Names and pronunciation
(klon′i-deen) Catapres, Catapres-TTS, Duraclon, Kapvay
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Drug reference
(klon′i-deen) Catapres, Catapres-TTS, Duraclon, Kapvay
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Func. class.: Antihypertensive
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Chem. class.: Central alpha-adrenergic agonist
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Do not confuse: cloNIDine/KlonoPIN/clonazePAM
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ACTION: Inhibits sympathetic vasomo- tor center in CNS, which reduces impulses in sympathetic nervous system; B/P, pulse rate, cardiac output are decreased; pre- vents pain signal transmission in CNS by alpha-adrenergic receptor stimulation of the spinal cord
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USES: Mild to moderate hyperten- sion, used alone or in combination; severe pain in cancer patients (epi- dural), attention-deficit/hyperactivity disorder (ADHD)
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CONTRAINDICATIONS: Hyper- sensitivity; (epidural) bleeding disorders, anticoagulants Precautions: Pregnancy, breastfeeding, children <12 yr (transdermal), geriatric patients, noncompliant patients, MI (recent), diabetes mellitus, chronic renal failure, Raynaud’s disease, thyroid disease, depression, COPD, asthma, pheochromocytoma
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Black Box Warning: Labor (epidermal cloNIDIne) Black Box Warning: Dilute 500 mcg/mL with 0.9% NaCl (100 mcg/mL) Black Box Warning: Do not use for labor Black Box Warning: Pregnancy/breast- feeding: do not use for labor/epidural; excreted in breast milk, discontinue breastfeeding or product
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SIDE EFFECTS CNS: Drowsiness, nightmares, anxiety, depression, hallucinations, syncope, dizziness CV: Orthostatic hypotension, HF, ECG abnormalities, sinus tachycardia EENT: Taste change, dry eyes ENDO: Hyperglycemia GI: Nausea, vomiting, constipation, dry mouth GU: Impotence, urinary retention, decreased libido INTEG: Rash, pruritus, excoriation (transdermal patches) MISC: Withdrawal symptoms
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INTERACTIONS • Increase: bradycardia, verapamil, dil- TIAZem • Life-threatening elevations of B/P: tricyclics, beta-blockers Increase: CNS depression—opiates, sedatives, hypnotics, anesthetics, alcohol Increase: hypotensive effects—diuretics, other antihypertensive nitrates Increase: bradycardia—amphetamines, beta-blockers, digoxin, dilTIAZem, MAO inhibitors, verapamil Decrease: hypotensive effects—tricyclics, MAOIs, appetite suppressants, amphet- amines, prazosin, antipsychotics Decrease: effect of levodopa Drug/Herb Increase: antihypertensive effect— hawthorn Decrease: antihypertensive effect— ephedra, ginseng Drug/Lab Test Increase: blood glucose Decrease: VMA, urinary catecholamines, aldosterone Positive: Coombs’ test
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TREATMENT OF OVERDOSE: Supportive treatment; administer tolazo- line, atropine, DOPamine prn HIGH ALERT
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DOSAGE AND ROUTES Hypertension • Adult: PO 0.1 mg bid then increase by 0.1-0.2 mg/day at weekly intervals until de- sired response; max 2.4 mg; range 0.2-0.6 mg/day in divided doses or TRANSDER- MAL q7days, start 0.1 mg and adjust q1-2wk • Geriatric: PO 0.1 mg at bedtime; may increase gradually • Child: PO 5-10 mcg/kg/day in divided doses q8-12hr, max 0.9 mg/day Severe pain • Adult: CONTINUOUS EPIDURAL INFUSION 30 mcg/hr • Child: CONTINUOUS EPIDURAL INFUSION 0.5 mcg/kg/hr, then titrate to response ADHD • Adolescent/child ≥6 yr: PO 0.05 mg/ kg/day in 3-4 divided doses, may increase by 0.1 mg/day weekly up to 0.4 mg/day; extended release 0.1 mg at bedtime, in- crease dose by 0.1 mg/day up to 0.4 mg/day
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Available forms: Tablets 0.1, 0.2, 0.3 mg; transdermal 2.5, 5, 7.5 mg delivering 0.1, 0.2, 0.3 mg/24 hr, respectively; injection 100, 500 mcg/mL; extended-release tablet 0.1 mg
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Administer: • Store patches in cool environment, tab- lets in tight container PO route • Give last dose at bedtime • Do not crush, cut, chew, or break extended-release tablets; Kapvay is not interchangeable with other products Transdermal route • Once weekly; apply to site without hair; best absorption over chest or upper arm; rotate sites; clean site before application; apply firmly, especially around edges; may secure with adhesive tape if loose; fold sticky sides together and discard • Should be removed before MRI Epidural route • Used for severe cancer pain • May be used with opiates • Use only if familiar with epidural infu- sion devices C
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Assess: • Hypertension: B/P, pulse; report sig- nificant changes • Allergic reaction: rash, fever, pruritus, urticaria; product should be discontinued if antihistamines fail to help • HF: edema, dyspnea, wet crackles, B/P, more common in geriatric patients • ADHD: B/P, pulse, palpitations, syn- cope • Beers: avoid as first-line in older adults; high risk of CNS effects, bradycar- dia, orthostatic hypotension
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Evaluate: • Therapeutic response: decrease in B/P with hypertension, decrease in withdrawal symptoms (opioid), decrease in pain
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CLINICAL CONSIDERATIONS
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Patient and caregiver information: • To avoid hazardous activities and driv- ing until response is known, product may cause drowsiness • To notify all health care providers of medication use • Not to discontinue product abruptly or withdrawal symptoms may occur: anxi- ety, increased B/P, headache, insomnia, increased pulse, tremors, nausea, sweat- ing; to comply with dosage schedule even if feeling better • Not to use OTC (cough, cold, or al- lergy), alcohol, or CNS depressant prod- ucts unless directed by prescriber • To rise slowly to sitting or standing position to minimize orthostatic hypoten- sion, especially among geriatric patients • To notify prescriber of mouth sores, sore throat, fever, swelling of hands or feet, irregular heartbeat, chest pain, signs of angioedema • About excessive perspiration, dehy- dration, vomiting; diarrhea may lead to fall in B/P; consult prescriber if these occur; that product may cause dizziness, fainting; that light headedness may occur during first few days of therapy • That product may cause dry mouth; to use hard candy, saliva product, sugarless gum, or frequent rinsing of mouth • Not to skip or stop product unless di- rected by prescriber; tolerance may de- velop with long-term use • Transdermal: how to use patch; that patch comes in 2 parts: product patch and overlay to keep patch in place; not to trim or cut; that response may take 2-3 days, if switching from tablets to patch, to taper tablets to avoid withdrawal; to remove for MRI; can use during bathing, swimming
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PHARMACOKINETICS PO: Onset ½ to 1 hr, peak 2-4 hr, dura- tion 8-12 hr, half-life 6-12 hr TRANSDERMAL: Onset 3 days; duration 1 wk; metabolized by liver (metabolites); excreted in urine (45% unchanged, inac- tive metabolites), feces; crosses blood- brain barrier; excreted in breast milk
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• Child: PO 5-10 mcg/kg/day in divided doses q8-12hr, max 0.9 mg/day Severe pain
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• Child: CONTINUOUS EPIDURAL INFUSION 0.5 mcg/kg/hr, then titrate to response ADHD
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• Adolescent/child ≥6 yr: PO 0.05 mg/ kg/day in 3-4 divided doses, may increase by 0.1 mg/day weekly up to 0.4 mg/day; extended release 0.1 mg at bedtime, in- crease dose by 0.1 mg/day up to 0.4 mg/day
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