Correlation between EEG changes indicative of sedation and subjective responses

Area of Science:

• Neuroscience
• Pharmacology
• Clinical Trials

Background:

• Ketotifen (Zaditen) is a benzocycloheptathiophene derivative used for asthma prophylaxis.
• Understanding the central nervous system (CNS) effects of ketotifen is crucial for its therapeutic application.

Purpose of the Study:

• To determine the central activity of ketotifen using quantitative pharmaco-electroencephalography (EEG).
• To assess the subjective side effects of ketotifen in healthy volunteers.

Main Methods:

• A single-blind trial involving 7 healthy volunteers.
• Administration of placebo followed by ketotifen (1 mg twice daily for 3 weeks) and then placebo again.
• Quantitative EEG analysis (spectral analysis of lead O2-Cz) measuring dominant alpha frequency and relative power in delta, theta, and alpha bands.
• Comparison of EEG parameters and subjective side effects with baseline.

Main Results:

• Statistically significant slowing of dominant alpha frequency observed.
• Decrease in relative power of fast alpha activity and increase in relative power of theta rhythm.
• EEG changes indicated mild sedation, peaking around the 3rd day of the first week and gradually decreasing.
• No subjects reported sedation or tiredness despite objective EEG findings.

Conclusions:

• Quantitative pharmaco-EEG detected mild sedative effects of ketotifen not reported by subjects.
• The study highlights the sensitivity of EEG in detecting CNS effects of medications.
• Ketotifen may induce subclinical CNS effects that warrant consideration in clinical practice.