Midazolam Side Effects

Medically reviewed by Philip Thornton, DipPharm. Last updated on Jan 22, 2025.

Applies to midazolam: nasal spray.

Other dosage forms:

• injection solution
• oral syrup

Important warnings This medicine can cause some serious health issues

Nasal route (spray)

Warning: Risks from concomitant use with opioids; abuse, misuse, and addiction; dependence and withdrawal reactionsConcomitant use of benzodiazepines and opioids may result in profound sedation, respiratory depression, coma, and death.

Reserve concomitant prescribing of these drugs for patients for whom alternative treatment options are inadequate.

Limit dosages and durations to the minimum required.

Follow patients for signs and symptoms of respiratory depression and sedation.The use of benzodiazepines, including midazolam, exposes users to risks of abuse, misuse, and addiction, which can lead to overdose or death.

Abuse and misuse of benzodiazepines commonly involve concomitant use of other medications, alcohol, and/or illicit substances, which is associated with an increased frequency of serious adverse outcomes.

Before prescribing midazolam and throughout treatment, assess each patient's risk for abuse, misuse, and addiction.The continued use of benzodiazepines may lead to clinically significant physical dependence.

The risks of dependence and withdrawal increase with longer treatment duration and higher daily dose.

Although midazolam is indicated only for intermittent use, if used more frequently than recommended abrupt discontinuation or rapid dosage reduction of midazolam may precipitate acute withdrawal reactions, which can be life-threatening.

For patients using midazolam more frequently than recommended, to reduce the risk of withdrawal reactions, use a gradual taper to discontinue midazolam.

Common side effects of midazolam

Some side effects of midazolam may occur that usually do not need medical attention. These side effects may go away during treatment as your body adjusts to the medicine. Also, your health care professional may be able to tell you about ways to prevent or reduce some of these side effects.

Check with your health care professional if any of the following side effects continue or are bothersome or if you have any questions about them:

More common side effects

• nasal discomfort

Less common side effects

• abnormal product taste
• changes in patterns and rhythms of speech
• headache
• runny nose
• slurred speech
• throat irritation
• trouble in speaking

Serious side effects of midazolam

Along with its needed effects, midazolam may cause some unwanted effects. Although not all of these side effects may occur, if they do occur they may need medical attention.

Check with your doctor immediately if any of the following side effects occur while taking midazolam:

Incidence not known

• agitation
• blindness
• blurred vision
• combativeness
• decreased vision
• difficult or trouble breathing
• difficulty sleeping
• discouragement
• dizziness
• eye pain
• feeling sad or empty
• headache
• irregular, fast or slow, or shallow breathing
• irritability
• jerking or shaking
• lack of appetite
• lightheadedness
• loss of interest or pleasure
• mood or other mental changes
• muscle tremor
• nausea
• pale or blue lips, fingernails, or skin
• restlessness
• seeing, hearing, or feeling things that are not there
• tearing
• thoughts or attempts at killing oneself
• trouble concentrating
• trouble sitting still
• trouble sleeping
• unusual drowsiness, dullness, tiredness, weakness, or feeling of sluggishness

Get emergency help immediately if any of the following symptoms of overdose occur while taking midazolam:

Symptoms of overdose

• agitation
• changes in patterns and rhythms of speech
• confusion
• drowsiness
• lack of coordination
• loss of consciousness
• loss of strength or energy
• nightmares
• relaxed and calm feeling
• shakiness and unsteady walk
• sleepiness
• slurred speech
• talkativeness
• trouble speaking
• unsteadiness, trembling, or other problems with muscle control or coordination
• unusual drowsiness, dullness, tiredness, weakness, or feeling of sluggishness
• unusual excitement, nervousness, restlessness, or irritability
• unusual weak feeling

For healthcare professionals

Applies to midazolam: compounding powder, injectable solution, intramuscular solution, intravenous solution, nasal spray, oral syrup.

General adverse events

The most commonly reported side effects with oral formulations include emesis and nausea. Decreased tidal volume/respiratory rate and apnea were most commonly reported with parenteral formulations.^[Ref]

Respiratory

Oral:

• Very common (10% or more): Respiratory adverse events (up to 11%)
• Common (1% to 10%): Respiratory depression, hypoxia, laryngospasm, upper airway obstruction, rhonchi, congestion
• Uncommon (0.1% to 1%): Sneezing/rhinorrhea
• Frequency not reported: Apnea, hypercarbia, desaturation, stridor, hiccough

Parenteral:

• Very common (10% or more): Decreased tidal volume/respiratory rate (up to 23.3%), apnea (up to 15.4%)
• Common (1% to 10%): Hiccoughs, coughing, desaturation
• Very rare (less than 0.01%): Dyspnea, hiccup, laryngospasm, respiratory arrest
• Frequency not reported: Respiratory depression
• Postmarketing reports: Bronchospasm, hyperventilation, wheezing, shallow respirations, airway obstruction, tachypnea, dysphonia, yawning, continued phonation^[Ref]

Respiratory adverse events included hypoxia, laryngospasm, rhonchi, coughing, respiratory depression, airway obstruction, upper airway congestion, and shallow respirations; these side effects occurred more frequently at higher doses.

