Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0020538 (hypertension)
 170,190 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Clonidine hydrochloride poisoning in children has become more frequent with increasing availability of this drug. We report four cases of accidental clonidine poisoning that demonstrate the various signs and symptoms of clonidine poisoning. The most frequent and significant toxic effects are depression of consciousness, bradycardia, hypotension, and respiratory depression. Ventilatory support must be available if apnea occurs. Bradycardia can be treated with atropine sulfate, epinephrine chloride, dopamine hydrochloride, or tolazoline hydrochloride. Hypotension is treated with intravenous fluids and dopamine, reserving tolazoline for refractory cases. Hypothermia is common but is of minor clinical significance. Paradoxical hypertension should be treated with tolazoline. Clonidine may not be detected in body fluids by routine toxicology-screening procedures, so poisoning should be suspected on clinical grounds.
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PMID:Clonidine poisoning. A complex problem. 684 4

Clonidine hydrochloride (Catapres), a potent antihypertensive agent, has been in clinical use since 1974 in the United States. Clonidine, an alpha-adrenergic receptor agonist, stimulates central alpha receptors in the depressor site of the vasomotor center of the medulla oblongata and hypothalamus, which diminishes efferent sympathetic tone to the heart, kidneys, and peripheral vasculature with a concomitant increase in vagal activity. Hemodynamic and renal effects include reduction in supine and erect blood pressure, heart rate, total peripheral resistance, plasma renin activity, and urinary aldosterone and catecholamine excretion, with little effect on resting cardiac output, response to exercise, and preservation of renal function. Clonidine alone produces a significant reduction in mean arterial pressure in all degrees of hypertension during acute and chronic administration, with little or no tendency toward tolerance or postural hypotension. Its antihypertensive potency is enhanced with the concomitant use of a diuretic or vasodilator, and it may be used in place of a beta blocker with equal efficacy in the diuretic plus vasodilator combination. Serious adverse effects are uncommon, with more than 93% of patients tolerating the drug well. Sedation and dry mouth, the most common adverse effects, are usually related to dose and duration and are minimized by gradually increasing the dose and by taking the major portion of the twice-daily schedule at bedtime. Clonidine may be safely given to patients with congestive heart failure, ischemic heart disease, obstructive lung disease, chronic renal insufficiency, and diabetes mellitus. Clonidine is one of the most versatile and effective agents presently available for the treatment of hypertension.
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PMID:Clonidine hydrochloride. 704 65

The pharmacokinetic as well as pharmacodynamic properties of a transdermal clonidine, M-5041T (M) and its safety were compared with those of oral clonidine, Catapres (Nippon Boehringer Ingelheim, Hyogo, Japan). One patch of M containing 6 mg of clonidine was applied on the right chest for 3 days or one tablet of Catapres (.075 mg) was given orally every 12 hours for 3 days in eight healthy subjects. The study was conducted by a crossover design with 14 to 16 days' interval between the cross-over. Blood and urine samples for clonidine concentration were obtained, and blood pressure (BP) was measured for a 168-hour period after application of M and for a 96-hour period after initiation of Catapres therapy. Plasma concentration of clonidine increased gradually after application of M and decreased gradually after removal, whereas this parameter increased rapidly during the absorption phase and decreased rapidly in the elimination phase after each dosage of Catapres. Elimination half-life of clonidine after removal of M was significantly greater than that after the final dosage of Catapres. No significant difference was observed in maximum plasma concentration or area under the plasma concentration-time curve between the two trials. The BP lowering effects of M and Catapres did not differ significantly. Adverse symptoms occurred more frequently during Catapres therapy than during treatment with M. Most of these symptoms were observed when plasma clonidine concentration was relatively higher in each trial. These results suggest that M is effective for the treatment of hypertension with a lower incidence of adverse symptoms.(ABSTRACT TRUNCATED AT 250 WORDS)
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PMID:Comparison of the pharmacokinetics, pharmacodynamics, and safety of oral (Catapres) and transdermal (M-5041T) clonidine in healthy subjects. 802 35

Blood pressure control is an important part of any surgical procedure and is especially important during rhytidectomy to reduce the risk of bleeding, improve visualization, and reduce the risk of postoperative fluid accumulations. For patients given general anesthetic, b blood pressure control is regulated by intravenous fluids, inhalational gas concentrations, and pharmacologic manipulation. For those given local anesthetic with intravenous sedation, blood pressure manipulation can be difficult. Clonidine (Catapres, Boehringer Ingelheim) has been shown to effectively reduce blood pressure in individuals with hypertension, as well as those with normal blood pressure. We compared both intraoperative and postoperative blood pressure, pulse, and drug use, as well as complications in 100 patients treated with preoperative oral clonidine (0.1 mg) and in 100 patients who did not receive clonidine. The group that received clonidine had reduced systolic, diastolic, and mean blood pressure, and pulse rate (114/64, 80, 79 vs 129/74, 92, 86, p<0.001). Blood pressure measured 12 hours after surgery remained lower in the clonidine group (119/67 vs 126/72, p<0.001). There was no difference in intraoperative diazepam (Valium) or midazolem (Versed) requirements. Intraoperative fentanyl requirements were lower in the non-Catapres-treated group. Postoperative narcotic requirements were reduced in the clonidine-treated group. The patients treated with clonidine had a lower rate of hematoma and postoperative antihypertensive drug requirement than the untreated group. We propose that clonidine is a safe and effective drug to use in the perioperative period in patients undergoing rhytidectomy to regulate blood pressure.
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PMID:Clonidine in the management of blood pressure during rhytidectomy. 1932 16


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