Halcion Side Effects

Generic Name: triazolam

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

Not all side effects for Halcion 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 triazolam: oral tablet

In addition to its needed effects, some unwanted effects may be caused by triazolam (the active ingredient contained in Halcion). In the event that any of these side effects do occur, they may require medical attention.

You should check with your doctor immediately if any of these side effects occur when taking triazolam:

Less common
  • Shakiness and unsteady walk
  • unsteadiness, trembling, or other problems with muscle control or coordination
  • Being forgetful
  • burning, crawling, itching, numbness, prickling, "pins and needles", or tingling feelings
  • continuing ringing or buzzing or other unexplained noise in the ears
  • discouragement
  • false or unusual sense of well-being
  • fast, pounding, or irregular heartbeat or pulse
  • feeling sad or empty
  • hearing loss
  • irritability
  • lack of appetite
  • loss of interest or pleasure
  • nightmares
  • sleeplessness
  • tiredness
  • trouble concentrating
  • trouble sleeping
  • unable to sleep
Incidence not known
  • Abdominal or stomach pain
  • actions that are out of control
  • aggressiveness
  • anxiety
  • changes in patterns and rhythms of speech
  • chest pain
  • chills
  • clay-colored stools
  • confusion about identity, place, and time
  • dark urine
  • decrease in frequency of urination
  • decrease in urine volume
  • difficulty in passing urine (dribbling)
  • dizziness
  • drowsiness
  • dry mouth
  • environment seems unreal
  • fainting
  • falling
  • false beliefs that cannot be changed by facts
  • feeling of unreality
  • fever
  • headache
  • hyperventilation
  • inability to move eyes
  • increased blinking or spasms of the eyelid
  • increased muscle spasm
  • irregular heartbeats
  • loss of appetite
  • loss of bladder control
  • loss of memory
  • nausea
  • nervousness
  • nightmares
  • painful urination
  • problems with memory
  • rash
  • relaxed and calm
  • restlessness
  • seeing, hearing, or feeling things that are not there
  • sense of detachment from self or body
  • shortness of breath
  • sleep walking
  • sleepiness
  • slurred speech
  • sticking out of tongue
  • talking, feeling, and acting with excitement
  • trouble in breathing, speaking, or swallowing
  • uncontrolled twisting movements of the neck, trunk, arms, or legs
  • unpleasant breath odor
  • unusual excitement, nervousness, restlessness, or irritability
  • unusual facial expressions
  • unusual tiredness or weakness
  • vomiting of blood
  • yellow eyes or skin

Some of the side effects that can occur with triazolam may not need medical attention. As your body adjusts to the medicine during treatment these side effects may go away. Your health care professional may also be able to tell you about ways to reduce or prevent some of these side effects. If any of the following side effects continue, are bothersome or if you have any questions about them, check with your health care professional:

More common
  • Lightheadedness
  • Any change in vision
  • blistering, crusting, irritation, itching, or reddening of skin
  • change in taste or bad, unusual, or unpleasant (after) taste
  • cracked, dry, or scaly skin
  • cramps
  • diarrhea
  • difficulty having a bowel movement (stool)
  • dry mouth
  • swelling
  • weakness
Incidence not known
  • Decreased interest in sexual intercourse
  • inability to have or keep an erection
  • increase in sexual ability, desire, drive, or performance
  • increase interest in sexual intercourse
  • itching skin
  • loss in sexual ability, desire, drive, or performance
  • menstrual changes
  • redness, swelling, or soreness of the tongue
  • swelling or inflammation of the mouth
  • weight loss

For Healthcare Professionals

Applies to triazolam: oral tablet

Nervous system

Nervous system side effects have been common and have included drowsiness, dizziness, and headache most frequently and occur in approximately 8% to 14% of treated patients. Sleep disturbances, morning "hang-over" symptoms, hyperexcitability, confusion, amnesia, and ataxia have been observed. Anterograde amnesia and transient global amnesia have also been reported in association with triazolam (the active ingredient contained in Halcion) therapy. Triazolam may cause a greater degree of sedation and psychomotor impairment in older patients than in younger patients. The reason for this increased sensitivity is most likely related to reduced plasma clearance.[Ref]

Anterograde amnesia associated with triazolam therapy has been reported to occur in as many as 50% of psychiatric patients treated with very high doses of triazolam (2 mg nightly). The incidence of anterograde amnesia, however, appears to be lower at the doses generally used for insomnia.

While many reports have suggested that residual sedative effects and impairment of psychomotor performance may occur, some studies have not supported these observations.

Cases of seizures associated with use of triazolam have also been reported.

One study has reported that triazolam significantly impairs standing steadiness one and two hours after drug administration.[Ref]


The frequency and extent to which triazolam (the active ingredient contained in Halcion) therapy is associated with adverse behavioral effects is controversial.