Decreased tidal volume/respiratory rate occurred in 23.3% of patients given IV formulations and in 10.8% of patients given IM formulations.

Apnea occurred in 15.4% of patients given IV formulations.^[Ref]

Gastrointestinal

Oral:

• Very common (10% or more): Emesis/vomiting (up to 11%)
• Common (1% to 10%): Nausea
• Frequency not reported: Gagging, salivation

Parenteral:

• Common (1% to 10%): Nausea, vomiting
• Very rare (less than 0.01%): Constipation, dry mouth
• Postmarketing reports: Acid taste, excessive salivation, retching, toothache^[Ref]

Nervous system

Oral:

• Common (1% to 10%): Sedation/prolonged sedation, somnolence, depressed levels of consciousness
• Frequency not reported: Drooling, dizziness, ataxia, vertigo, dysarthria, loss of balance

Parenteral:

• Common (1% to 10%): Headache, oversedation, drowsiness, seizure-like activity
• Very rare (less than 0.01%): Movement disorder, ataxia, dizziness, seizure, anterograde amnesia
• Frequency not reported: Involuntary movements, hyperactivity, decreased alertness, somnolence, prolonged/postoperative sedation, convulsions/drug withdrawal convulsions, feeling faint, tonic/clonic movements and muscle tremor
• Postmarketing reports: Vasovagal episode, retrograde amnesia, grogginess, athetoid movements, lethargy, slurred speech, paresthesia, loss of balance, lightheadedness, feeling of burning, emergence delirium or agitation^[Ref]

Cardiovascular

Oral:

• Common (1% to 10%): Bradycardia, bigeminy
• Frequency not reported: Increased heart rate, cardiac arrest, heart failure, decreased systolic and diastolic blood pressure

Parenteral:

• Common (1% to 10%): Hypotension
• Very rare (less than 0.01%): Bradycardia, cardiac arrest, vasodilation
• Frequency not reported: Thrombophlebitis, thrombosis, variations in blood pressure and pulse rate
• Postmarketing reports: Bigeminy, premature ventricular contractions, tachycardia, nodal rhythm, hematoma, cardiovascular collapse, cardiovascular reactions, severe cardiorespiratory adverse events^[Ref]

Local

Parenteral:

• Common (1% to 10%): IM injection site pain, IV site tenderness/pain during injection/redness/induration
• Uncommon (0.1% to 1%): IM injection site induration/redness/muscle stiffness, IV site phlebitis
• Frequency not reported: Injection site erythema, injection site pain
• Postmarketing reports: Hive-like elevation at injection site, warmth or coldness at injection site^[Ref]

Psychiatric

Oral:

• Common (1% to 10%): Agitation
• Frequency not reported: Dysphoria, disinhibition, excitation, aggression, mood swings, hallucinations, confusion, inappropriate/adverse behavior, behavioral/emotional disorders, euphonia, libido disorders, restlessness, irritability, delusions, anger eruptions, nightmares, psychosis, physical dependency, withdrawal symptoms, abuse, depression (existing, unobserved depression)

Parenteral:

• Very rare (less than 0.01%): Aggression/aggressiveness, agitation, anger, hallucination, hostility, confusion/confusional state, euphoric mood/euphoria
• Frequency not reported: Rage, excitement/paroxysmal excitement, abuse, physical drug dependence and withdrawal syndrome
• Postmarketing reports: Argumentativeness, nervousness, anxiety, restlessness, sleep disturbance, insomnia, nightmares, dysphoria, irritability, tension, mood changes, dreaming during sleep^[Ref]

Dermatologic

Oral:

• Common (1% to 10%): Rash
• Uncommon (0.1% to 1%): Pruritus and urticaria

Parenteral:

• Frequency not reported: Angioedema
• Postmarketing reports: Hives, rash, pruritus, skin reactions^[Ref]

Ocular

Oral:

• Frequency not reported: Diplopia, strabismus, blurred vision

Parenteral:

• Common (1% to 10%): Nystagmus
• Postmarketing reports: Blurred vision, diplopia, pinpoint pupils, visual disturbance, difficulty focusing eyes, cyclic movement of the eyelids^[Ref]

Other

Oral:

• Frequency not reported: Fatigue, falls

Parenteral:

• Common (1% to 10%): Paradoxical reaction
• Very rare (less than 0.01%): Fatigue, falls, assault/physical assault
• Postmarketing reports: Prolonged emergence from anesthesia, blocked ears, chills, weakness, swelling, dreaming during emergence^[Ref]

Hypersensitivity

Oral:

• Frequency not reported: Hypersensitivity

Parenteral:

• Frequency not reported: Hypersensitivity, anaphylactic shock
• Postmarketing reports: Allergic reaction, anaphylactoid reactions^[Ref]

Musculoskeletal

Oral:

• Frequency not reported: Muscle weakness, fractures

Parenteral:

• Frequency not reported: Fractures^[Ref]

Frequently asked questions

• What is the correct way to use Nayzilam Nasal Spray?

Further information

Midazolam side effects can vary depending on the individual. Always consult your healthcare provider to ensure the information displayed on this page applies to your personal circumstances.

Note: Medication side effects may be underreported. If you are experiencing side effects that are not listed, submit a report to the FDA by following this guide.

Medical Disclaimer