SIDE EFFECTS
The following serious adverse reactions are discussed in greater detail in other sections of the labeling:
- CNS-depressant effects and next-day impairment [see WARNINGS AND PRECAUTIONS]
- Serious anaphylactic and anaphylactoid reactions [see WARNINGS AND PRECAUTIONS]
- Abnormal thinking and behavior changes, and complex behaviors [see WARNINGS AND PRECAUTIONS]
- Withdrawal effects [see WARNINGS AND PRECAUTIONS]
Clinical Trials Experience
Associated With Discontinuation Of Treatment
Approximately 4% of 1,701 patients who received
zolpidem at all doses (1.25 to 90 mg) in U.S. premarketing clinical trials discontinued treatment because
of an adverse reaction. Reactions most commonly associated with discontinuation from U.S. trials were
daytime drowsiness (0.5%), dizziness (0.4%), headache (0.5%), nausea (0.6%), and vomiting (0.5%).
Approximately 4% of 1,959 patients who received zolpidem at all doses (1 to 50 mg) in similar foreign
trials discontinued treatment because of an adverse reaction. Reactions most commonly associated
with discontinuation from these trials were daytime drowsiness (1.1%), dizziness/vertigo (0.8%),
amnesia (0.5%), nausea (0.5%), headache (0.4%), and falls (0.4%).
Data from a clinical study in which selective serotonin reuptake inhibitor (SSRI)-treated patients were
given zolpidem revealed that four of the seven discontinuations during double-blind treatment with
zolpidem (n=95) were associated with impaired concentration, continuing or aggravated depression,
and manic reaction; one patient treated with placebo (n =97) was discontinued after an attempted
suicide.
Most Commonly Observed Adverse Reactions In Controlled Trials
During short-term treatment (up to 10
nights) with AMBIEN at doses up to 10 mg, the most commonly observed adverse reactions associated
with the use of zolpidem and seen at statistically significant differences from placebo-treated patients
were drowsiness (reported by 2% of zolpidem patients), dizziness (1%), and diarrhea (1%). During
longer-term treatment (28 to 35 nights) with zolpidem at doses up to 10 mg, the most commonly
observed adverse reactions associated with the use of zolpidem and seen at statistically significant
differences from placebo-treated patients were dizziness (5%) and drugged feelings (3%).
Adverse reactions Observed At An Incidence Of ≥ 1% In Controlled Trials
The following tables enumerate
treatment-emergent adverse reactions frequencies that were observed at an incidence equal to 1% or
greater among patients with insomnia who received zolpidem tartrate and at a greater incidence than
placebo in U.S. placebo-controlled trials. Events reported by investigators were classified utilizing a
modified World Health Organization (WHO) dictionary of preferred terms for the purpose of establishing
event frequencies. The prescriber should be aware that these figures cannot be used to predict the
incidence of side effects in the course of usual medical practice, in which patient characteristics and
other factors differ from those that prevailed in these clinical trials. Similarly, the cited frequencies
cannot be compared with figures obtained from other clinical investigators involving related drug
products and uses, since each group of drug trials is conducted under a different set of conditions.
However, the cited figures provide the physician with a basis for estimating the relative contribution of
drug and nondrug factors to the incidence of side effects in the population studied.
The following table was derived from results of 11 placebo-controlled short-term U.S. efficacy trials
involving zolpidem in doses ranging from 1.25 to 20 mg. The table is limited to data from doses up
to and including 10 mg, the highest dose recommended for use.
