Overdose
Because of the potency of triazolam, some manifestations
of overdosage may occur at 2 mg, four times the maximum recommended therapeutic
dose (0.5 mg).
Manifestations of overdosage with HALCION Tablets include
somnolence, confusion, impaired coordination, slurred speech, and ultimately,
coma. Respiratory depression and apnea have been reported with overdosages of
HALCION. Seizures have occasionally been reported after overdosages.
Death has been reported in association with overdoses of
triazolam by itself, as it has with other benzodiazepines. In addition,
fatalities have been reported in patients who have overdosed with a combination
of a single benzodiazepine, including triazolam, and alcohol; benzodiazepine
and alcohol levels seen in some of these cases have been lower than those
usually associated with reports of fatality with either substance alone.
As in all cases of drug overdosage, respiration, pulse,
and blood pressure should be monitored and supported by general measures when
necessary. Immediate gastric lavage should be performed. An adequate airway
should be maintained. Intravenous fluids may be administered.
Flumazenil, a specific benzodiazepine receptor
antagonist, is indicated for the complete or partial reversal of the sedative
effects of benzodiazepines and may be used in situations when an overdose with a
benzodiazepine is known or suspected. Prior to the administration of
flumazenil, necessary measures should be instituted to secure airway,
ventilation and intravenous access. Flumazenil is intended as an adjunct to,
not as a substitute for, proper management of benzodiazepine overdose. Patients
treated with flumazenil should be monitored for resedation, respiratory
depression, and other residual benzodiazepine effects for an appropriate period
after treatment. The prescriber should be aware of a risk of seizure
in association with flumazenil treatment, particularly in long-term
benzodiazepine users and in cyclic antidepressant overdose. The complete
flumazenil package insert including
Contraindications
HALCION Tablets are contraindicated in patients with
known hypersensitivity to this drug or other benzodiazepines.
Benzodiazepines may cause fetal damage when administered
during pregnancy. An increased risk of congenital malformations associated with
the use of diazepam and chlordiazepoxide during the first trimester of pregnancy
has been suggested in several studies. Transplacental distribution has resulted
in neonatal CNS depression following the ingestion of therapeutic doses of a
benzodiazepine hypnotic during the last weeks of pregnancy.
HALCION is contraindicated in pregnant women. If there is
a likelihood of the patient becoming pregnant while receiving HALCION, she
should be warned of the potential risk to the fetus. Patients should be
instructed to discontinue the drug prior to becoming pregnant. The possibility
that a woman of childbearing potential may be pregnant at the time of
institution of therapy should be considered.
HALCION is contraindicated with medications that
significantly impair the oxidative metabolism mediated by cytochrome P450 3A
(CYP 3A) including ketoconazole, itraconazole, nefazodone, and several HIV protease inhibitors, (see WARNINGS and DRUG INTERACTIONS).
Undesirable effects
During placebo-controlled clinical studies in which 1,003
patients received HALCION Tablets, the most troublesome side effects were extensions
of the pharmacologic activity of triazolam, eg, drowsiness, dizziness, or
light-headedness.
The figures cited below are estimates of untoward
clinical event incidence among subjects who participated in the relatively
short duration (i.e., 1 to 42 days) placebo-controlled clinical trials of HALCION.
The figures cannot be used to predict precisely the incidence of untoward
events in the course of usual medical practice where patient characteristics
and other factors often differ from those in clinical trials. These figures
cannot be compared with those obtained from other clinical studies involving
related drug products and placebo, as each group of drug trials is conducted
under a different set of conditions.
Comparison of the cited figures, however, can provide the
prescriber with some basis for estimating the relative contributions of drug
and nondrug factors to the untoward event incidence rate in the population
studied. Even this use must be approached cautiously, as a drug may relieve a
symptom in one patient while inducing it in others. (For example, an
anticholinergic, anxiolytic drug may relieve dry mouth [a sign of anxiety] in
some subjects but induce it [an untoward event] in others.)
| Number of Patients % Patients Reporting: |
HALCION 1003 |
PLACEBO 997 |
| Central Nervous System |
| Drowsiness |
14.0 |
6.4 |
| Headache |
9.7 |
8.4 |
| Dizziness |
7.8 |
3.1 |
| Nervousness |
5.2 |
4.5 |
| Light-headedness |
4.9 |
0.9 |
| Coordination disorders/ataxia |
4.6 |
0.8 |
| Gastrointestinal |
| Nausea/vomiting |
4.6 |
3.7 |
In addition to the relatively common (i.e., 1% or greater)
untoward events enumerated above, the following adverse events have been
reported less frequently (i.e., 0.9% to0.5%): euphoria, tachycardia, tiredness,
confusional states/memory impairment, cramps/pain, depression, visual
disturbances.
