Table 3.
Adverse effect frequency by treatment group.
| Mirtazapine | Placebo | ||||
|---|---|---|---|---|---|
| N | % | N | % | p1 | |
| Sedation/drowsiness | 12 | 60 | 6 | 60 | 1.00 |
| Appetite increase | 10 | 50 | 2 | 20 | 0.24 |
| Irritability | 7 | 35 | 3 | 30 | 1.00 |
| Nausea | 6 | 30 | 3 | 30 | 1.00 |
| Stomach or abdominal discomfort | 5 | 25 | 4 | 40 | 0.43 |
| Aggression | 5 | 25 | 4 | 40 | 0.43 |
| Diarrhea | 5 | 25 | 2 | 20 | 1.00 |
| Sadness | 4 | 20 | 3 | 30 | 0.66 |
| Vomiting | 3 | 15 | 4 | 40 | 0.18 |
| Nasal congestion or cold | 4 | 20 | 2 | 20 | 1.00 |
| Nightmares or dreams | 4 | 20 | 2 | 20 | 1.00 |
| Constipation | 3 | 15 | 3 | 30 | 0.37 |
| Headache | 3 | 15 | 2 | 20 | 1.00 |
| Difficulty falling asleep | 3 | 15 | 1 | 10 | 1.00 |
| Enuresis | 3 | 15 | 1 | 10 | 1.00 |
| Appetite decrease | 2 | 10 | 2 | 20 | 0.58 |
| Fever | 2 | 10 | 2 | 20 | 0.58 |
| Social withdrawal2 | 2 | 10 | 2 | 20 | 0.58 |
| Concentration difficulty | 2 | 10 | 1 | 10 | 1.00 |
| Dizziness/faintness | 2 | 10 | 1 | 10 | 1.00 |
| Unspecified or not otherwise listed nose/throat2,3 | 2 | 10 | 1 | 10 | 1.00 |
| Localized rash | 2 | 10 | 1 | 10 | 1.00 |
| Anxiety/nervousness/worry | 2 | 10 | 0 | 0 | 0.54 |
| Body-focused repetitive behavior2 | 2 | 10 | 0 | 0 | 0.54 |
| Change in speech | 2 | 10 | 0 | 0 | 0.54 |
| Dry mouth | 2 | 10 | 0 | 0 | 0.54 |
| Interrupted sleep/other sleep problems | 2 | 10 | 0 | 0 | 0.54 |
| Self-injurious behavior | 2 | 10 | 0 | 0 | 0.54 |
| Sinus condition | 2 | 10 | 0 | 0 | 0.54 |
| Tiredness/fatigue | 2 | 10 | 0 | 0 | 0.54 |
| Allergies not otherwise specified | 1 | 5 | 1 | 10 | 1.00 |
| Restlessness/agitation | 1 | 5 | 1 | 10 | 1.00 |
| Stereotypy | 1 | 5 | 1 | 10 | 1.00 |
| Flu or upper respiratory problems | 0 | 0 | 2 | 20 | 0.10 |
Adverse effects are listed in order of descending frequency. Effects reported by two or more participants are included in the table. Adverse effects reported by one participant assigned to mirtazapine (5%) and no participants assigned to placebo were accidental injury, compulsions2, decreased motor activity, disinhibition, ear infection, emotional outburst, euphoria/giddiness, eye irritation, hair problems, increased motor activity, intermittent nosebleed, other pain, sensory sensitivity2, sore throat, sweating, taste abnormality, throat infection, unspecified or not otherwise listed musculoskeletal effect (muscle twitching in both arms)2, and unspecified or not otherwise listed psychological/behavioral effect (firesetting)2. Adverse effects reported by one participant assigned to placebo (10%) and no participants assigned to mirtazapine were indigestion and unspecified or not otherwise listed effect, mouth (inflamed salivary gland)2.
1Frequencies were compared using Fisher’s exact test.
2Effects originally classified by study physician as not otherwise specified and reclassified by study staff.
3One participant each assigned to mirtazapine reported laryngitis and hoarseness; one participant assigned to placebo reported itchy throat.