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Intuniv (Guanfacine Hydrochloride) - Side Effects and Adverse Reactions

 
 



ADVERSE REACTIONS

The following serious adverse reactions are described elsewhere in the labelling:  

  • Hypotension, bradycardia, and syncope [ ] see Warnings and Precautions
  • Sedation and somnolence [ ] see Warnings and Precautions

Clinical Trials Experience

Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice.

A total of 2,028 subjects have been exposed to INTUNIV while participating in clinical trials. This includes 1,533 patients from completed studies in children and adolescents, and 495 subjects in completed studies in adult healthy volunteers. ®

The mean duration of exposure of 446 patients that previously participated in two 2-year, open-label long-term studies was approximately 10 months.

Monotherapy Trials

The most commonly observed adverse reactions (incidence ≥ 5% and at least twice the rate for placebo) in the monotherapy trials (Studies 1 and 2) with INTUNIV were: somnolence, fatigue, nausea, lethargy, and hypotension. Most Common Adverse Reactions - ®

Twelve percent (12%) of patients receiving INTUNIV discontinued from the monotherapy clinical studies (Studies 1 and 2) due to adverse reactions, compared to 4% in the placebo group. The most common adverse reactions leading to discontinuation of INTUNIV -treated patients from the studies were somnolence/sedation (6%) and fatigue (2%). Less common adverse reactions leading to discontinuation (occurring in approximately 1% of patients) included: hypotension, headache, and dizziness. Adverse Reactions Leading to Discontinuation - ® ®

Adjunctive Trial

The most commonly observed adverse reactions (incidence ≥ 5% and at least twice the rate for placebo) in the adjunctive trial with INTUNIV were: somnolence, fatigue, insomnia, dizziness, and abdominal pain. Most Common Adverse Reactions - ®

In the adjunctive clinical study, 3% of patients receiving INTUNIV discontinued due to adverse reactions, compared to 1% in the placebo group.  Each adverse reaction leading to discontinuation occurred in less than 1% of INTUNIV -treated patients. Adverse Reactions Leading to Discontinuation – ® ®

Short Term Monotherapy Clinical Studies

- Two short-term, placebo-controlled, double-blind pivotal studies (Studies 1 and 2) were conducted in children and adolescents with ADHD, using fixed doses of INTUNIV (1 mg, 2 mg, 3 mg, and 4 mg/day).  The most commonly reported adverse reactions (occurring in ≥ 2% of patients) that were considered drug-related and reported in a greater percentage of patients taking INTUNIV compared to patients taking placebo are shown in Table 2. Adverse reactions that were dose-related include: somnolence/sedation, abdominal pain, dizziness, hypotension, dry mouth and constipation. Common Adverse Reactions ® ®

   Table 2:  Percentage of Patients Experiencing Common (≥ 2%)    Adverse Reactions in Short-Term
Monotherapy Studies 1 and 2

Adverse Reaction Term All Doses of INTUNIV (N=513)
®
    Placebo   
(N=149)
  Somnolence a              38%   12%
  Headache   24%   19%
  Fatigue   14%   3%
  Abdominal pain b   11%   9%
  Hypotension c   7%   3%
  Nausea   6%   2%
  Lethargy   6%   3%
  Dizziness   6%   4%
  Irritability   6%   4%
  Decreased appetite   5%   3%
  Dry mouth   4%   1%
  Constipation   3%   1%
a: The somnolence term includes somnolence, sedation, and hypersomnia. b: The abdominal pain term includes abdominal pain, abdominal pain upper, and abdominal pain lower. c: The hypotension term includes hypotension, orthostatic hypotension, and decreased blood pressure.



In an 8-week, placebo-controlled study in children 6-12 years of age with ADHD in which INTUNIV was dosed once (1-4 mg/day) in the morning or evening (Study 4), the safety profile was consistent with the once daily morning dosing of INTUNIV. ® ®

Short Term Adjunctive Clinical Study

- A 8-week, placebo-controlled, double-blind, dose-optimized pivotal study (Study 3) was conducted in children and adolescents aged 6-17 years with a diagnosis of ADHD who were identified as having a sub-optimal response to psychostimulants. Patients received INTUNIV (1 mg, 2 mg, 3 mg, and 4 mg/day) or placebo, dosed in the morning or in the evening, in combination with their morning dose of psychostimulant. The most commonly reported adverse reactions (occurring in ≥ 2% of patients in the overall INTUNIV group) that were reported in a greater percentage of patients taking INTUNIV compared to patients taking placebo are shown in Table 3. Common Adverse Reactions ® ® ®

Table 3:  Percentage of Patients Experiencing Common (≥ 2%) Adverse Reactions in Short-Term Adjunctive Study 3
  Adverse Reaction Term   All Doses of INTUNIV ®
(N=302) a
    Placebo   (N=153)
  Headache   21%   13%
  Somnolence b   18%   7%
  Insomnia c   12%   6%
  Fatigue   10%   3%
  Abdominal pain d   10%   3%
  Dizziness   8%   4%
  Decreased appetite   7%   4%
  Nausea   5%   3%
  Diarrhea   4%   1%
  Hypotension e   3%   0%
  Affect lability   2%   1%
  Bradycardia   2%   0%
  Constipation   2%   0%
  Dry mouth   2%   0%
a: The morning and evening dose groups of INTUNIV are combined. b: The somnolence term includes somnolence, sedation, and hypersomnia. c: The insomnia term includes insomnia, initial insomnia, and middle insomnia. d: The abdominal pain term includes abdominal pain, abdominal pain upper, and abdominal pain lower. e: The hypotension term includes hypotension, orthostatic hypotension, and decreased blood pressure. ®



