Familiarization with complementary medicine: report of a new course for primary care physicians

A course entitled "Familiarization in Complementary Medicine" has been established at Exeter University. The syllabus of the course is presented, together with significant issues for debate that were raised by the attending primary care physicians. The delegates started with a positive but questioning attitude toward complementary medicine (CM) and acknowledge that they gained useful information, leading to increased confidence in discussing CM with patients. The course to a large extent met their needs and expectations. Benefits and draw-backs of integrating CM within general practice were explored. The main advantage of CM, apart from the potential intrinsic value of the techniques themselves, was identified as the time to establish a good therapeutic relationship with the patient. The particular concerns about CM that were expressed by the doctors included poor dialogue with CM practitioners, doubts about competence, and lack of readily identifiable and recognized qualifications. The risk of holding out unrealistic hope of cure was their greatest concern, however, especially if patients were thereby denied an effective orthodox treatment. The course was popular and will be repeated on a regular basis; similar courses for other health professionals including nurses are being planned.

Complementary medicine: use and attitudes among GPs

BACKGROUND

Information about use and attitudes of GPs towards complementary medicine is required in order to inform the debate about its place within mainstream medicine. There is evidence that public use of complementary medicine is particularly high in the South-West of England.

OBJECTIVE

This study aimed to determine the use of, and attitudes towards, complementary medicine among GPs.

METHODS

A questionnaire survey was performed of all primary care physicians working in the health service in Devon and Cornwall.

RESULTS

Replies were received from 461 GPs, a response rate of 47%. A total of 314 GPs (68%, range 32-85%) had been involved in complementary medicine in some way during the previous week. One or other form of complementary medicine was practised by 74 of the respondents (16%), the two most common being homoeopathy (5.9%) and acupuncture (4.3%). In addition, 115 of the respondents (25%) had referred at least one patient to a complementary therapist in the previous week, and 253 (55%) had endorsed or recommended treatment with complementary medicine. Chiropractic, acupuncture and osteopathy were rated as the three most effective therapies, and the majority of respondents believed that these three therapies should be funded by the health service. A total of 176 (38%) of respondents reported adverse effects, most commonly after manipulation.

CONCLUSION

Over two-thirds of the GPs in Devon and Cornwall who responded to the survey had been involved with complementary medicine in some way during the previous week. This figure is higher than the national average. The majority of respondents believed that acupuncture, chiropractic and osteopathy were effective and should be funded by the NHS.

Isolation of bioactive compounds from Helix aspersa nerve tissue and the effect of pQPPLPRYamide on heart, esophagus and central neurons of H. aspersa and rectum of Anodonta woodiana

1. Both acetone and methanol extraction was used to isolate bioactive compounds from 1000 Helix aspersa brains. 2. Seven compounds were isolated of which four were identified as follows: Ha-1, 5-hydroxytryptamine; Ha-3, GSPYFVamide; Ha-4, pQPPLPRYamide; Ha-5, SGYLAFPRMamide. There was insufficient material to identify Ha-2, Ha-6 and Ha-7. 3. Ha-4, pQPPLPRYamide, was found to excite the heart of H. aspersa, relax the esophagus and both excite (mainly) and inhibit central neurons. In addition, this peptide contracted the rectum of Anodonta woodiana. 4. It is concluded that pQPPLPRYamide is an example of a new molluscan peptide family, designated as PRYamide.

A review of problems in clinical acupuncture research

Although laboratory studies indicate that acupuncture can have physiological effects, clinical studies of acupuncture are frequently inconclusive. Randomized controlled trials are the best way to test for the specific effectiveness of a therapy. Problems in clinical acupuncture research include the diversity of forms of therapy, individualised treatments, binding, choosing a credible control procedure, selecting suitable endpoints and traditional diagnosis. The enthusiasm of proponents of acupuncture may bias the research they are performing. None of these difficulties is insurmountable. Examples of rigorous trials are listed and some suggestions are offered on ways of improving research.

Complementary medicine. What physicians think of it: a meta-analysis

BACKGROUND

Complementary (or alternative) medicine has become a prevalent phenomenon in most industrialized countries. At present the evidence from randomized controlled trials investigating its effectiveness is fragmentary and therefore inconclusive.

OBJECTIVE

To assess whether physicians perceive complementary medicine as useful and/or effective.

METHOD

A literature search was performed to retrieve all relevant articles. Twelve surveys addressing this question were found and analyzed by evaluating perceived usefulness and/or effectiveness.