Rare (i.e., less than 0.5%) adverse reactions included
constipation, taste alterations, diarrhea, dry mouth, dermatitis/allergy,
dreaming/nightmares, insomnia, paresthesia, tinnitus, dysesthesia, weakness, congestion,
death from hepatic failure in a patient also receiving diuretic drugs.
In addition to these untoward events for which estimates
of incidence are available, the following adverse events have been reported in
association with the use of HALCION and other benzodiazepines: amnestic
symptoms (anterograde amnesia with appropriate or inappropriate behavior),
confusional states (disorientation, derealization, depersonalization, and/or
clouding of consciousness), dystonia, anorexia, fatigue, sedation, slurred
speech, jaundice, pruritus, dysarthria, changes in libido, menstrual irregularities,
incontinence, and urinary retention. Other factors may contribute to some of
these reactions, eg, concomitant intake of alcohol or other drugs, sleep
deprivation, an abnormal premorbid state, etc.
Other events reported include: paradoxical reactions such
as stimulation, mania, an agitational state (restlessness, irritability, and
excitation), increased muscle spasticity, sleep disturbances, hallucinations, delusions,
aggressiveness, falling, somnambulism, syncope, inappropriate behavior and
other adverse behavioral effects. Should these occur, use of the drug should be
discontinued.
The following events have also been reported: chest pain,
burning tongue/glossitis/stomatitis.
Laboratory analyses were performed on all patients
participating in the clinical program for HALCION. The following incidences of
abnormalities were observed in patients receiving HALCION and the corresponding
placebo group. None of these changes were considered to be of physiological significance.
| Number of Patients % of Patients Reporting: |
HALCION 380 |
PLACEBO 361 |
| Low |
High |
Low |
Hig |
| Hematology |
| Hematocrit |
* |
* |
* |
* |
| Hemoglobin |
* |
* |
* |
* |
| T otal WBC count |
1.7 |
2.1 |
* |
1.3 |
| Neutrophil count |
1.5 |
1.5 |
3.3 |
1.0 |
| Lymphocyte count |
2.3 |
4.0 |
3.1 |
3.8 |
| Monocyte count |
3.6 |
* |
4.4 |
1.5 |
| Eosinophil count |
10.2 |
3.2 |
9.8 |
3.4 |
| Basophil count |
1.7 |
2.1 |
* |
1.8 |
| Urinalysis |
| Albumi |
— |
1.1 |
— |
* |
| Sugar |
— |
* |
— |
* |
| RBC/HPF |
— |
2.9 |
— |
2.9 |
| WBC/HPF Blood chemistry |
— |
11.7 |
— |
7.9 |
| Creatinine |
2.4 |
1.9 |
3.6 |
1.5 |
| Bilirubin |
* |
1.5 |
1.0 |
* |
| SGOT |
* |
5.3 |
* |
4.5 |
| Alkaline phosphatase |
* |
2.2 |
* |
2.6 |
| * Less than 1% |
When treatment with HALCION is protracted, periodic blood
counts, urinalysis, and blood chemistry analyses are advisable.
Minor changes in EEG patterns, usually low-voltage fast
activity, have been observed in patients during therapy with HALCION and are of
no known significance.
Drug Abuse And Dependence
Abuse and addiction are separate and distinct from
physical dependence and tolerance. Abuse is characterized by misuse of the drug
for non-medical purposes, often in combination with other psychoactive
substances. Physical dependence is a state of adaptation that is manifested by
a specific withdrawal syndrome that can be produced by abrupt cessation, rapid
dose reduction, decreasing blood level of the drug and/or administration of an
antagonist. Tolerance is a state of adaptation in which exposure to a drug
induces changes that result in a diminution of one or more of the drug's
effects over time. Tolerance may occur to both the desired and undesired
effects of drugs and may develop at different rates for different effects.
Addiction is a primary, chronic, neurobiological disease
with genetic, psychosocial, and environmental factors influencing its
development and manifestations. It is characterized by behaviors that include
one or more of the following: impaired control over drug use, compulsive use,
continued use despite harm, and craving. Drug addiction is a treatable disease,
utilizing a multidisciplinary approach, but relapse is common.