Effects on Blood Pressure and Heart Rate

In the monotherapy pediatric, short-term, controlled trials (Studies 1 and 2), the maximum mean changes from baseline in systolic blood pressure, diastolic blood pressure, and pulse were −5 mmHg, −3 mmHg, and −6 bpm, respectively, for all dose groups combined (generally one week after reaching target doses of 1 mg/day, 2 mg/day, 3 mg/day or 4 mg/day). These changes were dose dependent. Decreases in blood pressure and heart rate were usually modest and asymptomatic; however, hypotension and bradycardia can occur. Hypotension was reported as an adverse reaction for 7% of the INTUNIV group and 3% of the placebo group. This includes orthostatic hypotension, which was reported for 1% of the INTUNIV group and none in the placebo group. In the adjunctive trial, hypotension (3%) and bradycardia (2%) were observed in patients treated with INTUNIV as compared to none in the placebo group.  In long-term, open label studies, (mean exposure of approximately 10 months), maximum decreases in systolic and diastolic blood pressure occurred in the first month of therapy. Decreases were less pronounced over time. Syncope occurred in 1% of pediatric subjects in the clinical program. The majority of these cases occurred in the long-term, open-label studies. ® ® ®

Other Adverse Reactions Observed in Clinical Studies

Table 4 includes additional adverse reactions observed in short-term, placebo-controlled and long-term, open-label clinical studies not included elsewhere in section 6.1, listed by organ system.

Table 4: Other adverse reactions observed in clinical studies  
  Body System  
  Adverse Reaction
  Cardiac  
  Atrioventricular block, sinus arrhythmia
  Gastrointestinal  
  Dyspepsia, stomach discomfort, vomiting
  General  
  Asthenia, chest pain
  Immune System            Disorders       

  Hypersensitivity
  Investigations  
  Increased alanine amino transferase, increased weight
  Nervous system  
  Convulsion
  Psychiatric  
  Agitation, anxiety, depression, nightmare
  Renal  
  Increased urinary frequency, enuresis
  Respiratory  
  Asthma
  Vascular  
  Hypertension, pallor

Post-marketing Experience

The following adverse reactions have been identified during post-approval use of guanfacine.  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.

An open-label post-marketing study involving 21,718 patients was conducted to assess the safety of guanfacine (as the hydrochloride) 1 mg/day given at bedtime for 28 days. Guanfacine was administered with or without other antihypertensive agents. Adverse events reported in the post-marketing study at an incidence greater than 1% included dry mouth, dizziness, somnolence, fatigue, headache and nausea. The most commonly reported adverse events in this study were the same as those observed in controlled clinical trials.

Less frequent, possibly guanfacine-related events observed in the post-marketing study and/or reported spontaneously, not included in, include: section 6.1

edema, malaise, tremor General:

palpitations, tachycardia Cardiovascular:

paresthesias, vertigo Central Nervous System:

blurred vision Eye Disorders:

arthralgia, leg cramps, leg pain, myalgia Musculo-Skeletal System:

confusion, hallucinations Psychiatric:

impotence Reproductive System, Male:

dyspnea Respiratory System:

alopecia, dermatitis, exfoliative dermatitis, pruritus, rash Skin and Appendages:

alterations in taste Special Senses:



REPORTS OF SUSPECTED INTUNIV SIDE EFFECTS / ADVERSE REACTIONS

Below is a sample of reports where side effects / adverse reactions may be related to Intuniv. The information is not vetted and should not be considered as verified clinical evidence.

Possible Intuniv side effects / adverse reactions in 8 year old male

Reported by a consumer/non-health professional from United States on 2011-10-17

Patient: 8 year old male

Reactions: Hallucination

Suspect drug(s):
Intuniv



Possible Intuniv side effects / adverse reactions in 13 year old male

Reported by a consumer/non-health professional from United States on 2011-10-18

Patient: 13 year old male

Reactions: Syncope, Bradycardia

Suspect drug(s):
Intuniv
    Dosage: 3 mg, unknown
    Administration route: Oral
    Indication: Product Used FOR Unknown Indication

Intuniv
    Dosage: unk, unknown
    Administration route: Oral



Possible Intuniv side effects / adverse reactions in 6 year old female

Reported by a physician from United States on 2011-10-21

Patient: 6 year old female weighing 16.5 kg (36.3 pounds)

Reactions: Grand MAL Convulsion, Drug Effect Decreased, Dyskinesia, Fear, Screaming, Mood Swings, Somnolence, Tremor

Suspect drug(s):
MAS (Mixed Amphetamine Salts)(amphetamine Aspartate, Amphetamine Sulfa
    Dosage: 10 mg(in the afternoon), 1x/day:gd, oral
    Administration route: Oral
    Indication: Product Used FOR Unknown Indication
    Start date: 2011-01-01

Vyvanse
    Dosage: 50 mg, oral
    Administration route: Oral
    Indication: Attention Deficit/hyperactivity Disorder
    Start date: 2010-01-01

Intuniv
    Dosage: 1 mg, oral, 2 mg, oral
    Administration route: Oral
    Indication: Attention Deficit/hyperactivity Disorder
    Start date: 2011-01-01
    End date: 2011-01-01

Intuniv
    Dosage: 1 mg, oral, 2 mg, oral
    Administration route: Oral
    Indication: Attention Deficit/hyperactivity Disorder
    Start date: 2011-04-28
    End date: 2011-01-01

Other drugs received by patient: Corticosteroid NOS (Corticosteroid Nos); Guanfacine (Guanfacine) Tablet



See index of all Intuniv side effect reports >>

Drug label data at the top of this Page last updated: 2013-08-31

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