What do systematic reviews say?

Zinc vs placebo

• Antioxidant vitamin and mineral supplements for slowing the progression of age‐related macular degeneration 2023 · Cochrane Headline outcomes only
  no estimate extracted
  286 participants
  Very low

Antioxidant multivitamin and mineral supplement vs placebo or no treatment

Antioxidant multivitamin and mineral supplement may leads to lower adverse effects compared with placebo or no treatment (low certainty).

• Antioxidant vitamin and mineral supplements for slowing the progression of age‐related macular degeneration 2023 · Cochrane Headline outcomes only
  OR 0.87
  0 participants
  Low

Statins vs placebo

• Statins for women with polycystic ovary syndrome not actively trying to conceive 2023 · Cochrane Headline outcomes only
  no estimate extracted
  2 studies · 2 participants
  GRADE not reported

Attention deficit hyperactivity disorder (ADHD)‐related drugs vs placebo

It is very uncertain whether attention deficit hyperactivity disorder (ADHD)‐related drugs changes adverse effects compared with placebo (very low certainty).

• Pharmacological intervention for irritability, aggression, and self‐injury in autism spectrum disorder (ASD) 2023 · Cochrane Headline outcomes only
  RR 3.42
  9 studies · 511 participants
  Very low

Antidepressants vs placebo

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

• Pharmacological intervention for irritability, aggression, and self‐injury in autism spectrum disorder (ASD) 2023 · Cochrane Headline outcomes only
  RR 4.16
  10 studies · 815 participants
  Low

Neurohormones vs placebo

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

• Pharmacological intervention for irritability, aggression, and self‐injury in autism spectrum disorder (ASD) 2023 · Cochrane Headline outcomes only
  RR 0.58 [0.38, 0.89]
  10 studies · 863 participants
  Very low

Botulinum toxin vs placebo

Botulinum toxin injection may leads to lower adverse effects compared with placebo (low certainty).

• Treatment for sialorrhea (excessive saliva) in people with motor neuron disease/amyotrophic lateral sclerosis 2022 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 20 participants
  Low

Add‐on felbamate vs placebo

• Felbamate add‐on therapy for drug‐resistant focal epilepsy 2022 · Cochrane Headline outcomes only
  no estimate extracted
  4 studies · 236 participants
  Very low

Rituximab vs placebo

It is very uncertain whether summary of findings table ‐ Rituximab changes adverse effects compared with placebo (very low certainty).

• Rituximab for thyroid‐associated ophthalmopathy 2022 · Cochrane Headline outcomes only
  RR 2.46 [0.84, 7.18]
  1 study · 25 participants
  Very low

Topical antibiotics vs another topical antibiotic or placebo

• Antibiotic prophylaxis for corneal abrasion 2022 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  Low

Summary of findings ‐ initiation of penicillin prophylaxis vs placebo

• Prophylactic antibiotics for preventing pneumococcal infection in children with sickle cell disease 2021 · Cochrane Headline outcomes only
  no estimate extracted
  2 studies · 457 participants
  Low

Recombinant human growth hormone vs placebo or no intervention

• Recombinant growth hormone therapy for X‐linked hypophosphatemia in children 2021 · Cochrane Headline outcomes only
  no estimate extracted
  2 studies · 20 participants
  Low

Vitamin C vs placebo

The review found no eligible studies for this question.

• Vitamin C supplementation for prevention and treatment of pneumonia 2021 · Cochrane Headline outcomes only
  no estimate extracted
  Studies not reported
  No studies found

Systemic antibiotic prophylaxis (any regimen; topical therapy excluded) administered before and/or after tooth extraction vs placebo

It is very uncertain whether systemic antibiotic prophylaxis (any regimen; topical therapy… changes adverse effects compared with placebo (very low certainty).

• Antibiotics to prevent complications following tooth extractions 2021 · Cochrane All outcomes

  1st to 7th day
  RR 1.46 [0.81, 2.64]
  8 studies · 1277 participants
  Very low

Chlorhexidine (mouthrinse or gel), as part of oral hygiene care vs placebo or usual care

• Oral hygiene care for critically ill patients to prevent ventilator‐associated pneumonia 2020 · Cochrane All outcomes
  Adverse effects: information from 2 studies; one stated there were none, the other reported mild reversible irritation of the oral mucosa; very low certainty. There was a lack of evidence about adverse effects.
  2 studies
  Very low

Dexamethasone + nystatin + curcumin (adjunctive) vs Dexamethasone + nystatin + placebo

• Interventions for treating oral lichen planus: corticosteroid therapies 2020 · Cochrane All outcomes
  Amirchaghmaghi 2016: no adverse effects recorded in either group (low-certainty)
  1 study
  Low

Aromatherapy vs placebo or control

• Aromatherapy for dementia 2020 · Cochrane Headline outcomes only
  no estimate extracted
  4 studies · 206 participants
  Very low

Pentoxifylline (oral 400 mg thrice daily) plus meglumine antimoniate (IMMA) (20 mg/ kg /day for 20 days) vs IMMA plus placebo

• Interventions for American cutaneous and mucocutaneous leishmaniasis 2020 · Cochrane Headline outcomes only
  no estimate extracted
  1 study · 70 participants
  Moderate

Cooling treatment (cold gel pad)+compression vs placebo (gel pad+compression)

• Local cooling for relieving pain from perineal trauma sustained during childbirth 2020 · Cochrane Headline outcomes only
  no estimate extracted
  0 studies · 0 participants
  GRADE not reported

Add‐on lamotrigine vs placebo

It is very uncertain whether add‐on lamotrigine changes adverse effects compared with placebo (very low certainty).

• Lamotrigine add‐on therapy for drug‐resistant generalised tonic‐clonic seizures 2020 · Cochrane Headline outcomes only
  RR 0.91 [0.29, 2.86]
  2 studies · 270 participants
  Very low