SIDE EFFECTS
Associated With Discontinuation Of Treatment
Nineteen percent (537/2897) of venlafaxine patients in Phase
2 and Phase 3 depression studies discontinued treatment due to an adverse
event. The more common events ( ≥ 1%) associated with discontinuation and
considered to be drug-related (i.e., those events associated with dropout at a
rate approximately twice or greater for venlafaxine compared to placebo)
included:
CNS |
Venlafaxine |
Placebo |
Somnolence |
3% |
1% |
Insomnia |
3% |
1% |
Dizziness |
3% |
- |
Nervousness |
2% |
- |
Dry mouth |
2% |
- |
Anxiety |
2% |
1% |
Gastrointestinal |
|
Nausea |
6% |
1% |
Urogenital |
|
Abnormal ejaculation* |
3% |
- |
Other |
|
|
Headache |
3% |
1% |
Asthenia  |
2% |
- |
Sweating  |
2% |
- |
* Percentages based on the number of males.
- Less than 1% |
Incidence In Controlled Trials
Commonly Observed Adverse Events In Controlled Clinical
Trials
The most commonly observed adverse events associated with
the use of venlafaxine tablets, USP (incidence of 5% or greater) and not seen
at an equivalent incidence among placebo-treated patients (i.e., incidence for
venlafaxine tablets, USP at least twice that for placebo), derived from the 1%
incidence table below, were asthenia, sweating, nausea, constipation, anorexia,
vomiting, somnolence, dry mouth, dizziness, nervousness, anxiety, tremor, and
blurred vision as well as abnormal ejaculation/orgasm and impotence in men.
Adverse Events Occurring at an Incidence of 1% or More Among
Venlafaxine tablets, USP-Treated Patients
The table that follows enumerates adverse events that
occurred at an incidence of 1% or more, and were more frequent than in the
placebo group, among venlafaxine tablets, USP-treated patients who participated
in short-term (4 to 8 week) placebo-controlled trials in which patients were
administered doses in a range of 75 to 375 mg/day. This table shows the
percentage of patients in each group who had at least one episode of an event
at some time during their treatment. Reported adverse events were classified
using a standard COSTART-based Dictionary terminology.
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 where patient characteristics and other factors differ from those
which prevailed in the clinical trials. Similarly, the cited frequencies cannot
be compared with figures obtained from other clinical investigations involving
different treatments, uses and investigators. The cited figures, however, do
provide the prescribing physician with some basis for estimating the relative
contribution of drug and nondrug factors to the side effect incidence rate in
the population studied.
TABLE 2: Treatment-Emergent Adverse Experience Incidence
in 4 to 8 Week Placebo-Controlled Clinical Trials1
Body System/
Preferred Term |
Effexor (n=1033) |
Placebo
(n=609) |
Body as a Whole |
|
|
Headache |
25% |
24% |
Asthenia |
12% |
6% |
Infection |
6% |
5% |
Chills |
3% |
- |
Chest pain |
2% |
1% |
Trauma |
2% |
1% |
Cardiovascular |
|
Vasodilatation |
4% |
3% |
Increased blood pressure/hypertension |
2% |
- |
Tachycardia |
2% |
- |
Postural hypotension  |
1% |
- |
Dermatological  |
|
Sweating  |
12% |
3% |
Rash  |
3% |
2% |
Pruritus  |
1% |
- |
Gastrointestinal  |
|
Nausea  |
37% |
11% |
Constipation  |
15% |
7% |
Anorexia  |
11% |
2% |
Diarrhea  |
8% |
7% |
Vomiting  |
6% |
2% |
Dyspepsia  |
5% |
4% |
Flatulence  |
3% |
2% |
Metabolic  |
|
Weight loss  |
1% |
- |
Nervous System  |
|
Somnolence  |
23% |
9% |
Dry mouth  |
22% |
11% |
Dizziness  |
19% |
7% |
Insomnia  |
18% |
10% |
Nervousness  |
13% |
6% |
Anxiety  |
6% |
3% |
Tremor  |
5% |
1% |
Abnormal dreams  |
4% |
3% |
Hypertonia  |
3% |
2% |
Paresthesia  |
3% |
2% |
Libido decreased  |
2% |
- Â |
Agitation  |
2% |
- Â |
Confusion  |
2% |
1% |
Thinking abnormal  |
2% |
1% |
Depersonalization  |
1% |
- Â |
Depression  |
1% |
- Â |
Urinary retention  |
1% |
- Â |
Twitching  |
1% |
- |
Respiration  |
|
Yawn  |
3% |
- |
Special Senses  |
|
Blurred vision  |
6% |
2% |
Taste perversion |
2% |
- |
Tinnitus |
2% |
- |
Mydriasis |
2% |
- |
Urogenital System  |
|
Abnormal ejaculation/ orgasm  |
12%2 Â |
- 2 Â |
Impotence  |
6%2 Â |
- 2 Â |
Urinary frequency  |
3% |
2% |
Urination impaired  |
2% |
- Â |
Orgasm disturbance  |
2%3 Â |
- 3 |
1 Events reported by at least 1% of patients
treated with venlafaxine tablets, USP are included, and are rounded to the
nearest %. Events for which the venlafaxine tablets, USP incidence was equal to
or less than placebo are not listed in the table, but included the following:
abdominal pain, pain, back pain, flu syndrome, fever, palpitation, increased
appetite, myalgia, arthralgia, amnesia, hypesthesia, rhinitis, pharyngitis,
sinusitis, cough increased, and dysmenorrhea3.
