Catapres, Catapres-TTS, Dixaril , Duraclon
Classifications: central-acting antihypertensive; analgesic; Therapeutic: antihypertensive, central-acting; analgesic
Pregnancy Category: C
0.1 mg, 0.2 mg, 0.3 mg tablets; 0.1 mg/24 h, 0.2 mg/24 h, 0.3 mg/24 h transdermal patch; 100 mcg/mL, 500 mcg/mL injection
Centrally acting antiadrenergic derivative. Stimulates alpha2-adrenergic receptors in CNS to inhibit sympathetic vasomotor centers. Central actions reduce plasma concentrations of norepinephrine.
It decreases systolic and diastolic BP and heart rate. Orthostatic effects tend to be mild and occur infrequently.
Decreases systolic and diastolic BP and heart rate. Reportedly minimizes or eliminates many of the common clinical S&S associated
with withdrawal of heroin, methadone, or other opiates.
Step 2 drug in stepped-care approach to treatment of hypertension, either alone or with diuretic or other antihypertensive
agents. Epidural administration as adjunct therapy for severe pain.
Prophylaxis for migraine; treatment of dysmenorrhea, menopausal flushing, diarrhea, paroxysmal localized hyperhidroses;
alcohol, smoking, opiate, and benzodiazepine withdrawal; in the clonidine suppression test for diagnosis of pheochromocytoma;
Gilles de la Tourette syndrome; attention deficit disorder with hyperactivity (ADDH) in children.
Anticoagulant therapy, coagulopathy; use of clonidine patch in polyarteritis nodosa, scleroderma, SLe on affected areas;
pregnancy (category C), lactation.
Severe coronary insufficiency, recent MI, sinus node dysfunction, cerebrovascular disease; diabetes mellitus; older adult;
chronic renal failure; Raynaud's disease, thromboangiitis obliterans; history of major depression.
Route & Dosage
Adult: PO 0.1 mg b.i.d. or t.i.d., may increase by 0.10.2 mg/d until desired response is achieved (max: 2.4 mg/d) Transdermal 0.1 mg patch once q7d, may increase by 0.1 mg q12 wk
Geriatric: PO Start with 0.1 mg once daily
Child: PO 510 mcg/kg/d divided q812h, may increase to 525 mcg/kg/d divided q6h (max: 0.9 mg/d)
Adult: Epidural Start infusion at 30 mcg/h and titrate to response. Use rates >40 mcg/h with caution
Child: Epidural Start infusion at 0.5 mcg/kg/h and titrate to response
Child: PO 5 mcg/kg/d in 4 divided doses (average dose, 0.150.2 mg/d) Transdermal 0.20.3 mg/d q57d
- Give last PO dose immediately before patient retires to ensure overnight BP control and to minimize daytime drowsiness.
- Oral dosage is increased gradually over a period of weeks so as not to lower BP abruptly (especially important in the older
adult). Follow-up visits should be scheduled every 24 wk until BP stabilizes, then every 24 mo.
- Apply transdermal patch to dry skin, free of hair and rash. Avoid irritated, abraded, or scarred skin. Recommended areas
for applying transdermal patch are upper outer arm and anterior chest. Less drug is absorbed from thighs. Rotate application
sites and keep a record.
- During change from PO clonidine to transdermal system, PO clonidine should be maintained for at least 24 h after patch is
applied. Consult physician.
- Do not abruptly discontinue drug. It should be withdrawn over a period of 24 d. Abrupt withdrawal resembles sympathetic
stimulation and may result in restlessness and headache 23 h after a missed dose and a hypertensive crisis within
- Store in tightly closed container at 15°30° C (59°86° F) unless otherwise directed.
Adverse Effects (≥1%)CV: Hypotension (epidural),
postural hypotension (mild), peripheral edema, ECG changes, tachycardia, bradycardia, flushing, rapid increase in BP with
abrupt withdrawal. GI: Dry mouth, constipation,
abdominal pain, pseudo-obstruction of large bowel, altered taste, nausea, vomiting, hepatitis
, hyperbilirubinemia, weight
gain (sodium retention). CNS: Drowsiness, sedation,
dizziness, headache, fatigue
, weakness, sluggishness, dyspnea
, vivid dreams, nightmares, insomnia
, behavior changes, agitation,
hallucination, nervousness, restlessness, anxiety, mental depression
Rash, pruritus, thinning of hair, exacerbation of psoriasis; with transdermal patch: hyperpigmentation, recurrent herpes
simplex, skin irritation, contact dermatitis, mild erythema
. Special Senses:
Dry eyes. Urogenital:
Impotence, loss of libido.
Diagnostic Test Interference
Avoid use of transdermal patch during MRI. Possibility of decreased urinary excretion of aldosterone, catecholamines, and VMA (however, sudden withdrawal of clonidine may cause increases in these values); transient increases in blood glucose; weakly positive direct antiglobulin (Coombs') tests.
and other cns depressants
add to CNS
depression; tricyclic antidepressants
may reduce antihypertensive effects. opiate analgesics
increase hypotension with epidural clonidine. Increased risk of bradycardia or AV block when epidural clonidine is used
with digoxin, calcium channel blockers
, or beta-blockers
Readily absorbed from GI tract. Onset:
3060 min PO; 13 d transdermal. Peak:
24 h PO; 23 d transdermal. Duration:
8 h PO; 7 d transdermal. Distribution:
Widely distributed; crosses bloodbrain barrier; not known if crosses placenta or distributed into breast milk. Metabolism:
In liver. Elimination:
80% in urine, 20% in feces. Half-Life:
Assessment & Drug Effects
- Monitor BR closely. Determine positional changes (supine, sitting, standing).
- With epidural administration, frequently monitor BP and HR. Hypotension is a common side effect that may require intervention.
- Monitor BP closely whenever a drug is added to or withdrawn from therapeutic regimen.
- Monitor I&O during period of dosage adjustment. Report change in I&O ratio or change in voiding pattern.
- Determine weight daily. Patients not receiving a concomitant diuretic agent may gain weight, particularly during first 3
or 4 d of therapy, because of marked sodium and water retention.
- Supervise closely patients with history of mental depression, as they may be subject to further depressive episodes.
Patient & Family Education
- Although postural hypotension occurs infrequently, make position changes slowly, and in stages, particularly from recumbent
to upright position, and dangle and move legs a few minutes before standing. Lie down immediately if faintness or dizziness
- Avoid potentially hazardous activities until reaction to drug has been determined due to possible sedative effects.
- Do not omit doses or stop the drug without consulting the physician.
- Do not take OTC medications, alcohol, or other CNS depressants without prior discussion with physician.
- Examine site when transdermal patch is removed and report to physician if erythema, rash, irritation, or hyperpigmentation
- If transdermal patch loosens, tape it in place with adhesive. The patch should never be cut or trimmed.