4. Adverse event outcomes.
| Antidepressants/antipsychotics versus placebo | ||||||
| Intervention | Outcome | No of studies | No of patients | Risk ratio (M‐H, Fixed, 95% CI) | Overall effect (P value) | Heterogeneity (P value; I2) |
| Antidepressants (trazodone) |
Dizziness | 1 | 37 | 11.61 (1.66 to 81.04) | P = 0.01 | Not applicable |
| Drowsiness | 1 | 37 | 4.75 (1.18 to 19.07) | P = 0.03 | Not applicable | |
| Abdominal pains | 1 | 37 | 1.32 (0.42 to 4.15) | P = 0.64 | Not applicable | |
| Headache | 1 | 37 | 1.58 (0.30 to 8.40) | P = 0.59 | Not applicable | |
| Palpitations | 1 | 37 | 1.06 (0.17 to 6.72) | P = 0.95 | Not applicable | |
| Tremor | 1 | 37 | 2.11 (0.21 to 21.32) | P = 0.53 | Not applicable | |
| Dry mouth | 1 | 37 | 3.17 (0.36 to 27.72) | P = 0.30 | Not applicable | |
| Urinary incontinence | 1 | 37 | 3.16 (0.14 to 72.84) | P = 0.47 | Not applicable | |
| Antipsychotics | Adverse effect data were not available for analysis from the single included study comparing antipsychotics versus placebo (Bogetto 1999) | |||||
| Anticonvulsants versus placebo | ||||||
| Intervention | Outcome | No of studies | No of patients | Risk ratio (M‐H, Fixed, 95% CI) | Overall effect (P value) | Heterogeneity (P value; I2) |
| Gabapentin | Drowsiness | 1 | 80 | 31.95 (1.84 to 553.64) | P = 0.02 | Not applicable |
| Gabapentin + ALA | Drowsiness | 1 | 80 | 14.52 (0.73 to 290.44) | P = 0.08 | Not applicable |
| Mild headache | 1 | 80 | 8.71 (0.37 to 205.80) | P = 0.18 | Not applicable | |
| Benzodiazepines versus placebo | ||||||
| Intervention | Outcome | No of studies | No of patients | Risk ratio (M‐H, Fixed, 95% CI) | Overall effect (P value) | Heterogeneity (P value; I2) |
| Topical clonazepam | Drowsiness | 2 | 114 | 2.71 (0.84 to 8.74) | P = 0.09 | P = 0.16; I2 = 48% |
| Dry mouth | 1 | 48 | 3.00 (0.13 to 70.16) | P = 0.49 | Not applicable | |
| Spasmophilia | 1 | 48 | 3.00 (0.13 to 70.16) | P = 0.49 | Not applicable | |
| Euphoric behaviour | 1 | 48 | 3.00 (0.13 to 70.16) | P = 0.49 | Not applicable | |
| Cholinergics versus placebo | ||||||
| Bethanechol | Adverse effect data presented collectively and not usable for analysis from the single included study comparing cholinergics versus placebo (Femiano 2002b) | |||||
| Dietary supplements versus placebo | ||||||
| Intervention | Outcome | No of studies | No of patients | Risk ratio (M‐H, Fixed, 95% CI) | Overall effect (P value) | Heterogeneity (P value; I2) |
| ALA (+/‐ adjunctive ingredients) | Gastrointestinal complaints | 3 | 138 | 4.00 (1.21 to 13.27) | P = 0.02 | P = 0.78; I2 = 0% |
| Headache | 2 | 118 | 10.87 (1.36 to 87.03) | P = 0.02 | P = 0.82; I2 = 0% | |
| Drowsiness | 1 | 38 | 1.00 (0.07 to 14.85) | P = 1.00 | Not applicable | |
| Increase in blood pressure | 1 | 38 | 1.00 (0.07 to 14.85) | P = 1.00 | Not applicable | |
| Intermittent facial skin rash | 1 | 80 | 8.71 (0.37 to 205.80) | P = 0.18 | Not applicable | |
| 'Catuama' herbal compound | Drowsiness | 1 | 72 | 2.69 (0.11 to 63.96) | P = 0.54 | Not applicable |
| Weight gain | 1 | 72 | 2.69 (0.11 to 63.96) | P = 0.54 | Not applicable | |
| Insomnia | 1 | 72 | 2.69 (0.11 to 63.96) | P = 0.54 | Not applicable | |
| Exacerbation of symptoms | 1 | 72 | 1.12 (0.33 to 3.83) | P = 0.86 | Not applicable | |
| Electromagnetic radiation versus placebo | ||||||
| Low‐level laser therapy | Adverse effect data were not available for analysis from the single included study comparing electromagnetic radiation versus placebo (Spanemberg 2015) | |||||
| Physical barriers versus placebo | ||||||
| Tongue protector | Adverse effect data were not available for analysis from the single included study comparing physical barriers versus placebo (López‐Jornet 2011) | |||||
| Psychological therapies versus placebo | ||||||
| Cognitive therapy | Adverse effect data were not available for analysis from the single included study comparing psychological therapies versus placebo (Bergdahl 1995a) | |||||
| Topical treatments versus placebo | ||||||
| Benzydamine hydrochloride oral rinse | Adverse data only presented for benzydamine hydrochloride oral rinse against placebo; narratively reported that no adverse effects occurred (Sardella 1999) | |||||
ALA = alpha lipoic acid; CI = confidence interval; M‐H = Mantel‐Haenszel.