• Generic Name: alprazolam
  • Brand Name: Xanax XR
  • Drug Class: How Do Benzodiazepine Anxiolytics Work?
Last updated on MDtodate: 10/7/2022


The following clinically significant adverse reactions are described elsewhere in the labeling:

  • Risks from Concomitant Use with Opioids
  • Abuse, Misuse, and Addiction
  • Dependence and Withdrawal Reactions
  • Effects on Driving and Operating Machinery
  • Neonatal Sedation and Withdrawal Syndrome
  • Patients with Depression
  • Risks in Patients with Impaired Respiratory Function

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.

The information included in the section on Adverse Reactions Observed in Short-Term, Placebo-Controlled Trials with XANAX XR is based on pooled data of five 6- and 8-week placebo-controlled clinical studies in panic disorder.

Adverse Reactions Observed In Short-Term, Placebo-Controlled Trials Of XANAX XR

Adverse Reactions Reported as Reasons for Discontinuation of Treatment in Placebo-Controlled Trials

Approximately 17% of the 531 patients who received XANAX XR in placebo-controlled clinical trials for panic disorder had at least 1 adverse event that led to discontinuation compared to 8% of 349 placebo-treated patients. The most common events leading to discontinuation and considered to be drug-related (i.e., leading to discontinuation in at least 1% of the patients treated with XANAX XR at a rate at least twice that of placebo) are shown in Table 1.

Table 1: Adverse Reactions Leading to Discontinuation in ≥1% of XANAX XR-treated Patients and at least twice the Rate of Placebo-treated Patients in Placebo-Controlled Trials

Percentage of Patients Discontinuing Due to Adverse Reactions
Nervous system disorders
  Sedation 7.5 0.6
  Somnolence 3.2 0.3
  Dysarthria 2.1 0
  Coordination abnormal 1.9 0.3
  Memory impairment 1.5 0.3
General disorders/administration site conditions
  Fatigue 1.7 0.6
Psychiatric disorders
  Depression 2.5 1.2
n=number of patients


Adverse Reactions Occurring at an Incidence of 1% or More Among Patients Treated with XANAX XR

Table 2 shows the incidence of adverse reactions that occurred during 6- and 8-week placebo-controlled trials in 1% or more of patients treated with XANAX XR where the incidence in patients treated with XANAX XR was greater than the incidence in placebo-treated patients. The most commonly observed adverse reactions in panic disorder patients treated with XANAX XR (incidence of 5% or greater and at least twice the incidence in placebo patients) were: sedation, somnolence, memory impairment, dysarthria, coordination abnormal, ataxia, libido decreased.

Table 2: Adverse Reactions Occuring in ≥ 1% in XANAX-treated Patients and Greater than Placebo-treated Patients in 6 and 8 week Placebo-Controlled Trials Panic Disorder

Nervous system disorders
  Sedation 45% 23%
  Somnolence 23% 6%
  Memory impairment 15% 7%
  Dysarthria 11% 3%
  Coordination abnormal 9% 1%
  Mental impairment 7% 6%
  Ataxia 7% 3%
  Disturbance in attention 3% 1%
  Balance impaired 3% 1%
  Dyskinesia 2% 1%
  Hypoesthesia 1% <1%
  Hypersomnia 1% 0%
General disorders/administration site conditions
  Fatigue 14% 9%
  Lethargy 2% 1%
Psychiatric disorders
  Depression 12% 9%
  Libido decreased 6% 2%
  Disorientation 2% 0%
  Confusion 2% 1%
  Depressed mood 1% <1%
Metabolism and nutrition disorders
  Appetite increased 7% 6%
  Anorexia 2% 0%
Gastrointestinal disorders
  Constipation 8% 4%
  Nausea 6% 3%
  Weight increased 5 4
Injury, poisoning, and procedural complications
  Road traffic accident 2% 0%
Reproductive system and breast disorders
  Dysmenorrhea 4% 3%
  Sexual dysfunction 2% 1%
Musculoskeletal and connective tissue disorder
  Arthralgia 2% 1%
  Myalgia 2% 1%
  Pain in limb 1% 0%
Respiratory, thoracic, and mediatinal disorders
  Dyspnea 2% 0%


Other Adverse Reactions Observed During The Premarketing Evaluation Of XANAX XR

Following is a list of other adverse reaction reported by 531 patients with panic disorder treated with XANAX XR. Adverse reactions are further categorized by body system and listed in order of decreasing frequency according to the following definitions: those occurring in at least l/l00 patients (frequent); those occurring in less than l/100 patients but at least l/1000 patients (infrequent); those occurring in fewer than l/1000 patients (rare).

