1. Overview of studies and outcomes.
Group | Study ID | Number participants | Treatment and duration | Outcome and result | Notes |
1. Antitussives | |||||
Antitussives Adults |
Adams | 108 | Moguisteine 3.5 days | Cough score (10‐point scale) MD 0.9 on day 4 | NS |
Eccles | 81 | Codeine 4 days |
16‐item cough severity score MD 1.6 | NS | |
Freestone | 82 | Codeine Single dose |
5‐point symptom rating scale MD 1.0 | NS | |
Lee | 44 | Dextromethorphan Single dose |
Cough severity score (3‐point scale) MD at 180 minutes 0.5 | NS | |
Parvez | 451 | Dextromethorphan Single dose |
Cough recordings at 180 minutes | Significant reduction in cough counts with treatment | |
Pavesi | 710 | Dextromethorphan Single dose |
Cough recordings at 180 minutes | Significant reduction in various cough measures with treatment | |
Antitussives Children |
Bhattacharya | 120 | Dextromethorphan 3 days | Composite 5‐item symptom score MD 0.4 | NS |
Korppi | 50 | Dextromethorphan 3 days |
4‐item cough symptoms score day 3 MD 0.04 | NS | |
Paul | 100 | Dextromethorphan Single dose |
Composite 5‐item symptom score MD 0.79 | NS | |
Taylor | 57 | Dextromethorphan or codeine (3 arms) 3 nights |
4‐item symptom score | NS | |
2. Expectorants | |||||
Expectorants Adults |
Albrecht | 378 | Guaifenesin 1600 mg bd 7 days | 8‐item composite symptom score, day 4 MD 2.6, P value = 0.04 | NS difference at day 7, reported day 4 outcomes |
Kuhn | 65 | Guaifenesin 480 mg qid 30 hours | Cough recordings and patient‐rated improvement in cough frequency and severity | NS | |
Robinson | 239 | Guaifenesin 200 mg qid 3 days | Patient rating as 'helpful' Int 75% versus Con 31% | P value < 0.01 | |
Expectorants Children |
No studies | ||||
3. Mucolytics | |||||
Mucolytics Adults |
Nesswetha | 99 | Bromhexine 4 days |
Cough frequency (cough every 2 to 4 minutes) Int 8.6% versus Con 15.2% |
P value < 0.02 |
Mucolytics Children |
Nespoli | 40 | Letosteine 10 days | Composite symptom score Average 2‐point difference between intervention and control favouring intervention day 4 to 10 | P value < 0.01 |
4. Antihistamine/decongestants | |||||
Antihistamine/ decongestants Adults |
Berkowitz | 283 | Loratadine and pseudoephedrine 5 days | 3‐item cough score MD 0.2 | NS |
Curley | 73 | Dexbrompheniramine and pseudoephedrine 7 days |
4‐item cough score MD 0.6 | P value < 0.05 | |
Antihistamine/ decongestants Children |
Clemens | 59 | Brompheniramine and phenylpropanolamine 2 days |
7‐item cough scores MD 0.1 | NS |
Hutton | 96 | Brompheniramine and phenylephrine and propanolamine 2 days |
9‐item symptom score, % reported as improved Int 67% versus Con 58% | NS | |
5. Other combinations | |||||
Other combinations Adults |
Kurth | 113 | Dextromethorphan plus salbutamol 3 days |
% improved day 3 Int 45% versus Con 27% | P value = 0.05 |
Mizoguchi | 485 | Combination syrup Single dose | Cough score MD 0.42, day 2 |
P value < 0.0001 | |
Thackray | 70 | 'Vicks' 2 days, cross‐over after 24 hours | Patient preference Int 66% versus Con 27% |
P value < 0.01 | |
Tukiainen | 108 | Dextromethorphan with and without salbutamol 4 days |
5‐item symptom score MD 0.11 |
NS | |
Other combinations Children |
Korppi | 51 | Dextromethorphan plus salbutamol 3 days |
Cough symptoms MD 0.12, day 3 |
NS |
Reece | 43 | Combination syrups | Satisfactory antitussive response Int both 69% versus Con 57% | NS | |
6. Antihistamines | |||||
Antihistamines Adults |
Berkowitz | 91 | Terfenadine 4 to 5 days |
3‐item symptom score MD 0.2 |
NS |
Gaffey | 250 | Terfenadine 3.5 days |
Symptom score (scores not reported) | NS | |
Antihistamines Children |
Bhattacharya | 120 | Promethazine 3 days |
5‐item symptom score MD 0.3 |
NS |
Paul | 100 | Diphenhydramine Single dose |
5‐item symptom score MD 1.73 | NS | |
Sakchainanont | 143 | Clemastine and chlorpheniramine 3 days |
4‐item symptom score, % reporting improvement Int 40% versus Con 28% | NS | |
7. Honey | |||||
Honey Adults |
No studies | ||||
Honey Children | Avner‐Cohen | 300 | 3 types honey (4 arms) Single dose | 5‐item composite symptom score | Significant symptom reductions in all honey groups compared to controls |
Con: control Int: intervention MD: mean difference NS: not significant qid: 4 times a day