Advantages of Azithromycin Over Erythromycin in Improving the Gastric Emptying Half-Time in Adult Patients With Gastroparesis

Abstract

Background/AimsCurrent therapy for gastroparesis with prokinetic agents is limited by options and side effects. One macrolide, erythromycin (ERY), is associated with possible sudden cardiac death from QT prolongation due to P450 iso-enzyme inhibition. An alternative, azithromycin (AZI), lacks P450 inhibition. We compared the effect on gastric emptying half-times (t½) between AZI and ERY in patients diagnosed with gastroparesis by gastric emptying scintigraphy.MethodsPatients stopped medications known to affect gastric emptying prior to the study, and then ingested 1 scrambled egg meal labeled with 18.5-37 MBq of technetium-99m sulfur colloid followed by continuous imaging for 120 minutes, at 1 minute per frame. A simple linear fit was applied to the rate of gastric emptying, and gastric emptying t½ was calculated (normal = 45-90 minutes). At 75-80 minutes, if the stomach had clearly not emptied, patients were given either ERY (n = 60) or AZI (n = 60) 250 mg IV and a new post-treatment gastric emptying t½ was calculated.ResultsComparison of gastric emptying t½ showed a similar positive effect (mean gastric emptying t½ for AZI = 10.4 ± 7.2 minutes; mean gastric emptying t½ for ERY = 11.9 ± 8.4 minutes; p = 0.30).ConclusionsAZI is equivalent to ERY in accelerating the gastric emptying of adult patients with gastroparesis. Given the longer duration of action, better side effect profile and lack of P450 interaction for AZI as compared with ERY, further research should evaluate the long term effectiveness and safety of AZI as a gastroparesis treatment.

Prokinetics in Gastroparesis

“…38,39 However, there are no randomized controlled trials comparing these drugs with placebo or other medications, and their use should be balanced with the potential for tachyphylaxis, cardiac risk, and antibiotic resistance.…”

Scrub typhus, myocarditis and a possible drug interaction

“…Though azithromycin was also used and is approved for the treatment of scrub typhus, it is not considered as an inhibitor of CYP450 enzymes. 9,10 Doxycycline has been shown to be a moderate inhibitor of these enzymes and the use of these drugs together may lead to increased levels of ivabradine which is a substrate for these enzymes. 11,12 Bradycardia is a known side effect of ivabradine and though we could not confirm that the bradycardia in this patient was a side effect of ivabradine alone or was due to increased blood levels of ivabradine caused by CYP inhibition by doxycline, we would like to highlight the importance of this possible drug interaction in this disease.…”

Treatment approaches of gastrointestinal dysfunction in Parkinson's disease, therapeutical options and future perspectives

“…It has very recently been demonstrated that azithromycin has advantages over erythromycin in improving gastric emptying in PD patients with gastroparesis [70].…”