No abstract available.
Bupivacaine* ; Clonidine* ; Yohimbine

Background: Epidural anesthesia is a widely used anesthesia technique commonly for surgeries involving the lower extremities up to the abdomen.It is beneficial for long duration surgeries because the epidural catheter in place allows additional of local anesthetic as needed. However, this technique has a slower onset of action and requires a larger volume of local anesthetic compared with spinal anesthesia. This study aims to determine if clonidine when used as an adjuvant can hasten the onset of action of levobupivacaine epidural anesthesia thus allowing the early commencement of surgery. Methodology: This is a double blind randomized controlled trial. After approval from the institution‘s research ethics and review committee,a total of 36 patients of American Society of Anesthesiologist ClassificationI or II for elective lower limb orthopedic surgery under levobupivacaine epidural anesthesia were purposively enrolled in this study and randomly assigned by match pairing of characteristics to two groups: GroupA—Clonidine and Group B—plain normal saline solution. Group A were given 0.5% levobupivocaine 15cc with 30 yg (0.2cc) clonidine and groupB were given 0.5% levobupivocaine 15cc with 0.2cc plain normal saline solution. In both groups the onset of levobupivacaine epidural anesthesia (sensory block atT10dermotomal level/Bromage 1) were observed. Side effects such as hypotension, decreased in respiratory rate, oxygen saturation, and any untoward incidence were noted. All data gathered: statistical mean, median, standard deviation, and T test were analyzed using the SPSS software at 5% significance level. Results: The mean onset of action of group A— Clonidine group (5.62 minutes) was foster compared to group B—control (11.33 minutes), which was statistically significant (P«0.05). The highest dermotomal level for the clonidine group was at T6 and T7forthecontrol group. Two segments regression was at 180 minutes forthe Clonidine group while 60 minutes for the control group. The patients given clonidine experienced side effects such as sedation, bradycardio (20% decrease in cardiac rote from baseline), and shivering. Hypotension was not observed in both clonidine and control groups. Conclusion Clonidine ata dose of30 |Jgwhen used as an adjuvant to levobupivacaine epidural anesthesia can hasten its onset of action among patients undergoing elective lower limb orthopedic surgery.
Anesthesia, Epidural ; Clonidine

No abstract available.
Clonidine ; Horner Syndrome ; Meningitis, Viral

The antihypertensive effect of clonidine was evaluated in 129 patients with essential hypertension of mild to moderate severity with a dosage of one tablet(0.075mg) a day for 71 patients of Group I and two tablets a day for 58 patients of Group II. The results were as follows : 1) Of 71 patients of Group I, 34 patients(47.9%)showed good antihypertensive effect(greater than 15 mmHg drop in mean diastolic pressure) and 11 patients(15.5%) showed fair effect(10-14 mmHg drop in mean diastolic pressure). 2) Of 58 patients of Group II, 39 patients(67.2%) showed good effect and 7 patients(12.1%) showed fair effect. 3) The side effect observed was transient and tolerable dry mouth, which developed in 5.6% of Group I patients and 13.6% of Group II patients.
Clonidine* ; Humans ; Hypertension ; Mouth ; Tablets

The influence of clonidine on the analgesic effect of epidural fentanyl was investigated in 45 patients who underwent total abdominsl hysterectomy by epidural admistration of fentanyl 100 g alone, clonidine 150ug alone, or in combination of the two drugs. Changes in the mean arteral pressure and pulse rate were observed after drug administration, and the analgesic effects was assessed by measuring analgesic duration, pain score, sedation score, and side effects. Analgesic duration was prolonged with improved quality by adding 150 ug of clonidine to 100 ug of epidural fentanyl. Mean arteral pressure and pulse rate were decreased more in fentanyl plus clonidine group than each drug alone group. But these changes were restored rapidly by injection of small dose of vasopressor. The clonidine alone group showed the least analgesic effect among three groups indicatings that clonidine would not be a sole analgesic agent and would be used as an adjunct to other opiate such as fentanyl.
Clonidine* ; Fentanyl* ; Heart Rate ; Humans ; Hysterectomy

Coronary spasm may be induced by a variety of physiologic and pharmacologic stimuli but specific receptor blockade has not been consistently shown to prevent the attacks. Most patients with variant angina respond well to treatment with calcium antagonists and nitrates. A small proportion of patients are refractory to this therapy. We report a case of the patient with a 9-year-history of variant angina who has been refractory to high doses of calcium antagonists and nitrates. The repeated addition of clonidine was consistently effective in abolishing both symptoms and objective evidence of myocardial ischemia in this particular patient.
Calcium ; Clonidine* ; Humans ; Myocardial Ischemia ; Nitrates ; Spasm

1) The author investigated whether presynaptic alpha-adrenoceptors exist in the cardioaccelerator nerves of cold-blooded animals(frog, tortoise) as in ones of in mammals. 2) Each atrial preparation of a frog, tortoise and guinea-pig produced the positive chronotropic and inotropic responces to field stimulation. Each ventricular muscle preparation of frog and tortoise produced positive inotropic responces to field stimulation. 3) Both the responces of frog atrium and the inotropic response of frog ventrice to the stimulation were abolished or markedly inhibited by the presence of tetrodotoxin, guanethidine and proparanolo. Both responses of tortoise atrium to the stimulation were markedly inhibited by propranolol and the inotropic response ventricle to the stimulation was markedly inhibited by tetrodotoxin. 4) Both responses of frog and tortoise atrium, and the inotropic response of frog and tortoise ventricle to the stimulation were not affected by clonidine and yohimbine. 5) Both responses of guinea-pig atrium to the stimulation were markedly inhibited in the presence of clonidine and this clonidine-induced inhibition was not observed in the presence of yohimbine. 6) The above results suggest that presynaptic alpha-adrenoceptors do not exist in the cardioaccelerator nerves of frog and tortoise, being different from those of mammalisn animals.
Animals* ; Clonidine ; Guanethidine ; Mammals ; Propranolol ; Tetrodotoxin ; Yohimbine

