Dixarit


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cloNIDine

(klon-i-deen) ,

Catapres

(trade name),

Catapres-TTS

(trade name),

Dixarit

(trade name),

Duraclon

(trade name),

Kapvay

(trade name)

Classification

Therapeutic: antihypertensives
Pharmacologic: adrenergics
Pregnancy Category: C

Indications

Oral: Transdermal: Mild to moderate hypertension. Oral: Attention-deficit hyperactivity disorder (ADHD) (as monotherapy or as adjunctive to stimulants) (Kapvay only). Epidural: Management of cancer pain unresponsive to opioids alone.Management of opioid withdrawal.Adjunctive treatment of neuropathic pain.

Action

Stimulates alpha-adrenergic receptors in the CNS, which results in decreased sympathetic outflow inhibiting cardioacceleration and vasoconstriction centers.
Prevents pain signal transmission to the CNS by stimulating alpha-adrenergic receptors in the spinal cord.

Therapeutic effects

Decreased BP.
Decreased pain.
Improvement in ADHD symptoms.

Pharmacokinetics

Absorption: Well absorbed from the GI tract and skin. Enters systemic circulation following epidural use. Some absorption follows sublingual administration.
Distribution: Widely distributed; enters CNS. Crosses the placenta readily; enters breast milk in high concentrations.
Metabolism and Excretion: Mostly metabolized by the liver; 40–60% eliminated unchanged in urine.
Half-life: Neonates—44–72 hr; Children—8–12 hr; Adults: Plasma—12–16 hr (↑ in renal impairment); CNS—1.3 hr.

Time/action profile (PO, TD = antihypertensive effect; epidural = analgesia)

ROUTEONSETPEAKDURATION
PO30–60 min1–3 hr8–12 hr
Transdermal2–3 daysunknown7 days†
Epiduralunknownunknownunknown
†8 hr following removal of patch

Contraindications/Precautions

Contraindicated in: Hypersensitivity;Epidural—injection site infection, anticoagulant therapy, or bleeding problems.
Use Cautiously in: Serious cardiac or cerebrovascular disease;Renal insufficiency; Pediatric: Safety and efficacy not established for ADHD in children <6 yr; evaluation for cardiac disease should precede initiation of therapy for ADHD in children; Geriatric: Appear on Beers list due to ↑ risk of orthostatic hypotension and adverse CNS effects in geriatric patients (↓ dose recommended); Obstetric / Lactation: Safety not established.

Adverse Reactions/Side Effects

Central nervous system

  • drowsiness (most frequent)
  • depression
  • dizziness
  • hallucinations
  • nervousness
  • nightmares

Ear, Eye, Nose, Throat

  • dry eyes

Cardiovascular

  • AV block
  • bradycardia
  • hypotension (↑ with epidural)
  • palpitations

Gastrointestinal

  • dry mouth (most frequent)
  • constipation
  • nausea
  • vomiting

Genitourinary

  • erectile dysfunction

Dermatologic

  • rash
  • sweating

Fluid and Electrolyte

  • sodium retention

Metabolic

  • weight gain

Neurologic

  • paresthesia

Miscellaneous

  • withdrawal phenomenon (most frequent)

Interactions

Drug-Drug interaction

Additive sedation with CNS depressants, including alcohol, antihistamines, opioid analgesics, and sedative/hypnotics.Additive hypotension with other antihypertensives and nitrates.Additive bradycardia with beta blockers, diltiazem, verapamil, or digoxin.MAO inhibitors, amphetamines, or tricyclic antidepressants may ↓ antihypertensive effect.Withdrawal phenomenon may be ↑ by discontinuation of beta blockers.Epidural clonidine prolongs the effects of epidurally administered local anesthetics.May ↓ effectiveness of levodopa.