RESULTS

The results show a remarkable variability between surveys. On average physicians perceive complementary medicine as moderately effective--the rating was 46 +/- 18 on a scale of 0 to 100 points. Young physicians seem to judge complementary medicine more optimistically than their more seasoned colleagues. There is no trend to suggest that complementary medicine is increasingly perceived as useful and/or effective. The data do not answer the question whether physicians view complementary medicine as a nonspecific powerful placebo or as specifically effective.

CONCLUSION

Complementary medicine may be useful; however, the notion urgently needs to be tested in randomized controlled trials.

Acupuncture as an adjuvant therapy in stroke rehabilitation?

The optimal treatment during stroke rehabilitation has not yet been identified. Several recent reports claim that acupuncture may be a useful addition to conventional stroke rehabilitation. The aim of this paper is to critically review these data. All controlled trials published on this subject were identified by systematic literature searches. Without exception, these trials suggest positive effects of acupuncture on functional recovery. None of them, however, attempted to account for a possible placebo effect. Several other methodological flaws must be considered as well. It is therefore concluded that, according to the data published to date, the evidence that acupuncture is a useful adjunct for stroke rehabilitation is encouraging but not compelling. More and better trials are required to clarify this highly relevant issue.

Complementary medicine. What physicians think of it: a meta-analysis

BACKGROUND

Complementary (or alternative) medicine has become a prevalent phenomenon in most industrialized countries. At present the evidence from randomized controlled trials investigating its effectiveness is fragmentary and therefore inconclusive.

OBJECTIVE

To assess whether physicians perceive complementary medicine as useful and/or effective.

METHOD

A literature search was performed to retrieve all relevant articles. Twelve surveys addressing this question were found and analyzed by evaluating perceived usefulness and/or effectiveness.

RESULTS

The results show a remarkable variability between surveys. On average physicians perceive complementary medicine as moderately effective--the rating was 46 +/- 18 on a scale of 0 to 100 points. Young physicians seem to judge complementary medicine more optimistically than their more seasoned colleagues. There is no trend to suggest that complementary medicine is increasingly perceived as useful and/or effective. The data do not answer the question whether physicians view complementary medicine as a nonspecific powerful placebo or as specifically effective.

CONCLUSION

Complementary medicine may be useful; however, the notion urgently needs to be tested in randomized controlled trials.

Mechanism of cellulose synthesis in Agrobacterium tumefaciens

Extracts of Agrobacterium tumefaciens incorporated UDP-[14C]glucose into cellulose. When the extracts were fractionated into membrane and soluble components, neither fraction was able to synthesize cellulose. A combination of the membrane and soluble fractions restored the activity found in the original extracts. Extracts of cellulose-minus mutants showed no significant incorporation of UDP-glucose into cellulose. When mixtures of the extracts were made, the mutants were found to fall into two groups: extracts of mutants from the first group could be combined with extracts of the second group to obtain cellulose synthesis. No synthesis was observed when extracts of mutants from the same group were mixed. The groups of mutants corresponded to the two operons identified in sequencing the cel genes (A. G. Matthysse, S. White, and R. Lightfoot. J. Bacteriol. 177:1069-1075, 1995). Extracts of mutants were fractionated into membrane and soluble components, and the fractions were mixed and assayed for the ability to synthesize cellulose. When the membrane fraction from mutants in the celDE operon was combined with the soluble fraction from mutants in the celABC operon, incorporation of UDP-glucose into cellulose was observed. In order to determine whether lipid-linked intermediates were involved in cellulose synthesis, permeablized cells were examined for the incorporation of UDP-[14C]glucose into material extractable with organic solvents. No radioactivity was found in the chloroform-methanol extract of mutants in the celDE operon, but radioactive material was recovered in the chloroform-methanol extract of mutants in the celABC operon. The saccharide component of these compounds was released after mild acid hydrolysis and was found to be mainly glucose for the celA insertion mutant and a mixture of cellobiose, cellotriose, and cellotetrose for the celB and celC insertion mutants. The radioactive compound extracted with chloroform-methanol form the celC insertion mutant was incorporated into cellulose by membrane preparations from celE mutants, which suggests that this compound is a lipid-linked intermediate in cellulose synthesis.

