Midazolam Side Effects

Medically reviewed by Philip Thornton, DipPharm. Last updated on Jul 20, 2024.

Applies to midazolam: oral syrup.

Other dosage forms:

• injection solution
• nasal spray

Important warnings This medicine can cause some serious health issues

Oral route (syrup)

Midazolam has been associated with respiratory depression and respiratory arrest, especially when used for sedation in noncritical care settings.

Use only in settings that can provide for continuous monitoring of respiratory and cardiac function.

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

• vomiting

Less common

• rash

Rare

• blurred vision
• double vision
• gagging
• hiccups
• seeing double
• watering of mouth and drooling

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 or nurse immediately if any of the following side effects occur while taking midazolam:

Less common

• anxiety
• chest pain or discomfort
• choking
• confusion
• difficult or troubled breathing
• drowsiness
• dry mouth
• fast heartbeat
• hyperventilation
• irregular heartbeats
• irregular, fast or slow, or shallow breathing
• irritability
• lightheadedness, dizziness, or fainting
• nausea
• nervousness
• noisy breathing
• pale or blue lips, fingernails, or skin
• restlessness
• shaking
• shortness of breath
• slow or irregular heartbeat
• tightness in the chest
• trouble sleeping
• unable to speak
• unusual tiredness
• weakness
• wheezing

Rare

• attack, assault, or force
• changes in patterns and rhythms of speech
• feeling of constant movement of self or surroundings
• headache
• lack or loss of self-control
• loss of balance
• mood swings
• noisy breathing
• not breathing
• restlessness
• seeing, hearing, or feeling things that are not there
• sensation of spinning
• shakiness and unsteady walk
• sleepiness
• slow to respond
• slurred speech
• trouble in speaking
• unconsciousness
• unsteadiness, trembling, or other problems with muscle control or coordination

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

Symptoms of overdose

• change in consciousness
• difficulty with coordination
• loss of consciousness
• sleepiness or unusual drowsiness

For healthcare professionals

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

General

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.

Some side effects may not be reported. You may report them to the FDA.

Medical Disclaimer