Route/Dosage

Oral (Adults and Adolescents ≥12 yr) Hypertension (immediate-release)—100 mcg (0.1 mg) BID, ↑ by 100–200 mcg (0.1–0.2 mg)/day q 2–4 days; usual maintenance dose is 200–600 mcg (0.2–0.6 mg)/day in 2–3 divided doses (up to 2.4 mg/day). Urgent treatment of hypertension (immediate-release)—200 mcg (0.2 mg) loading dose, then 100 mcg (0.1 mg) q hr until BP is controlled or 800 mcg (0.8 mg) total has been administered; follow with maintenance dosing; Opioid withdrawal (immediate-release)—300 mcg (0.3 mg)–1.2 mg/day, may be ↓ by 50%/day for 3 days, then discontinued or ↓ by 100–200 mcg (0.1–0.2 mg)/day.
Oral (Geriatric Patients) Hypertension (immediate–release)—100 mcg (0.1 mg) at bedtime initially, ↑ as needed.
Oral (Children) Hypertension (immediate-release)—Initial 5–10 mcg/kg/day divided BID-TID, then ↑ gradually to 5–25 mcg/kg/day in divided doses q 6 hr; maximum dose: 0.9 mg/day. ADHD (Kapvay-extended release) (children >6 yr)—0.1 mg once daily at bedtime; after 1 wk, ↑ dose to 0.1 mg in AM and at bedtime; after 1 wk, ↑ dose to 0.1 mg in AM and 0.2 mg at bedtime; after 1 wk, ↑ dose to 0.2 mg in AM and at bedtime (max dose = 0.4 mg/day). ADHD (Immediate release) (children >6 yr, <45 kg)—0.05 mg once daily at bedtime; then ↑ q 3–7 days to 0.05 mg BID; then 0.05 mg TID; then 0.05 mg QID. Neuropathic pain (immediate-release)—2 mcg/kg/dose q 4–6 hr then ↑ gradually over days up to 4 mcg/kg/dose q 4–6 hr.
Oral (Neonates) Neonatal abstinence syndrome—0.5–1 mcg/kg/dose q 4–6 hr. Once stabilized taper by 0.25 mcg/kg/dose q 6 hr.
Transdermal (Adults) Hypertension—Transdermal system delivering 100–300 mcg (0.1–0.3 mg)/24 hr applied every 7 days. Initiate with 100 mcg (0.1 mg)/24 hr system; dosage increments may be made q 1–2 wk when system is changed.
Transdermal (Children) Once stable oral dose is reached, children may be switched to a transdermal system equivalent closest to the total daily oral dose.
Epidural (Adults) 30 mcg/hr initially; titrated according to need.
Epidural (Children) 0.5 mcg/kg/hr initially; titrated according to need up to 2 mcg/kg/hr.

Availability (generic available)

Tablets: 25 mcg (0.025 mg), 100 mcg (0.1 mg), 200 mcg (0.2 mg), 300 mcg (0.3 mg) Cost: Generic — 0.1 mg $6.80 / 100, 0.2 mg $6.99 / 100, 0.3 mg $6.99 / 100
Extended-release tablets (Kapvay): 0.1 mg, 0.2 mg Cost: All strengths $366.60 / 60
Transdermal systems: Catapres-TTS 1, releases 0.1 mg/24 hr, Catapres-TTS 2, releases 0.2 mg/24 hr, Catapres-TTS 3, releases 0.3 mg/24 hr Cost: Generic — 0.1 mg/24 hr $132.49 / 4 patches, 0.2 mg/24 hr $223.06 / 4 patches, 0.3 mg/24 hr $309.44 / 4 patches
Solution for epidural injection (Duraclon): 100 mcg/mL, 500 mcg/mL
In combination with: chlorthalidone (Clorpres). See combination drugs.

Nursing implications

Nursing assessment

  • Hypertension: Monitor intake and output ratios and daily weight, and assess for edema daily, especially at beginning of therapy.
  • Monitor BP and pulse prior to starting, frequently during initial dose adjustment and dose increases and periodically throughout therapy. Titrate slowly in patients with cardiac conditions or those taking other sympatholytic drugs. Report significant changes.
  • Pain: Assess location, character, and intensity of pain prior to, frequently during first few days, and routinely throughout administration.
    • Monitor for fever as potential sign of catheter infection.
  • Opioid Withdrawal: Monitor patient for signs and symptoms of opioid withdrawal (tachycardia, fever, runny nose, diarrhea, sweating, nausea, vomiting, irritability, stomach cramps, shivering, unusually large pupils, weakness, difficulty sleeping, gooseflesh).
  • ADHD: Assess attention span, impulse control, and interactions with others.
  • Lab Test Considerations: May cause transient ↑ in blood glucose levels.
    • May cause ↓ urinary catecholamine and vanillylmandelic acid (VMA) concentrations; these may ↑ on abrupt withdrawal.
    • May cause weakly positive Coombs’ test result.