Xyloglucan glucosyltransferase in Golgi membranes from Pisum sativum (pea)

Cell membranes from etiolated Pisum sativum (pea) tissues were separated by ultracentrifugation on linear sucrose density gradients and assayed for membrane marker and glycosyltransferase activity. Membrane fractions were shown to incorporate glucose from UDP-D-[14C]glucose into polysaccharides with glycosyl linkages consistent with synthesis of xyloglucan. A combined assay using g.c., radiogas proportional counting and m.s. was employed to determine the identities of 14C-labelled glycosyl residues and the glycosyl linkages between them. In glucan synthase I assays, membrane fractions enriched for Golgi membranes showed 14C incorporation into 4- and 4,6-glucose residues, with minor incorporation into 3-glucose residues. In glucan synthase II assays, all 14C incorporation was into 3- and 3,4-glucose. There was a shift in glycosyl linkage of 14C incorporation from predominantly 4-glucose at low UDP-glucose concentration to predominantly 3- and 3,4-glucose at high UDP-glucose concentrations. Mn2+ stimulated incorporation of radioactivity into 4,6-glucose residues characteristic of xyloglucan polysaccharides. Addition of exogenous UDP-xylose to assay mixtures stimulated incorporation into 4,6-glucose, with a maximum at 15 microM UDP-xylose.

Neuropharmacological studies on identified central neurones of the snail, Helix aspersa

Central neurones of the snail, Helix aspersa, possess both synaptic and somatic receptors to a wide range of classical transmitters and neuroactive peptides. The range of receptors and the type of response is reasonably constant for a specific neurone. This review will provide data concerning the pharmacology of acetylcholine, serotonin, dopamine, noradrenaline, octopamine, glutamate, GABA and purine receptors on identified neurones. Many of these neurones also respond to neuroactive peptides including molluscan peptides, e g, AMPMLRLamide, LSSFVRIamide, SGQSWRQGRPFamide, FMRFamide; coelenterate peptides, e g, pQGRFamide; echinoderm peptides, e g, GFNSALMFamide; and nematode peptides, e g, KNEFIRFamide, KHEYLRFamide, SDPNFLRFamide. Using this data, the pharmacological profiles of identified neurones will be summarised.

Activity of human extravascular temocillin concentrations simulated in an in-vitro kinetic model against beta-lactamase producing gram-negative bacilli

An in-vitro kinetic model was used to demonstrate the bactericidal activity of concentrations of temocillin achieved in extravascular body fluids following a 1 g intravenous dosage in man. Concentrations of temocillin attainable in peripheral lymph were bactericidal for ampicillin-resistant strains of Escherichia coli, Enterobacter cloacae and Klebsiella oxytoca. Likewise, concentrations of temocillin achieved in human blister fluid following a 12-hourly dosage regimen were bactericidal for cultures of Ent. cloacae and K. oxytoca which were resistant, respectively, to simulated blister fluid concentrations of cefotaxime and aztreonam. The bactericidal activity of extravascular concentrations of temocillin against these multiresistant, Gram-negative bacteria was a reflection of the beta-lactamase-stability and good pharmacokinetic properties of temocillin.

Effect of low concentrations of clavulanic acid on the in-vitro activity of amoxycillin against beta-lactamase-producing Branhamella catarrhalis and Haemophilus influenzae

Concentrations of amoxycillin/clavulanic acid achievable in the respiratory tract following oral dosage were assessed for in-vitro activity against beta-lactamase-producing strains of Branhamella catarrhalis and Haemophilus influenzae. In agar-dilution studies, 8 mg amoxycillin/l was required to inhibit 45 strains of beta-lactamase-producing B. catarrhalis, whereas all the strains were inhibited by 0.5 mg amoxycillin/l in the presence of 0.01 mg clavulanic acid/l. Similarly, 0.1 mg amoxycillin plus 0.05 mg clavulanic acid/l were bactericidal against beta-lactamase-producing strain of B. catarrhalis and prevented regrowth within 24 h. In tests against 43 beta-lactamase-producing strains of H. influenzae, concentrations of up to 128 mg amoxycillin/l were required for inhibition, whereas 32 strains (75%) were fully sensitive to amoxycillin (MIC 0.5 mg/l) in the presence of 0.12 mg clavulanic acid/l. These concentrations of amoxycillin/clavulanic acid were also bactericidal for a beta-lactamase-producing strain of H. influenzae. The study therefore showed that amoxycillin/clavulanic acid, at concentrations similar to those likely to be achieved in the respiratory tract following oral dosage, was bactericidal in vitro for beta-lactamase-producing isolates of B.catarrhalis and H. influenzae.