Cardiac disorders: Frequent: palpitation; Infrequent: sinus tachycardia

Ear and Labyrinth disorders: Frequent: Vertigo; Infrequent: tinnitus, ear pain

Eye disorders: Frequent: blurred vision; Infrequent: mydriasis, photophobia

Gastrointestinal disorders: Frequent: diarrhea, vomiting, dyspepsia, abdominal pain; Infrequent: dysphagia, salivary hypersecretion

General disorders and administration site conditions: Frequent: malaise, weakness, chest pains; Infrequent: fall, pyrexia, thirst, feeling hot and cold, edema, feeling jittery, sluggishness, asthenia, feeling drunk, chest tightness, increased energy, feeling of relaxation, hangover, loss of control of legs, rigors

Musculoskeletal and connective tissue disorders: Frequent: back pain, muscle cramps, muscle twitching

Nervous system disorders: Frequent: headache, dizziness, tremor; Infrequent: amnesia, clumsiness, syncope, hypotonia, seizures, depressed level of consciousness, sleep apnea syndrome, sleep talking, stupor

Psychiatric system disorders: Frequent: irritability, insomnia, nervousness, derealization, libido increased, restlessness, agitation, depersonalization, nightmare; Infrequent: abnormal dreams, apathy, aggression, anger, bradyphrenia, euphoric mood, logorrhea, mood swings, dysphonia, hallucination, homicidal ideation, mania, hypomania, impulse control, psychomotor retardation, suicidal ideation

Renal and urinary disorders: Frequent: difficulty in micturition; Infrequent: urinary frequency, urinary incontinence

Respiratory, thoracic, and mediastinal disorders: Frequent: nasal congestion, hyperventilation; Infrequent: choking sensation, epistaxis, rhinorrhea

Skin and subcutaneous tissue disorders: Frequent: sweating increased; Infrequent: clamminess, rash, urticaria

Vascular disorders: Infrequent: hypotension

Discontinuation-Emergent Adverse Reactions Occurring At An Incidence Of 5% Or More Among Patients Treated With XANAX XR

Table 3 shows the incidence of discontinuation-emergent adverse reactions that occurred during short-term, placebo-controlled trials in 5% or more of patients treated with XANAX XR where the incidence in patients treated with XANAX XR was 2 times greater than the incidence in placebo-treated patients.

Table 3: Discontinuation-Emergent Symptom Incidence Reported in ≥5% of XANAX XR-treated Patients and at least twice the Rate of Placebo-treated Patients in Short-Term, Placebo-Controlled Trials

n=422 (%)
Nervous system disorders
  Tremor 28.2 10.7
  Headache 26.5 12.6
  Hypoesthesia 7.8 2.3
  Paraesthesia 7.1 2.7
Psychiatric disorders
  Insomnia 24.2 9.6
  Nervousness 21.8 8.8
  Depression 10.9 5.0
  Derealization 8.0 3.8
  Anxiety 7.8 2.7
  Depersonalization 5.7 1.9
Gastrointestinal disorders
  Diarrhea 12.1 3.1
Respiratory, thoracic and mediastinal disorders
  Hyperventilation 8.5 2.7
Metabolism and nutrition disorders
  Appetite decreased 9.5 3.8
Musculosketal and connective tissue disorders
  Muscle twitching 7.4 2.7
Vascular disorders
  Hot flushes 5.9 2.7


There have also been reports of withdrawal seizures upon rapid decrease or abrupt discontinuation of Xanax.

Paradoxical reactions such as stimulation, increased muscle spasticity, sleep disturbances, hallucinations, and other adverse behavioral effects such as agitation, rage, irritability, and aggressive or hostile behavior have been reported rarely. In many of the spontaneous case reports of adverse behavioral effects, patients were receiving other CNS drugs concomitantly and/or were described as having underlying psychiatric conditions. Should any of the above events occur, alprazolam should be discontinued. Isolated published reports involving small numbers of patients have suggested that patients who have borderline personality disorder, a prior history of violent or aggressive behavior, or alcohol or substance abuse may be at risk for such events. Instances of irritability, hostility, and intrusive thoughts have been reported during discontinuation of alprazolam in patients with posttraumatic stress disorder.

Postmarketing Experience

The following adverse reactions have been identified during post-approval use of XANAX and/or XANAX XR. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure.

Endocrine disorders: Hyperprolactinemia

General disorders and administration site conditions: Edema peripheral

Hepatobiliary disorders: Hepatitis, hepatic failure, jaundice

Investigations: Liver enzyme elevations

Psychiatric disorders: Hypomania, mania

Reproductive system and breast disorders: Gynecomastia, galactorrhea, menstruation irregular

Skin and subcutaneous tissue disorders: Photosensitivity reaction, angioedema, Stevens-Johnson syndrome