Atomoxetine Side Effects

Brand Names: Strattera

Please note - some side effects for Atomoxetine may not be reported. Always consult your doctor or healthcare specialist for medical advice. You may also report side effects to the FDA.

Side Effects of Atomoxetine - for the Consumer

Atomoxetine

All medicines may cause side effects, but many people have no, or minor, side effects. Check with your doctor if any of these most COMMON side effects persist or become bothersome when using Atomoxetine:

Constipation; coughing; decreased appetite; decreased sexual desire; dizziness; drowsiness; dry mouth; fatigue; flushing; headache; increased sweating; mild stomach pain or upset; nausea; tiredness; trouble sleeping; vomiting.

Seek medical attention right away if any of these SEVERE side effects occur when using Atomoxetine:

Severe allergic reactions (rash; hives; itching; difficulty breathing; tightness in the chest; swelling of the mouth, face, lips, or tongue; unusual hoarseness); abnormal thoughts or elevated mood (mania); change in feeling of touch or other senses (eg, smell, taste); chest pain; confusion; decreased or difficult urination; decreased sexual ability (eg, impotence, ejaculation problems); fainting; fast or irregular heartbeat; fever, chills, or sore throat; hallucinations; menstrual cycle changes; mental or mood changes (eg, agitation, anxiety, depression, irritability, persistent crying, unusual sadness); new or worsening behavior changes (eg, aggression, hostility, impulsivity, restlessness); numbness or tingling; one-sided weakness; panic attacks; prolonged or painful erection; seizure; severe or persistent headache or dizziness; severe or persistent trouble sleeping, fatigue, or tiredness; shortness of breath; stomach pain or tenderness; suicidal thoughts or attempts; symptoms of liver damage (eg, yellowing of the skin or eyes, itching, dark urine, pale stools, loss of appetite, right upper stomach pain, unexplained flu-like symptoms); tics; unusual vision or speech changes; unusually cold or blue fingers or toes.

This is not a complete list of all side effects that may occur. If you have questions about side effects, contact your health care provider. Call your doctor for medical advice about side effects. To report side effects to the appropriate agency, please read the Guide to Reporting Problems to FDA.

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Atomoxetine Side Effects - for the Professional

Atomoxetine

Clinical Trials Experience

Atomoxetine hydrochloride was administered to 5,382 children or adolescent patients with ADHD and 1,007 adults with ADHD in clinical studies. During the ADHD clinical trials, 1,625 children and adolescent patients were treated for longer than one year and 2,529 children and adolescent patients were treated for over 6 months.

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 practice.

Child and Adolescent Clinical Trials

Reasons for Discontinuation of Treatment Due to Adverse Reactions in Child and Adolescent Clinical Trials

In acute child and adolescent placebo-controlled trials, 3% (48/1,613) of Atomoxetine subjects and 1.4% (13/945) placebo subjects discontinued for adverse reactions. For all studies, (including open-label and long-term studies), 6.3% of extensive metabolizer (EM) patients and 11.2% of poor metabolizer (PM) patients discontinued because of an adverse reaction. Among Atomoxetine hydrochloride-treated patients, irritability (0.3%, N = 5); somnolence (0.3%, N = 5); aggression (0.2%, N = 4); nausea (0.2%, N = 4); vomiting (0.2%, N = 4); abdominal pain (0.2%, N = 4); constipation (0.1%, N = 2); fatigue (0.1%, N = 2); feeling abnormal (0.1%, N = 2); and headache (0.1%, N = 2) were the reasons for discontinuation reported by more than one patient.

Seizures

Atomoxetine hydrochloride has not been systematically evaluated in pediatric patients with seizure disorder as these patients were excluded from clinical studies during the product’s premarket testing. In the clinical development program, seizures were reported in 0.2% (12/5,073) of children whose average age was 10 years (range 6 to 16 years). In these clinical trials, the seizure risk among poor metabolizers was 0.3% (1/293) compared to 0.2% (11/4,741) for extensive metabolizers.