Antibacterial activity of resolved temocillin epimers

The antibacterial activity of pure resolved R and S epimers of temocillin was determined in a variety of in-vitro test systems, including those that allowed measurement of activity during the early period following exposure to the agents, thus minimising the effect of epimerization. In conventional agar- and broth-dilution susceptibility tests involving incubation at 37 degrees C for 18 h, little difference was evident between the activities of the individual epimers. In contrast, in other tests of antibacterial activity, such as time-kill and turbidimetric studies, the R epimer and temocillin (R/S mixture 1.8:1.0) were shown to be more rapidly bactericidal than the S epimer. Overall, the R epimer and temocillin (R/S) exhibited a similar degree of bactericidal activity in vitro.

Antibacterial activity of ticarcillin in the presence of clavulanate potassium

The antibacterial effects produced by ticarcillin disodium plus clavulanate potassium, a combination of the broad-spectrum penicillin ticarcillin, and the beta-lactamase inhibitor clavulanic acid as the potassium salt, have been measured in vitro and in experimental infection studies. The presence of clavulanic acid resulted in a significant enhancement of the activity of ticarcillin against a wide range of beta-lactamase-producing bacteria. These included ticarcillin-resistant strains of Escherichia coli, Klebsiella pneumoniae, Proteus mirabilis, P. vulgaris, Yersinia enterocolitica, and the anaerobe Bacteroides fragilis. In addition, beta-lactamase-producing isolates of Hemophilus influenzae, Branhamella catarrhalis, Neisseria gonorrhoeae, and Staphylococcus aureus were susceptible to ticarcillin and clavulanate. Clavulanic acid did not influence the activity of ticarcillin against ticarcillin-susceptible bacteria. The bactericidal effects of the antibiotic combination were measured in an in vitro kinetic model in which the drug concentrations were varied to simulate those measured in humans after intravenous dosing with ticarcillin (3.0 g) and clavulanate potassium (100 mg clavulanic acid). In these tests, ticarcillin plus clavulanic acid had pronounced bactericidal activity against ticarcillin-resistant bacteria. The protection of ticarcillin by clavulanic acid from inactivation by bacterial beta-lactamases in vivo was demonstrated in experimental infection models in which the efficacy of the ticarcillin plus clavulanic acid combination against infections caused by beta-lactamase-producing bacteria was correlated with the presence of effective concentrations of both antibiotic and inhibitor at the site of infection.

Antibacterial activity of mupirocin (pseudomonic acid), a new antibiotic for topical use

Mupirocin (pseudomonic acid A), an antibiotic produced by Pseudomonas fluorescens, showed a high level of activity against staphylococci and streptococci and against certain gram-negative bacteria, including Haemophilus influenzae and Neisseria gonorrhoeae, but was much less active against most gram-negative bacilli an anaerobes. Nearly all clinical isolates of Staphylococcus aureus and Staphylococcus epidermidis, including multiply resistant strains, were susceptible (mupirocin MIC, less than or equal to 0.5 microgram/ml). There was no cross-resistance between mupirocin and clinically available antibiotics, and the selection of resistant variants in vitro occurred at a low frequency. Mupirocin was highly bound (95% bound) to the protein of human serum, and activity was reduced 10- to 20-fold in the presence of human serum. The activity of mupirocin was not greatly influenced by inoculum size but was significantly enhanced in acid medium. In tests of bactericidal activity, MBCs were 8- to 32-fold higher than MICs and the antibiotic demonstrated a slow bactericidal action in time-kill tests, resulting in 90 to 99% killing after 24 h at 37 degrees C.

Bactericidal effects of amoxycillin/clavulanic acid and ticarcillin/clavulanic acid in in-vitro kinetic models

The bactericidal effects of amoxycillin and ticarcillin in the presence of clavulanic acid against beta-lactamase-producing bacteria were investigated in in-vitro kinetic models. Amoxycillin/clavulanic acid was rapidly bactericidal as a simulated intravenous 1.2 g bolus dose, against a strain of Klebsiella pneumoniae highly resistant to amoxycillin. Similarly, ticarcillin/clavulanic acid at concentrations similar to those achieved with a 30 min iv infusion of ticarcillin/clavulanic acid (5.0 g/200 mg) produced bactericidal effects against a ticarcillin-resistant strain of Pseudomonas aeruginosa. Addition of gentamicin to the system resulted in a further enhancement of activity.

