[The use of fenspiride for the combined treatment of exacerbation of chronic laryngitis]

Utilization of mechanistic modelling and simulation to analyse fenspiride proarrhythmic potency - Role of physiological and other non-drug related parameters

WHAT IS KNOWN AND OBJECTIVE

Fenspiride, a drug that had been used for decades for the treatment of respiratory diseases, was recently withdrawn from the market due to the potential risk of QT prolongation and proarrhythmia. This is the first such withdrawal for many years and hence poses a question whether such risk could have been predicted and to what degree non-drug-specific parameters play a role in the reported QT prolongation and cases of TdP. The study aim was to test various 'what-if' scenarios to assess the influence of age, gender, heart rate, and plasma potassium concentration on QT interval prolongation due to various doses of fenspiride with the use of mechanistic mathematical modelling.

METHODS

Concentration-time profiles were simulated with the use of a PBPK model developed based on published physico-chemical data, data from in vitro ADME experiments, and in vivo PK study results. Pharmacodynamic effect, that is, drug-triggered pseudoECG signal modification was simulated using a biophysically detailed model of human cardiac myocytes. Analysis of the qNet metric was also performed to classify proarrhythmic risk related to fenspiride.

RESULTS

In the simulation study, arrhythmia was not observed even in the 'what-if' scenarios with extreme exposure, age, heart rate, and plasma potassium concentration. The qNet metric value positioned fenspiride in the intermediate risk class.

WHAT IS NEW AND CONCLUSION

It can be hypothesized that the clinically observed arrhythmia cases were not directly caused by fenspiride alone but a combination of multiple factors, including comedications.

[Chronic catarrhal laryngitis in singers]

The article deals with optimization of treatment policy for singers with chronic catarrhal laryngitis. The survey sample is 51 singers with chronic catarrhal laryngitis of the age from 29 to 54 and the length of time worked from 8 to 22 years. The following methods are used: anamnesis, microbiological investigation, voice evaluation according to Visual Analog Scale (VAS), microlaryngoscopy, videolaryngostroboscopy, voice acoustic analysis (MDVP Kay Pentax system), statistical processing of results. It is shown that the cause of chronic catarrhal laryngitis in professional singers is non-bacterial irritants that provoke the appearance of an inflammatory process in the larynx, as well as uncontrolled use of drugs that irritate and dry out the mucous membrane and imperfect vocal technique. Pathogenic flora as an etiologic factor in the occurrence of laryngitis does not play an important role. A comprehensive treatment scheme for chronic catarrhal laryngitis using inhalation therapy and drugs that improve trophic processes in the laryngeal mucosa, which allows to increase the effectiveness of treatment and achieve stable remission of the disease, is suggested.