Azithromycin versus pivampicillin in the treatment of acute exacerbations of chronic bronchitis: a single-blind, double-dummy, multicentre study.

This single-blind, double-dummy, multicentre study compared oral azithromycin, administered as tablets, 500 mg once daily for 3 days, versus oral pivampicillin, 700 mg twice daily for 10 days, in adults with acute exacerbations of chronic bronchitis (not needing parenteral antibiotic therapy, hospitalization or oxygen support). Clinical success (cure + improvement) rates were similar for both groups at the end of treatment (day 10; azithromycin, 124 of 133 [93%]; pivampicillin, 79 of 92 [86%]) and at follow-up (day 52; 98 of 126 [78%] versus 66 of 81 [81%]). The treatments produced similar levels of pathogen eradication at the end of treatment (49 of 54 [91%] versus 32 of 37 [86%]). Azithromycin-treated patients had significantly reduced chest discomfort at the end of treatment, and a trend towards improved lung function. The two groups were similar with respect to improvements in other clinical symptoms and patient well-being, and to the incidences of adverse events and treatment discontinuations. This oral azithromycin regime is an effective treatment for acute exacerbations of chronic bronchitis, similar in efficacy to the longer pivampicillin regime and may offer superior patient compliance.

A follow-up study of birth outcome in users of pivampicillin during pregnancy.

BACKGROUND: Pivampicillin is a prodrug which is widely used in Scandinavian countries for oral antibiotic therapy. The pivaloyl moiety has a carnitine depleting effect, which has caused doubts about the safety of administering pivampicillin during pregnancy. The aim of the study was to evaluate the risk of congenital malformations in general, preterm delivery and low birth weight in users of pivampicillin. METHODS: Seven hundred and ninety-one women who had redeemed a prescription of pivampicillin during their first pregnancy from 1 January 1991 to 31 December 1996 were identified in the North Jutland Pharmaco-Epidemiological Prescription Database. By linkage to the Danish Medical Birth Registry and Regional Hospital Discharge Registry we compared their birth outcomes (malformations, preterm delivery and low birth weight) with the outcomes in 7472 reference pregnancies on which the mother had not redeemed any prescription at all during pregnancy. RESULTS: The prevalence of malformations was 5.5% (11 cases) in offspring of 199 women who had used pivampicillin during the first trimester, and 5.6% (420 cases) in offspring of controls (OR: 0.95, 95% CI: 0.51-1.76). Furthermore, we did not find any significant risk of preterm delivery (OR: 0.75, 95% CI: 0.54-1.05) or low birth weight (OR: 0.93, 95% CI: 0.55-1.57). CONCLUSION: This study showed no increased risk of congenital malformations, preterm delivery or low birth weight in offspring of women who had redeemed a prescription for pivampicillin during pregnancy.

Randomised trial of pivampicillin plus pivmecillinam vs. pivampicillin in children and young adults with chronic obstructive pulmonary disease and infection with Haemophilus influenzae.

A prospective, randomised, single-blind comparative trial was carried out to determine whether double beta-lactam treatment with pivampicillin plus pivmecillinam is more effective than pivampicillin alone in the treatment of recurrent and chronic lung infections with Haemophilus influenzae in patients with chronic obstructive pulmonary disease (COPD) or cystic fibrosis (CF). Fifty-six children and young adults with COPD or CF were randomised to the clinical study. The patients were allocated at random to receive perorally either pivmecillinam, 40 mg/kg/day, combined with pivampicillin, 50 mg/kg/day, or pivampicillin 50 mg/kg/day alone for 14 days. A cross-over pharmacokinetic study using the same drugs was carried out in 10 CF patients to determine the antibiotic concentrations in serum and sputum after a single dose of each drug. The clinical study showed no significant differences in clinical scoring, lung function tests or adverse events after treatment with pivampicillin plus pivmecillinam or pivampicillin alone. Follow-up microbiological evaluation 2 and 6 weeks after the end of treatment showed that the offending pathogen was eradicated in 68% of the patients treated with pivampicillin plus pivmecillinam and in 67% of the patients treated with pivampicillin alone. Reinfection with another biotype was more common in the combination group (50% vs. 21%) than in the pivampicillin group. In the pharmacokinetic study the median peak serum concentration occurred two hours after intake of tablets. The efficacy of double beta lactam treatment in lung infections with H. influenzae appears to be equivalent to that of ampicillin on clinical lung symptoms, lung function tests, adverse effects and bacteriology.