Human pharmacokinetics and antimicrobial activities of the temocillin epimers

The pharmacokinetics of the epimers of temocillin were investigated in 4 healthy male subjects following intravenous administration of 1g of temocillin disodium (free acid) which contains a R : S epimer ratio of approximately 65 : 35. The R epimer had a 2-fold greater total plasma clearance, a 23% larger volume of distribution and a shorter beta half-life than the S epimer. Intermediate values were obtained for total temocillin (R + S) from high pressure liquid chromatography (HPLC) data. In each plasma sample, the unbound fraction of the R epimer was generally 2-fold higher than that of the S epimer, which is suggested as the reason for the differences in the pharmacokinetic properties of the epimers. The temocillin pharmacokinetic parameters obtained from the microbiological assay data reflect most closely those for the R epimer derived from HPLC data. The resolved R epimer exhibited twice the potency of the S epimer against the microbiological assay organism Pseudomonas aeruginosa NCTC 10701. However, in tests for antibacterial susceptibility, for instance minimum inhibitory concentration (MIC) determinations involving prolonged incubation, there was little difference in the inhibitory activities of the resolved R and S epimers compared with temocillin (R + S), presumably as a consequence of the epimerization of the individual epimers. In contrast, in rapid tests for bactericidal activity, which minimise the effect of epimerization, the R epimer exhibited greater bactericidal activity than the S epimer.

Temocillin. In vitro antibacterial activity

Temocillin, a 6-alpha-methoxy penicillin derivative, was tested in vitro against 516 recent clinical isolates of Enterobacteriaceae. The compound exhibited good antibacterial activity, with 95% of isolates inhibited by a range 2 to 16 mg/L. Further studies, against selected isolates resistant to ticarcillin, piperacillin and cefuroxime (Klebsiella oxytoca, 25; Enterobacter species, 34; and Citrobacter species, 5), showed about half of the isolates of K. oxytoca (11/25) to be resistant to aztreonam (MIC range 16-greater than or equal to 128 mg/L), but susceptible to temocillin, cefotaxime and latamoxef. In general, the resistant strains of Enterobacter species tested were not susceptible to cefotaxime (MIC range 16-128 mg/L), or aztreonam (MIC range 1.0-64 mg/L), and many exhibited reduced susceptibility to latamoxef (MIC range 2-128 mg/L). In contrast, all the strains were susceptible to temocillin (MIC range 4-16 mg/L). The bactericidal activity of temocillin was confirmed against selected aztreonam-resistant strains of K. oxytoca and Enterobacter cloacae by conventional time-kill studies, and against a strain of E. cloacae in an in vitro model system designed to simulate the temocillin concentration profiles attained in extravascular fluid such as peripheral lymph. In the time-kill studies, temocillin concentrations of 16 and 32 mg/L were shown to effectively reduce the numbers of viable bacteria by 99 and 99.9%, respectively, within 12 hours. In the in vitro model system the numbers of bacteria were reduced 99.9% over the initial 4-hour period. In combination with aminoglycoside antibiotics, temocillin exerted a synergistic or partially synergistic effect (sigma FIC less than or equal to 0.75) against the majority of strains of Pseudomonas aeruginosa tested. When combined with piperacillin, cefotaxime or latamoxef, temocillin, unlike cefoxitin, exhibited no antagonism against strains of Enterobacteriaceae producing inducible cephalosporinases.

Long-term hemodialysis at reduced dialysate flow rates

20 stable hemodialysis patients were maintained on a dialysate flow rate of 300 ml/min (QD 300) to determine the safety of prolonged reductions in dialysate flow rate. After 24 months, QD 300 compared to QD 500 resulted in no change in weight, blood pressure, BUN, hematocrit, creatinine, bicarbonate, potassium, cholesterol, or calcium. Serum phosphate concentration increased between month 13 and month 17 but then stabilized. No adverse symptoms developed. EEGs and motor nerve conduction studies following 24 months at QD 300 were normal. We conclude that QD 300 does not impair dialysis efficiency for most small molecules and saves $1.38 per patient per dialysis.

Specialty hospitals: the challenge of the 1980s

Specialty care institutions will face many concerns during the remainder of this decade. Increased intermediary and community education, establishing reliable benchmarks, understanding and dealing with a competitive marketplace, and establishing improved professional productivity are some of the major challenges.

Improvement in disequilibrium symptoms during dialysis with low glucose dialyzate

This study compares the frequency of dialysis disequilibrium symptoms (DDS), in 17 stable non-diabetic chronic hemodialysis patients, during a period using low glucose (200 mg/100 ml) dialyzate to a similar period using a glucose free dialyzate. There was a significant decrease in the total number of symptoms as well as the frequency of headache and post-dialysis fatigue during the low glucose period as compared to the glucose free period. The decrease in nausea or vomiting, and cramps was not significant while frequency of hypotension was unchanged. Evaluation of serum sodium, potassium, BUN, glucose and osmolarity did not reveal significant differences during the two periods. Dialysis with a low glucose bath produces less DDS than glucose free dialyzate.