Controlled Substance
Triazolam is a controlled substance under the Controlled
Substance Act, and HALCION Tablets have been assigned to Schedule IV.
Abuse, Dependence And Withdrawal
Withdrawal symptoms, similar in character to those noted
with barbiturates and alcohol (convulsions, tremor, abdominal and muscle
cramps, vomiting, sweating, dysphoria, perceptual disturbances and insomnia),
have occurred following abrupt discontinuance of benzodiazepines, including
HALCION. The more severe symptoms are usually associated with higher dosages
and longer usage, although patients at therapeutic dosages given for as few as
1-2 weeks can also have withdrawal symptoms and in some patients there may be
withdrawal symptoms (daytime anxiety, agitation) between nightly doses (see CLINICAL
PHARMACOLOGY). Consequently, abrupt discontinuation should be avoided and a
gradual dosage tapering schedule is recommended in any patient taking more than
the lowest dose for more than a few weeks. The recommendation for tapering is
particularly important in any patient with a history of seizure.
The risk of dependence is increased in patients with a
history of alcoholism, drug abuse, or in patients with marked personality
disorders. Such dependence-prone individuals should be under careful surveillance
when receiving HALCION. As with all hypnotics, repeat prescriptions should be
limited to those who are under medical supervision.
Therapeutic indications
HALCION is indicated for the short-term treatment of
insomnia (generally 7-10 days). Use for more than 2-3 weeks requires complete
reevaluation of the patient (see WARNINGS).
Prescriptions for HALCION should be written for
short-term use (7-10 days) and it should not be prescribed in quantities
exceeding a 1-month supply.
Name of the medicinal product
Halcion
Fertility, pregnancy and lactation
Teratogenic effects
Pregnancy category X
(see CONTRAINDICATIONS).
Non-teratogenic Effects
It is to be considered that the child born of a mother
who is on benzodiazepines may be at some risk for withdrawal symptoms from the
drug, during the postnatal period. Also, neonatal flaccidity has been reported
in an infant born of a mother who had been receiving benzodiazepines.
Qualitative and quantitative composition
HALCION Tablets are available in the following strengths
and package sizes:
0.25 mg (powder blue, elliptical, scored,
imprinted HALCION 0.25):
Reverse numbered
Unit Dose (100) NDC 0009-0017-55
Bottles of 10 NDC 0009-0017-58
Bottles of 500 NDC 0009-0017-02
Store at controlled room temperature 20° to 25°C (68° to
77°F).
Distributed by: Pharmacia & Upjohn Co., Division of
Pfizer Inc., NY, NY, 10017. December 2016
Special warnings and precautions for use
WARNINGS
Risks From Concomitant Use With Opioids
Concomitant use of benzodiazepines, including HALCION,
and opioids may result in profound sedation, respiratory depression, coma, and
death. Because of these risks, reserve concomitant prescribing of these drugs
for use in patients for whom alternative treatment options are inadequate.
Observational studies have demonstrated that concomitant
use of opioid analgesics and benzodiazepines increases the risk of drug-related
mortality compared to use of opioids alone. If a decision is made to prescribe
HALCION concomitantly with opioids, prescribe the lowest effective dosages and
minimum durations of concomitant use, and follow patients closely for signs and
symptoms of respiratory depression and sedation. In patients already receiving
an opioid analgesic, prescribe a lower initial dose of HALCION than indicated
in the absence of an opioid and titrate based on clinical response. If an opioid
is initiated in a patient already taking HALCION, prescribe a lower initial
dose of the opioid and titrate based upon clinical response.
Advise both patients and caregivers about the risks of
respiratory depression and sedation when HALCION is used with opioids. Advise
patients not to drive or operate heavy machinery until the effects of
concomitant use with the opioid have been determined.
Persistent Or Worsening Insomnia
Because sleep disturbances may be the presenting
manifestation of a physical and/or psychiatric disorder, symptomatic treatment
of insomnia should be initiated only after a careful evaluation of the patient.
The failure of insomnia to remit after 7 to 10 days of treatment may
indicate the presence of a primary psychiatric and/or medical illness that should
be evaluated. Worsening of insomnia or the emergence of new thinking or
behavior abnormalities may be the consequence of an unrecognized psychiatric or
physical disorder. Such findings have emerged during the course of treatment
with sedative-hypnotic drugs. Because some of the important adverse effects of
sedative-hypnotics appear to be dose related (see PRECAUTIONS and DOSAGE
AND ADMINISTRATION), it is important to use the smallest possible effective
dose, especially in the elderly.
