Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot directly be compared to rates in the clinical trials of another drug and may not reflect the rates observed in practice.
The safety data for paroxetine are from:
- 6-week clinical trials in MDD patients who received paroxetine 20 mg to 50 mg once daily
- 12-week clinical trials in OCD patients who received paroxetine 20 mg to 60 mg once daily
- 10- to 12-week clinical trials in PD patients who received paroxetine 10 mg to 60 mg once daily
- 8-week clinical trials in GAD patients who received paroxetine 10 mg to 50 mg once daily
Adverse Reactions Leading to Discontinuation
Twenty percent (1199/6145) of patients treated with paroxetine in clinical trials in MDD and 11.8% (64/542), 9.4% (44/469), and 10.7% (79/735) of patients treated with paroxetine in clinical trials in OCD, PD, and GAD, respectively, discontinued treatment due to an adverse reaction. Table 3 shows the most common reactions (≥1%) associated with discontinuation and considered to be drug related (i.e., those reactions associated with dropout at a rate approximately twice or greater for paroxetine compared to placebo).
TABLE 3: Adverse Reactions Reported as Leading to Discontinuation (≥1% of Paroxetine-Treated Patients and (≥2% Placebo) in MDD, OCD, PD, and GAD Trials |
|
| MDD | OCD | PD | GAD |
| Paroxetine % | Placebo % | Paroxetine % | Placebo % | Paroxetine % | Placebo % | Paroxetine % | Placebo % |
| CNS | | | | | | | | |
| Somnolence | 2.3% | 0.7% | - | - | 1.9% | 0.3% | 2.0% | 0.2% |
| Insomnia | - | - | 1.7% | 0% | 1.3% | 0.3% | - | - |
| Agitation | 1.1% | 0.5% | - | - | - | - | - | - |
| Tremor | 1.1% | 0.3% | - | | | | | |
| Dizziness | - | - | 1.5% | 0% | - | - | 1.0% | 0.2% |
| Gastrointestinal | | | | | | | | |
| Constipation | - | - | 1.1% | 0% | - | - | - | - |
| Nausea | 3.2% | 1.1% | 1.9% | 0% | 3.2% | 1.2% | 2.0% | 0.2% |
| Diarrhea | 1.0% | 0.3% | - | - | - | - | - | - |
| Dry mouth | 1.0% | 0.3% | - | - | - | - | - | - |
| Vomiting | 1.0% | 0.3% | - | - | - | - | - | - |
| Other | | | | | | | | |
| Asthenia | 1.6% | 0.4% | 1.9% | 0.4% | - | - | 1.8% | 0.2% |
Abnormal
Ejaculation
1
| 1.6% | 0% | 2.1% | 0% | - | - | 2.5% | 0.5% |
| Sweating | 1.0% | 0.3% | - | - | - | - | 1.1% | 0.2% |
| Impotence
1
| - | - | 1.5% | 0% | - | - | - | - |
Most Common Adverse Reactions in MDD, OCD, PD, and GAD
The most commonly observed adverse reactions associated with the use of PEXEVA (incidence of 5% or greater and at least twice that for placebo) were:
Major Depressive Disorder: asthenia, sweating, nausea, decreased appetite, somnolence, dizziness, insomnia, tremor, nervousness, ejaculatory disturbance, and other male genital disorders.
Obsessive Compulsive Disorder:nausea, dry mouth, decreased appetite, constipation, dizziness, somnolence, tremor, sweating, impotence, and abnormal ejaculation.
Panic Disorder:asthenia, sweating, decreased appetite, libido decreased, tremor, abnormal ejaculation, female genital disorders, and impotence.
Generalized Anxiety Disorder:asthenia, infection, constipation, decreased appetite, dry mouth, nausea, libido decreased, somnolence, tremor, sweating, and abnormal ejaculation.
Adverse Reactions Occurring at an Incidence of 1% or More in Paroxetine Treated Patients
Major Depressive Disorder:Table 4 enumerates adverse reactions that occurred at an incidence of 1% or more and greater than placebo in clinical trials of paroxetine-treated patients with MDD.
