Drug Name
Generic Name
: clonidine hydrochloride
Brand Name:
§
Antihypertensives: Apo-Clonidine (CAN), Catapres, Catapres-TTS
(transdermal preparation), Dixarit (CAN), Duraclon, Novo-Clonidine (CAN),
Nu-Clonidine (CAN)
§
Analgesic: Duraclon
Classification: Antihypertensive,
Sympatholytic (centrally acting), Central analgesic
Pregnancy Category C
Dosage & Route
Adults
Oral therapy
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Individualize dosage. Initial dose is 0.1 mg bid; for
maintenance dosage, increase in increments of 0.1 or 0.2 mg to reach desired
response. Common range is 0.2–0.6 mg/day, in divided doses; maximum dose is 2.4
mg/day. Minimize sedation by slowly increasing daily dosage; giving majority of
daily dose at bedtime.
Transdermal system
§
Apply to a hairless area of intact skin of upper arm or torso
once every 7 days. Change skin site for each application. If system loosens
while wearing, apply adhesive overlay directly over the system to ensure
adhesion. Start with the 0.1-mg system (releases 0.1 mg/24 hr); if, after 1–2
wk, desired BP reduction is not achieved, add another 0.1-mg system, or use a
larger system. Dosage of more than two 0.3-mg systems does not improve
efficacy. Antihypertensive effect may only begin 2–3 days after application;
therefore, when substituting transdermal systems, a gradual reduction of prior
dosage is advised. Remove old system before applying new one. Previous
antihypertensive medication may have to be continued, particularly with severe
hypertension.
Epidural injection
§
Pain
management: 30 mcg/hr by continuous epidural infusion.
Pediatric Patients
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Safety and efficacy not established.
Therapeutic actions
§
Clonidine stimulates alpha-2 receptors in brain stem which
results in reduced sympathetic outflow from the CNS and a decrease in
peripheral resistance leading to reduced BP and pulse rate. It does not alter
normal hemodynamic response to exercise at recommended dosages.
Indications
- Hypertension, used alone or as part of combination therapy
- Treatment of severe pain in cancer patients in combination with
opiates; epidural more effective with neuropathic pain (Duraclon)
- Unlabeled uses: Tourette’s syndrome; migraine, decreases
severity and frequency; menopausal flushing, decreases severity and frequency
of episodes; chronic methadone detoxification; rapid opiate detoxification (in
doses up to 17 mcg/kg/day); alcohol and benzodiazepine withdrawal treatment; management
of hypertensive “urgencies”; (oral clonidine “loading” is used; initial dose of
0.2 mg then 0.1 mg every hour until a dose of 0.7 mg is reached or until BP is
controlled)
Adverse effects
§
Dry mouth, drowsiness, dizziness, headache, constipation,
impotence, vivid dreams, urinary retention; dry, itching, burning sensation in
the eye; fluid or electrolyte imbalance, GI upset, paralytic ileus, orthostatic
hypotension, weakness, sedation, pruritus, myalgia, urticaria, nausea,
insomnia, arrhythmias, agitation. Reduced GI motility at times may cause
paralytic ileus.
§
Potentially Fatal: Transient hypertension or profound
hypotension, respiratory depression, convulsion. Clonidine withdrawal syndrome
could be life threatening. Bradycardia, coma and disturbances in conduction (in
individuals with preexisting diseases of SA/AV nodes, overdose or on
digitalis).
Contraindications
§
Hypersensitivity. Disorders of cardiac pacemaker activity and
conduction. Pregnancy and lactation.
Nursing considerations
CLINICAL ALERT! Name
confusion has occurred between clonidine and Klonopin (clonazepam); use
caution.
Assessment
§
History: Hypersensitivity
to clonidine or adhesive layer components of the transdermal system; severe
coronary insufficiency, recent MI, cerebrovascular disease; chronic renal
failure; lactation, pregnancy
§
Physical: Body
weight; T; skin color, lesions, T; mucous membranes color, lesions; breast
examination; orientation, affect, reflexes; ophthalmologic examination; P, BP,
orthostatic BP, perfusion, edema, auscultation; bowel sounds, normal output,
liver evaluation, palpation of salivary glands; normal urinary output, voiding
pattern; LFTs, ECG
Interventions
§
WARNING: Do not discontinue abruptly; discontinue therapy by
reducing the dosage gradually over 2–4 days to avoid rebound hypertension,
tachycardia, flushing, nausea, vomiting, cardiac arrhythmias (hypertensive encephalopathy
and death have occurred after abrupt cessation of clonidine).
§
Do not discontinue transdermal therapy prior to surgery; monitor
BP carefully during surgery; have other BP-controlling drugs readily available.
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Continue oral clonidine therapy within 4 hr of surgery then
resume as soon as possible thereafter.
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Store epidural injection at room temperature; discard any unused
portions.
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Reevaluate therapy if clonidine tolerance occurs; giving
concomitant diuretic increases the antihypertensive efficacy of clonidine.
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Monitor BP carefully when discontinuing clonidine; hypertension
usually returns within 48 hr.
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WARNING: Remove transdermal patch before defibrillation
to prevent arcing.
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Assess compliance with drug regimen in a supportive manner with
pill counts, or other methods.
Teaching points
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Take this drug exactly as prescribed. Do not miss doses. Do not
discontinue the drug unless instructed by your health care provider. Do not
discontinue abruptly; life-threatening adverse effects may occur. If you
travel, take an adequate supply of drug.
§
Use the transdermal system as prescribed; refer to directions in
package insert, or contact your health care provider with questions. Be sure to
remove old systems before applying new ones.
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Attempt lifestyle changes that will reduce your blood pressure:
Stop smoking and using alcohol; lose weight; restrict intake of salt; exercise
regularly.
§
Use caution with alcohol. Your sensitivity may increase while
using this drug.
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You may experience these side effects: Drowsiness, dizziness,
light-headedness, headache, weakness (often transient; observe caution driving
or performing other tasks that require alertness or physical dexterity); dry
mouth (sucking on sugarless lozenges or ice chips may help); GI upset (eat
frequent small meals); dreams, nightmares (reversible); dizziness,
light-headedness when you change position (get up slowly; use caution climbing
stairs); impotence, other sexual dysfunction, decreased libido (discuss with
your health care provider); breast enlargement, sore breasts; palpitations.
§
Report urinary retention, changes in vision, blanching of
fingers, rash.
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