“Sleep-driving” And Other Complex Behaviors
Complex behaviors such as “sleep-driving”
(i.e., driving while not fully awake after ingestion of a sedative-hypnotic,
with amnesia for the event) have been reported. These events can occur in
sedativehypnotic- naïve as well as in sedative-hypnotic-experienced persons.
Although behaviors such as sleepdriving may occur with sedative-hypnotics alone
at therapeutic doses, the use of alcohol and other CNS depressants with
sedative-hypnotics appears to increase the risk of such behaviors, as does the
use of sedative-hypnotics at doses exceeding the maximum recommended dose. Due
to the risk to the patient and the community, discontinuation of
sedative-hypnotics should be strongly considered for patients who report a
“sleep-driving” episode.
Other complex behaviors (e.g., preparing and eating food,
making phone calls, or having sex) have been reported in patients who are not
fully awake after taking a sedative-hypnotic. As with sleep-driving, patients
usually do not remember these events.
Severe Anaphylactic And Anaphylactoid Reactions
Rare cases of angioedema involving the tongue, glottis or
larynx have been reported in patients after taking the first or subsequent
doses of sedative-hypnotics, including HALCION. Some patients have had additional
symptoms such as dyspnea, throat closing, or nausea and vomiting that suggest
anaphylaxis. Some patients have required medical therapy in the emergency
department. If angioedema involves the tongue, glottis or larynx, airway
obstruction may occur and be fatal. Patients who develop angioedema after
treatment with HALCION should not be rechallenged with the drug.
Central Nervous System Manifestations
An increase in daytime anxiety has been reported for
HALCION after as few as 10 days of continuous use. In some patients this may be
a manifestation of interdose withdrawal (see CLINICAL PHARMACOLOGY). If
increased daytime anxiety is observed during treatment, discontinuation of treatment
may be advisable.
A variety of abnormal thinking and behavior changes have
been reported to occur in association with the use of benzodiazepine hypnotics
including HALCION. Some of these changes may be characterized by decreased
inhibition, eg, aggressiveness and extroversion that seem excessive, similar to
that seen with alcohol and other CNS depressants (eg, sedative/hypnotics).
Other kinds of behavioral changes have also been reported, for example, bizarre
behavior, agitation, hallucinations, depersonalization. In primarily depressed
patients, the worsening of depression, including suicidal thinking, has been reported
in association with the use of benzodiazepines.
It can rarely be determined with certainty whether a particular
instance of the abnormal behaviors listed above is drug induced, spontaneous in
origin, or a result of an underlying psychiatric or physical disorder.
Nonetheless, the emergence of any new behavioral sign or symptom of concern
requires careful and immediate evaluation.
Because of its depressant CNS effects, patients receiving
triazolam should be cautioned against engaging in hazardous occupations
requiring complete mental alertness such as operating machinery or driving a
motor vehicle. For the same reason, patients should be cautioned about the
concomitant ingestion of alcohol and other CNS depressant drugs during
treatment with HALCION Tablets.
As with some, but not all benzodiazepines, anterograde
amnesia of varying severity and paradoxical reactions have been reported
following therapeutic doses of HALCION. Data from several sources suggest that
anterograde amnesia may occur at a higher rate with HALCION than with other benzodiazepine
hypnotics.
Triazolam Interaction With Drugs That Inhibit Metabolism
Via Cytochrome P450 3A
The initial step in triazolam metabolism is hydroxylation
catalyzed by cytochrome P450 3A (CYP 3A). Drugs that inhibit this metabolic
pathway may have a profound effect on the clearance of triazolam. Consequently,
triazolam should be avoided in patients receiving very potent inhibitors of CYP
3A. With drugs inhibiting CYP 3A to a lesser but still significant degree,
triazolam should be used only with caution and consideration of appropriate
dosage reduction. For some drugs, an interaction with triazolam has been
quantified with clinical data; for other drugs, interactions are predicted from
in vitro data and/or experience with similar drugs in the same pharmacologic
class.
The following are examples of drugs known to inhibit the metabolism
of triazolam and/or related benzodiazepines, presumably through inhibition of
CYP 3A.
Potent CYP 3A inhibitors
Potent inhibitors of CYP 3A that should not be used
concomitantly with triazolam include ketoconazole, itraconazole, nefazodone and
several HIV protease inhibitors including ritonavir, indinavir, nelfinavir, saquinavir
and lopinavir. Although data concerning the effects of azole-type antifungal
agents other than ketoconazole and itraconazole on triazolam metabolism are not
available, they should be considered potent CYP 3A inhibitors, and their
coadministration with triazolam is not recommended (see CONTRAINDICATIONS).