TABLE 4: Adverse Reactions (≥1% of Paroxetine-treated Patients and Greater than Placebo) in 6-Week Clinical Trials for MDD |
|
|
|
|
|
|
| Body System | Preferred Term | Paroxetine (n=421)
% | Placebo (n=421) % |
| Body as a Whole | Headache | 18 | 17 |
| Asthenia | 15 | 6 |
| Cardiovascular | Palpitation | 3 | 1 |
| Vasodilation | 3 | 1 |
| Dermatologic | Sweating | 11 | 2 |
| Rash | 2 | 1 |
| Gastrointestinal | Nausea | 26 | 9 |
| Dry Mouth | 18 | 12 |
| Constipation | 14 | 9 |
| Diarrhea | 12 | 8 |
| Decreased Appetite | 6 | 2 |
| Flatulence | 4 | 2 |
| Oropharynx Disorder
1
| 2 | 0 |
| Dyspepsia | 2 | 1 |
| Musculoskeletal | Myopathy | 2 | 1 |
| Myalgia | 2 | 1 |
| Myasthenia | 1 | 0 |
| Nervous System | Somnolence | 23 | 9 |
| Dizziness | 13 | 6 |
| Insomnia | 13 | 6 |
| Tremor | 8 | 2 |
| Nervousness | 5 | 3 |
| Anxiety | 5 | 3 |
| Paresthesia | 4 | 2 |
| Libido Decreased | 3 | 0 |
| Drugged Feeling | 2 | 1 |
| Confusion | 1 | 0 |
| Respiration | Yawn | 4 | 0 |
| Special Senses | Blurred Vision | 4 | 1 |
| Taste Perversion | 2 | 0 |
| Urogenital System | Ejaculatory Disturbance
2,3
| 13 | 0 |
| Other Male Genital Disorders
2,4
| 10 | 0 |
| Urinary Frequency | 3 | 1 |
| Urination Disorder
5
| 3 | 0 |
| Female Genital Disorders
2,6
| 2 | 0 |
Obsessive Compulsive Disorder and Panic Disorder:Table 5 enumerates adverse reactions that occurred at a frequency of 2% or more in clinical trials in patients with OCD and PD.
|
| TABLE 5: Adverse Reactions (≥2% of Paroxetine-Treated Patients and Greater than Placebo) in 10- to 12-Week Clinical Trials for OCD and PD |
| | ObsessiveCompulsive Disorder | PanicDisorder |
Body System | Preferred Term | Paroxetine (n=542) % | Placebo (n=265) % | Paroxetine (n=469) % | Placebo (n=324) % |
| Body as a Whole | Asthenia | 22 | 14 | 14 | 5 |
| Abdominal Pain | - | - | 4 | 3 |
| Chest Pain | 3 | 2 | - | - |
| Back Pain | - | - | 3 | 2 |
| Chills | 2 | 1 | 2 | 1 |
| Cardiovascular | Vasodilation | 4 | 1 | - | - |
| Palpitation | 2 | 0 | - | - |
| Dermatologic | Sweating | 9 | 3 | 14 | 6 |
| Rash | 3 | 2% | - | - |
| Gastrointestinal | Nausea | 23 | 10 | 23 | 17 |
| Dry Mouth | 18 | 9 | 18 | 11 |
| Constipation | 16 | 6 | 8 | 5 |
| Diarrhea | 10 | 10 | 12 | 7 |
| Decreased Appetite | 9 | 3 | 7 | 3 |
| Increased Appetite | 4 | 3 | 2 | 1 |
| Nervous System | Insomnia | 24 | 13 | 18 | 10 |
| Somnolence | 24 | 7 | 19 | 11 |
| Dizziness | 12 | 6 | 14 | 10 |
| Tremor | 11 | 1 | 9 | 1 |
| Nervousness | 9 | 8 | - | - |
| Libido Decreased | 7 | 4 | 9 | 1 |
| Agitation | - | - | 5 | 4 |
| Anxiety | - | - | 5 | 4 |
| Abnormal Dreams | 4 | 1 | - | - |
| Concentration Impaired | 3 | 2 | - | - |
| Depersonalization | 3 | 0 | - | - |
| Myoclonus | 3 | 0 | 3 | 2 |
| Amnesia | 2 | 1 | - | - |
Respiratory
System
| Rhinitis | - | - | 3 | 0 |
| Special Senses | Abnormal Vision | 4 | 2 | - | - |
| Taste Perversion | 2 | 0 | - | - |
| Urogenital System | Abnormal Ejaculation
