Drug
Metaxalone
Important: Reactions below are the flagged terms from this drug’s
FAERS report history (min. 3 co-reports per term) — PRR/ROR indicate
disproportionality in spontaneous reporting, not causation.
Data from FDA FAERS via openFDA. Last recalculated: 2026-09-14.
| Reaction | Co-reports (a) | PRR | ROR | Signal | |
|---|---|---|---|---|---|
| 1 | Completed Suicide | 261 | 19.6 | 21.2 | signal |
| 2 | Serotonin Syndrome | 59 | 19.5 | 19.8 | signal |
| 3 | End Stage Renal Disease | 36 | 12.3 | 12.5 | signal |
| 4 | Muscle Rigidity | 22 | 11.6 | 11.7 | signal |
| 5 | Poisoning | 23 | 11.5 | 11.6 | signal |
| 6 | Chronic Kidney Disease | 111 | 9.1 | 9.4 | signal |
| 7 | Sleep Apnoea Syndrome | 27 | 8.9 | 9.0 | signal |
| 8 | Fibromyalgia | 32 | 8.3 | 8.4 | signal |
| 9 | Respiratory Arrest | 35 | 7.9 | 8.0 | signal |
| 10 | Respiratory Depression | 15 | 7.7 | 7.7 | signal |
| 11 | Nerve Compression | 11 | 7.5 | 7.6 | signal |
| 12 | Impaired Gastric Emptying | 15 | 7.4 | 7.4 | signal |
| 13 | Mydriasis | 15 | 7.4 | 7.4 | signal |
| 14 | Drug Toxicity | 16 | 7.3 | 7.3 | signal |
| 15 | Spinal Operation | 14 | 7.3 | 7.3 | signal |
| 16 | Osteopenia | 17 | 7.0 | 7.1 | signal |
| 17 | Cardio-respiratory Arrest | 46 | 6.9 | 7.0 | signal |
| 18 | Vasculitis | 12 | 6.5 | 6.5 | signal |
| 19 | Bursitis | 12 | 6.3 | 6.3 | signal |
| 20 | Toxicity To Various Agents | 164 | 6.2 | 6.4 | signal |
| 21 | Intervertebral Disc Degeneration | 9 | 6.1 | 6.1 | signal |
| 22 | Blood Sodium Decreased | 18 | 6.0 | 6.1 | signal |
| 23 | Back Injury | 10 | 5.8 | 5.8 | signal |
| 24 | Vitamin D Deficiency | 9 | 5.8 | 5.8 | signal |
| 25 | Disability | 18 | 5.7 | 5.8 | signal |
| 26 | Hypotonia | 9 | 5.7 | 5.7 | signal |
| 27 | Subarachnoid Haemorrhage | 9 | 5.6 | 5.6 | signal |
| 28 | Brain Oedema | 11 | 5.5 | 5.5 | signal |
| 29 | Intervertebral Disc Protrusion | 19 | 5.5 | 5.5 | signal |
| 30 | Foot Fracture | 16 | 5.3 | 5.3 | signal |
| 31 | Renal Tubular Necrosis | 8 | 5.1 | 5.1 | signal |
| 32 | No Therapeutic Response | 10 | 5.1 | 5.1 | signal |
| 33 | Nerve Injury | 9 | 5.1 | 5.1 | signal |
| 34 | Muscle Tightness | 13 | 5.1 | 5.1 | signal |
| 35 | Osteoporosis | 33 | 5.1 | 5.1 | signal |
| 36 | Renal Failure | 107 | 5.0 | 5.2 | signal |
| 37 | Temperature Intolerance | 8 | 4.9 | 4.9 | signal |
| 38 | Carpal Tunnel Syndrome | 11 | 4.9 | 5.0 | signal |
| 39 | Osteoarthritis | 33 | 4.9 | 4.9 | signal |
| 40 | Rotator Cuff Syndrome | 10 | 4.9 | 4.9 | signal |
| 41 | Sciatica | 12 | 4.8 | 4.8 | signal |
| 42 | Wrist Fracture | 9 | 4.7 | 4.7 | signal |
| 43 | Irritable Bowel Syndrome | 16 | 4.7 | 4.7 | signal |
| 44 | Tubulointerstitial Nephritis | 14 | 4.7 | 4.7 | signal |
| 45 | Body Height Decreased | 8 | 4.7 | 4.7 | signal |
| 46 | Therapeutic Response Unexpected | 33 | 4.6 | 4.7 | signal |
| 47 | Glaucoma | 14 | 4.6 | 4.6 | signal |
| 48 | Ankle Fracture | 11 | 4.5 | 4.5 | signal |
