Clonidine Hydrochloride	(KLOE-nih-DEEN HIGH-droe-KLOR-ide)
Trade Name(s):	Catapres   ·Tablets 0.1 mg   ·Tablets 0.2 mg   ·Tablets 0.3 mg   Catapres-TTS-1   ·Transdermal system 2.5 mg   Catapres-TTS-2   ·Transdermal system 5 mg   Catapres-TTS-3   ·Transdermal System 7.5 mg   Duraclon   ·Injection 100?mcg/mL   ·Injection 500?mcg/mL APO-Clonidine Dixarit Indicates Canadian Trade Name.
Class:	Antiadrenergic Centrally acting analgesic
Action:	Stimulates central alpha-adrenergic receptors to inhibit sympathetic cardioaccelerator and vasoconstrictor centers. Absorption:
	Oral Oral - T max is about 3 to 5 h.
	Epidural Epidural - C max is about 4.4 ng/mL. T max is about 19 min.
	Transdermal Transdermal - Therapeutic levels are achieved in 2 to 3 days.
	Distribution: Vd is about 2.1 L/kg. Clonidine is 20% to 40% protein bound.
	IV IV - Distribution t ½ is about 11 min.
	Metabolism: About 50% metabolized in the liver. The major metabolite is p-hydroxyclonidine.
	Excretion:
	Oral Oral - The t ½ is 12 to 16 h. 40% to 60% is excreted unchanged in urine in 24 h.
	IV IV - The t ½ is about 9 h. 72% is excreted in urine in 96 h (40% to 50% as unchanged drug). Renal Cl is about 133 mL/min. Cl is about 219 mL/min.
	Epidural Epidural - The t ½ is about 22 h. Cl is about 190 ? min.
	Transdermal Transdermal - After removal, therapeutic levels persist for about 8 h and decline slowly over several days.
	Onset:
	Oral Oral - 30 to 60 min.
	Peak:
	Oral Oral - 2 to 4 h.
	Special Populations: Renal Function Impairment - The t ½ increases up to 41 ? h in those with severe renal impairment. Dosage adjustment is recommended.
Indications:	Management of hypertension. Used in combination with opiates for epidural use for relief of cancer pain.
Indications:	Unlabeled use(s): Treatment of constitutional growth delay in children; diabetic diarrhea; Tourette syndrome; hypertensive urgencies; menopausal flushing; postherpetic neuralgia; diagnosis of pheochromocytoma; ulcerative colitis; reduction of allergen-induced inflammatory reactions in patients with extrinsic asthma; facilitation of smoking cessation; alcohol withdrawal; methadone/opiate detoxification.
Contraindications:	Hypersensitivity to clonidine or any component of adhesive layer of transdermal system.
	Injection In the presence of an injection-site infection; patients on anticoagulant therapy; patients with a bleeding diathesis; administration above the C4 dermatome because there are not adequate safety data to support such use.
Interactions:
	Alcohol, CNS depressants Clonidine may enhance depressant effects.
	Beta-adrenergic blocking agents May increase potential for rebound hypertension when clonidine therapy is discontinued.
	Local anesthetics Epidural clonidine may prolong the duration of pharmacologic effects of epidural local anesthetics, including sensory and motor blockade.
	Narcotic analgesics May potentiate the hypotensive effects of clonidine.
	Tricyclic antidepressants May reduce effect of clonidine.
Lab Test Interferences:	None well documented.
Adverse Reactions:
	cardiovascular: CHF; orthostatic symptoms; palpitations; tachycardia; bradycardia.
	cns: Drowsiness; dizziness; sedation; nightmares; insomnia; nervousness or agitation; headache; fatigue; hypotension (epidural only); confusion (epidural only).
	dermatologic: Rash; urticaria; erythema (with transdermal form); transient localized skin reactions; pruritus.
	eent: Itching, burning, or dry eyes; retinal degeneration; dry nasal polyps.
	gi: Dry mouth; constipation; anorexia; nausea; vomiting.
	gu: Impotence; decreased libido; nocturia; difficulty in micturition; urinary retention.
	metabolic: Weight gain; gynecomastia; transient elevations in blood glucose or serum creatinine phosphokinase.
	miscellaneous: Increased sensitivity to alcohol; pallor; muscle weakness; muscle or joint pain; cramps of lower limbs; weakly positive Coombs test.
Precautions:
Warning:	Not recommended for obstetrical, postpartum, or perioperative pain management as the risk of hemodynamic instability (eg, hypotension, bradycardia) may be unacceptable in this population. Dilute the 500 mcg/mL strength prior to use.
	Monitoring:
	BP Assess BP and apical pulse before administering drug. If systolic BP is less than 90 ? mm ? Hg or pulse is less than 60 bpm, withhold drug and notify health care provider.
	Epidural Implantable epidural catheters are associated with a risk of catheter-related infections. Evaluation of fever in a patient receiving epidural clonidine should include the possibility of a catheter-related infection such as meningitis or epidural abscess.
	Rash/Skin irritation Note any rash or skin irritation when removing patch.
	Pregnancy: Category C .
	Lactation: Excreted in breast milk.
	Children: Restrict the use of clonidine to children with severe intractable pain from malignancy that is unresponsive to epidural or spinal opiates or other more conventional analgesia techniques. Select the starting dose on a per kilogram basis (0.5 mcg/kg/h) and cautiously adjust based on clinical response.
	Elderly: Reduced dosage may be required.
	Labor and delivery: Use of epidural clonidine during labor and delivery is not indicated.
	Debilitated patients Reduced dosage may be required.
	Cardiac effects Clonidine frequently causes decreases in heart rate. Rarely, AV block greater than first degree has been reported. Clonidine does not alter the hemodynamic response to exercise but may mask the increase in heart-associated hypovolemia.
	Depression Depression is commonly seen in cancer patients and may be exacerbated by clonidine treatment.
	Hypotension Because severe hypotension may follow clonidine administration, use with caution in all patients. It is not recommended in most patients with severe CV disease or in those who are otherwise hemodynamically unstable. Balance the benefit of administration in these patients against the potential risks resulting from hypotension. Monitor vital signs frequently, especially during the first few days of epidural administration. When clonidine is infused into the upper thoracic spinal segments, more pronounced decreases in BP may be seen.
	Perioperative considerations Continue clonidine therapy to within 4 h of surgery and resume as soon as possible thereafter.
	Rebound hypertension Discontinue therapy by reducing dose gradually over 2 to 4 days to avoid rapid increase in BP.
	Respiratory depression and sedation Clonidine administration may result in sedation. High clonidine doses cause sedation and ventilatory abnormalities that are usually mild. Tolerance to these effects can develop with chronic administration.
	Sensitization to transdermal clonidine Generalized skin rash may develop in patients with localized reaction to patch if they are switched to oral clonidine.
Overdosage:	Signs & symptoms Bradycardia, hypotension, CNS depression, respiratory depression, constricted pupils, seizures, lethargy, agitation, vomiting, hypothermia, drowsiness, decreased or absent reflexes, irritability.