1
| 23 | 1 | 21 | 1 |
| Female Genital Disorder
1
| 3 | 0 | 9 | 1 |
| Impotence
1
| 8 | 1 | 5 | 0 |
| Urinary Frequency | 3 | 1 | 2 | 0 |
| Urination Impaired | 3 | 0 | - | - |
| Urinary Tract Infection | 2 | 1 | 2 | 1 |
Generalized Anxiety Disorder:Table 6 enumerates adverse reactions that occurred at a frequency of 2% or more among GAD patients on paroxetine who participated in placebo-controlled trials of 8-weeks duration in which patients were dosed in a range of 10 mg/day to 50 mg/day.
|
| TABLE 6: Adverse Reactions (≥2% of Paroxetine-Treated Patients and Greater than Placebo) in 8-Week Clinical Trials for GAD |
Body System | Preferred Term | Paroxetine(n=735) % | Placebo(n=529) % |
| Body as a Whole | Asthenia | 14 | 6 |
| Headache | 17 | 14 |
| Infection | 6 | 3 |
| Cardiovascular | Vasodilation | 3 | 1 |
| Dermatologic | Sweating | 6 | 2 |
| Gastrointestinal | Nausea | 20 | 5 |
| Dry Mouth | 11 | 5 |
| Constipation | 10 | 2 |
| Diarrhea | 9 | 7 |
| Decreased Appetite | 5 | 1 |
| Vomiting | 3 | 2 |
| Nervous System | Insomnia | 11 | 8 |
| Somnolence | 15 | 5 |
| Dizziness | 6 | 5 |
| Tremor | 5 | 1 |
| Nervousness | 4 | 3 |
| Libido Decreased | 9 | 2 |
| Respiratory System | Respiratory Disorder | 7 | 5 |
| Sinusitis | 4 | 3 |
| Yawn | 4 | - |
| Special Senses | Abnormal Vision | 2 | 1 |
| Urogenital System | Abnormal Ejaculation
1
| 25 | 2 |
| Female Genital Disorder
1
| 4 | 1 |
| Impotence
1
| 4 | 3 |
Dose Dependency of Adverse Reactions:A comparison of adverse reaction rates in a fixed-dose study comparing paroxetine 10, 20, 30, and 40 mg/day with placebo in the treatment of MDD revealed a clear dose dependency for some of the more common adverse reactions associated with paroxetine use, as shown in Table 7:
| TABLE 7: Adverse Reactions (≥5% of Paroxetine-Treated Patients and Twice that of Placebo) in a Dose-Comparison Trial in the Treatment of MDD* |
Body System/
Preferred Term
| Placebo | Paroxetine |
n=51
% | 10 mg
n=102
% | 20 mg
n=104
% | 30 mg
n=101
% | 40 mg
n=102
% |
| Body as a Whole | | | | | |
| Asthenia | 0 | 2.9 | 10.6 | 13.9 | 12.7 |
| Dermatology | | | | | |
| Sweating | 2.0 | 1.0 | 6.7 | 8.9 | 11.8 |
| Gastrointestinal | | | | | |
| Constipation | 5.9 | 4.9 | 7.7 | 9.9 | 12.7 |
| Decreased Appetite | 2.0 | 2.0 | 5.8 | 4.0 | 4.9 |
| Diarrhea | 7.8 | 9.8 | 19.2 | 7.9 | 14.7 |
| Dry Mouth | 2.0 | 10.8 | 18.3 | 15.8 | 20.6 |
| Nausea | 13.7 | 14.7 | 26.9 | 34.7 | 36.3 |
| Nervous System | | | | | |
| Anxiety | 0 | 2.0 | 5.8 | 5.9 | 5.9 |
| Dizziness | 3.9 | 6.9 | 6.7 | 8.9 | 12.7 |
| Nervousness | 0.0 | 5.9 | 5.8 | 4.0 | 2.9 |
| Paresthesia | 0.0 | 2.9 | 1.0 | 5.0 | 5.9 |
| Somnolence | 7.8 | 12.7 | 18.3% | 20.8 | 21.6 |
| Tremor | 0 | 0 | 7.7 | 7.9 | 14.7 |
| Special Senses | | | | | |
| Blurred Vision | 2.0 | 2.9 | 2.9 | 2.0 | 7.8 |
| Urogenital System | | | | | |
| Abnormal Ejaculation | 0 | 5.8 | 6.5 | 10.6 | 13.0 |
