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Flurazepam Side Effects

Medically reviewed by Last updated on Feb 19, 2023.

Applies to flurazepam: oral capsule.


Oral route (Capsule)

Concomitant use of benzodiazepines and opioids may result in profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing for patients with inadequate alternative treatment options. Limit dosages and durations to the minimum required and follow patients for signs and symptoms of respiratory depression and sedation.

Serious side effects of Flurazepam

Along with its needed effects, flurazepam 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 flurazepam:


  • Black, tarry stools
  • blurred vision
  • chest pain
  • chills
  • confusion
  • cough
  • dizziness, faintness, or lightheadedness when getting up suddenly from a lying or sitting position
  • feeling like you will pass out
  • fever
  • large, hive-like swelling on the face, eyelids, lips, tongue, throat, hands, legs, feet, or sex organs
  • painful or difficult urination
  • slurred speech
  • sore throat
  • sores, ulcers, or white spots on the lips or in the mouth
  • sweating
  • swollen glands
  • unusual bleeding or bruising
  • unusual tiredness or weakness

Incidence not known

  • Change in consciousness
  • clumsy movement, moving from side to side
  • confusion about identity, place, and time
  • falling
  • fast, irregular, pounding, or racing heartbeat or pulse
  • loss of consciousness
  • shakiness and unsteady walk
  • unsteadiness, trembling, or other problems with muscle control or coordination
  • unusual drowsiness, dullness, tiredness, weakness or feeling of sluggishness

Other side effects of Flurazepam

Some side effects of flurazepam 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:


  • Bitter taste
  • blurred vision
  • burning eyes
  • difficulty in focusing
  • discouragement
  • dry mouth
  • false or unusual sense of well-being
  • feeling of warmth
  • feeling sad or empty
  • hallucinations
  • increased watering of the mouth
  • itching skin or skin rash
  • loss of appetite
  • loss of interest or pleasure
  • mood or mental changes
  • nightmares
  • redness of the face, neck, arms and occasionally, upper chest
  • restlessness
  • sweating
  • trouble concentrating
  • trouble sleeping
  • unusual excitement, nervousness, restlessness, or irritability
  • weight loss

Incidence not known

For Healthcare Professionals

Applies to flurazepam: oral capsule.

Nervous system

Common (1% to 10%): Reduced alertness, confusion, headache, dizziness, ataxia

Rare (less than 0.1%): Difficulty in focusing, faintness, slurred speech, confusion, restlessness, vertigo

Frequency not reported: CNS-depressant effects, next-day impairment, nervousness, talkativeness, drowsiness, staggering[Ref]


Common (1% to 10%): Numbed emotions

Rare (less than 0.1%): Euphoria, depression, hallucinations

Frequency not reported: Withdrawal syndrome, abnormal thinking, behavior changes, complex behaviors, worsening of depression, apprehension, irritability[Ref]


Common (1% to 10%): Fatigue

Frequency not reported: Weakness[Ref]


Rare (less than 0.1%): Dry mouth, bitter taste, excessive salivation

Frequency not reported: Heartburn, upset stomach, nausea, vomiting, diarrhea, constipation, gastrointestinal pain[Ref]


Rare (less than 0.1%): Elevated SGOT/SGPT, total and direct bilirubin elevations, elevated alkaline phosphatase

Frequency not reported: Jaundice[Ref]


Very rare (less than 0.01%): Severe anaphylactic/anaphylactoid reactions[Ref]


Frequency not reported: Palpitation, chest pain[Ref]


Rare (less than 0.1%): Sweating, pruritus, skin rash[Ref]


The most commonly reported side effects were headache, dizziness, muscle weakness, ataxia, and double vision.[Ref]


Frequency not reported: Genitourinary complaints, changes in libido, urinary retention[Ref]


Rare (less than 0.1%): Leukopenia, granulocytopenia

Frequency not reported: Blood dyscrasias[Ref]


Rare (less than 0.1%): Anorexia[Ref]


Common (1% to 10%): Muscle weakness

Frequency not reported: Body/joint pain[Ref]


Common (1% to 10%): Double vision

Rare (less than 0.1%): Blurred vision, burning eyes

Frequency not reported: Visual disturbance[Ref]


1. Product Information. Dalmane (flurazepam). Roche Laboratories. 2001.

2. Cerner Multum, Inc. UK Summary of Product Characteristics.

Further information

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.