Alteration of in vivo cellulose ribbon assembly by carboxymethylcellulose and other cellulose derivatives

In vivo cellulose ribbon assembly by the Gram-negative bacterium Acetobacter xylinum can be altered by incubation in carboxymethylcellulose (CMC), a negatively charged water-soluble cellulose derivative, and also by incubation in a variety of neutral, water-soluble cellulose derivatives. In the presence of all of these substituted celluloses, normal fasciation of microfibril bundles to form the typical twisting ribbon is prevented. Alteration of ribbon assembly is most extensive in the presence of CMC, which often induces synthesis of separate, intertwining bundles of microfibrils. Freeze-etch preparations of the bacterial outer membrane suggest that particles that are thought to be associated with cellulose synthesis or extrusion may be specifically organized to mediate synthesis of microfibril bundles. These data support the previous hypothesis that the cellulose ribbon of A. xylinum is formed by a hierarchical, cell-directed, self-assembly process. The relationship of these results to the regulation of cellulose microfibril size and wall extensibility in plant cell walls is discussed.

Experimenter naiveté and imaginal judgments

Finke and Kurtzman report that fields of resolution increase with increases in the diameter of both perceived and imagined circular patterns. Their study apparently was conducted by an experimenter who was aware of the hypotheses under test. In contrast to these results, we find no such increase for imagined circular patterns when the experimenter is not aware of the experimental predictions, even though our subjects received imagery training as extensive as that used by Finke and Kurtzman. Our results cannot readily be attributed to differences between the experiments, other than those associated with experimenter naiveté, for we replicated Finke and Kurtzman's observations that (a) the fields of resolution in perception increase with both the diameter and the relative brightness of the patterns and (b) the fields of resolution in imagery do not increase with the relative brightness of the patterns. Our results also challenge Finke and Kurtzman's contentions that imagery and perception are treated as functionally equivalent at area-processing levels of the visual system but not at contrast-processing levels.

Comparative bactericidal effects of azlocillin and ticarcillin against Pseudomonas aeruginosa

Azlocillin was relatively ineffective against actively growing cultures of Pseudomonas aeruginosa in tests of bacteriolytic and bactericidal activity in which ticarcillin demonstrated pronounced bactericidal effects over a wide range of concentrations. Microscopic observation showed that azlocillin generally induced the formation of filamentous cells of P. aeruginosa which lysed only slowly, but ticarcillin caused the production of spheroplasts and subsequent rapid lysis. During the course of the bactericidal tests, azlocillin was inactivated, presumably by the beta-lactamase produced by P. aeruginosa, and the filamentous cells resumed normal cell division and growth. In contrast, there was no loss of ticarcillin activity, and there was no evidence of resumption of growth of P. aeruginosa in the presence of ticarcillin. These results suggest that the different bactericidal effects demonstrated by azlocillin and ticarcillin against P. aeruginosa are related primarily to dose-related differences in inhibition of cell wall synthesis and secondarily to the instability of azlocillin to pseudomonal beta-lactamase.

Comparative activities of ampicillin, epicillin and amoxycillin in vitro and in vivo

The antibacterial activities of three aminopenicillins ampicillin, epicillin and amoxycillin were compared in vitro and in vivo. The minimum inhibitory concentrations (MIC) of the three penicillins were very similar and the compounds were active against non-beta-lactamase-producing strains of Escherichia coli, Salmonella and Shigella species, Proteus mirabilis, Haemophilus influenzae and Neisseria gonorrhoeae. Streptococci including Streptococcus faecalis, and non-beta-lactamase-producing staphylococci were also sensitive to the compounds but Pseudomonas aeruginosa, Klebsiella aerogenes, Enterobacter and indole-positive Proteus species were resistant. At concentrations close to MIC value epicillin and ampicillin showed similar bactericidal activity against E. coli and against S. typhi and both compounds caused a slower rate of kill than was seen with amoxycillin. Microscopical observation of the cells exposed to ampicillin and epicillin for 1 h showed the presence of filamentous forms which lysed slowly, whereas cells exposed to amoxycillin for the same period rapidly. Epicillin was similar to or slightly less active than ampicillin against experimental mouse infections, and against the majority of infections both compounds were significantly less effective than amoxycillin by the oral and subcutaneous routes of administration.