Incidence of Treatment-Emergent Adverse Experiences in Placebo-Controlled Clinical Trials
Lasting up to 10 Nights (Percentage of patients reporting)
Body System/
Adverse Event* |
Zolpidem
(≤10 mg)
(N=685) |
Placebo
(N=473) |
Central and Peripheral Nervous System |
Headache |
7 |
6 |
Drowsiness |
2 |
- |
Dizziness |
1 |
- |
Gastrointestinal System |
Diarrhea |
1 |
- |
*Reactions reported by at least 1% of patients treated with AMBIEN and at a greater frequency than
placebo. |
The following table was derived from results of three placebo-controlled long-term efficacy trials
involving AMBIEN (zolpidem tartrate). These trials involved patients with chronic insomnia who were
treated for 28 to 35 nights with zolpidem at doses of 5, 10, or 15 mg. The table is limited to data from
doses up to and including 10 mg, the highest dose recommended for use. The table includes only
adverse events occurring at an incidence of at least 1% for zolpidem patients.
Incidence of Treatment-Emergent Adverse Experiences in Placebo-Controlled Clinical Trials
Lasting up to 35 Nights (Percentage of patients reporting)
Body System/
Adverse Event* |
Zolpidem
(≤10 mg)
(N=152) |
Placebo
(N=161) |
Autonomic Nervous System |
Dry mouth |
3 |
1 |
Body as a Whole |
Allergy |
4 |
1 |
Back Pain |
3 |
2 |
Influenza-like symptoms |
2 |
- |
Chest pain |
1 |
- |
Cardiovascular System |
Palpitation |
2 |
- |
Central and Peripheral Nervous System |
Drowsiness |
8 |
5 |
Dizziness |
5 |
1 |
Lethargy |
3 |
1 |
Drugged feeling |
3 |
- |
Lightheadedness |
2 |
1 |
Depression |
2 |
1 |
Abnormal dreams |
1 |
- |
Amnesia |
1 |
- |
Sleep disorder |
1 |
- |
Gastrointestinal System |
Diarrhea |
3 |
2 |
Abdominal pain |
2 |
2 |
Constipation |
2 |
1 |
Respiratory System |
Sinusitis |
4 |
2 |
Pharyngitis |
3 |
1 |
Skin and Appendages |
Rash |
2 |
1 |
*Reactions reported by at least 1% of patients treated with AMBIEN and at a greater frequency than
placebo. |
Dose Relationship For Adverse Reactions
There is evidence from dose comparison trials suggesting
a dose relationship for many of the adverse reactions associated with zolpidem use, particularly for
certain CNS and gastrointestinal adverse events.
Adverse Event Incidence Across The Entire Preapproval Database
AMBIEN was administered to,660 subjects in clinical trials throughout the U.S., Canada, and Europe. Treatment-emergent adverse
events associated with clinical trial participation were recorded by clinical investigators using
terminology of their own choosing. To provide a meaningful estimate of the proportion of individuals
experiencing treatment-emergent adverse events, similar types of untoward events were grouped into
a smaller number of standardized event categories and classified utilizing a modified World Health
Organization (WHO) dictionary of preferred terms.
The frequencies presented, therefore, represent the proportions of the 3,660 individuals exposed to
zolpidem, at all doses, who experienced an event of the type cited on at least one occasion while
receiving zolpidem. All reported treatment-emergent adverse events are included, except those already
listed in the table above of adverse events in placebo-controlled studies, those coding terms that are
so general as to be uninformative, and those events where a drug cause was remote. It is important
to emphasize that, although the events reported did occur during treatment with AMBIEN, they were
not necessarily caused by it.
Adverse events are further classified within body system categories and enumerated in order of
decreasing frequency using the following definitions: frequent adverse events are defined as those
occurring in greater than 1/100 subjects; infrequent adverse events are those occurring in 1/100 to
1/1,000 patients; rare events are those occurring in less than 1/1,000 patients.
Autonomic nervous system:
Infrequent: increased sweating, pallor, postural hypotenson, syncope.
Rare: abnormal accommodation, altered saliva, flushing, glaucoma, hypotension, impotence, increased
saliva, tenesmus.
Body as a whole:
Frequent: asthenia. Infrequent: edema, falling, fatigue, fever, malaise, trauma. Rare:
allergic reaction, allergy aggravated, anaphylactic shock, face edema, hot flashes, increased ESR,
pain, restless legs, rigors, tolerance increased, weight decrease.
