Summary of findings 3. Benzodiazepines versus placebo for treating people with burning mouth syndrome.
| Benzodiazepines compared with placebo for treating burning mouth syndrome | ||||||
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Patient or population: people diagnosed with burning mouth syndrome Settings: secondary care Intervention: benzodiazepines (topical/systemic clonazepam) Comparison: placebo | ||||||
| Outcomes | Anticipated absolute effects* (95% CI) | Relative effect (95% CI) | Number of participants (studies) | Quality of the evidence (GRADE) | Comments | |
| Assumed risk | Corresponding risk | |||||
| Placebo | Benzodiazepines | |||||
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Symptom relief: short‐term (≤ 3 months) ‐ Mean VAS pain score (Scale 0‐10: lower better) |
4.76 | 1.89 lower (2.19 to 1.59 lower) | ‐ | 111 (2 RCTs) | ⊕⊝⊝⊝ very low1 | There was evidence of a difference between subgroups between the 2 subgroups: systemic and topical clonazepam Short‐term relief is estimated from 2 topical clonazepam studies. Long‐term symptom relief (> 3 to ≤ 6 months) was 1.39 lower (1.96 to 0.83 lower) than the placebo group (1 RCT, 66 participants) No evidence of short‐term symptom relief from a single study assessing systemic clonazepam (≤ 3 months): mean VAS score in both placebo and intervention groups was 4.5 (MD 0.00 lower, 95% CI 1.86 lower to 1.86 higher) (1 RCT, 20 participants) No data were available to estimate the effect of other benzodiazepines |
| Change in quality of life (QoL): short‐term (≤ 3 months) ‐ Mean depression score(Scale 0‐4: lower better) | 0.8 | 0.20 lower (0.95 lower to 0.55 higher) | ‐ | 20 (1 RCT) | ⊕⊝⊝⊝ very low2 | Single study assessing systemic clonazepam No data were available to estimate long‐term change in QoL |
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Change in taste: short‐term (≤ 3 months) ‐ Mean taste test score (Scale 0‐16: higher better) |
12.3 | 1.00 lower (3.11 lower to 1.11 higher) | ‐ | 20 (1 RCT) | ⊕⊝⊝⊝ very low3 | Single study assessing systemic clonazepam No data were available to estimate long‐term change in taste |
| Change in feeling of dryness | No included studies reported change in feeling of dryness | |||||
| Adverse effects | There was no difference in the adverse events reported (drowsiness: 2 RCTs, 114 participants; dry mouth, spasmophilia, or euphoric behaviour: 1 RCT, 48 participants) for people treated with benzodiazepines | ⊕⊝⊝⊝ very low4 | Both studies used topical clonazepam We were unable to estimate the harms of systemic clonazepam as adverse events were not reported by its study No data were available to estimate the harms of other benzodiazepines |
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| *The basis for the assumed risk is provided in footnotes. The corresponding risk (and its 95% CI) is based on the assumed risk in the comparison group and the relative effect of the intervention (and its 95% CI) CI: confidence interval; MD: mean difference; OIS: optimal information size; RCT: randomised controlled trial; RR: risk ratio; VAS: visual analogue scale | ||||||
| GRADE Working Group grades of evidence High quality: further research is very unlikely to change our confidence in the estimate of effect Moderate quality: further research is likely to have an important impact on our confidence in the estimate of effect and may change the estimate Low quality: further research is very likely to have an important impact on our confidence in the estimate of effect and is likely to change the estimate Very low quality: we are very uncertain about the estimate | ||||||
1Assumed placebo risk based on mean placebo group pain score at short‐term (≤ 3 months) follow‐up; downgraded once due to studies being assessed at unclear risk of bias across multiple domains; downgraded once due to inconsistency: substantial heterogeneity (I2 = 56%); downgraded once due to indirectness: concerns relating to applicability, only 1 type of benzodiazepine (clonazepam ‐ irrespective of mode of administration) assessed, effects of other benzodiazepines may differ; downgraded once due to imprecision: OIS not met. 2Assumed placebo risk based on mean placebo group depression score at short‐term (≤ 3 months) follow‐up; downgraded once due to high risk of selective reporting bias; downgraded twice due to indirectness: use of surrogate measure, and also concerns relating to applicability, only 1 type of benzodiazepine (clonazepam ‐ irrespective of mode of administration) assessed, effects of other benzodiazepines may differ; downgraded twice due to imprecision: OIS not met, and 95% CI includes no effect. 3Assumed placebo risk based on mean placebo group taste score at short‐term (≤ 3 months) follow‐up; downgraded once due to indirectness: concerns relating to applicability, only 1 type of benzodiazepine (clonazepam ‐ irrespective of mode of administration) assessed, effects of other benzodiazepines may differ; downgraded once due to high risk of selective reporting bias; downgraded twice due to imprecision: OIS not met, and 95% CI includes no effect. 4Downgraded once due to studies being assessed at unclear risk of bias across multiple domains; downgraded once due to indirectness: concerns relating to applicability, only 1 type of benzodiazepine (clonazepam ‐ irrespective of mode of administration) assessed, effects of other benzodiazepines may differ; downgraded twice due to imprecision: OIS not met, and 95% CI includes no effect.