What do systematic reviews say?

NSAIDs vs placebo

NSAIDs may leads to higher all adverse effects compared with placebo (low certainty).

• Nonsteroidal anti‐inflammatory drugs for dysmenorrhoea 2015 · Cochrane Headline outcomes only
  OR 1.29 [1.11, 1.51]
  Studies not reported
  Low

ASENAPINE vs placebo

It is very uncertain whether ASENAPINE changes adverse effects: Incidence of serious adverse effects compared with PLACEBO (very low certainty).

• Asenapine versus placebo for schizophrenia 2015 · Cochrane Headline outcomes only
  RR 0.29 [0.14, 0.63]
  1 study · 386 participants
  Very low

FLUPHENAZINE (ORAL) vs placebo

ORAL FLUPHENAZINE showed no clear difference in adverse effects: Death ‐ long termOccurrences of death compared with PLACEBO (low certainty).

• Fluphenazine (oral) versus placebo for schizophrenia 2018 · Cochrane Headline outcomes only
  RR 2.38 [0.1, 55.72]
  1 study · 50 participants
  Low

α‐FLUPENTHIXOL vs PLACEBO or β‐FLUPENTHIXOL

• Flupenthixol versus placebo for schizophrenia 2012 · Cochrane Headline outcomes only
  no estimate extracted
  0 studies · 0 participants
  GRADE not reported

Analgesic‐decongestant vs placebo

Analgesic‐decongestant leads to higher adverse effects: all compared with placebo (high certainty).

• Oral antihistamine‐decongestant‐analgesic combinations for the common cold 2022 · Cochrane Headline outcomes only
  OR 1.62 [1.18, 2.23]
  6 studies · 1797 participants
  High

Antihistamine‐decongestant vs placebo

Antihistamine‐decongestant showed no clear difference in adverse effects: all compared with placebo (moderate certainty).

• Oral antihistamine‐decongestant‐analgesic combinations for the common cold 2022 · Cochrane Headline outcomes only
  OR 1.58 [0.78, 3.21]
  7 studies · 842 participants
  Moderate

Intravenous iron vs placebo

It is very uncertain whether intravenous iron changes mild adverse effects compared with placebo (very low certainty).

• Intravenous iron therapy for non‐anaemic, iron‐deficient adults 2019 · Cochrane Headline outcomes only
  RR 1.19 [0.97, 1.45]
  3 studies · 440 participants
  Very low

Vitamin E vs placebo

• Antioxidant vitamin and mineral supplements for preventing age‐related macular degeneration 2017 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  Low

ASENAPINE vs placebo

The review found no eligible studies for this question.

• Asenapine versus placebo for schizophrenia 2015 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Topical corticosteroids vs placebo or no treatment

Topical corticosteroids showed no clear difference in adverse effects (any) compared with placebo or no treatment (low certainty).

• Topical corticosteroids for treating phimosis in boys 2024 · Cochrane Headline outcomes only
  RR 0.28 [0.03, 2.62]
  11 studies · 1091 participants
  Low

Atypical antipsychotics vs placebo

Atypical antipsychotics may leads to higher adverse effects (AEs) compared with placebo (low certainty).

• Pharmacological intervention for irritability, aggression, and self‐injury in autism spectrum disorder (ASD) 2023 · Cochrane Headline outcomes only
  RR 4.19
  11 studies · 974 participants
  Low

Intranasal steroid spray vs placebo or no intervention

• Interventions for the prevention of persistent post‐COVID‐19 olfactory dysfunction 2022 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 77 participants
  Very low

Intranasal steroid drops vs placebo

The review found no eligible studies for this question.

• Interventions for the prevention of persistent post‐COVID‐19 olfactory dysfunction 2022 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Nifedipine vs placebo

It is very uncertain whether nifedipine changes total adverse effects compared with placebo (very low certainty).

• Nifedipine for primary dysmenorrhoea 2021 · Cochrane Headline outcomes only
  OR 0.94 [0.08, 10.9]
  1 study · 24 participants
  Very low

GnRH agonists vs placebo

The review found no eligible studies for this question.

• Endometrial preparation for women undergoing embryo transfer with frozen embryos or embryos derived from donor oocytes 2020 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Antibiotics vs placebo

It is very uncertain whether antibiotics changes total adverse effects compared with placebo (very low certainty).

• Antibiotic prophylaxis for elective hysterectomy 2017 · Cochrane Headline outcomes only
  RR 1.8 [0.62, 5.18]
  2 studies · 430 participants
  Very low

Hydroxyurea vs placebo or usual care

The review found no eligible studies for this question.

• Hydroxyurea for reducing blood transfusion in non‐transfusion dependent beta thalassaemias 2016 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

BIFEPRUNOX vs placebo

BIFEPRUNOX showed no clear difference in adverse effects: Weight ‐ Total number of participants with ≥ 7%… compared with PLACEBO (moderate certainty).

• Bifeprunox versus placebo for schizophrenia 2016 · Cochrane Headline outcomes only
  RR 1.02 [0.31, 3.33]
  1 study · 483 participants
  Moderate

Perioperative statins vs placebo or no treatment

• Perioperative statin therapy for improving outcomes during and after noncardiac vascular surgery 2013 · Cochrane Headline outcomes only
  no estimate extracted
  3 studies · 188 participants
  GRADE not reported

FLUPHENAZINE (ORAL) vs placebo

ORAL FLUPHENAZINE probably leads to higher adverse effects: Extrapyramidal effects (rigidity) ‐ short… compared with PLACEBO (moderate certainty).

• Fluphenazine (oral) versus placebo for schizophrenia 2018 · Cochrane Headline outcomes only
  RR 3.54 [1.76, 7.14]
  2 studies · 227 participants
  Moderate