| Impotence | 0 | 1.9 | 4.3 | 6.4 | 1.9 |
| Male Genital Disorders | 0 | 3.8 | 8.7 | 6.4 | 3.7 |
In a fixed-dose study comparing placebo and paroxetine 20, 40, and 60 mg in the treatment of OCD, there was no clear relationship between adverse reactions and the dose of paroxetine to which patients were assigned. No new adverse reactions were observed in the paroxetine 60 mg dose group compared to any of the other treatment groups.
In a fixed-dose study comparing placebo and paroxetine 10, 20, and 40 mg in the treatment of PD, there was no clear relationship between adverse reactions and the dose of paroxetine to which patients were assigned, except for asthenia, dry mouth, anxiety, libido decreased, tremor, and abnormal ejaculation. In flexible-dose studies, no new adverse reactions were observed in patients receiving 60 mg of paroxetine compared to any of the other treatment groups.
In a fixed-dose study comparing placebo and 20 and 40 mg of paroxetine in the treatment of GAD, for most of the adverse reactions, there was no clear relationship between adverse reactions and the dose of paroxetine to which patients were assigned, except for the following adverse reactions: asthenia, constipation, and abnormal ejaculation.
Male and Female Sexual Dysfunction
Although changes in sexual desire, sexual performance, and sexual satisfaction often occur as manifestations of a psychiatric disorder, they may also be a consequence of SSRI treatment. However, reliable estimates of the incidence and severity of untoward experiences involving sexual desire, performance, and satisfaction are difficult to obtain, in part because patients and healthcare providers 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 their actual incidence.
The percentage of patients reporting symptoms of sexual dysfunction in males and females with MDD, OCD, PD, , GAD, and two other indications are displayed in Table 8.
| Table 8: Incidence of Sexual Adverse Reactions in Controlled Clinical Trials |
| Paroxetine | Placebo |
| n (males) | 1446 | 1042 |
| % | % |
| Decreased Libido | 6 to 15 | 0 to 5 |
| Ejaculatory Disturbance | 13 to 28 | 0 to 2 |
| Impotence | 2 to 9 | 0 to 3 |
| n (females) | 1822 | 1340 |
| % | % |
| Decreased Libido | 0 to 9 | 0 to 2 |
| Orgasmic Disturbance | 2 to 9 | 0 to 1 |
There are no adequate and well-controlled studies examining sexual dysfunction with paroxetine treatment.
Paroxetine treatment has been associated with several cases of priapism. In those cases with a known outcome, patients recovered without sequelae.
While it is difficult to know the precise risk of sexual dysfunction associated with the use of SSRIs, healthcare providers should routinely inquire about such possible side effects.
Hallucinations: In pooled clinical trials of immediate-release paroxetine hydrochloride, hallucinations were observed in 0.2% of paroxetine-treated patients compared to 0.1% of patients receiving placebo.