Cardiovascular system:
Infrequent: cerebrovascular disorder, hypertension, tachycardia. Rare: angina
pectoris, arrhythmia, arteritis, circulatory failure, extrasystoles, hypertension aggravated, myocardial
infarction, phlebitis, pulmonary embolism, pulmonary edema, varicose veins, ventricular tachycardia.
Central and peripheral nervous system:
Frequent: ataxia, confusion, euphoria, headache, insomnia,
vertigo Infrequent: agitation, anxiety, decreased cognition, detached, difficulty concentrating, dysarthria,
emotional lability, hallucination, hypoesthesia, illusion, leg cramps, migraine, nervousness, paresthesia,
sleeping (after daytime dosing), speech disorder, stupor, tremor. Rare: abnormal gait, abnormal
thinking, aggressive reaction, apathy, appetite increased, decreased libido, delusion, dementia,
depersonalization, dysphasia, feeling strange, hypokinesia, hypotonia, hysteria, intoxicated feeling,
manic reaction, neuralgia, neuritis, neuropathy, neurosis, panic attacks, paresis, personality disorder,
somnambulism, suicide attempts, tetany, yawning.
Gastrointestinal system:
Frequent: dyspepsia, hiccup, nausea. Infrequent: anorexia, constipation,
dysphagia, flatulence, gastroenteritis, vomiting. Rare: enteritis, eructation, esophagospasm, gastritis,
hemorrhoids, intestinal obstruction, rectal hemorrhage, tooth caries.
Hematologic and lymphatic system:
Rare: anemia, hyperhemoglobinemia, leukopenia, lymphadenopathy,
macrocytic anemia, purpura, thrombosis.
Immunologic system:
Infrequent: infection. Rare: abscess herpes simplex herpes zoster, otitis externa,
otitis media.
Liver and biliary system:
Infrequent: abnormal hepatic function, increased SGPT. Rare: bilirubinemia,
increased SGOT.
Metabolic and nutritional:
Infrequent: hyperglycemia, thirst. Rare: gout, hypercholesteremia, hyperlipidemia,
increased alkaline phosphatase, increased BUN, periorbital edema.
Musculoskeletal system:
Frequent: arthralgia, myalgia. Infrequent: arthritis. Rare: arthrosis, muscle
weakness, sciatica, tendinitis.
Reproductive system:
Infrequent: menstrual disorder, vaginitis. Rare: breast fibroadenosis, breast
neoplasm, breast pain.
Respiratory system:
Frequent: upper respiratory infection, lower respiratory infection. Infrequent:
bronchitis, coughing, dyspnea, rhinitis. Rare: bronchospasm, respiratory depression, epistaxis, hypoxia,
laryngitis, pneumonia.
Skin and appendages:
Infrequent: pruritus. Rare: acne, bullous eruption, dermatitis, furunculosis,
injection-site inflammation, photosensitivity reaction, urticaria.
Special senses:
Frequent: diplopia, vision abnormal. Infrequent: eye irritation, eye pain, scleritis, taste
perversion, tinnitus. Rare: conjunctivitis, corneal ulceration, lacrimation abnormal, parosmia, photopsia.
Urogenital system:
Frequent: urinary tract infection. Infrequent: cystitis, urinary incontinence. Rare:
acute renal failure, dysuria, micturition frequency, nocturia, polyuria, pyelonephritis, renal pain, urinary
retention.
Postmarketing Experience
The following adverse reactions have been identified during post-approval use of AMBIEN. Because
these reactions are reported voluntarily from a population of uncertain size, it is not always possible
to reliably estimate their frequency or establish a causal relationship to drug exposure.
Liver and biliary system: acute hepatocellular, cholestatic or mixed liver injury with or without jaundice
(i.e., bilirubin >2×ULN, alkaline phosphatase ≥2×ULN, transaminase ≥5×ULN).