Efficacy and Safety of Ambroxol Lozenges in the Treatment of Acute Uncomplicated Sore Throat

Abstract

Sore throat is the hallmark of acute pharyngitis. Although usually caused by viral infections, it is frequently treated with antibiotics. Such inappropriate use of antibiotics might best be challenged by offering efficacious and safe symptomatic pain relief instead. However, there is need for robust evidence to support such alternatives. Presently, the evidence from randomised, placebo-controlled, double-blind clinical trials (RCT) with the local anaesthetic ambroxol (CAS 23828-92-4) in the treatment of sore throat is being reviewed. This relates to five RCT in 1,772 patients; 1,713 were evaluable with regard to efficacy. Treatment with ambroxol lozenges was statistically significantly superior to placebo in reducing sore throat pain intensity with a high level of consistency of the estimated effect across the different studies. The effect had an early onset and lasted up to at least 3 h after a single first lozenge. The pain relief was associated with a statistically superior regression of pharyngeal redness and inflammation; with ambroxol, the overall efficacy was more frequently rated as at least "good". Treatment with the ambroxol lozenges was well tolerated. There was heterogeneity in reporting adverse events: in one later study with less severe baseline pain intensity there was more frequent reporting of hypoaesthesia of the oral cavity and tongue as an untoward phenomenon. In patients with more severe baseline pain this reflection of the medication's pharmacological action was only rarely reported as untoward. It is concluded that lozenges containing 20 mg ambroxol are a safe and efficacious treatment for acute uncomplicated sore throat of recent onset in adult patients.

Characterization of differential patient profiles and therapeutic responses of pharmacy customers for four ambroxol formulations

“…Randomized, placebo-controlled short-term (up to 2 weeks of treatment) studies showed efficacy against endpoints such as ease of expectoration, phlegm loosening, sputum volume and sputum viscosity [11–13]. Moreover, more recent studies have demonstrated the efficacy of ambroxol lozenges in the treatment of sore throat [14]. …”

Efficacy of Ambroxol lozenges for pharyngitis: a meta-analysis

“…Three RCTs were published twice [14,16]. One publication summarized all previously published trials providing additionally data from two so far unpublished trials in a so called EBM-based clinical documentation [15]. We identified additionally two unpublished registered and completed RCTs in the study registry ClinicalTrial.gov .These did not provide enough data to be included in the meta-analysis.…”

“…All trials compared 20 mg ambroxol with placebo. There was a dose finding study comparing additionally 5 and 10 mg ambroxol [15] with placebo and two studies had a treatment arm with 30 mg ambroxol [14,16]. One study included a treatment arm with the local anaesthetic benzocaine, but outcomes were not reported [15].…”

“…The number of eligible patients screened is not shown for any of the other trials included in this review. Age of the included patients cannot be assessed for the two newly reported trials in the summary report [15]. Data was analysed as intention to treat (ITT) and per protocol (PP) with last observation carried forward (LOCF).…”

Topical Treatments for Localized Neuropathic Pain

“…Ambroxol is a well-tolerated agent commonly used for the treatment of respiratory disorders via its secretolytic, secretomotor and local anaesthetic effects in cases of pharyngalgia [108]. Regarding mechanisms of action, ambroxol is a potent voltage-dependent sodium channel blocker, blocking these channels approximately 40 times more strongly than lidocaine [109].…”