Drugs demonstrated to be CYP 3A inhibitors on the basis
of clinical studies involving triazolam (caution and consideration of dose
reduction are recommended during coadministration with triazolam)
Macrolide Antibiotics
Coadministration of erythromycin increased the maximum
plasma concentration of triazolam by 46%, decreased clearance by 53%, and
increased half-life by 35%; caution and consideration of appropriate triazolam
dose reduction are recommended. Similar caution should be observed during
coadministration with clarithromycin and other macrolide antibiotics.
Cimetidine
Coadministration of cimetidine increased the maximum
plasma concentration of triazolam by 51%, decreased clearance by 55%, and
increased half-life by 68%; caution and consideration of appropriate triazolam
dose reduction are recommended.
Other drugs possibly affecting triazolam metabolism
Other drugs possibly affecting triazolam metabolism by
inhibition of CYP 3A are discussed in the PRECAUTIONS section (see
DRUG INTERACTIONS).
PRECAUTIONS
General
In elderly and/or debilitated patients it is recommended
that treatment with HALCION Tablets be initiated at 0.125 mg to decrease the
possibility of development of oversedation, dizziness, or impaired coordination.
Some side effects reported in association with the use of
HALCION appear to be dose related. These include drowsiness, dizziness,
light-headedness, and amnesia.
The relationship between dose and what may be more
serious behavioral phenomena is less certain. Specifically, some evidence,
based on spontaneous marketing reports, suggests that confusion, bizarre or
abnormal behavior, agitation, and hallucinations may also be dose related, but
this evidence is inconclusive. In accordance with good medical practice it is
recommended that therapy be initiated at the lowest effective dose (see
DOSAGE AND ADMINISTRATION).
Cases of “traveler's amnesia” have been
reported by individuals who have taken HALCION to induce sleep while traveling,
such as during an airplane flight. In some of these cases, insufficient time
was allowed for the sleep period prior to awakening and before beginning
activity. Also, the concomitant use of alcohol may have been a factor in some
cases.
Caution should be exercised if HALCION is prescribed to
patients with signs or symptoms of depression that could be intensified by
hypnotic drugs. Suicidal tendencies may be present in such patients and
protective measures may be required. Intentional over-dosage is more common in
these patients, and the least amount of drug that is feasible should be
available to the patient at any one time.
The usual precautions should be observed in patients with
impaired renal or hepatic function, chronic pulmonary insufficiency, and sleep
apnea. In patients with compromised respiratory function, respiratory depression
and apnea have been reported infrequently.
Information For Patients
The text of a Medication Guide for patients is included
at the end of this insert. To assure safe and effective use of HALCION, the
information and instructions provided in this Medication Guide should be
discussed with patients.
Risks From Concomitant Use With Opioids
Advise both patients and caregivers about the risks of
potentially fatal respiratory depression and sedation when HALCION is used with
opioids and not to use such drugs concomitantly unless supervised by a
healthcare provider. Advise patients not to drive or operate heavy machinery
until the effects of concomitant use with the opioid have been determined.
“Sleep-driving” And Other Complex Behaviors
There have been reports of people getting out of bed
after taking a sedative-hypnotic and driving their cars while not fully awake,
often with no memory of the event. If a patient experiences such an episode, it
should be reported to his or her doctor immediately, since
“sleep-driving” can be dangerous. This behavior is more likely to
occur when sedative-hypnotics are taken with alcohol or other central nervous
system depressants (see WARNINGS). Other complex behaviors (e.g.,
preparing and eating food, making phone calls, or having sex) have been
reported in patients who are not fully awake after taking a sedative hypnotic.
As with sleep-driving, patients usually do not remember these events.
Laboratory Tests
Laboratory tests are not ordinarily required in otherwise
healthy patients.
Carcinogenesis, Mutagenesis, Impairment Of Fertility
No evidence of carcinogenic potential was observed in
mice during a 24-month study with HALCION in doses up to 4,000 times the human
dose.
Pregnancy
Teratogenic effects
Pregnancy category X
(see CONTRAINDICATIONS).
Non-teratogenic Effects
It is to be considered that the child born of a mother
who is on benzodiazepines may be at some risk for withdrawal symptoms from the
drug, during the postnatal period. Also, neonatal flaccidity has been reported
in an infant born of a mother who had been receiving benzodiazepines.
