Azithromycin is as effective as and better tolerated than erythromycin estolate for the treatment of pertussis.

OBJECTIVE: Although universal immunization against Bordetella pertussis (whooping cough) infection has resulted in dramatic reductions in the incidence of pertussis, outbreaks continue to occur in countries with excellent vaccine coverage. Treatment of infection may ameliorate symptom severity during the catarrhal phase of pertussis but has no effect on established paroxysms, emesis, or apnea if given during the paroxysmal or convalescent phases. Erythromycin, recommended for treatment of pertussis to prevent transmission of infection, is poorly tolerated because of gastrointestinal side effects. We compared the safety and efficacy of erythromycin with azithromycin for treatment of pertussis in a large, randomized, controlled trial that enrolled children from primary care practices in 1 American and 11 Canadian urban centers. METHODS: Children who were 6 months to 16 years of age and had cough illness that was suspected to be or was culture confirmed as pertussis were randomized to azithromycin (10 mg/kg on day 1 and 5 mg/kg on days 2-5 as a single dose) or erythromycin estolate (40 mg/kg/day in 3 divided doses for 10 days) with stratification by center. The primary outcome measure was bacteriologic cure of infection as determined by cultures of nasopharyngeal aspirates. Culture-positive participants had a second aspirate collected at the end of therapy (days 5-7 for azithromycin, days 10-12 for erythromycin) and 1 week after therapy. Bacteriologic cure was defined as negative cultures at the end of therapy. Bacteriologic relapse was defined as a positive culture 1 week after completion of therapy and after a negative end-of-therapy culture. Secondary outcomes were pertussis diagnosed by serology and polymerase chain reaction (PCR), treatment-associated adverse events, compliance, and presence of clinical symptoms at the end of the treatment course. Serology was performed using standard enzyme-linked immunosorbent assay methods. A participant was considered to have pertussis when the PCR was positive or a 4-fold increase in pertussis toxin antibody between baseline and follow-up visits was observed. PCR was performed using a 1046-bp ClaI DNA fragment from B pertussis. Adverse events (nausea, vomiting, diarrhea, any gastrointestinal complaint, or other) were determined by a parent-completed diary that was reviewed with study personnel during study visits. Compliance was measured by review of the parent medication diary during study visits and observation of medication containers by the pharmacist at study completion. Symptoms were determined by history collected by study personnel at enrollment and subsequently from the diary. The design of the study was an equivalence trial, aimed at demonstrating that the bacteriologic failure rates with the 2 therapies did not differ by >8%. For the safety analysis, all participants who received at least 1 dose of study drug were included. In the per-protocol efficacy analysis, all culture-positive participants with end-of-treatment cultures were considered. RESULTS: A total of 477 children were enrolled and randomly assigned to either azithromycin (n = 239) or erythromycin (n = 238). Of these children, 114 (24%) grew B pertussis from nasopharyngeal specimens (azithromycin group: 58 of 239 [24%]; erythromycin group: 56 of 238 [23%]); these children composed the efficacy cohort for the per-protocol and intention-to-treat analyses. Serology and PCR added 52 children to the number considered to have pertussis for a total of 35% (166 of 477) of all children who presented with cough illness. In the safety analysis (antibiotic side effects, compliance) and comparison of cough symptoms after treatment, all randomized children are reported in their assigned treatment group. At end of therapy, bacterial eradication was demonstrated in all 53 patients in the azithromycin group and all 53 patients in the erythromycin group with follow-up cultures available (eradication 100%; 95% confidence interval [CI]: 93.3-100). No bacterial recurrence was demonstrated in children with 1 week posttreatment nasopharyngeal cultures available (51 and 53 participants in the azithromycin and erythromycin arms, respectively [0%, 95% CI: 0-7.0; and 0%, 95% CI: 0-6.7]). No serious adverse events attributable to study drug were observed. Gastrointestinal adverse events were reported less frequently in azithromycin (18.8%; 45 of 239) than in erythromycin estolate (41.2%; 98 of 238) recipients (90% CI on difference: -29.0% to -15.7%) as a result of less nausea (2.9% vs 8.4%; 95% CI: -8.9% to -2.0%), less vomiting (5.0% vs 13.0%; 95% CI: -4.9% to -1.4%), and less diarrhea (7.1% vs 11.8%; 95% CI: -9.0% to -0.3%). Children who were randomized to azithromycin were much more likely to have complied with antimicrobial therapy over the treatment period. In the azithromycin group, 90% of children took 100% of prescribed doses, whereas only 55% of children in the erythromycin group took 100% of prescribed doses. CONCLUSIONS: In this large, multicenter, randomized trial, we found that azithromycin is as effective as erythromycin estolate for the treatment of pertussis in children. Gastrointestinal adverse events were much more common with erythromycin treatment than azithromycin. Compliance with therapy was markedly better with azithromycin than with erythromycin in this study.

