/2, renal clearance (CLR) remained independent of dose. These observations confirm that cefadroxil and cephalexin obey linear pharmacokinetics. The CLr of both the cephalosporins were significantly higher than the average glomerular filtration rate at each dose level. The urinary recovery (% Xu) of each cephalosporin, accounted for over 80 per cent of the administered dose, and no significant differences in % Xu were observed between the two cephalosporins. These data suggest that the systemic availability of cefadroxil and cephalexin is similar at each dose level.

Adult↗
PubMed1989

Effective prophylaxis of recurrent urinary tract infections in premenopausal women by postcoital administration of cephalexin.

A total of 31 sexually active premenopausal women, prone to have recurrent urinary tract infections but who otherwise were healthy, underwent postcoital prophylaxis consisting of a single oral dose of 250 mg. cephalexin. While 127 urinary tract infections occurred in these patients during a mean of 6 months before treatment, only 1 occurred during a mean of 12 months after postcoital cephalexin prophylaxis. This difference was statistically highly significant. Each of these patients ingested approximately 120 cephalexin tablets per year of postcoital prophylaxis. Postcoital oral cephalexin prophylaxis is highly effective in the prevention of recurrent urinary tract infection in the nonpregnant as well as pregnant premenopausal women because of easy compliance, the high urine concentration achieved and the minimal induction of resistance to cephalexin in the introital gram-negative bacterial flora. Postcoital cephalexin prophylaxis achieves identical results to daily cephalexin prophylaxis but uses only a third of the tablets required in the daily regimens. Finally, cephalexin represents an additional valuable antibacterial drug in postcoital prophylaxis along with cotrimoxazole, nitrofurantoin and cinoxacin.

Adult↗
PubMedDate not supplied

Cefdinir versus cephalexin for the treatment of skin and skin-structure infections. The Cefdinir Adult Skin Infection Study Group.

Because of increasing resistance to older antimicrobial agents, newer drugs need to be evaluated for the treatment of skin and skin-structure infections (SSSIs). This double-masked, randomized, comparative, multicenter study enrolled patients aged 13 years or older with SSSIs to receive either cefdinir 300 mg BID or cephalexin 500 mg QID for 10 days. Nine hundred fifty-two patients (474 in the cefdinir group and 478 in the cephalexin group) took part, primarily white males between 18 and 65 years of age. There were two follow-up visits, with efficacy determined at the test-of-cure visit, 7 to 16 days posttherapy. Many patients were not microbiologically assessable, primarily because of negative cultures at study admission. Patients who required surgical intervention (e.g., incision and drainage) at the site of infection more than 24 hours after the initiation of drug therapy were defined as treatment failures. Significantly more isolated pathogens were resistant to cephalexin than to cefdinir. In the 178 efficacy-assessable cefdinir-treated patients, the rate of pathogen eradication was 93% (200/215), and the rate of successful clinical response was 88% (157/178), compared with 89% (221/247) and 87% (177/204), respectively, in the 204 efficacy-assessable cephalexin-treated patients. Using confidence-interval analysis, the microbiologic and clinical response rates of the cefdinir-treated patients were statistically equivalent to those of the cephalexin-treated patients. At the follow-up visits, patients were questioned about any adverse events occurring since their previous visit. Any untoward symptom occurring during or within 2 days after completion of drug treatment was considered an adverse reaction if the investigator judged it to be definitely, probably, or possibly related to the study drug. One hundred twenty-three (26%) cefdinir-treated patients and 77 (16%) cephalexin-treated patients experienced at least one adverse reaction, a statistically significant difference. Study drug was discontinued for adverse reactions in 20 (4%) cefdinir-treated patients and 13 (3%) cephalexin-treated patients; in the two groups, 10 and 7 patients, respectively, were discontinued for diarrhea. Cefdinir taken BID was as effective as cephalexin taken QID in the treatment of mild-to-moderate SSSIs and was well tolerated by most patients. The increased antibacterial activity of cefdinir must be balanced against the higher rate of diarrhea seen in patients treated with this drug.

Adolescent↗
PubMed2002

A comparison of the efficacy and safety of mupirocin cream and cephalexin in the treatment of secondarily infected eczema.

The efficacy and safety of mupirocin calcium cream were compared with those of oral cephalexin in the treatment of secondarily infected eczema. In this multicentre, double-blind, double-dummy study, 159 patients with secondarily infected eczema (suitable for treatment with topical antimicrobials) and a total skin infection rating scale score of 8 or more were randomized to receive either topical mupirocin cream three times daily or oral cephalexin, 250 mg four times daily, for 10 days (intent-to-treat group). Clinical success (per-protocol group), defined in part as a patient with a response of improvement in the skin infection rating scale, was similar in the two groups: 89% for mupirocin (n = 44) and 82% for cephalexin (n = 38) [P = 0.29; 95% confidence interval (-8.4%, 22.5%)]. Bacteriological success (intent-to-treat group), defined as a patient with a response of eradication, improvement or colonization of bacteria at the end of therapy, however, was significantly higher for mupirocin [50% and 28% in the mupirocin (n = 48) and cephalexin (n = 47) groups, respectively; P=0.005]. Mupirocin cream was as well tolerated as cephalexin; 9% and 13% of patients reported adverse events related or possibly related to study medication in the mupirocin and cephalexin groups, respectively. The most common adverse events overall were diarrhoea and nausea. Mupirocin cream applied three times daily is as effective clinically and superior bacteriologically compared with oral cephalexin given four times daily in the treatment of secondarily infected eczema of limited depth and severity. Mupirocin cream is as well tolerated as oral cephalexin, and more patients prefer the topical regimen, which should improve patient compliance.

