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Assessment of the Antitussive Efficacy of Codeine Using Cough Sound Pressure Levels as a Means of Measuring Cough
Pulmonary Pharmacology (1996) 9, 365 PULMONARY PHARMACOLOGY
Short Papers Assessment of the Antitussive Efficacy of Codeine Using Cough Sound Pressure Levels as a Means of Measuring Cough C. Freestone, R. Eccles, S. Morris, M. S. M. Jawad Common Cold Centre, School of Molecular and Medical Biosciences, University of Wales College Cardiff, PO Box 911, Cardiff, U.K. was assessed at baseline and 90 min following treatment administration. A total of 82 volunteers (51 females and 31 males, mean age 23.5 years, range 18–46 years), with cough due to acute upper respiratory tract infection (URTI), were included in the study. Cough severity as measured by all three methods, in both codeine and placebo groups, significantly decreased from baseline measurements to those recorded post treatment administration (Table 1). No significant differences were found between the treatment groups for measure of cough severity at baseline or following treatment administration. These results demonstrate that codeine was no more effective than placebo in reducing cough symptom severity as measured by CSPLs, CF or SUB. The finding of no antitussive effect of codeine administration above placebo in human subjects with acute URTI, has previously been demonstrated.1 These results support the validity of measures of CSPLs as a potentially useful parameter for the evaluation of antitussive medications which is on par with the two well established methods of cough frequency and subjective scores.
Investigators have over the years employed many different methods in their evaluation of antitussive agents. However, at present there is no universally accepted method of screening antitussive agents in man. In the present study, a new method of cough assessment, employing a digital sound level meter (GA111, Castle Associates Ltd., Scarborough, U.K.) to record the amount of sound produced by cough as ‘cough sound pressure levels’ (CSPLs), was used to evaluate the antitussive agent, codeine. The aim of the study was to validate the sound level meter as a tool for assessing antitussive efficacy. Changes in CSPLs from baseline measurements to those obtained following treatment administration (matched capsules of either 50 mg codeine or placebo), were compared with changes in two well established measures of evaluating cough severity: the subjective impression of symptom severity scored on a five point rating scale (SUB) and the cough frequency (CF) recorded via a microphone placed on the floor in front of the subject with the sound trace displaced on an ink pen recorder. CSPLs were recorded by a microphone attached to the subject’s throat by means of a neck band, which was connected to a digital sound level meter. The experimental protocol was approved by the local ethics committee. The study was double blind, placebo-controlled, stratified and randomized. Cough symptom severity
REFERENCES 1. Eccles R, Morris S, Jawad M. Lack of effect of codeine in the treatment of cough associated with acute upper respiratory tract infection. J Clin Pharm Therap 1992; 17: 175–180.
Baseline Codeine CSPLs CF SUB Placebo CSPLs CF SUB
0952–0600/96/5/60365+01 $25.00/0
Post treatment
P-value
83.07 (SD 5.9) 25.58 (SD 21.1) 2.0 (IQR 2.0, 3.0)
76.55 (SD 9.2) 13.23 (SD 18.0) 1.0 (IQR 1.0, 2.0)
<0.0001 <0.0001 <0.0001
81.76 (SD 6.5) 25.44 (SD 19.0) 2.0 (IQR 2.0, 3.0)
76.10 (SD 7.3) 12.71 (SD 14.1) 1.0 (IQR 1.0, 2.0)
<0.0001 <0.0001 <0.0001
365
1996 Academic Press Limited
Short Papers Assessment of the Antitussive Efficacy of Codeine Using Cough Sound Pressure Levels as a Means of Measuring Cough C. Freestone, R. Eccles, S. Morris, M. S. M. Jawad Common Cold Centre, School of Molecular and Medical Biosciences, University of Wales College Cardiff, PO Box 911, Cardiff, U.K. was assessed at baseline and 90 min following treatment administration. A total of 82 volunteers (51 females and 31 males, mean age 23.5 years, range 18–46 years), with cough due to acute upper respiratory tract infection (URTI), were included in the study. Cough severity as measured by all three methods, in both codeine and placebo groups, significantly decreased from baseline measurements to those recorded post treatment administration (Table 1). No significant differences were found between the treatment groups for measure of cough severity at baseline or following treatment administration. These results demonstrate that codeine was no more effective than placebo in reducing cough symptom severity as measured by CSPLs, CF or SUB. The finding of no antitussive effect of codeine administration above placebo in human subjects with acute URTI, has previously been demonstrated.1 These results support the validity of measures of CSPLs as a potentially useful parameter for the evaluation of antitussive medications which is on par with the two well established methods of cough frequency and subjective scores.
Investigators have over the years employed many different methods in their evaluation of antitussive agents. However, at present there is no universally accepted method of screening antitussive agents in man. In the present study, a new method of cough assessment, employing a digital sound level meter (GA111, Castle Associates Ltd., Scarborough, U.K.) to record the amount of sound produced by cough as ‘cough sound pressure levels’ (CSPLs), was used to evaluate the antitussive agent, codeine. The aim of the study was to validate the sound level meter as a tool for assessing antitussive efficacy. Changes in CSPLs from baseline measurements to those obtained following treatment administration (matched capsules of either 50 mg codeine or placebo), were compared with changes in two well established measures of evaluating cough severity: the subjective impression of symptom severity scored on a five point rating scale (SUB) and the cough frequency (CF) recorded via a microphone placed on the floor in front of the subject with the sound trace displaced on an ink pen recorder. CSPLs were recorded by a microphone attached to the subject’s throat by means of a neck band, which was connected to a digital sound level meter. The experimental protocol was approved by the local ethics committee. The study was double blind, placebo-controlled, stratified and randomized. Cough symptom severity
REFERENCES 1. Eccles R, Morris S, Jawad M. Lack of effect of codeine in the treatment of cough associated with acute upper respiratory tract infection. J Clin Pharm Therap 1992; 17: 175–180.
Baseline Codeine CSPLs CF SUB Placebo CSPLs CF SUB
0952–0600/96/5/60365+01 $25.00/0
Post treatment
P-value
83.07 (SD 5.9) 25.58 (SD 21.1) 2.0 (IQR 2.0, 3.0)
76.55 (SD 9.2) 13.23 (SD 18.0) 1.0 (IQR 1.0, 2.0)
<0.0001 <0.0001 <0.0001
81.76 (SD 6.5) 25.44 (SD 19.0) 2.0 (IQR 2.0, 3.0)
76.10 (SD 7.3) 12.71 (SD 14.1) 1.0 (IQR 1.0, 2.0)
<0.0001 <0.0001 <0.0001
365
1996 Academic Press Limited