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.
Two clonidine hydrochloride extended-release tablets ADHD clinical studies (Study 1, CLON-301 and Study 2, CLON-302) evaluated 256 patients in two 8-week placebo-controlled studies.
A third clonidine hydrochloride extended-release tablets ADHD clinical study (Study 3, SHN-KAP-401) evaluated 135 children and adolescents in a 40- week placebo-controlled randomized-withdrawal study.
Study 1: Fixed-dose Clonidine Hydrochloride Extended-Release Tablets Monotherapy
Study 1 (CLON-301) was a short-term, multi-center, randomized, double-blind, placebo-controlled study of two fixed doses (0.2 mg/day or 0.4 mg/day) of clonidine hydrochloride extended-release tablets in children and adolescents (6 to 17 years of age) who met DSM-IV criteria for ADHD hyperactive or combined inattentive/hyperactive subtypes.
Most Common Adverse Reactions (incidence of ≥ 5% and at least twice the rate of placebo): somnolence, fatigue, irritability, insomnia, nightmare, constipation, dry mouth.
Adverse Events Leading to Discontinuation of Clonidine Hydrochloride Extended-Release Tablets –Five patients (7%) in the low dose group (0.2 mg), 15 patients (20%) in the high dose group (0.4 mg), and 1 patient in the placebo group (1%) reported adverse reactions that led to discontinuation. The most common adverse reactions that led to discontinuation were somnolence and fatigue.
Commonly observed adverse reactions (incidence of ≥2% in either active treatment group and greater than the rate on placebo) during the treatment period are listed in Table 2.
Table 2 Common Adverse Reactions in the Fixed-Dose Monotherapy Trial- Treatment Period (Study 1)
| Percentage of Patients Reporting Event
|
Preferred Term
| Clonidine Hydrochloride Extended-Release Tablets 0.2 mg/day N=76
| Clonidine Hydrochloride Extended-Release Tablets 0.4 mg/day N=78
|
Placebo (N=76)
|
PSYCHIATRIC DISORDERS
| | | |
| Somnolence Somnolence includes the terms "somnolence" and "sedation".
| 38%
| 31%
| 4%
|
Nightmare
| 4%
| 9%
| 0%
|
Emotional Disorder
| 4%
| 4%
| 1%
|
Aggression
| 3%
| 1%
| 0%
|
Tearfulness
| 1%
| 3%
| 0%
|
Enuresis
| 0%
| 4%
| 0%
|
Sleep Terror
| 3%
| 0%
| 0%
|
Poor Quality Sleep
| 0%
| 3%
| 1%
|
NERVOUS SYSTEM DISORDERS
| | | |
Headache
| 20%
| 13%
| 16%
|
Insomnia
| 5%
| 6%
| 1%
|
Tremor
| 1%
| 4%
| 0%
|
Abnormal Sleep-Related Event
| 3%
| 1%
| 0%
|
GASTROINTESTINAL DISORDERS
| | | |
Upper Abdominal Pain
| 15%
| 10%
| 12%
|
Nausea
| 4%
| 5%
| 3%
|
Constipation
| 1%
| 6%
| 0%
|
Dry Mouth
| 0%
| 5%
| 1%
|
GENERAL DISORDERS
| | | |
| Fatigue Fatigue includes the terms "fatigue" and "lethargy".
| 16%
| 13%
| 1%
|
Irritability
| 9%
| 5%
| 4%
|
CARDIAC DISORDERS
| | | |
Dizziness
| 7%
| 3%
| 5%
|
Bradycardia
| 0%
| 4%
| 0%
|
INVESTIGATIONS
| | | |
Increased Heart Rate
| 0%
| 3%
| 0%
|
METABOLISM AND NUTRITION DISORDERS
| | | |
Decreased Appetite
| 3%
| 4%
| 4%
|
Commonly observed adverse reactions (incidence of ≥2% in either active treatment group and greater than the rate on placebo) during the taper period are listed in Table 3.
Table 3 Common Adverse Reactions in the Fixed-Dose Monotherapy Trial- Taper Period Taper Period: 0.2 mg dose, week 8; 0.4 mg dose, weeks 6 to 8; Placebo dose, weeks 6 to 8
(Study 1) Preferred Term
| Percentage of Patients Reporting Event
|
Clonidine Hydrochloride Extended-Release Tablets 0.2 mg/day N=76
| Clonidine Hydrochloride Extended-Release Tablets 0.4 mg/day N=78
|
Placebo (N=76)
|
Abdominal Pain Upper
| 0%
| 6%
| 3%
|
Headache
| 5%
| 2%
| 3%
|
Gastrointestinal Viral
| 0%
| 5%
| 0%
|
Somnolence
| 2%
| 3%
| 0%
|
Heart Rate Increased
| 0%
| 3%
| 0%
|
Otitis Media Acute
| 3%
| 0%
| 0%
|
Study 2: Flexible-dose Clonidine Hydrochloride Extended-Release Tablets as Adjunctive Therapy to Psychostimulants
Study 2 (CLON-302) was a short-term, randomized, double-blind, placebo-controlled study of a flexible dose of clonidine hydrochloride extended-release tablets as adjunctive therapy to a psychostimulant in children and adolescents (6 to 17 years) who met DSM-IV criteria for ADHD hyperactive or combined inattentive/hyperactive subtypes during which clonidine hydrochloride extended-release tablets were initiated at 0.1 mg/day and titrated up to 0.4 mg/day over a 3-week period. Most clonidine hydrochloride extended-release tablets treated patients (75.5%) were escalated to the maximum dose of 0.4 mg/day.