BACKGROUND: Clonidine is an alpha2-adrenergic drug used for analgesic effect, reducing sympathetic stimulation and anesthetic requirement. We examined the analgesic effect of clonidine on incisional pain after its intrathecal administration using a rat postincisional model. METHODS: After an intrathecal (IT) catheter insertion in 20 Spraw Dawley rats, they were divided into two groups; one group (Group S, n = 10) received a saline 20microl injection through an IT catheter, and another (Group C, n = 10) received clonidine 20microgram in 10microl volume followed by another 10microl of saline for washing the catheter. The measurements of the threshold of tactile allodynia (TTA) were performed at 20, 40, 60, 80, 120, 180 and 240 mins after the IT injection. Additionally, 1, 2 and 3 days after the first IT injection, IT injection and the measurements of TTA of pre- and post-injection were repeated. The measurements of TTA were performed in both areas, 5 mm (N-area) and 10 mm (R-area) away from incision by using von Frey hair and up-down method. RESULTS: TTA (N-area) and TTA (R-area) during 4 hours after IT injection in Group C were greater than those in Group S (P< 0.05). TTA (N-area) of post-injection 2 and 3 days after the first IT injection were greater than those of pre-injection in Group C (P< 0.05), and TTA (R-area) after the IT injection 1, 2 and 3 days after the first IT injection were greater than those of pre-injection in Group C (P< 0.05). CONCLUSIONS: A single IT injection of clonidine 20microgram had analgesic effects lasting more than 4 hours in the rat postincisional model. Additional IT clonidine could show antiallodynic effects during three days after the first IT clonidine.
Animals ; Catheters ; Clonidine* ; Hair ; Hyperalgesia ; Rats*

BACKGROUND: In anesthesia, clonidine has been proven to be clinically useful in producing sedation, anxiolysis, and decreasing the requirement for both general and regional anesthetics. Studies have shown that oral clonidine is able to prolong the duration of spinal anesthesia when bupivacaine or isobaric tetracaine is used. This study was conducted to determine the effects of oral clonidine premedication on the duration of hyperbaric tetracaine spinal anesthesia. METHODS: Forty-six patients for lower extremity and perineal surgery under hyperbaric tetracaine spinal anesthesia were randomly grouped into two: group I - control and group II - clonidine. The clonidine group received 150 mcg oral clonidine premedication 1 hour prior to the spinal anesthesia. Sensory level was measured using the pinprick method. The onset, maximal sensory block, duration and the hemodynamic variables were determined and compared between the two groups. RESULTS: No significant differences were noted as to onset and the maximal level of sensory blockade. The mean duration of sensory analgesia was significantly prolonged in the clonidine group (298.33 min) as compared to the control group (176.73 min). Hemodynamic variables were significantly decreased in the clonidine group. CONCLUSION: This study demonstrated that 150 mcg oral clonidine given 1 hour prior to tetracaine spinal anesthesia significantly prolonged the duration of the blockade.
Human ; ANESTHESIA, SPINAL ; HEMODYNAMICS ; CLONIDINE ; BUPIVACAINE

BACKGROUND: Clonidine, an alpha-agonist has been postulated to produce analgesia centrally by stimulating the post-synaptic activity of norepinephrine through receptors distinct from opioid receptors and peripherally through a mechanism similar to local anesthetics. It has been suggested that the use of a combination of local anesthetics and clonidine both at lower doses may be effective in providing adequate analgesia at the same time minimizing the deleterious side effects of each drug when used alone at higher doses. The objective of the study was the determination of the minimum dosage of clonidine in combination with bupivacaine necessary for epidural administration that would provide optimal intraoperative and postoperative analgesia with the least occurrence of side effects such as hypotension and bradycardia. METHODOLOGY: One hundred randomly selected, healthy ASA l and 2 gynecologic patients undergoing lower abdominal surgery under epidural anesthesia were given bupivacaine 0.5 percent epidurally compounded with either saline as placebo (Group 1), or clonidine in variable doses: 0.5 ug/kg (Group 2), 1.0 ug/kg (Group 3), and 1.5 ug/kg (Group 4) in a randomized, double-blind fashion. The vital signs were noted every 5 minutes. Analgesia was monitored and recorded using the Visual Analog Scale (VAS), Verbal Rate Scoring and the systemic indicators of pain perception (SBP 30 min Hg increase from baseline or heart rate 20 percent from baseline). A top-up dose of Lidocaine 2 percent was given with systemic indications of pain perception noted intraoperatively or rescue doses of opioids were given when the systemic indications of pain perception were noted at the post anesthesia care unit, upon which data collection was terminated Eighty two patients completed the course of data collection while eighteen were dropped out because of sacral sparing, retraction pain and extension of incision. The statistical tool utilized to test significant differences between the groups was the Kruskal-Wallis Analysis of Variance test and the Partitioned Chi-square test. RESULTS: There is prolongation in the duration of analgesia with incremental increase in clonidine dose. Hypotension occurred even without the addition of clonidine with higher incidence as the dose of clonidine increased. The least side effects occurred with doses of clonidine between 0.5 and 1.0 ug/kg. CONCLUSION: The optimal dosage of clonidine for intraoperative analgesia that would extend to the postoperative period in Filipino women would fall between 0.5 to 1.0 ug/kg. (Author)
Human ; ANALGESIA ; BUPIVACAINE ; CLONIDINE ; ANALGESIA, EPIDURAL