Nursing Mothers
Human studies have not been performed; however, studies
in rats have indicated that HALCION and its metabolites are secreted in milk.
Therefore, administration of HALCION to nursing mothers is not recommended.
Pediatric Use
Safety and effectiveness of HALCION in individuals below
18 years of age have not been established.
Geriatric Use
The elderly are especially susceptible to the dose
related adverse effects of HALCION. They exhibit higher plasma triazolam
concentrations due to reduced clearance of the drug as compared with younger subjects
at the same dose. To minimize the possibility of development of oversedation,
the smallest effective dose should be used (see CLINICAL PHARMACOLOGY, WARNINGS,
PRECAUTIONS, and DOSAGE AND ADMINISTRATION).
Tolerance/Withdrawal Phenomena
Some loss of effectiveness or adaptation to the sleep
inducing effects of these medications may develop after nightly use for more
than a few weeks and there may be a degree of dependence that develops. For the
benzodiazepine sleeping pills that are eliminated quickly from the body, a
relative deficiency of the drug may occur at some point in the interval between
each night's use. This can lead to (1) increased wakefulness during the last
third of the night, and (2) the appearance of increased signs of daytime
anxiety or nervousness. These two events have been reported in particular for
HALCION.
There can be more severe 'withdrawal' effects when a
benzodiazepine sleeping pill is stopped. Such effects can occur after
discontinuing these drugs following use for only a week or two, but may be more
common and more severe after longer periods of continuous use. One type of
withdrawal phenomenon is the occurrence of what is known as 'rebound insomnia'.
That is, on the first few nights after the drug is stopped, insomnia is
actually worse than before the sleeping pill was given. Other withdrawal
phenomena following abrupt stopping of benzodiazepine sleeping pills range from
mild unpleasant feelings to a major withdrawal syndrome which may include
abdominal and muscle cramps, vomiting, sweating, tremor, and rarely,
convulsions.
Dosage (Posology) and method of administration
It is important to individualize the dosage of HALCION
Tablets for maximum beneficial effect and to help avoid significant adverse
effects.
The recommended dose for most adults is 0.25 mg before
retiring. A dose of 0.125 mg may be found to be sufficient for some patients
(e.g., low body weight). A dose of 0.5 mg should be used only for exceptional
patients who do not respond adequately to a trial of a lower dose since the
risk of several adverse reactions increases with the size of the dose
administered. A dose of 0.5 mg should not be exceeded.
In geriatric and/or debilitated patients the recommended
dosage range is 0.125 mg to 0.25 mg. Therapy should be initiated at 0.125 mg in
these groups and the 0.25 mg dose should be used only for exceptional patients
who do not respond to a trial of the lower dose. A dose of 0.25 mg should not
be exceeded in these patients.
As with all medications, the lowest effective dose should
be used.
Interaction with other medicinal products and other forms of interaction
SIDE EFFECTS
During placebo-controlled clinical studies in which 1,003
patients received HALCION Tablets, the most troublesome side effects were extensions
of the pharmacologic activity of triazolam, eg, drowsiness, dizziness, or
light-headedness.
The figures cited below are estimates of untoward
clinical event incidence among subjects who participated in the relatively
short duration (i.e., 1 to 42 days) placebo-controlled clinical trials of HALCION.
The figures cannot be used to predict precisely the incidence of untoward
events in the course of usual medical practice where patient characteristics
and other factors often differ from those in clinical trials. These figures
cannot be compared with those obtained from other clinical studies involving
related drug products and placebo, as each group of drug trials is conducted
under a different set of conditions.
Comparison of the cited figures, however, can provide the
prescriber with some basis for estimating the relative contributions of drug
and nondrug factors to the untoward event incidence rate in the population
studied. Even this use must be approached cautiously, as a drug may relieve a
symptom in one patient while inducing it in others. (For example, an
anticholinergic, anxiolytic drug may relieve dry mouth [a sign of anxiety] in
some subjects but induce it [an untoward event] in others.)
| Number of Patients % Patients Reporting: |
HALCION 1003 |
PLACEBO 997 |
| Central Nervous System |
| Drowsiness |
14.0 |
6.4 |
| Headache |
9.7 |
8.4 |
| Dizziness |
7.8 |
3.1 |
| Nervousness |
5.2 |
4.5 |
| Light-headedness |
4.9 |
0.9 |
| Coordination disorders/ataxia |
4.6 |
0.8 |
| Gastrointestinal |
| Nausea/vomiting |
4.6 |
3.7 |
In addition to the relatively common (i.e., 1% or greater)
untoward events enumerated above, the following adverse events have been
reported less frequently (i.e., 0.9% to0.5%): euphoria, tachycardia, tiredness,
confusional states/memory impairment, cramps/pain, depression, visual
disturbances.