| 49 | Ligament Sprain | 7 | 4.5 | 4.5 | signal |
| 50 | Tendonitis | 11 | 4.5 | 4.5 | signal |
| 51 | Status Epilepticus | 8 | 4.5 | 4.5 | signal |
| 52 | Bronchitis | 52 | 4.4 | 4.5 | signal |
| 53 | Hiatus Hernia | 9 | 4.4 | 4.4 | signal |
| 54 | Drug Abuse | 58 | 4.4 | 4.4 | signal |
| 55 | Muscle Twitching | 16 | 4.4 | 4.4 | signal |
| 56 | Initial Insomnia | 7 | 4.3 | 4.3 | signal |
| 57 | Mental Status Changes | 19 | 4.3 | 4.3 | signal |
| 58 | Gastroenteritis Viral | 12 | 4.2 | 4.2 | signal |
| 59 | Incontinence | 7 | 4.2 | 4.2 | signal |
| 60 | Intentional Drug Misuse | 14 | 4.2 | 4.2 | signal |
| 61 | Sinusitis | 67 | 4.1 | 4.2 | signal |
| 62 | Seasonal Allergy | 9 | 4.0 | 4.0 | signal |
| 63 | Laceration | 6 | 4.0 | 4.0 | signal |
| 64 | Infusion Site Pain | 8 | 3.9 | 4.0 | signal |
| 65 | Migraine | 59 | 3.9 | 4.0 | signal |
| 66 | Haemorrhoids | 12 | 3.9 | 3.9 | signal |
| 67 | Kidney Infection | 12 | 3.9 | 3.9 | signal |
| 68 | Cholelithiasis | 20 | 3.8 | 3.9 | signal |
| 69 | Coma | 29 | 3.8 | 3.9 | signal |
| 70 | Pulmonary Congestion | 8 | 3.8 | 3.8 | signal |
| 71 | Ear Infection | 16 | 3.8 | 3.8 | signal |
| 72 | Haemorrhage Intracranial | 9 | 3.8 | 3.8 | signal |
| 73 | Gastrooesophageal Reflux Disease | 48 | 3.8 | 3.8 | signal |
| 74 | Surgery | 34 | 3.7 | 3.7 | signal |
| 75 | Rib Fracture | 12 | 3.7 | 3.7 | signal |
| 76 | Economic Problem | 9 | 3.7 | 3.7 | signal |
| 77 | Weight Fluctuation | 6 | 3.6 | 3.6 | signal |
| 78 | Joint Dislocation | 6 | 3.6 | 3.6 | signal |
| 79 | Joint Injury | 12 | 3.5 | 3.5 | signal |
| 80 | Acute Kidney Injury | 85 | 3.5 | 3.6 | signal |
| 81 | Blood Potassium Increased | 9 | 3.5 | 3.5 | signal |
| 82 | Prescribed Underdose | 11 | 3.5 | 3.5 | signal |
| 83 | Bipolar Disorder | 6 | 3.5 | 3.5 | signal |
| 84 | Dental Caries | 6 | 3.4 | 3.4 | signal |
| 85 | Diverticulitis | 15 | 3.4 | 3.4 | signal |
| 86 | Increased Tendency To Bruise | 5 | 3.4 | 3.4 | signal |
| 87 | Cardiomyopathy | 8 | 3.4 | 3.4 | signal |
| 88 | Psychomotor Hyperactivity | 9 | 3.4 | 3.4 | signal |
| 89 | Muscle Spasms | 97 | 3.3 | 3.4 | signal |
| 90 | Hypersomnia | 15 | 3.3 | 3.3 | signal |
| 91 | Orthostatic Hypotension | 9 | 3.3 | 3.3 | signal |
| 92 | Choking | 10 | 3.2 | 3.3 | signal |
| 93 | Spinal Pain | 6 | 3.2 | 3.2 | signal |
| 94 | Fungal Infection | 17 | 3.2 | 3.2 | signal |
| 95 | Unresponsive To Stimuli | 13 | 3.2 | 3.2 | signal |
| 96 | Renal Injury | 15 | 3.1 | 3.2 | signal |
| 97 | Mass | 7 | 3.1 | 3.2 | signal |
| 98 | Drug Hypersensitivity | 97 | 3.1 | 3.2 | signal |
| 99 | Neuropathy Peripheral | 47 | 3.1 | 3.2 | signal |
| 100 | Restless Legs Syndrome | 9 | 3.1 | 3.1 | signal |
| 101 | Back Disorder | 8 | 3.1 | 3.1 | signal |
| 102 | Eye Discharge | 5 | 3.1 | 3.1 | signal |
| 103 | Small Intestinal Obstruction | 6 | 3.1 | 3.1 | signal |
| 104 | Ear Discomfort | 5 | 3.1 | 3.1 | signal |