Most Common Adverse Reactions (incidence of ≥ 5% and at least twice the rate of placebo): somnolence, fatigue, decreased appetite, dizziness.
Adverse Events Leading to Discontinuation –There was one patient in the CLON+STM group (1%) who discontinued because of an adverse event (severe bradyphrenia, with severe fatigue).
Commonly observed adverse reactions (incidence of ≥2% in the treatment group and greater than the rate on placebo) during the treatment period are listed in Table 4.
Table 4 Common Adverse Reactions in the Flexible-Dose Adjunctive to Stimulant Therapy Trial- Treatment Period (Study 2) Preferred Term
| Percentage of Patients Reporting Event
|
Clonidine Hydrochloride Extended-Release Tablets + STM (N=102)
| PBO + STM (N=96)
|
PSYCHIATRIC DISORDERS
| | |
| Somnolence Somnolence includes the terms: "somnolence" and "sedation".
| 19%
| 7%
|
Aggression
| 2%
| 1%
|
Affect Lability
| 2%
| 1%
|
Emotional Disorder
| 2%
| 0%
|
GENERAL DISORDERS
| | |
| Fatigue Fatigue includes the terms "fatigue" and "lethargy".
| 14%
| 4%
|
Irritability
| 2%
| 7%
|
NERVOUS SYSTEM DISORDERS
| | |
Headache
| 7%
| 12%
|
Insomnia
| 4%
| 3%
|
GASTROINTESTINAL DISORDERS
| | |
Upper Abdominal Pain
| 7%
| 4%
|
RESPIRATORY DISORDERS
| | |
Nasal Congestion
| 2%
| 2%
|
METABOLISM AND NUTRITION DISORDERS
| | |
Decreased Appetite
| 6%
| 3%
|
CARDIAC DISORDERS
| | |
Dizziness
| 5%
| 1%
|
Commonly observed adverse reactions (incidence of ≥2% in the treatment group and greater than the rate on placebo) during the taper period are listed in Table 5.
Table 5 Common Adverse Reactions in the Flexible-Dose Adjunctive to Stimulant Therapy Trial- Taper Period* (Study 2) |
Preferred Term
| Percentage of Patients Reporting Event
|
Clonidine Hydrochloride Extended-Release Tablets + STM (N=102)
| PBO + STM (N=96)
|
Nasal Congestion
| 4%
| 2%
|
Headache
| 3%
| 1%
|
Irritability
| 3%
| 2%
|
Throat Pain
| 3%
| 1%
|
Gastroenteritis Viral
| 2%
| 0%
|
Rash
| 2%
| 0%
|
Adverse Reactions Leading to Discontinuation
Thirteen percent (13%) of patients receiving clonidine hydrochloride extended-release tablets discontinued from the pediatric monotherapy study due to adverse events, compared to 1% in the placebo group. The most common adverse reactions leading to discontinuation of clonidine hydrochloride extended-release tablets monotherapy treated patients were from somnolence/sedation (5%) and fatigue (4%).
Effect on Blood Pressure and Heart Rate
In patients that completed 5 weeks of treatment in a controlled, fixed-dose monotherapy study in pediatric patients, during the treatment period the maximum placebo-subtracted mean change in systolic blood pressure was -4.0 mmHg on clonidine hydrochloride extended-release tablets 0.2 mg/day and -8.8 mmHg on clonidine hydrochloride extended-release tablets 0.4 mg/day. The maximum placebo-subtracted mean change in diastolic blood pressure was -4.0 mmHg on clonidine hydrochloride extended-release tablets 0.2 mg/day and -7.3 mmHg on clonidine hydrochloride extended-release tablets 0.4 mg/day. The maximum placebo-subtracted mean change in heart rate was -4.0 beats per minute on clonidine hydrochloride extended-release tablets 0.2 mg/day and -7.7 beats per minute on clonidine hydrochloride extended-release tablets 0.4 mg/day.
During the taper period of the fixed-dose monotherapy study the maximum placebo-subtracted mean change in systolic blood pressure was +3.4 mmHg on clonidine hydrochloride extended-release tablets 0.2 mg/day and -5.6 mmHg on clonidine hydrochloride extended-release tablets 0.4 mg/day. The maximum placebo-subtracted mean change in diastolic blood pressure was +3.3 mmHg on clonidine hydrochloride extended-release tablets 0.2 mg/day and -5.4 mmHg on clonidine hydrochloride extended-release tablets 0.4 mg/day. The maximum placebo-subtracted mean change in heart rate was -0.6 beats per minute on clonidine hydrochloride extended-release tablets 0.2 mg/day and -3.0 beats per minute on clonidine hydrochloride extended-release tablets 0.4 mg/day.