Commonly Observed Adverse Reactions in Acute Child and Adolescent, Placebo-Controlled Trials

Commonly observed adverse reactions associated with the use of Atomoxetine hydrochloride (incidence of 2% or greater) and not observed at an equivalent incidence among placebo-treated patients (Atomoxetine hydrochloride incidence greater than placebo) are listed in Table 1. Results were similar in the BID and the QD trial except as shown in Table 2, which shows both BID and QD results for selected adverse reactions based on statistically significant Breslow-Day tests. The most commonly observed adverse reactions in patients treated with Atomoxetine hydrochloride (incidence of 5% or greater and at least twice the incidence in placebo patients, for either BID or QD dosing) were: nausea, vomiting, fatigue, decreased appetite, abdominal pain and somnolence.

Table 1: Common Treatment-Emergent Adverse Reactions Associated with the Use of Atomoxetine Hydrochloride in Acute (up to 18 weeks) Child and Adolescent Trials

* Reactions reported by at least 2% of patients treated with Atomoxetine and greater than placebo. The following reactions did not meet this criterion but were reported by more Atomoxetine-treated patients than placebo-treated patients and are possibly related to Atomoxetine treatment: blood pressure increased, early morning awakening, flushing, mydriasis, sinus tachycardia, asthenia, palpitations, mood swings, constipation. The following reactions were reported by at least 2% of patients treated with Atomoxetine and equal to or less than placebo: pharyngolaryngeal pain, insomnia (insomnia includes the terms, insomnia, initial insomnia, middle insomnia). The following reaction did not meet this criterion but shows a statistically significant dose relationship: pruritus. † Abdominal pain includes the terms: abdominal pain upper, abdominal pain, stomach discomfort, abdominal discomfort, epigastric discomfort. ‡ Somnolence includes the terms: sedation, somnolence.
Adverse Reaction*	Percentage of Patients Reporting Reaction
	Atomoxetine Hydrochloride (N = 1,597)	Placebo (N = 934)
Gastrointestinal Disorders
Abdominal pain†	18	10
Vomiting	11	6
Nausea	10	5
General Disorders and Administration Site Conditions
Fatigue	8	3
Irritability	6	3
Therapeutic response unexpected	2	1
Investigations
Weight decreased	3	0
Metabolism and Nutritional Disorders
Decreased appetite	16	4
Anorexia	3	1
Nervous System Disorders
Headache	19	15
Somnolence‡	11	4
Dizziness	5	2
Skin and Subcutaneous Tissue Disorders
Rash	2	1

Table 2: Common Treatment-Emergent Adverse Reactions Associated with the Use of Atomoxetine Hydrochloride in Acute (up to 18 weeks) Child and Adolescent Trials

* Abdominal pain includes the terms: abdominal pain upper, abdominal pain,  stomach discomfort, abdominal discomfort, epigastric discomfort. † Constipation didn't meet the statistical significance on Breslow-Day test but is included in the table because of pharmacologic plausibility. ‡ Mood swings didn't meet the statistical significance on Breslow-Day test at 0.05 level but p-value was < 0.1 (trend).
Adverse Reaction	Percentage of Patients Reporting Reaction from BID Trials		Percentage of Patients Reporting Reaction from QD Trials
	Atomoxetine Hydrochloride (N = 715)	Placebo (N = 434)	Atomoxetine Hydrochloride (N = 882)	Placebo (N = 500)
Gastrointestinal Disorders
Abdominal pain*	17	13	18	7
Vomiting	11	8	11	4
Nausea	7	6	13	4
Constipation†	2	1	1	0
General Disorders
Fatigue	6	4	9	2
Psychiatric Disorders
Mood swings‡	2	0	1	1