- Incidence less than 1%.
2 Incidence based on number of male patients.
3 Incidence based on number of female patients. |
Dose Dependency Of Adverse Events
A comparison of adverse event rates in a fixed-dose study
comparing venlafaxine tablets, USP 75, 225, and 375 mg/day with placebo
revealed a dose dependency for some of the more common adverse events associated
with venlafaxine tablets, USP use, as shown in the table that follows. The rule
for including events was to enumerate those that occurred at an incidence of 5%
or more for at least one of the venlafaxine groups and for which the incidence
was at least twice the placebo incidence for at least one venlafaxine tablets,
USP group. Tests for potential dose relationships for these events (Cochran- Armitage
Test, with a criterion of exact 2 sided p-value ≤ 0.05) suggested a
dose-dependency for several adverse events in this list, including chills,
hypertension, anorexia, nausea, agitation, dizziness, somnolence, tremor,
yawning, sweating, and abnormal ejaculation.
TABLE 3: Treatment-Emergent Adverse Experience Incidence
in a Dose Comparison Trial
Body System/
Preferred Term  |
|
Effexor |
Placebo
(n=92) Â |
75
(n=89) Â |
225
(n=89) Â |
375
(n=88) |
Body as a Whole |
Abdominal pain |
3.30% |
3.40% |
2.20% |
8.00% |
Asthenia |
3.30% |
16.90% |
14.60% |
14.80% |
Chills |
1.10% |
2.20% |
5.60% |
6.80% |
Infection |
2.20% |
2.20% |
5.60% |
2.30% |
Cardiovascular System |
Hypertension |
1.10% |
1.10% |
2.20% |
4.50% |
Vasodilatation |
0.00% |
4.50% |
5.60% |
2.30% |
Digestive System |
Anorexia |
2.20% |
14.60% |
13.50% |
17.00% |
Dyspepsia |
2.20% |
6.70% |
6.70% |
4.50% |
Nausea |
14.10% |
32.60% |
38.20% |
58.00% |
Vomiting |
1.10% |
7.90% |
3.40% |
6.80% |
Nervous System |
|
|
|
Agitation |
0.00% |
1.10% |
2.20% |
4.50% |
Anxiety |
4.30% |
11.20% |
4.50% |
2.30% |
Dizziness |
4.30% |
19.10% |
22.50% |
23.90% |
Insomnia |
9.80% |
22.50% |
20.20% |
13.60% |
Libido decreased |
1.10% |
2.20% |
1.10% |
5.70% |
Nervousness |
4.30% |
21.30% |
13.50% |
12.50% |
Somnolence |
4.30% |
16.90% |
18.00% |
26.10% |
Tremor |
0.00% |
1.10% |
2.20% |
10.20% |
Respiratory System |
Yawn |
0.00% |
4.50% |
5.60% |
8.00% |
Skin and Appendages |
Sweating |
5.40% |
6.70% |
12.40% |
19.30% |
Special Senses |
Abnormality of accommodation |
0.00% |
9.10% |
7.90% |
5.60% |
Urogenital System |
Abnormal ejaculation/orgasm |
0.00% |
4.50% |
2.20% |
12.50% |
Impotence |
0.00% |
5.80% |
2.10% |
3.60% |
(Number of men) |
(n=63) |
(n=52) |
(n=48) |
(n=56) |
Adaptation To Certain Adverse Events
Over a 6 week period, there was evidence of adaptation to
some adverse events with continued therapy (e.g., dizziness and nausea), but
less to other effects (e.g., abnormal ejaculation and dry mouth).
