Dalmane Side Effects

Generic Name: flurazepam

Note: This page contains information about the side effects of flurazepam. Some of the dosage forms included on this document may not apply to the brand name Dalmane.

Not all side effects for Dalmane may be reported. You should always consult a doctor or healthcare professional for medical advice. Side effects can be reported to the FDA here.

For the Consumer

Applies to flurazepam: oral capsule

Along with its needed effects, flurazepam (the active ingredient contained in Dalmane) 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 from a lying or sitting position suddenly
  • feeling like you will pass out
  • fever
  • painful or difficult urination
  • shortness of breath
  • 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

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
  • loss of appetite
  • loss of interest or pleasure
  • mood or mental changes
  • nightmares
  • redness of the face, neck, arms and occasionally, upper chest
  • restlessness
  • skin rash
  • sweating
  • trouble concentrating
  • trouble sleeping
  • unusual excitement, nervousness, restlessness, or irritability
  • weight loss
Incidence not known
  • Constipation
  • diarrhea
  • fear
  • headache
  • heartburn
  • joint pain
  • nausea
  • stomach upset
  • talkativeness
  • vomiting

For Healthcare Professionals

Applies to flurazepam: oral capsule

Nervous system

Nervous system side effects have been common and most frequently have included drowsiness, dizziness, and sedation. Headache, anterograde amnesia, hyperexcitability, cognitive disturbances, oral-buccal dyskinesia, and ataxia have also been observed.

Flurazepam may cause a greater degree of sedation and psychomotor impairment in older patients compared to other benzodiazepines commonly used as hypnotics. The reason for this increased sensitivity may be related to a prolonged elimination half-life of desalkylflurazepam in elderly patients. One study has suggested that elderly patients who experienced a fall in the hospital were more likely to be taking flurazepam than those elderly patients who did not experience a fall.


Psychiatric side effects have included confusion, agitation, depression, secondary mania, and hallucinations.


Other side effects have included tolerance to the pharmacologic effects of flurazepam (the active ingredient contained in Dalmane) and withdrawal symptoms after either abrupt cessation or fast tapering of flurazepam. Withdrawal symptoms may include agitation, restlessness, anxiety, depression, insomnia, tremor, abdominal discomfort, blurred vision, vomiting, and sweating. Psychosis, delirium, and seizures have been observed during withdrawal from other benzodiazepines.

Daytime sedation and, less frequently, rebound insomnia (a worsening of sleep following cessation of therapy) and other sleep disturbances have been reported.


Gastrointestinal side effects have included nausea, vomiting, bad taste, dry mouth, constipation, and diarrhea. Many of these symptoms have occurred at frequencies similar to or less than placebo.


Respiratory side effects have included cases of respiratory depression manifested by an increase in the number of obstructive apneas during sleep.


Hepatic side effects have included several cases of intrahepatic cholestasis.


Hypersensitivity side effects to flurazepam (the active ingredient contained in Dalmane) have rarely been reported.

A number of case reports have suggested that flurazepam may cause a drug-induced encephalopathy in patients with end-stage renal disease undergoing hemodialysis. Specific findings reported include altered consciousness, asterixis, abnormal EEG, and in one patient, biochemical evidence of liver disease.


Local side effects have included a case of peripheral ischemia following injection of flurazepam (the active ingredient contained in Dalmane) In that case, a known intravenous drug abuser crushed oral flurazepam tablets (and possibly other tablets) and injected them into a finger. Distal necrosis ensued and required amputation of the affected finger.

Disclaimer: Every effort has been made to ensure that the information provided is accurate, up-to-date and complete, but no guarantee is made to that effect. In addition, the drug information contained herein may be time sensitive and should not be utilized as a reference resource beyond the date hereof. This material does not endorse drugs, diagnose patients, or recommend therapy. This information is a reference resource designed as supplement to, and not a substitute for, the expertise, skill , knowledge, and judgement of healthcare practitioners in patient care. The absence of a warning for a given drug or combination thereof in no way should be construed to indicate safety, effectiveness, or appropriateness for any given patient. Drugs.com does not assume any responsibility for any aspect of healthcare administered with the aid of materials provided. The information contained herein is not intended to cover all possible uses, directions, precautions, warnings, drug interactions, allergic reactions, or adverse effects. If you have questions about the substances you are taking, check with your doctor, nurse, or pharmacist.