Carnitine administration ameliorates the changes in energy metabolism caused by short-term pivampicillin medication.

UNLABELLED: Ten children receiving pivampicillin for 8 days were studied. On the first 4 days the drug was given alone (4 x 500 mg/day), and on the last 4 days in combination with carnitine (4 x 1 g/day). Pivampicillin treatment was associated with formation and urinary excretion of pivaloylcarnitine and administration of carnitine aided the elimination of pivalate as its carnitine ester. The resting respiratory quotient increased from 0.86 +/- 0.01 to 0.96 +/- 0.01 on the 4th day of pivampicillin treatment. A shift was observed in the metabolic fuel consumption: a significant decrease was found in the amount of fats oxidized (0.31 +/- 0.17 vs 1.27 +/- 0.17 g x kg[-1] x 24 h[-1]). while the utilization of carbohydrates increased (6.20 +/- 0.51 vs 4.00 +/- 0.50 g kg[-1] x 24 h[-1]). Administration of carnitine decreased the respiratory quotient to 0.90 +/- 0.01 on the 8th day of treatment, consumption of fats increased, and the oxidation of carbohydrates decreased. The resting energy expenditure was not affected by the treatment. CONCLUSION: Pivampicillin treatment results in inhibited oxidation of fats as metabolic fuel. This drug effect was partially reversed by carnitine which promotes the elimination of the pivaloyl moiety from the body.

Pivalic acid-induced carnitine deficiency and physical exercise in humans.

To study the effect of carnitine depletion on physical working capacity, healthy subjects were administered pivaloyl-conjugated antibiotics for 54 days. The mean carnitine concentration in serum decreased from 35.0 to 3.5 mmicromol/L, and in muscle from 10 to 4.3 micromol/g noncollagen protein (NCP). Exercise tests were performed before and after 54 days' administration of the drug. At submaximal exercise, there was a slight increase in the concentration of 3-hydroxybutyrate in serum, presumably caused by decreased fatty acid oxidation in the liver. There was also a decreased consumption of muscle glycogen, indicating decreased glycolysis in the skeletal muscle. The muscle presumably had enough energy available, since there was no significant decrease in the concentration of adenosine triphosphate (ATP) and creatine phosphate during exercise. The work at maximal oxygen uptake (VO2max) and the maximal heart rate were reduced. Since VO2max is considered dependent on heart function, carnitine depletion seemed to affect cardiac function.

Side effects of oral antimicrobial agents in the horse: a comparison of pivampicillin and trimethoprim/sulphadiazine.

To evaluate the side effects of oral pivampicillin and trimethoprim/ sulphadiazine, 200 horses receiving these antimicrobial agents were studied. The horses received either trimethoprim/ sulphadiazine (30 mg/kg twice daily) or pivampicillin (25 mg/kg twice daily) for three or more days. No adverse effects other than loose faeces and diarrhoea were detected. The risk of diarrhoea was significantly less after the oral administration of pivampicillin (3 per cent) than after trimethoprim/ sulphadiazine (7 per cent). Horses whose appetite was reduced appeared to be predisposed to develop diarrhoea after the administration of either oral antimicrobial agent.

[Slow replenishment of carnitine level after long-term treatment with pivampicillin/pivmecillinam]. / Langsom gjenoppbygging av karnitinnivå etter langtidsbehandling med pivampicillin/pivmecillinam.

Long-term treatment with pivampicillin and pivmecillinam for 6-24 months in five adults and one child reduced the total serum carnitine concentrations to 3.7-14.0 mumol/l (reference value 25-66 mumol/l). The muscle carnitine was reduced to 0.3-0.7 mumol/g wet weight (reference value 3-5 mumol/g) in two cases. All patients had asthenia and muscle symptoms with weakness and pain. One showed signs of carnitine depletion in the liver, with increased secretion of dicarboxylic acids (C6, C8, C10) in urine and limited ketone body formation during prolonged fasting (32 hours). The serum carnitine increased slowly after cessation of therapy and reached normal concentrations after 6-12 months. All symptoms caused by carnitine depletion disappeared after the serum carnitine reached 20 mumol/l. This was achieved on a normal diet without carnitine supplement.