One study based on the postmarketing surveillance Spontaneous Reporting System of the FDA has suggested that adverse behavioral reactions have been reported 22 to 99 times more frequently in association with triazolam therapy than with temazepam therapy for insomnia. An increased frequency of adverse behavioral effects was noted to occur most frequently in elderly patients and at higher doses of triazolam. The methodology of this study, however, has been questioned on the grounds that spontaneous reports of adverse effects do not necessarily correlate with the incidence of adverse effects.

Other studies and reports have concluded that little evidence exists to support the contention that triazolam therapy is associated with a greater risk of adverse behavioral effects than other benzodiazepines (including temazepam).[Ref]

Psychiatric side effects have been reported in association with triazolam therapy which have included confusion, amnesia, bizarre behavior (including acts of violence), aggressiveness, agitation, depression, anxiety, paranoia, secondary mania, and hallucinations.[Ref]


Other side effects have included tolerance to the pharmacologic effects of triazolam (the active ingredient contained in Halcion) and withdrawal symptoms after either abrupt cessation or fast tapering of triazolam may occur. Withdrawal symptoms have included agitation, restlessness, anxiety, insomnia, psychosis, delirium, convulsions, tremor, abdominal cramps, blurred vision, vomiting, and sweating.

Rebound insomnia (a worsening of sleep following cessation of therapy), has been observed and has sometimes been reported to occur in association with increased daytime anxiety.[Ref]


Gastrointestinal side effects including nausea and vomiting have been reported rarely.[Ref]


One study of patients with obstructive sleep apnea has suggested that triazolam (the active ingredient contained in Halcion) may increase the maximum apnea duration and lower the minimum oxygen saturation of apneic patients.[Ref]

Respiratory side effects including respiratory depression (after even small doses of triazolam) have been reported rarely. A case of noncardiogenic pulmonary edema has also been reported.[Ref]


Local side effects have included a case of intra-arterial injection of triazolam (the active ingredient contained in Halcion) In that case, a known intravenous drug abuser crushed oral triazolam tablets and injected them into the femoral artery. Distal necrosis ensued and resulted in the death of the patient.[Ref]


Hepatic side effects have included a case of fatal intrahepatic cholestasis circumstantially associated with triazolam (the active ingredient contained in Halcion) therapy.[Ref]


Ocular side effects have included cases of photic maculopathy which have been reported rarely in association with triazolam (the active ingredient contained in Halcion) therapy.[Ref]


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4. Muraoka M, Tada K, Nogami Y, Ishikawa K, Nagoya T "Residual effects of repeated administration of triazolam and nitrazepam in healthy volunteers." Neuropsychobiology 25 (1992): 134-9

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6. Bixler EO, Kales A, Manfredi RL, Vgontzas AN, Tyson KL, Kales JD "Next-day memory impairment with triazolam use." Lancet 337 (1991): 827-31

7. Tada K, Sato Y, Sakai T, Ueda N, Kasamo K, Kojima T "Effects of zopiclone, triazolam, and nitrazepam on standing steadiness." Neuropsychobiology 29 (1994): 17-22

8. Ansseau M, Poncelet PF, Schmitz D "High dose triazolam and anterograde amnesia." BMJ 304 (1992): 1178

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11. "Product Information. Halcion (triazolam)." Pharmacia and Upjohn, Kalamazoo, MI.

12. Morris HH, 3d Estes ML "Traveler's amnesia. Transient global amnesia secondary to triazolam." JAMA 258 (1987): 945-6

13. Medawar C, Rassaby E "Triazolam overdose, alcohol, and manslaughter." Lancet 338 (1991): 1515-6

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15. Rothschild AJ "Disinhibition, amnestic reactions, and other adverse reactions secondary to triazolam: a review of the literature." J Clin Psychiatry 53 (1992): 69-79

16. Wysowski DK, Barash D "Adverse behavioral reactions attributed to triazolam in the Food and Drug Administration's Spontaneous Reporting System." Arch Intern Med 151 (1991): 2003-8

17. Schogt B, Conn D "Paranoid symptoms associated with triazolam." Can J Psychiatry 30 (1985): 462-3

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23. Patterson WM "Triazolam withdrawal." J Clin Psychiatry 49 (1988): 369

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25. Sullivan RJ, Jr "Respiratory depression requiring ventilatory support following 0.5 mg of triazolam." J Am Geriatr Soc 37 (1989): 450-2

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27. Haiart DC, Andrade B, Murie JA "Gas gangrene following intra-arterial injection of oral medication in a drug abuser." Eur J Vasc Surg 6 (1992): 565-6

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29. Miyagawa M, Hayasaka S, Noda S "Photic maculopathy resulting from the light of a video camera in patients taking triazolam." Ophthalmologica 208 (1994): 145-6

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