Protective role of tetrahydrocurcumin against erythromycin estolate-induced hepatotoxicity.

Tetrahydrocurcumin (THC), one of the major metabolites of curcumin, was investigated for its possible hepatoprotective effect in Wistar rats against erythromycin estolate-induced toxicity. Oral administration of THC significantly prevented the occurrence of erythromycin estolate-induced liver damage. The increased level of serum enzymes (aspartate transaminase (AST), alanine transaminase (ALT), alkaline phosphatase (ALP)), bilirubin, cholesterol, triglycerides, phospholipids, free fatty acids and plasma thiobarbituric acid reactive substances (TBARS) and hydroperoxides observed in rats treated with erythromycin estolate were very much reduced in rats treated with THC and erythromycin estolate. This biochemical observation were supplemented by histopathological examination of liver section. Results of this study revealed that THC could afford a significant protection against erthromycin estolate-induced hepatocellular damage. Tetrahydrocurcumin had a better protective effect when compared with Silymarin, a reference drug.

Multicenter, randomized, double-blind comparison of erythromycin estolate versus amoxicillin for the treatment of acute otitis media in children. AOM Study Group.

Erythromycin is frequently prescribed in Germany for acute otitis media, but well-designed clinical trials under present epidemiological conditions are lacking. Therefore, a double-blind, randomized, multicenter trial was performed to compare the clinical efficacy and safety of erythromycin estolate versus amoxicillin in children with acute otitis media and to identify the risk factors associated with clinical failure. Investigators from 19 centers throughout Germany recruited 302 children with clinical, otoscopic, and tympanometric evidence of acute otitis media. In a double-blind fashion, patients were allocated randomly to a 10-day course of erythromycin estolate at 40 mg/kg/day in two divided doses or amoxicillin at 50 mg/kg/day in two divided doses. Clinical examinations, otoscopy, and tympanometry were performed at baseline, day 3-5, day 9-11, and at 5 weeks. Clinical outcome was assessed on day 9-11. Two-hundred eighty children were evaluable for efficacy (erythromycin group, 141; amoxicillin group, 139). Both groups were comparable with respect to demographic data and severity of disease at entry. Treatment was successful in 94% of the erythromycin-treated patients and in 96% of the amoxicillin-treated patients. Clinical outcome was statistically equivalent between groups within a range of 7 percentage points. Clinical recurrence was seen in eight erythromycin-treated children (5.7%) and in seven amoxicillin-treated children (5.0%) (P=0.81). Patients with bilateral disease at entry were at higher risk of unfavourable outcome, whereas age and presence/absence of otorrhea at entry were not associated with outcome. Treatment-related adverse events were recorded in eight (5.3%) of 151 erythromycin-treated patients and in 11 (7.3%) of 151 amoxicillin-treated patients. In this study in an outpatient setting in Germany, erythromycin estolate was as safe and effective as amoxicillin in the treatment of acute otitis media. Both drugs can be administered in a convenient twice-daily dosage schedule.

Seven days of erythromycin estolate is as effective as fourteen days for the treatment of Bordetella pertussis infections.

