The effectiveness of AKL1, a herbal treatment for asthma: a randomised placebo controlled double-blinded cross-over trial

Aims: The purpose of this study was to provide scientific evidence regarding the efficacy and safety of AKL 1, an herbal mixture with anecdotal reports of effectiveness in asthma, as an 'add-on' therapy for adult patients whose asthma remains uncontrolled on standard medication.

Methods: 32 asthmatics (7 male, median (range) age 40.5 (22–73)yrs., median (range) FEV1 (forced expiratory volume over 1s; %) predicted 87.5 (33–93)%, median (range) daily ICS (inhaled corticosteroid) dose 800 (0–4000) mcg beclomethasone) completed a 36 week randomized double blinded placebo controlled cross-over trial consisting of; four week baseline, twelve-week treatment with AKL or identical placebo, eight week washout and further twelve-week cross-over treatment period. The change occurring over treatment periods was observed for lung function, Asthma Control Questionnaire (ACQ), Asthma Quality of Life Questionnaire (AQLQ), Leicester Cough Questionnaire

(LCQ) scores. The mean (95% Confidence Interval) individual patient changes between active minus placebo periods was calculated.

Results: Trends to clinical improvements favoring active treatment were consistently seen in the patient-centered outcomes: ACQ mean difference (active – placebo)=-0.35 (-0.78 to 0.07, p=0.10, AQLQ difference 0.42 (-0.08 to 0.93, p=0.09), LCQ difference 0.49, (-0.12 to 1.16, p=0.15). A change in ACQ and AQLQ score of 0.5 signified clinically relevant changes in asthma control or health status. On the ACQ, 28% were unchanged, 22% better on placebo and 50% better on AKL 1. On the AQLQ 29% had no change, 29% were better on placebo and 42% better on AKL 1. No significant differences in lung function were found (FEV1: (active – placebo) mean (95% CI) difference=0.01 (-0.12 to 0.14)L, p=0.9. PEF: -3 (-22 to 28)L/min, p=0.9). Nine exacerbations occurred during placebo treatment and five whilst on AKL. No significant treatment associated adverse events were noted.

Conclusions: AKL1 treatment was well tolerated. It is now well established that asthma symptoms correlate poorly with the level of airway obstruction as determined by the FEV1 and PEF (peak expiry volume). Following treatment, subjective improvement in asthma symptoms may occur without improvement in the level of airway obstruction. AKL1 provided consistent trends to symptom and quality of life improvements. When taken these were taken together a statistical significance with a 99.9% of certainty was shown. While these results support recommendations to measure airway obstruction objectively they additionally point to a need for further investigational studies with AKL 1.