Rare (i.e., less than 0.5%) adverse reactions included
constipation, taste alterations, diarrhea, dry mouth, dermatitis/allergy,
dreaming/nightmares, insomnia, paresthesia, tinnitus, dysesthesia, weakness, congestion,
death from hepatic failure in a patient also receiving diuretic drugs.
In addition to these untoward events for which estimates
of incidence are available, the following adverse events have been reported in
association with the use of HALCION and other benzodiazepines: amnestic
symptoms (anterograde amnesia with appropriate or inappropriate behavior),
confusional states (disorientation, derealization, depersonalization, and/or
clouding of consciousness), dystonia, anorexia, fatigue, sedation, slurred
speech, jaundice, pruritus, dysarthria, changes in libido, menstrual irregularities,
incontinence, and urinary retention. Other factors may contribute to some of
these reactions, eg, concomitant intake of alcohol or other drugs, sleep
deprivation, an abnormal premorbid state, etc.
Other events reported include: paradoxical reactions such
as stimulation, mania, an agitational state (restlessness, irritability, and
excitation), increased muscle spasticity, sleep disturbances, hallucinations, delusions,
aggressiveness, falling, somnambulism, syncope, inappropriate behavior and
other adverse behavioral effects. Should these occur, use of the drug should be
discontinued.
The following events have also been reported: chest pain,
burning tongue/glossitis/stomatitis.
Laboratory analyses were performed on all patients
participating in the clinical program for HALCION. The following incidences of
abnormalities were observed in patients receiving HALCION and the corresponding
placebo group. None of these changes were considered to be of physiological significance.
| Number of Patients % of Patients Reporting: |
HALCION 380 |
PLACEBO 361 |
| Low |
High |
Low |
Hig |
| Hematology |
| Hematocrit |
* |
* |
* |
* |
| Hemoglobin |
* |
* |
* |
* |
| T otal WBC count |
1.7 |
2.1 |
* |
1.3 |
| Neutrophil count |
1.5 |
1.5 |
3.3 |
1.0 |
| Lymphocyte count |
2.3 |
4.0 |
3.1 |
3.8 |
| Monocyte count |
3.6 |
* |
4.4 |
1.5 |
| Eosinophil count |
10.2 |
3.2 |
9.8 |
3.4 |
| Basophil count |
1.7 |
2.1 |
* |
1.8 |
| Urinalysis |
| Albumi |
— |
1.1 |
— |
* |
| Sugar |
— |
* |
— |
* |
| RBC/HPF |
— |
2.9 |
— |
2.9 |
| WBC/HPF Blood chemistry |
— |
11.7 |
— |
7.9 |
| Creatinine |
2.4 |
1.9 |
3.6 |
1.5 |
| Bilirubin |
* |
1.5 |
1.0 |
* |
| SGOT |
* |
5.3 |
* |
4.5 |
| Alkaline phosphatase |
* |
2.2 |
* |
2.6 |
| * Less than 1% |
When treatment with HALCION is protracted, periodic blood
counts, urinalysis, and blood chemistry analyses are advisable.
Minor changes in EEG patterns, usually low-voltage fast
activity, have been observed in patients during therapy with HALCION and are of
no known significance.
Drug Abuse And Dependence
Abuse and addiction are separate and distinct from
physical dependence and tolerance. Abuse is characterized by misuse of the drug
for non-medical purposes, often in combination with other psychoactive
substances. Physical dependence is a state of adaptation that is manifested by
a specific withdrawal syndrome that can be produced by abrupt cessation, rapid
dose reduction, decreasing blood level of the drug and/or administration of an
antagonist. Tolerance is a state of adaptation in which exposure to a drug
induces changes that result in a diminution of one or more of the drug's
effects over time. Tolerance may occur to both the desired and undesired
effects of drugs and may develop at different rates for different effects.
Addiction is a primary, chronic, neurobiological disease
with genetic, psychosocial, and environmental factors influencing its
development and manifestations. It is characterized by behaviors that include
one or more of the following: impaired control over drug use, compulsive use,
continued use despite harm, and craving. Drug addiction is a treatable disease,
utilizing a multidisciplinary approach, but relapse is common.