Vital Sign Changes
Venlafaxine tablets, USP treatment (averaged over all dose
groups) in clinical trials was associated with a mean increase in pulse rate of
approximately 3 beats per minute, compared to no change for placebo. In a
flexible-dose study, with doses in the range of 200 to 375 mg/day and mean dose
greater than 300 mg/day, the mean pulse was increased by about 2 beats per
minute compared with a decrease of about 1 beat per minute for placebo.
In controlled clinical trials, venlafaxine tablets, USP was
associated with mean increases in diastolic blood pressure ranging from 0.7 to
2.5 mm Hg averaged over all dose groups, compared to mean decreases ranging
from 0.9 to 3.8 mm Hg for placebo. However, there is a dose dependency for
blood pressure increase (see WARNINGS).
Laboratory Changes
Of the serum chemistry and hematology parameters monitored
during clinical trials with venlafaxine tablets, USP, a statistically significant
difference with placebo was seen only for serum cholesterol. In premarketing
trials, treatment with venlafaxine tablets, USP was associated with a mean
final on-therapy increase in total cholesterol of 3 mg/dL.
Patients treated with venlafaxine tablets, USP for at least
3 months in placebo-controlled 12 month extension trials had a mean final
on-therapy increase in total cholesterol of 9.1 mg/dL compared with a decrease
of 7.1 mg/dL among placebo-treated patients. This increase was duration dependent
over the study period and tended to be greater with higher doses. Clinically
relevant increases in serum cholesterol, defined as 1) a final on-therapy
increase in serum cholesterol ≥ 50 mg/dL from baseline and to a value
≥ 261 mg/dL or 2) an average on-therapy increase in serum cholesterol
≥ 50 mg/dL from baseline and to a value ≥ 261 mg/dL, were recorded
in 5.3% of venlafaxine-treated patients and 0.0% of placebo-treated patients
(see PRECAUTIONS, General, Serum Cholesterol Elevation).
ECG Changes
In an analysis of ECGs obtained in 769 patients treated with
venlafaxine tablets, USP and 450 patients treated with placebo in controlled
clinical trials, the only statistically significant difference observed was for
heart rate, i.e., a mean increase from baseline of 4 beats per minute for
venlafaxine tablets, USP. In a flexible-dose study, with doses in the range of
200 to 375 mg/day and mean dose greater than 300 mg/day, the mean change in
heart rate was 8.5 beats per minute compared with 1.7 beats per minute for placebo
(see PRECAUTIONS, General, Use in Patients With Concomitant
Illness).
Other Events Observed During The Premarketing Evaluation Of Venlafaxine
During its premarketing assessment, multiple doses of
venlafaxine tablets, USP were administered to 2897 patients in Phase 2 and
Phase 3 studies. In addition, in premarketing assessment of venlafaxine hydrochloride
extended-release capsules, multiple doses were administered to 705 patients in
Phase 3 major depressive disorder studies and venlafaxine tablets, USP was
administered to 96 patients. During its premarketing assessment, multiple doses
of venlafaxine hydrochloride extended-release capsules were also administered
to 1381 patients in Phase 3 GAD studies and 277 patients in Phase 3 Social Anxiety
Disorder studies. The conditions and duration of exposure to venlafaxine in
both development programs varied greatly, and included (in overlapping
categories) open and double-blind studies, uncontrolled and controlled studies,
inpatient (venlafaxine tablets, USP only) and outpatient studies, fixed-dose
and titration studies. Untoward events associated with this exposure were
recorded by clinical investigators using terminology of their own choosing.
Consequently, it is not possible to provide a meaningful estimate of the
proportion of individuals experiencing adverse events without first grouping
similar types of untoward events into a smaller number of standardized event
categories.
In the tabulations that follow, reported adverse events were
classified using a standard COSTARTbased Dictionary terminology. The
frequencies presented, therefore, represent the proportion of the 5356 patients
exposed to multiple doses of either formulation of venlafaxine who experienced
an event of the type cited on at least one occasion while receiving
venlafaxine. All reported events are included except those already listed in
TABLE 2 and those events for which a drug cause was remote. If the COSTART term
for an event was so general as to be uninformative, it was replaced with a more
informative term. It is important to emphasize that, although the events
reported occurred during treatment with venlafaxine, they were not necessarily
caused by it.
Events are further categorized by body system and listed in
order of decreasing frequency using the following definitions: frequent adverse
events are defined as those occurring on one or more occasions in at least
1/100 patients; infrequent adverse events are those occurring in 1/100 to
1/1000 patients; rare events are those occurring in fewer than 1/1000 patients.