| 105 | Secretion Discharge | 6 | 3.1 | 3.1 | signal |
| 106 | Cardiac Arrest | 40 | 3.0 | 3.1 | signal |
| 107 | Tooth Extraction | 6 | 3.0 | 3.0 | signal |
| 108 | Brain Fog | 7 | 3.0 | 3.0 | signal |
| 109 | Fall | 159 | 3.0 | 3.1 | signal |
| 110 | Hereditary Angioedema | 5 | 3.0 | 3.0 | signal |
| 111 | Musculoskeletal Disorder | 9 | 3.0 | 3.0 | signal |
| 112 | Unevaluable Event | 35 | 2.9 | 2.9 | signal |
| 113 | Laryngitis | 5 | 2.9 | 2.9 | signal |
| 114 | Arthritis | 36 | 2.9 | 2.9 | signal |
| 115 | Gastrointestinal Pain | 5 | 2.9 | 2.9 | signal |
| 116 | Tooth Infection | 6 | 2.9 | 2.9 | signal |
| 117 | Systemic Lupus Erythematosus | 16 | 2.9 | 2.9 | signal |
| 118 | Product Substitution Issue | 26 | 2.8 | 2.9 | signal |
| 119 | Memory Impairment | 62 | 2.8 | 2.9 | signal |
| 120 | Sars-cov-2 Test Positive | 6 | 2.8 | 2.8 | signal |
| 121 | Activities Of Daily Living Impaired | 9 | 2.8 | 2.8 | signal |
| 122 | Tooth Disorder | 10 | 2.8 | 2.8 | signal |
| 123 | Oral Pain | 10 | 2.8 | 2.8 | signal |
| 124 | Head Injury | 14 | 2.8 | 2.8 | signal |
| 125 | Abasia | 11 | 2.8 | 2.8 | signal |
| 126 | Internal Haemorrhage | 5 | 2.8 | 2.8 | no signal |
| 127 | Knee Arthroplasty | 9 | 2.7 | 2.7 | signal |
| 128 | Oral Discomfort | 6 | 2.7 | 2.7 | signal |
| 129 | Deep Vein Thrombosis | 28 | 2.7 | 2.7 | signal |
| 130 | Psoriatic Arthropathy | 17 | 2.7 | 2.7 | signal |
| 131 | Drug Level Increased | 7 | 2.7 | 2.7 | signal |
| 132 | Fracture | 8 | 2.7 | 2.7 | signal |
| 133 | Pharyngeal Swelling | 4 | 2.6 | 2.6 | no signal |
| 134 | Anhedonia | 11 | 2.6 | 2.6 | signal |
| 135 | Therapy Change | 4 | 2.6 | 2.6 | no signal |
| 136 | Localised Infection | 10 | 2.6 | 2.6 | signal |
| 137 | Knee Operation | 4 | 2.6 | 2.6 | no signal |
| 138 | Coeliac Disease | 4 | 2.6 | 2.6 | no signal |
| 139 | Road Traffic Accident | 17 | 2.6 | 2.6 | signal |
| 140 | Menorrhagia | 8 | 2.5 | 2.5 | signal |
| 141 | Injection Site Irritation | 5 | 2.5 | 2.5 | no signal |
| 142 | Thirst | 7 | 2.5 | 2.5 | signal |
| 143 | Intentional Overdose | 25 | 2.5 | 2.5 | signal |
| 144 | Bone Disorder | 7 | 2.4 | 2.4 | signal |
| 145 | Multiple Sclerosis Relapse | 26 | 2.4 | 2.4 | signal |
| 146 | Blood Creatine Phosphokinase Increased | 11 | 2.4 | 2.4 | signal |
| 147 | Mental Impairment | 9 | 2.3 | 2.3 | signal |
| 148 | Hair Texture Abnormal | 5 | 2.3 | 2.3 | no signal |
| 149 | Dyskinesia | 15 | 2.3 | 2.3 | signal |
| 150 | Multiple Fractures | 6 | 2.3 | 2.3 | no signal |
| 151 | Lip Swelling | 12 | 2.3 | 2.3 | signal |
| 152 | Stevens-johnson Syndrome | 8 | 2.3 | 2.3 | signal |
| 153 | Impaired Driving Ability | 4 | 2.2 | 2.2 | no signal |
| 154 | Upper Limb Fracture | 7 | 2.2 | 2.2 | no signal |
| 155 | Polyneuropathy | 4 | 2.1 | 2.1 | no signal |
| 156 | Bone Loss | 5 | 2.1 | 2.1 | no signal |
| 157 | Procedural Pain | 9 | 2.1 | 2.1 | no signal |
| 158 | Blood Thyroid Stimulating Hormone Increased | 3 | 2.0 | 2.0 | no signal |
