Flurazepam Side Effects

Medically reviewed by Drugs.com. Last updated on Feb 5, 2025.

Applies to flurazepam: oral capsule.

Precautions

It is very important that your doctor check your progress at regular visits to make sure this medicine is working properly and to check for unwanted effects.

If your condition does not improve within 7 to 10 days, or if it becomes worse, check with your doctor.

Using this medicine while you are pregnant can harm your unborn baby. Use an effective form of birth control to keep from getting pregnant. If you think you have become pregnant while using this medicine, tell your doctor right away.

Flurazepam may cause serious allergic reactions, including anaphylaxis. Anaphylaxis can be life-threatening and requires immediate medical attention. Call your doctor right away if you have a rash, itching, hives, hoarseness, trouble breathing, trouble swallowing, or any swelling of your hands, face, or mouth while you are using this medicine.

This medicine will add to the effects of alcohol and other CNS depressants (medicines that slow down the nervous system, possibly causing drowsiness). Some examples of CNS depressants are antihistamines or medicine for hay fever, other allergies, or colds, sedatives, tranquilizers, or sleeping medicine, prescription pain medicine or narcotics, barbiturates or medicine for seizures, muscle relaxants, or anesthetics (numbing medicines), including some dental anesthetics. This effect may last for a few days after you Stop taking flurazepam. Check with your doctor before taking any of the above while you are using this medicine.

This medicine may cause some people, especially older persons, to become drowsy, dizzy, lightheaded, clumsy, unsteady, or less alert than they are normally. Even though flurazepam is taken at bedtime, it may cause some people to feel drowsy or less alert the next morning. Also, this medicine may cause double vision or other vision problems. Make sure you know how you react to flurazepam before you drive, use machines, or do anything else that could be dangerous if you are not alert or able to think or see well.

If you develop any unusual or strange thoughts and behavior while taking flurazepam, be sure to discuss it with your doctor. Some changes that have occurred in people taking this medicine are like those seen in people who drink too much alcohol. Other changes might be confusion, worsening of depression, hallucinations (seeing, hearing, or feeling things that are not there), suicidal thoughts, and unusual excitement, nervousness, or irritability.

This medicine may cause sleep-related behaviors such as driving a car (sleep-driving), walking (sleep-walking), having sex, making phone calls, or preparing and eating food while you are asleep or not fully awake. If these behaviors occur, tell your doctor right away.

Do not Stop taking flurazepam without checking with your doctor first. Your doctor may want you to gradually reduce the amount you are using before stopping it completely. This may help prevent a worsening of your condition and reduce the possibility of withdrawal symptoms, such as convulsions (seizures), hallucinations, stomach or muscle cramps, tremors, or unusual behavior.

This medicine may be habit-forming. If you feel that the medicine is not working as well, do not use more than your prescribed dose. Call your doctor for instructions.

Do not take other medicines unless they have been discussed with your doctor. This includes prescription or nonprescription (over-the-counter [OTC]) medicines and herbal or vitamin supplements.

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:

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:

For healthcare professionals

Applies to flurazepam: oral capsule.

General adverse events

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

Psychiatric

• 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]

Other

• Common (1% to 10%): Fatigue
• Frequency not reported: Weakness^[Ref]

Gastrointestinal

• Rare (less than 0.1%): Dry mouth, bitter taste, excessive salivation
• Frequency not reported: Heartburn, upset stomach, nausea, vomiting, diarrhea, constipation, gastrointestinal pain^[Ref]

Hepatic

• Rare (less than 0.1%): Elevated SGOT/SGPT, total and direct bilirubin elevations, elevated alkaline phosphatase
• Frequency not reported: Jaundice^[Ref]

Hypersensitivity

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

Cardiovascular

• Frequency not reported: Palpitation, chest pain^[Ref]

Dermatologic

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

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]

Genitourinary

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

Hematologic

• Rare (less than 0.1%): Leukopenia, granulocytopenia
• Frequency not reported: Blood dyscrasias^[Ref]

Metabolic

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

Musculoskeletal

• Common (1% to 10%): Muscle weakness
• Frequency not reported: Body/joint pain^[Ref]

Ocular

• Common (1% to 10%): Double vision
• Rare (less than 0.1%): Blurred vision, burning eyes
• Frequency not reported: Visual disturbance^[Ref]

See also:

Further information

Flurazepam 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