Body as a whole- Frequent: accidental injury,
chest pain substernal, neck pain; Infrequent: face edema, intentional
injury, malaise, moniliasis, neck rigidity, pelvic pain, photosensitivity
reaction, suicide attempt, withdrawal syndrome; Rare: appendicitis,
bacteremia, carcinoma, cellulitis.
Cardiovascular system- Frequent: migraine; Infrequent:
angina pectoris, arrhythmia, extrasystoles, hypotension, peripheral vascular
disorder (mainly cold feet and/or cold hands), syncope, thrombophlebitis; Rare:
aortic aneurysm, arteritis, first-degree atrioventricular block, bigeminy, bradycardia,
bundle branch block, capillary fragility, cardiovascular disorder (mitral valve
and circulatory disturbance), cerebral ischemia, coronary artery disease,
congestive heart failure, heart arrest, mucocutaneous hemorrhage, myocardial
infarct, pallor.
Digestive system- Frequent: eructation; Infrequent:
bruxism, colitis, dysphagia, tongue edema, esophagitis, gastritis,
gastroenteritis, gastrointestinal ulcer, gingivitis, glossitis, rectal
hemorrhage, hemorrhoids, melena, oral moniliasis, stomatitis, mouth ulceration;
Rare: cheilitis, cholecystitis, cholelithiasis, duodenitis, esophageal
spasm, hematemesis, gastrointestinal hemorrhage, gum hemorrhage, hepatitis,
ileitis, jaundice, intestinal obstruction, parotitis, periodontitis, proctitis,
increased salivation, soft stools, tongue discoloration.
Endocrine system- Rare: goiter,
hyperthyroidism, hypothyroidism, thyroid nodule, thyroiditis.
Hemic and lymphatic system- Frequent:
ecchymosis; Infrequent: anemia, leukocytosis, leukopenia, lymphadenopathy,
thrombocythemia, thrombocytopenia; Rare: basophilia, bleeding time
increased, cyanosis, eosinophilia, lymphocytosis, multiple myeloma, purpura.
Metabolic and nutritional- Frequent: edema,
weight gain; Infrequent: alkaline phosphatase increased, dehydration,
hypercholesteremia, hyperglycemia, hyperlipemia, hypokalemia, SGOT (AST)
increased, SGPT (ALT) increased, thirst; Rare: alcohol intolerance,
bilirubinemia, BUN increased, creatinine increased, diabetes mellitus,
glycosuria, gout, healing abnormal, hemochromatosis, hypercalcinuria, hyperkalemia,
hyperphosphatemia, hyperuricemia, hypocholesteremia, hypoglycemia,
hyponatremia, hypophosphatemia, hypoproteinemia, uremia.
Musculoskeletal system- Infrequent: arthritis,
arthrosis, bone pain, bone spurs, bursitis, leg cramps, myasthenia,
tenosynovitis; Rare: pathological fracture, myopathy, osteoporosis,
osteosclerosis, plantar fasciitis, rheumatoid arthritis, tendon rupture.
Nervous system- Frequent: trismus, vertigo; Infrequent:
akathisia, apathy, ataxia, circumoral paresthesia, CNS stimulation, emotional
lability, euphoria, hallucinations, hostility, hyperesthesia, hyperkinesia,
hypotonia, incoordination, libido increased, manic reaction, myoclonus,
neuralgia, neuropathy, psychosis, seizure, abnormal speech, stupor; Rare:
akinesia, alcohol abuse, aphasia, bradykinesia, buccoglossal syndrome,
cerebrovascular accident, loss of consciousness, delusions, dementia, dystonia,
facial paralysis, feeling drunk, abnormal gait, Guillain-Barre Syndrome, hyperchlorhydria,
hypokinesia, impulse control difficulties, neuritis, nystagmus, paranoid
reaction, paresis, psychotic depression, reflexes decreased, reflexes
increased, suicidal ideation, torticollis.
Respiratory system- Frequent: bronchitis,
dyspnea; Infrequent: asthma, chest congestion, epistaxis, hyperventilation,
laryngismus, laryngitis, pneumonia, voice alteration; Rare: atelectasis,
hemoptysis, hypoventilation, hypoxia, larynx edema, pleurisy, pulmonary
embolus, sleep apnea.
Skin and appendages- Infrequent: acne,
alopecia, brittle nails, contact dermatitis, dry skin, eczema, skin hypertrophy,
maculopapular rash, psoriasis, urticaria; Rare: erythema nodosum,
exfoliative dermatitis, lichenoid dermatitis, hair discoloration, skin
discoloration, furunculosis, hirsutism, leukoderma, petechial rash, pustular
rash, vesiculobullous rash, seborrhea, skin atrophy, skin striae.
