The G-308A polymorphism of the TNF-alpha gene does not predict changes in cardiac function in response to medical therapy for idiopathic dilated cardiomyopathy.
Suitable antimicrobials given during the catarrhal stage of whooping cough can attenuate the course of the disease. The efficacy of antibiotics administered prophylactically during the incubation period remains controversial but appears to be beneficial. Currently, erythromycin given for two weeks is the antibiotic of choice for pertussis. No treatment failures were observed with erythromycin estolate. Erythromycin ethylsuccinate and stearate must be given at high dosages (50-60 mg/kg/day) in order to achieve sufficient concentrations in the respiratory secretions. With ampicillin and amoxicillin treatment failures have been observed. The role of josamycin and co-trimoxazole in pertussis remains open.
Only penicillin has been adequately studied in treating syphilis during pregnancy. It is safe for the fetus and highly effective in doses currently recommended by the USPHS. Since these schedules appear to represent a minimal effective dose, smaller amounts should never be used. Whether higher doses would produce higher cure rates is not known. Penicillin is the drug of choice and the standard against which all others must be measured. Tetracyclines in any dose or form should not be used because of toxicity to both mother and child. Erythromycin (except the estolate) and cephalosporins are promising because of low toxicity, but their efficacy has not been established.
To determine whether erythromycins, sulfonamides, and tetracyclines are associated with an increased risk for acute hepatitis.
The effects of a new semisynthetic macrolide, roxithromycin, on drug metabolizing enzymes of rat liver were compared with two erythromycins, the base (EB) and the estolate (EE), after 7 days' treatment with high oral doses (400 and 800 mg/kg daily). Dose-related higher concentrations of roxithromycin were reached in serum and liver than after EB or EE. The two reference erythromycins induced the synthesis of microsomal enzymes and formed inactive cytochrome P-450-metabolite complexes. N-Demethylation of erythromycin itself and aminopyrine was increased by the treatment. Liver microsomal enzyme activities were not induced and the inactive cytochrome P-450-metabolite complex was not formed after 400 mg/kg of roxithromycin and only to a very limited extent after 800 mg/kg (10% vs. 50% after EE). At the higher dose microsomal activities were not changed by roxithromycin and only aminopyrine N-demethylation was reduced.
The clinical pharmacology of orally administered antibiotics was investigated in 106 infants and children. The antibiotic suspensions studied were ampicillin, cephalexin, erythromycin estolate, erythromycin ethylsuccinate, penicillin G, and penicillin V. The feeding status of the patients was evaluated in relation to the concentrations of drugs in serum, saliva, and tears. Peak concentrations and area-under-the-curve values of cephalexin, penicillin V, and penicillin G were reduced 40% to 60% in patients given milk and drug concurrently. Absorption was enhanced when erythromycin ethylsuccinate was given milk. After administration of both erythromycin formulations, penicillin V and ampicillin, salivary concentrations exceeded the minimal inhibitory concentrations for most pneumococci and group A streptococci and for many meningococci. The clinical implications of these pharmacokinetic data are discussed.
The pharmacokinetics of erythromycin and erythromycin 2'-propanoate were studied in healthy male volunteers following single and repeated doses of erythromycin stearate tablets, erythromycin estolate capsules, and a suspension. Estolate dosages gave rise to higher plasma levels of total drug than the stearate. However, the stearate yielded higher plasma levels of erythromycin base. Absorption of all dosage forms, except the suspension, was delayed, and pharmacokinetic interpretation of both single- and multiple-dose data required incorporation of an absorption lag time. The absorption of erythromycin stearate was inhibited by food and also by low fluid volumes in fasted subjects. Absorption of erythromycin estolate was increased in the presence of food and was not greatly affected by fluid volume. Although single-dose data poorly predicted circulating levels of erythromycin following repeated doses, trends observed after single doses were maintained during chronic treatment.
To determine pharmacokinetics and plasma concentrations of erythromycin and related compounds after intragastric administration of erythromycin phosphate and erythromycin estolate to healthy foals.
Based on our results brand name oral antibiotic formulations do not necessarily taste better than their generic counterparts.
Erythromycin base and its different salts and esters were given intragastrically to mice. Serum concentrations of erythromycin and its 2'-esters were determined by the bacterial growth inhibition method. Acetyl and propionyl erythromycin were the best absorbed 2'-esters, and differed significantly from butyryl erythromycin and erythromycin base. Erythromycin estolate yielded a larger area under the concentration curve than acistrate or stearate. Among the syrup preparations, erythromycin acistrate was significantly better absorbed than 2'-ethylsuccinyl erythromycin. Absorption of 2'-esters decreased with increasing number of esterified carbon atoms and increasing hydrophobicity and increasing log P value (the logarithm of octanol-water partition coefficient). In addition to sufficient lipophilicity, the optimum absorption of erythromycin esters seems to require a high hydrophilicity.