The following adverse reactions occurred in at least 2% of PM patients and were either twice as frequent or statistically significantly more frequent in PM patients compared with EM patients: insomnia (15% of PMs, 10% of EMs); weight decreased (7% of PMs, 4% of EMs); constipation (7% of PMs, 4% of EMs); depression1 (7% of PMs, 4% of EMs); tremor (5% of PMs, 1% of EMs); excoriation (4% of PMs, 2% of EMs); conjunctivitis 3% of PMs, 1% of EMs); syncope (3% of PMs, 1% of EMs); early morning awakening (2% of PMs, 1% of EMs); mydriasis (2% of PMs, 1% of EMs).

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1

Depression includes the following terms: depression, major depression, depressive symptoms, depressed mood, dysphoria.

Adult Clinical Trials

Reasons for Discontinuation of Treatment Due to Adverse Reactions in Acute Adult Placebo-Controlled Trials

In the acute adult placebo-controlled trials, 11.3% (61/541) Atomoxetine subjects and 3% (12/405) placebo subjects discontinued for adverse reactions. Among Atomoxetine hydrochloride-treated patients, insomnia (0.9%, N = 5); nausea (0.9%, N = 5); chest pain (0.6%, N = 3); fatigue (0.6%, N = 3); anxiety (0.4%, N = 2); erectile dysfunction (0.4%, N = 2); mood swings (0.4%, N = 2); nervousness (0.4%, N = 2); palpitations (0.4%, N = 2); and urinary retention (0.4%, N = 2) were the reasons for discontinuation reported by more than one patient.

Seizures

Atomoxetine hydrochloride has not been systematically evaluated in adult patients with a seizure disorder as these patients were excluded from clinical studies during the product’s premarket testing. In the clinical development program, seizures were reported on 0.1% (1/748) of adult patients. In these clinical trials, no poor metabolizers (0/43) reported seizures compared to 0.1% (1/705) for extensive metabolizers.

Commonly Observed Adverse Reactions in Acute Adult Placebo-Controlled Trials

Commonly observed adverse reactions associated with the use of Atomoxetine hydrochloride (incidence of 2% or greater) and not observed at an equivalent incidence among placebo-treated patients (Atomoxetine hydrochloride incidence greater than placebo) are listed in Table 3. The most commonly observed adverse reactions in patients treated with Atomoxetine hydrochloride (incidence of 5% or greater and at least twice the incidence in placebo patients) were: constipation, dry mouth, nausea, fatigue, decreased appetite, insomnia, erectile dysfunction, urinary hesitation and/or urinary retention and/or dysuria, dysmenorrhea and hot flush.

Table 3: Common Treatment-Emergent Adverse Reactions Associated with the Use of Atomoxetine Hydrochloride in Acute (up to 25 weeks) Adult Trials