Slow replenishment of carnitine deficiency after cessation of long-term treatment with pivaloyl-containing antibiotics.

Long-term treatment with pivampicillin and pivmecillinam for 6-24 months in five adults and one child reduced the total serum carnitine concentration to 3.7-14 mumol/l (reference value: 25-66 mumol/l). Muscle carnitine was reduced to 0.3-0.7 mumol/g wet weight (reference value: 3-5 mumol/g) in two cases. All patients had muscle symptoms with weakness, asthenia and pains. One showed signs of carnitine depletion in the liver with increased secretion of dicarboxylic acids (C6, C8, C10) in urine and limited ketone body formation during prolonged fasting. Serum carnitine increased slowly after cessation of therapy and reached normal concentrations after 6-12 months. All symptoms caused by carnitine depletion disappeared. This was achieved on a normal diet without carnitine supplementation.

Absorption of pivampicillin as related to dose, and tolerability of a 700 mg tablet.

To evaluate the absorption and tolerability of a new formulation of pivampicillin administered as a 700 mg tablet, 14 healthy volunteers received single doses of 350, 500 and 700 mg p.o. Maximum serum concentrations (Cmax) of 5.73, 7.05 and 8.61 mg/l were obtained. The corresponding values for the area under the concentration/time curve (AUC) were 12.32, 18.99 and 25.30 mg/lxh. Concomitant intake of food increased the Cmax of the 700 mg tablet to 9.5 mg/l, while the AUC remained unchanged. Co-administration of the 700 mg pivampicillin dose with an antacid reduced the Cmax to 7.45 mg/l and the AUC to 17.92 mg/l x h. The tolerance of the 700 mg tablet was evaluated in a double-blind placebo-controlled study involving 57 patients. Six percent of the patients in each treatment group reported minor adverse reactions.

Carnitine deficiency associated with long-term pivampicillin treatment: the effect of a replacement therapy regime.

A 51 year old female developed a skeletal muscle myopathy after 3 months of pivampicillin therapy. Pivampicillin can cause carnitine deficiency due to the pivalic acid side group. Plasma carnitine content and the patients symptoms failed to improve significantly on discontinuing the drug. Oral carnitine replacement therapy was administered for 6 weeks but the patient's plasma carnitine levels responded only slowly to this treatment. It is suggested that pivampicillin inhibits uptake of carnitine from the gut and may either directly or indirectly depress endogenous carnitine synthesis. In such cases a more aggressive carnitine replacement regime is indicated and pivampicillin should be avoided in patients requiring long-term antibiotic administration.

Effects of pivalic acid-containing prodrugs on carnitine homeostasis and on response to fasting in children.

Treatment of 17 children aged 2-9.5 years with a combination of pivmecillinam and pivampicillin (250-500 mumol 24 h-1) for more than 1 year resulted in a reduction of the free carnitine concentration in serum and muscle to less than 10% of the mean reference value. The decline in serum was slow, with an estimated half-life of about 5 months. Spontaneous replenishment occurred at about the same slow rate. Thus, there is no increase in endogenous carnitine synthesis as a response to increased demand of carnitine for detoxification. Supplementation with carnitine during treatment required at least a four-fold molar excess over pivalic acid to achieve and sustain a normal carnitine concentration. The replenishment of carnitine occurred with a half-life of 1.1-3.0 months. From determination of muscle-carnitine concentration in patients treated with pivaloyl-containing antibiotics and in patients with organic aciduris, we conclude that serum carnitine is a good predictor of carnitine stores in the body. Six non-supplemented patients with a serum free-carnitine concentration of 0.7-2.6 mumol l-1 had an inadequate ketone-body increase during a 24-h fast. Vomiting, nausea and tiredness occurred in three cases following the fasting period. After normalization of the serum-carnitine concentration, a normal response to fasting was observed. Thus, in some organic acidurias, for example medium-chain acyl-CoA dehydrogenase deficiency, a low liver concentration of carnitine may be an important contributing factor to hypoglycaemic and Reye-like attacks. We believe that prodrugs which contain pivalic acid should be avoided if acceptable alternatives exist. If used, supplementation with at least four-fold molar excess of carnitine is advisable.