Potential Nursing Diagnoses

Chronic pain (Indications)
Impaired social interaction (Indications)
Risk for injury (Side Effects)

Implementation

  • Do not confuse Catapres (clonidine) with Cataflam (diclofenac).
    • Do not confuse clonidine with clonazepam (Klonopin).
    • Do not confuse clonidine with clozapine.
    • Do not substitute between clonidine products on a mg-per-mg basis, because of differing pharmacokinetic profiles.
    • In the perioperative setting, continue clonidine up to 4 hr prior to surgery and resume as soon as possible thereafter. Do not interrupt transdermal clonidine during surgery. Monitor BP carefully.
  • Oral: Administer last dose of the day at bedtime. May be taken without regard for food.
    • Swallow extended-release tablets whole; do not crush, break, or chew
  • Transdermal: Transdermal system should be applied once every 7 days. May be applied to any hairless site; avoid cuts or calluses. Absorption is greater when placed on chest or upper arm and decreased when placed on thigh. Rotate sites. Wash area with soap and water; dry thoroughly before application. Apply firm pressure over patch to ensure contact with skin, especially around edges. Remove old system and discard. System includes a protective adhesive overlay to be applied over medication patch to ensure adhesion, should medication patch loosen.
  • Epidural: Dilute 500 mcg/mL with 0.9% NaCl for a concentration of 100 mcg/mL. Do not administer solutions that are discolored or contain a precipitate. Discard unused portion.

Patient/Family Teaching

  • Instruct patient to take clonidine at the same time each day, even if feeling well. Take missed dosed as soon as remembered. If dose of extended-release product is missed, omit dose and take next dose as scheduled. Do not take more than the prescribed daily dose in any 24 hr. If more than 1 oral dose in a row is missed or if transdermal system is late in being changed by 3 or more days, consult health care professional. All routes of clonidine should be gradually discontinued over 2–4 days to prevent rebound hypertension.
    • Advise patient to make sure enough medication is available for weekends, holidays, and vacations. A written prescription may be kept in wallet in case of emergency.
    • May cause drowsiness, which usually diminishes with continued use. Advise patient to avoid driving or other activities requiring alertness until response to medication is known.
    • Caution patient to avoid sudden changes in position to decrease orthostatic hypotension. Use of alcohol, standing for long periods, exercising, and hot weather may increase orthostatic hypotension.
    • If dry mouth occurs, frequent mouth rinses, good oral hygiene, and sugarless gum or candy may decrease effect. If dry mouth continues for more than 2 wk, consult health care professional.
    • Caution patients with contact lenses that clonidine may cause dryness of eyes.
    • Caution patient to avoid concurrent use of alcohol or other CNS depressants with this medication.
    • Instruct patient to notify health care professional of all Rx or OTC medications, vitamins, or herbal products being taken and to consult health care professional before taking any other Rx, OTC, or herbal products, especially cough, cold, or allergy remedies.
    • Advise patient to notify health care professional of medication regimen prior to treatment or surgery.
    • Advise patient to notify health care professional if itching or redness of skin (with transdermal patch), mental depression, swelling of feet and lower legs, paleness or cold feeling in fingertips or toes, or vivid dreams or nightmares occur. May require discontinuation of therapy, especially with depression.
  • Hypertension: Encourage patient to comply with additional interventions for hypertension (weight reduction, low-sodium diet, discontinuation of smoking, moderation of alcohol consumption, regular exercise, and stress management). Medication helps control but does not cure hypertension.
    • Instruct patient and family on proper technique for BP monitoring. Advise them to check BP at least weekly and report significant changes.
  • Transdermal: Instruct patient on proper application of transdermal system. Do not cut or trim unit. Transdermal system can remain in place during bathing or swimming.
    • Advise patient referred for MRI test to discuss patch with referring health care professional and MRI facility to determine if removal of patch is necessary prior to test and for directions for replacing patch.
  • Pediatric: Advise parents to notify school nurse of medication regimen.

Evaluation/Desired Outcomes

  • Decrease in BP.
  • Decrease in severity of pain.
  • Decrease in the signs and symptoms of opioid withdrawal.
  • Improved attention span and social interactions in ADHD.

Dixarit

A brand name for CLONIDINE.