* Reactions reported by at least 2% of patients treated with Atomoxetine and greater than placebo. The following reactions did not meet this criterion but were reported by more Atomoxetine-treated patients than placebo-treated patients and are possibly related to Atomoxetine treatment: early morning awakening, peripheral coldness, tachycardia, prostatitis, testicular pain and orgasm abnormal. The following reactions were reported by at least 2% of patients treated with Atomoxetine and equal to or less than placebo; headache, pharyngolaryngeal pain, irritability. † Abdominal pain includes the terms: abdominal pain upper, abdominal pain, stomach discomfort, abdominal discomfort, epigastric discomfort. ‡ Somnolence includes the terms: sedation, somnolence. § Insomnia includes the terms: insomnia, initial insomnia, middle insomnia. ¶ Based on total number of males (Atomoxetine hydrochloride, N = 326; placebo, N = 260). # Based on total number of females (Atomoxetine hydrochloride, N = 214; placebo, N = 142).
Adverse Reaction*	Percentage of Patients Reporting Reaction
System Organ Class/Adverse Reaction	Atomoxetine  Hydrochloride (N = 540)	Placebo (N = 402)
Cardiac Disorders
Palpitations	3	1
Gastrointestinal Disorders
Dry mouth	21	7
Nausea	21	5
Constipation	9	3
Abdominal pain†	7	5
Dyspepsia	4	2
Vomiting	3	2
General Disorders and Administration Site Conditions
Fatigue	9	4
Chills	3	1
Therapeutic response unexpected	3	1
Feeling jittery	2	0
Investigations
Weight decreased	2	1
Metabolism and Nutritional Disorders
Decreased appetite	11	2
Nervous System Disorders
Dizziness	6	4
Somnolence‡	4	3
Paraesthesia	3	1
Sinus headache	3	1
Tremor	2	0
Psychiatric Disorders
Insomnia§	15	7
Libido decreased	4	2
Sleep disorder	3	1
Renal and Urinary Disorders
Urinary hesitation and/or urinary retention	7	1
Dysuria	3	0
Reproductive System and Breast Disorders
Erectile dysfunction¶	9	1
Dysmenorrhea#	6	2
Ejaculation delayed¶ and/or ejaculation disorder¶	3	1
Menstruation irregular#	2	0
Skin and Subcutaneous Tissue Disorders
Hyperhidrosis	4	1
Rash	2	1
Vascular Disorders
Hot flush	8	1

Male and Female Sexual Dysfunction

Atomoxetine appears to impair sexual function in some patients. Changes in sexual desire, sexual performance and sexual satisfaction are not well assessed in most clinical trials because they need special attention and because patients and physicians may be reluctant to discuss them. Accordingly, estimates of the incidence of untoward sexual experience and performance cited in product labeling are likely to underestimate the actual incidence. Table 3 above displays the incidence of sexual side effects reported by at least 2% of adult patients taking Atomoxetine hydrochloride in placebo-controlled trials.

There are no adequate and well controlled studies examining sexual dysfunction with Atomoxetine hydrochloride treatment. While it is difficult to know the precise risk of sexual dysfunction associated with the use of Atomoxetine hydrochloride, physicians should routinely inquire about such possible side effects.

Post-Marketing Spontaneous Reports

The following adverse reactions have been identified during post-approval use of Atomoxetine hydrochloride. Unless otherwise specified, these adverse reactions have occurred in adults and children and adolescents. 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.

Cardiovascular System: QT prolongation, syncope.

General Disorders and Administration Site Conditions: Lethargy.

Nervous System Disorders: Hypoaesthesia, paraesthesia in children and adolescents; sensory disturbances; tics.

Psychiatric Disorders: Depression and depressed mood; anxiety.

Seizures: Seizures have been reported in the post-marketing period. The post-marketing seizure cases include patients with preexisting seizure disorders and those with identified risk factors for seizures, as well as patients with neither a history of nor identified risk factors for seizures. The exact relationship between Atomoxetine hydrochloride and seizures is difficult to evaluate due to uncertainty about the background risk of seizures in ADHD patients.

Skin and Subcutaneous Tissue Disorders: Hyperhidrosis.

Urogenital System: Male pelvic pain; urinary hesitation in children and adolescents; urinary retention in children and adolescents.

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Side Effects by Body System - for Healthcare Professionals

Genitourinary

Genitourinary side effects reported in adult placebo-controlled trials have included urinary hesitation and/or urinary retention and/or difficulty in micturition (8%), dysmenorrhea (7%), erectile disturbance (7%), ejaculation failure and/or ejaculation disorder (up to 5%), impotence (3%), menstrual disorder (3%), prostatitis (3%), delayed menses, irregular menstruation (2%), and abnormal orgasm (2%). Priapism, hemospermia, and male pelvic pain have been reported in postmarketing experience.

Cardiovascular

Cardiovascular side effects reported in adult placebo-controlled trials have included palpitations (up to 4%), tachycardia (3%), increased heart rate, and increased blood pressure. Orthostatic hypotension and syncope have been reported in clinical trials. New onset and exacerbation of existing Raynaud's phenomenon as well as QT prolongation have been reported in postmarketing experience.