OBJECTIVE AND METHODS: Although 14 days of erythromycin is recommended for the treatment of Bordetella pertussis infection, there have been no prospective controlled studies to support the contention that this long course of therapy is required to eradicate the microorganism from the nasopharynx or to prevent bacteriological relapse. We randomly allocated children and adults with culture-positive community-acquired pertussis to either 7 or 14 days of erythromycin estolate treatment (40 mg/kg/d; maximum dose 1 g/d). Nasopharyngeal aspirate cultures were obtained by study nurses during home visits before and at the end of treatment, and 1 week after the completion of treatment. B pertussis-specific antibodies were measured before treatment and 1 month later. Information about clinical symptoms, adverse reactions, and compliance were collected at each scheduled contact. RESULTS AND CONCLUSIONS: A total of 168 participants were eligible for analysis (74 treated for 7 days and 94 treated for 14 days). Bacteriological persistence (positive end of therapy culture) occurred once in each group, and bacteriological relapse (positive culture 1 week after completion of treatment) occurred in one participant treated for 7 days. The overall failure rate (persistence plus relapse) of 2.70% in the 7-day group was not different than the rate of 1.06% in the 14-day group. The study had a power of 99.99% at the 5% level to detect a difference in failure rates of 10% and a power of 80% to detect a difference of 5%. We conclude that 7 days of erythromycin estolate is as effective as 14 days for the eradication of B pertussis.

Erythromycin hepatotoxicity. A rare cause of a false-positive technetium-99m DISIDA study.

An unusual cause of a cholescintigraphic, false-positive, erythromycin-induced hepatotoxicity is presented. This occurred in the presence of preservation of hepatic uptake and the normal appearance of gut activity. Serial scintigraphy and serum chemistries documented underlying gallbladder normalcy.

Erythromycin estolate and jaundice.

Using prescription-event monitoring to determine whether erythromycin estolate was a more frequent cause of jaundice than erythromycin stearate or tetracycline 12 208 patients, for whom 5343 doctors had prescribed one of the three drugs, were identified by the Prescription Pricing Authority. Of the questionnaires sent to general practitioners about the possible occurrence of jaundice, 76% were returned. There were 16 reports of jaundice, of which four were attributable to gall stones, three to cancer, six to viral hepatitis, and only three were possibly related to an antibiotic. All three patients, in whom the antibiotic was a possible cause, had been treated with erythromycin stearate. No case was attributable to the estolate which had previously been suspected of being a more frequent cause of jaundice. Although the incidence is unknown, it is very unlikely to be more than one in 100.

Therapeutic doses of erythromycin esteolate is not cholestatic in rats in vivo.

The effect of erythromycin esteolate (EE) on bile flow and bile acid secretion was studied in male Wistar rats in vivo. Daily oral treatment with a dose of up to 100 mg/kg for 1 week increased the bile flow and the bile acid secretion. Increasing the days of treatment to 4 weeks with a dose of 20 mg/kg did not alter the measured parameters significantly. Acute intravenous injection of erythromycin lactobionate (50 mg/kg) also increased bile flow and biliary bile acid secretion temporarily. The increase in bile flow may partly be due to the osmotic effect of the drug and its metabolites in bile. Since EE failed to produce cholestasis in the range of therapeutic doses, rats do not seem to be a suitable experimental model for studying EE-cholestasis.

Hepatotoxicity to both erythromycin estolate and erythromycin ethylsuccinate.

Two patients experienced hepatotoxicity associated with erythromycin estolate (Ilosone) usage, followed 13 and 15 years later by an hepatotoxic reaction with administration of erythromycin ethylsuccinate (E.E.S.). These cases provide further evidence for erythromycin ethylsuccinate-associated hepatotoxicity and demonstrate erythromycin cross-sensitivity after previous erythromycin estolate liver injury. Hepatotoxicity to both sensitivity after previous erythromycin estolate liver injury. Hepatotoxicity to both estolate and ethylsuccinate preparations of erythromycin stimulates speculation regarding the potentially hepatotoxic moiety of the erythromycin molecule. Furthermore, these cases suggest that all erythromycin preparations should be avoided or used only with careful monitoring in patients with previous erythromycin-associated liver injury.