Table 1 Summary of evidence
| Â | Disease group & number of trials | Interventions with positive data | Interventions with negative data |
|---|---|---|---|
Overview of findings from systematic review in respiratory diseases [11]* | 1. Asthma (cough often secondary outcome) N = 23 trials, 1508 subjects | Steroids (particularly Beclomethasone-4 trials-and Budesonide-1 trial) Disodium Cromoglycate-1 trialLodoxadine-1 trial Nedocromil sodium-2 trials Leukotriene receptor antagonists-2 trials Th2 cytokine inhibitor-1 trial | Theophylline-1 trial Nedocromil sodium-2 trials |
| Â | 2. Chronic Bronchitis N = 8 trials, 731 subjects | Epinastine-1 trial Ipratropium bromide-1 trial Theophylline-1 trial Iodinised glycerol-2 trials | Low dose N-acetylcysteine-1 trial Budenoside-1 trial |
| Â | 3. COPD N = 8 trials, 8013 subjects | Fenspiridine-1 trial Fluticasone-1 trial Formoterol-1 trial Neltenexine-3 trials Helicidine-1 trial Oxtriphylline-1 trial High dose N-acetylcysteine-1 trial Salbutamol/Iprapropium bromide-1 trial Iprapropium bromide-1 trial | Budenoside-1 trial Codeine-1 trial Nesosteine-1 trial Oxitropium bromide-1 trial |
| Â | 4. Reflux disease N = 5 trials, 258 subjects | Lansoprazole-1 trial Omeprazole-2 trials | Esoprazole-1 trial Omeprazole-1 trial |
| Â | 5. Idiopathic cough N = 2 trials | Morphine-1 trial Speech pathology training-1 trial | Â |
| Â | 6. Other respiratory illnesses | Codeine-2 trials Benzonatate being equivalent to Codeine-1 trial Moguiesteine being equivalent to Dextromethophran-1 trial Neltenexine-2 trials Sinecod linctus (butamirate) with a similar effect to that of small dose of Codeine-1 trial | Â |
Overview of findings from Cochrane systematic review in cancer [12]** | Lung cancer patients, N = 7 trials | Brachytherapy in addition to EBRT resulted in higher improvements in cough at doses of 15 Gy in 3 fractions; 14-16 Gy in 2 fractions or 10 Gy in a single fraction | Â |
| Â | Lung cancer patients, N = 1 | Photodynamic therapy (PDT) showing similar results to laser therapy; its role as main treatment option questionable. | Â |
| Â | Pharmacological treatments, N = 9 (4 with mixed sample of patients with respiratory illnesses including cancer. Results extrapolated for cancer patients only) | Codeine 30 mg + Phenyltoloxamine 10 mg bd-1 trial Dihydrocodeine-1 trial Hydropropizine (= Levodropropizine)-1 trial Levodropropizine equivalent to Dihydrocodeine-1 trial A Morphine derivative equivalent to Codeine in capsules (unclear dose) Sodium Cromoglycate 40 mg (2 puffs) Butamirate linctus (overall no effect, but effective in cancer subsample) | Â |
Case studies and reviews | Cancer patients, often with advanced disease | Morphine, Methadone, Pholcodine, Quaifenesin, Hydromorphone (due to their antitussive activity) [review] [15] Benzonatate for opioid-resistant cough [16] Nebulized Morphine [17] Nebulized Lidocaine [18] Hydrocodone (phase II trial) 10 mg/d in divided doses [37] | Â |
Experimental studies or studies in non-cancer patients | Â | GABAB agonists (such as Baclofen) [7] Dextromethorphan 10-20 mg/4-6 hrs better than Codeine 20 mg [13] Moguestine 100 mg tid equivalent to Codeine 15-30 mg (non-cancer patients) [14] Nebulised Lidocaine [19, 20, 38] Levocloperastine (novel antitussive) [21] Paroxetine (in concomitant pruritus and cough) [22] Amitryptiline, Gabapentin, Carbamazepine (in chronic cough) [23] Thalidomide [24] | Â |