The following adverse reactions have been identified during post-approval use of clonidine transdermal system. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to estimate reliably their frequency or establish a causal relationship to drug exposure. Decisions to include these reactions in labeling are typically based on one or more of the following factors: (1) seriousness of the reaction, (2) frequency of reporting, or (3) strength of causal connection to clonidine transdermal system.
Body as a Whole: Fever; malaise; weakness; pallor; and withdrawal syndrome.
Cardiovascular: Congestive heart failure; cerebrovascular accident; electrocardiographic abnormalities (i.e., bradycardia, sick sinus syndrome disturbances and arrhythmias); chest pain; orthostatic symptoms; syncope; increases in blood pressure; sinus bradycardia and AV block with and without the use of concomitant digitalis; Raynaud’s phenomenon; tachycardia; bradycardia; and palpitations.
Central and Peripheral Nervous System/Psychiatric: Delirium; mental depression; hallucinations (including visual and auditory); localized numbness; vivid dreams or nightmares; restlessness; anxiety; agitation; irritability; other behavioral changes; and drowsiness.
Dermatological: Angioneurotic edema; localized or generalized rash; hives; urticaria; contact dermatitis; pruritus; alopecia; and localized hypo or hyper pigmentation.
Gastrointestinal: Anorexia and vomiting.
Genitourinary: Difficult micturition; loss of libido; and decreased sexual activity.
Metabolic: Gynecomastia or breast enlargement and weight gain.
Musculoskeletal: Muscle or joint pain; and leg cramps.
Ophthalmological: Blurred vision; burning of the eyes and dryness of the eyes.
Adverse Events Associated with Oral Clonidine Therapy: Most adverse effects are mild and tend to diminish with continued therapy. The most frequent (which appear to be dose-related) are dry mouth, occurring in about 40 of 100 patients; drowsiness, about 33 in 100; dizziness, about 16 in 100; constipation and sedation, each about 10 in 100. The following less frequent adverse experiences have also been reported in patients receiving clonidine hydrochloride, USP tablets, but in many cases patients were receiving concomitant medication and a causal relationship has not been established.
Body as a Whole: Fatigue, fever, headache, pallor, weakness, and withdrawal syndrome. Also reported were a weakly positive Coombs’ test and increased sensitivity to alcohol.
Cardiovascular: Bradycardia, congestive heart failure, electrocardiographic abnormalities (i.e., sinus node arrest, junctional bradycardia, high degree AV block and arrhythmias), orthostatic symptoms, palpitations, Raynaud’s phenomenon, syncope, and tachycardia. Cases of sinus bradycardia and AV block have been reported, both with and without the use of concomitant digitalis.
Central Nervous System: Agitation, anxiety, delirium, delusional perception, hallucinations (including visual and auditory), insomnia, mental depression, nervousness, other behavioral changes, paresthesia, restlessness, sleep disorder, and vivid dreams or nightmares.
Dermatological: Alopecia, angioneurotic edema, hives, pruritus, rash, and urticaria.
Gastrointestinal: Abdominal pain, anorexia, constipation, hepatitis, malaise, mild transient abnormalities in liver function tests, nausea, parotitis, pseudo-obstruction (including colonic pseudo-obstruction), salivary gland pain, and vomiting.
Genitourinary: Decreased sexual activity, difficulty in micturition, erectile dysfunction, loss of libido, nocturia, and urinary retention.
Hematologic: Thrombocytopenia.
Metabolic: Gynecomastia, transient elevation of blood glucose or serum creatine phosphokinase, and weight gain.
Musculoskeletal: Leg cramps and muscle or joint pain.
Oro-otolaryngeal: Dryness of the nasal mucosa.
Ophthalmological: Accommodation disorder, blurred vision, burning of the eyes, decreased lacrimation, and dryness of the eyes.