| 159 | Application Site Irritation | 4 | 2.0 | 2.0 | no signal |
| 160 | Hair Colour Changes | 4 | 2.0 | 2.0 | no signal |
| 161 | Skin Fissures | 6 | 2.0 | 2.0 | no signal |
| 162 | Bone Density Decreased | 10 | 2.0 | 2.0 | no signal |
| 163 | Drug Prescribing Error | 6 | 1.9 | 1.9 | no signal |
| 164 | Parkinsonism | 3 | 1.9 | 1.9 | no signal |
| 165 | Ankylosing Spondylitis | 4 | 1.9 | 1.9 | no signal |
| 166 | Anorexia | 4 | 1.9 | 1.9 | no signal |
| 167 | Rheumatoid Arthritis | 34 | 1.9 | 1.9 | no signal |
| 168 | Overdose | 65 | 1.9 | 1.9 | no signal |
| 169 | Ovarian Cyst | 3 | 1.9 | 1.9 | no signal |
| 170 | Therapy Cessation | 15 | 1.8 | 1.9 | no signal |
| 171 | Coronary Artery Occlusion | 4 | 1.8 | 1.8 | no signal |
| 172 | Suicidal Ideation | 26 | 1.8 | 1.8 | no signal |
| 173 | Breast Pain | 3 | 1.8 | 1.8 | no signal |
| 174 | Drug Effect Decreased | 15 | 1.7 | 1.7 | no signal |
| 175 | Expired Product Administered | 9 | 1.7 | 1.7 | no signal |
| 176 | Multiple Sclerosis | 13 | 1.7 | 1.7 | no signal |
| 177 | Mood Swings | 8 | 1.6 | 1.6 | no signal |
| 178 | Sleep Disorder Due To A General Medical Condition | 4 | 1.6 | 1.6 | no signal |
| 179 | Hepatitis C | 3 | 1.5 | 1.5 | no signal |
| 180 | Libido Decreased | 3 | 1.5 | 1.5 | no signal |
| 181 | Product Preparation Error | 5 | 1.5 | 1.5 | no signal |
| 182 | Injection Site Extravasation | 3 | 1.5 | 1.5 | no signal |
| 183 | Tooth Loss | 5 | 1.5 | 1.5 | no signal |
| 184 | Blood Glucose Decreased | 11 | 1.4 | 1.4 | no signal |
| 185 | Synovitis | 4 | 1.4 | 1.4 | no signal |
| 186 | Therapeutic Response Shortened | 7 | 1.4 | 1.4 | no signal |
| 187 | Application Site Rash | 3 | 1.4 | 1.4 | no signal |
| 188 | Drug Effect Incomplete | 8 | 1.4 | 1.4 | no signal |
| 189 | Plasma Cell Myeloma | 8 | 1.3 | 1.3 | no signal |
| 190 | Injection Site Mass | 7 | 1.2 | 1.2 | no signal |
| 191 | Withdrawal Syndrome | 8 | 1.2 | 1.2 | no signal |
| 192 | Injection Site Reaction | 13 | 1.2 | 1.2 | no signal |
| 193 | Suicide Attempt | 11 | 1.1 | 1.1 | no signal |
| 194 | Complication Of Device Removal | 3 | 1.1 | 1.1 | no signal |
| 195 | Drug Dose Omission | 29 | 1.1 | 1.1 | no signal |
| 196 | Injection Site Urticaria | 4 | 1.0 | 1.0 | no signal |
| 197 | Injection Site Erythema | 20 | 1.0 | 1.0 | no signal |
| 198 | Skin Burning Sensation | 11 | 1.0 | 1.0 | no signal |
| 199 | Injection Site Haemorrhage | 12 | 1.0 | 1.0 | no signal |
| 200 | Intentional Self-injury | 3 | 0.9 | 0.9 | no signal |
| 201 | Injection Site Warmth | 3 | 0.9 | 0.9 | no signal |
| 202 | Dermatitis Atopic | 7 | 0.9 | 0.9 | no signal |
| 203 | Injection Site Pruritus | 9 | 0.9 | 0.9 | no signal |
| 204 | Device Issue | 11 | 0.8 | 0.8 | no signal |
| 205 | Injection Site Pain | 37 | 0.8 | 0.8 | no signal |
| 206 | Product Adhesion Issue | 3 | 0.5 | 0.5 | no signal |
| 207 | Drug Dependence | 8 | 0.3 | 0.3 | no signal |