Administration, Cutaneous↗
PubMed2005

Pharmacokinetics and tissue fluid distribution of cephalexin in the horse after oral and i.v. administration.

The purpose of this study was to determine the pharmacokinetics and tissue fluid distribution of cephalexin in the adult horse following oral and i.v. administration. Cephalexin hydrate (10 mg/kg) was administered to horses i.v. and plasma samples were collected. Following a washout period, cephalexin (30 mg/kg) was administered intragastrically. Plasma, interstitial fluid (ISF) aqueous humor, and urine samples were collected. All samples were analyzed by high-pressure liquid chromatography (HPLC). Following i.v. administration, cephalexin had a plasma half-life (t(1/2)) of 2.02 h and volume of distribution [V(d(ss))] of 0.25 L/kg. Following oral administration, the average maximum plasma concentration (C(max)) was 3.47 mug/mL and an apparent half-life (t(1/2)) of 1.64 h. Bioavailability was approximately 5.0%. The AUC(ISF):AUC(plasma) ratio was 80.55% which corresponded to the percentage protein-unbound drug in the plasma (77.07%). The t(1/2) in the ISF was 2.49 h. Cephalexin was not detected in the aqueous humor. The octanol:water partition coefficient was 0.076 +/- 0.025. Cephalexin was concentrated in the urine with an average concentration of 47.59 microg/mL. No adverse events were noted during this study. This study showed that cephalexin at a dose of 30 mg/kg administered orally at 8 h dosage intervals in horses can produce plasma and interstitial fluid drug concentrations that are in a range recommended to treat susceptible gram-positive bacteria (MIC < or = 0.5 microg/mL). Because of the low oral bioavailability of cephalexin in the horse, the effect of chronic dosing on the normal intestinal bacterial flora requires further investigation.

Administration, Oral↗
PubMed2004

A randomized crossover study investigating the influence of ranitidine or omeprazole on the pharmacokinetics of cephalexin monohydrate.

Limited data characterize pharmacokinetic interactions between cephalexin and ranitidine, and no data exist for an interaction with proton pump inhibitors. The purpose of this study was to investigate the effects of ranitidine or omeprazole administration on the pharmacokinetics and pharmacodynamics of cephalexin. A randomized single- and multiple-dose crossover study was conducted in healthy subjects ingesting cephalexin before and after steady-state administration of ranitidine or omeprazole. Time-concentration profiles were determined and pharmacokinetic parameters were characterized using noncompartmental methods. Pharmacokinetic data were analyzed in accordance with the two 1-sided test for bioequivalence. The percentage of time that serum concentrations remain above the MIC(90) during the dosing interval (T > MIC(90)) for Streptococcus pyogenes and Staphylococcus aureus associated with the pharmacokinetic profiles was calculated. The coadministration of cephalexin with ranitidine or omeprazole resulted in relatively minor changes in C(max), AUC(infinity), t(1/2), or CL/F. t(max) was significantly prolonged when cephalexin was administered with ranitidine or omeprazole. Suboptimal T > MIC(90) was observed for cephalexin irrespective of acid suppression. Delay in absorption of cephalexin resulted in a decrease in the percentage of T > MIC(90) for certain acid-suppressive regimens and pathogen combinations. With the exception of an increase in t(max), there were no significant pharmacokinetic interactions between cephalexin and ranitidine or omeprazole. Delayed t(max) associated with acid suppression may result in a diminished T > MIC(90).

Adult↗
PubMed2006

Transfer of probenecid and cephalexin into breast milk.

OBJECTIVE: To report a case of the transfer of probenecid and cephalexin into human milk. CASE SUMMARY: A breast-fed infant of a 30-year-old woman being treated with oral probenecid and cephalexin for a breast infection developed severe diarrhea and associated symptoms. To investigate whether the maternal drug treatment was causative, milk was collected over a dose interval at steady-state, and concentrations of probenecid and cephalexin were measured by HPLC. The average concentrations of probenecid and cephalexin in milk were 964 and 745 microg/L, respectively, corresponding to absolute and relative infant doses of 145 microg/kg/day and 0.7% for probenecid and 112 mug/kg/day and 0.5% for cephalexin. The infant's adverse effects were rated as possible for probenecid and probable for cephalexin based on the Naranjo probability scale. DISCUSSION: On the basis of the calculated relative infant doses for both probenecid and cephalexin in milk and the notional 10% level of concern for infant exposure, neither drug would be expected to cause significant systemic effects. However, local adverse effects, notably diarrhea, were observed. The Naranjo probability scale rating suggested that cephalexin was more likely than probenecid to be the cause of the infant's diarrhea. CONCLUSIONS: When using cephalexin/probenecid to treat breast infections in lactating women, clinicians should anticipate the possibility of adverse gastrointestinal effects in the breast-fed infant.

Adult↗