In adult placebo-controlled trials the mean increase in heart rate was reported as 5 beats/minute and the mean increase in blood pressure was reported as 3 mm Hg systolic and 1 mm Hg diastolic.

Hepatic

Hepatic side effects have included severe hepatic injury.

Two cases of severe liver injury (a teenager and an adult) following treatment with atomoxetine for a duration of at least several months have been reported. Both patients recovered. Two additional cases of hepatitis have been reported in children (11 and 12 years of age) following treatment with atomoxetine (30 to 40 mg/day). Symptoms included jaundice, abdominal pain, fatigue, weight loss, arthralgias, diarrhea, vomiting, and elevated liver enzymes. Liver injury completely resolved in both patients following discontinuation of atomoxetine. The number of actual cases of severe liver injury is unknown because of underreporting of postmarketing adverse events.

Atomoxetine should be discontinued in patients who develop jaundice (yellowing of the skin or whites of the eyes) or have laboratory evidence of liver injury. Signs and symptoms of liver problems can include pruritus (itchy skin), jaundice, dark urine, upper right-sided abdominal tenderness, or unexplained flu-like symptoms. Health care professionals are encouraged to report any unexpected adverse events associated with atomoxetine directly to Eli Lilly at 1800-LillyRx or to the FDA MedWatch program at 1800-FDA-1088.

Gastrointestinal

Gastrointestinal side effects reported in adult placebo-controlled trials have included dry mouth (21%), nausea (up to 21%), constipation (up to 10%), abdominal pain (7%), dyspepsia (up to 6%), vomiting (3%), and flatulence (2%). One case of sialolithiasis in association with atomoxetine has been reported and confirmed upon several rechallenges.

Respiratory

Respiratory side effects reported in adult placebo-controlled trials have included sinusitis (6%).

Musculoskeletal

Musculoskeletal side effects reported in adult placebo-controlled trials have included myalgia (3%).

Nervous system

Nervous system side effects reported in adult placebo-controlled trials have included headache (17%), insomnia and/or middle insomnia (16%), dizziness (6%), paraesthesia (4%), somnolence (4%), sinus headache (3%), and tremor (2%). Seizures have been reported in 0.1% of adult patients. There have also been postmarketing reports of hypoesthesia and sensory disturbances.

Psychiatric

Psychiatric side effects reported in adult placebo-controlled trials have included insomnia (15%), decreased libido (up to 6%), abnormal dreams (4%), and sleep disorders (up to 4%). Mania has been reported rarely. Treatment emergent hostility-related effects have been reported in short-term clinical trials. Patients beginning therapy should be monitored for the appearance or worsening of aggression or hostility.

An 11-year-old male with attention deficit disorder developed mania after approximately 3 to 4 weeks of treatment with atomoxetine. The patient returned to his baseline behaviors within 7 days of discontinuing atomoxetine.

Dermatologic

Dermatologic side effects reported in adult placebo-controlled trials have included increased sweating (4%), dermatitis (2%), and rash (2%).

Hypersensitivity

Hypersensitivity side effects have rarely included angioneurotic edema, urticaria, and rash.

Ocular

Ocular side effects have included an increased risk of mydriasis.

Other

Other side effects reported in adult placebo-controlled trials have included decreased appetite (up to 11%), fatigue (up to 9%), hot flushes (up to 8%), pyrexia (3%), rigors (3%), unexpected therapeutic response (3%), chills (3%), jittery feeling (2%), and weight loss (2%).

Acute treatment studies of up to 9 weeks in duration have reported an average weight loss of 0.4 kg.

Renal

Renal side effects including urinary hesitation and/or urinary retention (7%), and dysuria (3%) have been reported.

General

General side effects including lethargy have been reported.

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