Special senses- Frequent: abnormality of
accommodation, abnormal vision; Infrequent: cataract, conjunctivitis,
corneal lesion, diplopia, dry eyes, eye pain, hyperacusis, otitis media,
parosmia, photophobia, taste loss, visual field defect; Rare:
blepharitis, chromatopsia, conjunctival edema, deafness, exophthalmos,
angle-closure glaucoma, retinal hemorrhage, subconjunctival hemorrhage, keratitis,
labyrinthitis, miosis, papilledema, decreased pupillary reflex, otitis externa,
scleritis, uveitis.
Urogenital system- Frequent: metrorrhagia*,
prostatic disorder (prostatitis and enlarged prostate)*, vaginitis*; Infrequent:
albuminuria, amenorrhea*, cystitis, dysuria, hematuria, leukorrhea*, menorrhagia*,
nocturia, bladder pain, breast pain, polyuria, pyuria, urinary incontinence,
urinary urgency, vaginal hemorrhage*; Rare: abortion*, anuria,
balanitis*, breast discharge, breast engorgement, breast enlargement,
endometriosis*, fibrocystic breast, calcium crystalluria, cervicitis*, ovarian
cyst*, prolonged erection*, gynecomastia (male)*, hypomenorrhea*, kidney
calculus, kidney pain, kidney function abnormal, female lactation*, mastitis,
menopause*, oliguria, orchitis*, pyelonephritis, salpingitis*, urolithiasis,
uterine hemorrhage*, uterine spasm*, vaginal dryness*.
* Based on the number of men and women as appropriate.
Postmarketing Reports
Voluntary reports of other adverse events temporally
associated with the use of venlafaxine that have been received since market
introduction and that may have no causal relationship with the use of venlafaxine
include the following: agranulocytosis, anaphylaxis, angioedema, aplastic
anemia, catatonia, congenital anomalies, impaired coordination and balance, CPK
increased, deep vein thrombophlebitis, delirium, EKG abnormalities such as QT
prolongation; cardiac arrhythmias including atrial fibrillation, supraventricular
tachycardia, ventricular extrasystole, and rare reports of ventricular
fibrillation and ventricular tachycardia, including torsade de pointes; toxic
epidermal necrolysis/Stevens-Johnson syndrome, erythema multiforme,
extrapyramidal symptoms (including dyskinesia and tardive dyskinesia), angle-closure
glaucoma, hemorrhage (including eye and gastrointestinal bleeding), hepatic
events (including GGT elevation; abnormalities of unspecified liver function
tests; liver damage, necrosis, or failure; and fatty liver), interstitial lung
disease, involuntary movements, LDH increased, neutropenia, night sweats,
pancreatitis, pancytopenia, panic, prolactin increased, renal failure,
rhabdomyolysis, shock-like electrical sensations or tinnitus (in some cases,
subsequent to the discontinuation of venlafaxine or tapering of dose), and
syndrome of inappropriate antidiuretic hormone secretion (usually in the
elderly).
There have been reports of elevated clozapine levels that
were temporally associated with adverse events, including seizures, following
the addition of venlafaxine. There have been reports of increases in
prothrombin time, partial thromboplastin time, or INR when venlafaxine was
given to patients receiving warfarin therapy.
Controlled Substance
Venlafaxine tablets, USP is not a controlled substance.
Physical And Psychological Dependence
In vitro studies revealed that venlafaxine has virtually no
affinity for opiate, benzodiazepine, phencyclidine (PCP), or
N-methyl-D-aspartic acid (NMDA) receptors.
Venlafaxine was not found to have any significant CNS
stimulant activity in rodents. In primate drug discrimination studies,
venlafaxine showed no significant stimulant or depressant abuse liability.
Discontinuation effects have been reported in patients
receiving venlafaxine (see DOSAGE AND ADMINISTRATION).
While venlafaxine tablets, USP has not been systematically
studied in clinical trials for its potential for abuse, there was no indication
of drug-seeking behavior in the clinical trials. However, it is not possible to
predict on the basis of premarketing experience the extent to which a CNS
active drug will be misused, diverted, and/or abused once marketed.
Consequently, physicians should carefully evaluate patients for history of drug
abuse and follow such patients closely, observing them for signs of misuse or
abuse of venlafaxine tablets, USP (e.g., development of tolerance,
incrementation of dose, drugseeking behavior).