Controlled Substance
Triazolam is a controlled substance under the Controlled
Substance Act, and HALCION Tablets have been assigned to Schedule IV.
Abuse, Dependence And Withdrawal
Withdrawal symptoms, similar in character to those noted
with barbiturates and alcohol (convulsions, tremor, abdominal and muscle
cramps, vomiting, sweating, dysphoria, perceptual disturbances and insomnia),
have occurred following abrupt discontinuance of benzodiazepines, including
HALCION. The more severe symptoms are usually associated with higher dosages
and longer usage, although patients at therapeutic dosages given for as few as
1-2 weeks can also have withdrawal symptoms and in some patients there may be
withdrawal symptoms (daytime anxiety, agitation) between nightly doses (see CLINICAL
PHARMACOLOGY). Consequently, abrupt discontinuation should be avoided and a
gradual dosage tapering schedule is recommended in any patient taking more than
the lowest dose for more than a few weeks. The recommendation for tapering is
particularly important in any patient with a history of seizure.
The risk of dependence is increased in patients with a
history of alcoholism, drug abuse, or in patients with marked personality
disorders. Such dependence-prone individuals should be under careful surveillance
when receiving HALCION. As with all hypnotics, repeat prescriptions should be
limited to those who are under medical supervision.
DRUG INTERACTIONS
The concomitant use of benzodiazepines and opioids
increases the risk of respiratory depression because of actions at different
receptor sites in the CNS that control respiration. Benzodiazepines interact at
GABA sites and opioids interact primarily at mu receptors. When benzodiazepines
and opioids are combined, the potential for benzodiazepines to significantly
worsen opioid-related respiratory depression exists. Limit dosage and duration
of concomitant use of benzodiazepines and opioids, and monitor patients closely
for respiratory depression and sedation.
Both pharmacodynamic and pharmacokinetic interactions
have been reported with benzodiazepines. In particular, triazolam produces
additive CNS depressant effects when coadministered with other psychotropic
medications, anticonvulsants, antihistamines, ethanol, and other drugs which
themselves produce CNS depression.
Drugs that inhibit triazolam metabolism via cytochrome
P450 3A
The initial step in triazolam metabolism is hydroxylation
catalyzed by cytochrome P450 3A (CYP 3A). Drugs which inhibit this metabolic
pathway may have a profound effect on the clearance of triazolam (see
CONTRAINDICATIONS and WARNINGS for additional drugs of this type).
HALCION is contraindicated with ketoconzaole, itraconazole, nefazodone, and
several HIV protease inhibitors.
Drugs and other substances demonstrated to be CYP 3A
inhibitors of possible clinical significance on the basis of clinical studies
involving triazolam (caution is recommended during coadministration with triazolam)
Isoniazid
Coadministration of isoniazid increased the maximum
plasma concentration of triazolam by 20%, decreased clearance by 42%, and
increased half-life by 31%.
Oral Contraceptives
Coadministration of oral contraceptives increased maximum
plasma concentration by 6%, decreased clearance by 32%, and increased half-life
by 16%.
Grapefruit Juice
Coadministration of grapefruit juice increased the
maximum plasma concentration of triazolam by 25%, increased the area under the
concentration curve by 48%, and increased half-life by 18%.
Drugs demonstrated to be CYP 3A inhibitors on the basis
of clinical studies involving benzodiazepines metabolized similarly to
triazolam or on the basis of in vitro studies with triazolam or other benzodiazepines
(caution is recommended during coadministration with triazolam)
Available data from clinical studies of benzodiazepines
other than triazolam suggest a possible drug interaction with triazolam for the
following: fluvoxamine, diltiazem, and verapamil. Data from in vitro studies of
triazolam suggest a possible drug interaction with triazolam for the following:
sertraline and paroxetine. Data from in vitro studies of benzodiazepines other
than triazolam suggest a possible drug interaction with triazolam for the
following: ergotamine, cyclosporine, amiodarone, nicardipine, and nifedipine.
Caution is recommended during coadministration of any of these drugs with
triazolam (see WARNINGS).
Drugs that affect triazolam pharmacokinetics by other
mechanisms
Ranitidine
Coadministration of ranitidine increased the maximum plasma
concentration of triazolam by 30%, increased the area under the concentration
curve by 27%, and increased half-life by 3.3%. Caution is recommended during
coadministration with triazolam.