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At least 127 records · Page 7Linked to original sources

PubMed2003

Comparison of electroacupuncture and butorphanol on respiratory and cardiovascular effects and rectal pain threshold after controlled rectal distention in mares.

OBJECTIVE: To compare effects of electroacupuncture and butorphanol on hemodynamic and respiratory variables and rectal analgesia in mares after controlled rectal distention. ANIMALS: 8 healthy mares. PROCEDURE: Each horse received saline (0.9% NaCl) solution (0.01 mL/kg, IV; control treatment), butorphanol tartrate (0.1 mg/kg, IV), or 2 hours of electroacupuncture (EA) at acupoints Bladder 21, 25, and 27 on both sides of the vertebral column, Bai hui, and Stomach 36 (right side only). Order of treatments in each mare was randomized. At least 7 days elapsed between treatments. A balloon was inserted in the rectum of each mare, and controlled distention of the balloon (pressures of < or = 220 mm Hg) was used to measure nociceptive rectal pain threshold. Rectal temperature and cardiovascular and respiratory variables were measured before (baseline) and 5,15, 30, 60, 90, and 120 minutes after onset of each treatment. RESULTS: Butorphanol produced greater increases in rectal pain threshold, compared with EA (mean +/- SD, 214 +/- 24 vs 174 +/- 35 mm Hg of balloon pressure). Electroacupuncture produced minimal cardiovascular and respiratory changes. Although clinically not important, butorphanol produced moderate significant increases in heart and respiratory rates, arterial blood pressure, and rectal temperature and decreases in arterial oxygen tension. Arterial pH, carbon dioxide tension, bicarbonate concentrations, base excess, Hct, and concentration of total solids were not significantly different from baseline values after EA, butorphanol, and control treatments. CONCLUSIONS AND CLINICAL RELEVANCE: Electroacupuncture and butorphanol (0.1 mg/kg, IV) may provide useful rectal analgesia in horses.

Animals↗

PubMed2006

Effect of meloxicam and butorphanol on minimum alveolar concentration of isoflurane in rabbits.

OBJECTIVE: To determine the effects of meloxicam and butorphanol on minimum alveolar concentration of isoflurane (MAC(ISO)) in rabbits. ANIMALS: 10 healthy young adult female rabbits. PROCEDURE: Rabbits were anesthetized with isoflurane on 3 occasions in a blinded, randomized complete block design to determine the MAC(ISO) associated with administration of meloxicam (0, 0.3, or 1.5 mg/kg, PO) and butorphanol (0.4 mg/kg, IV). The MAC(ISO) was determined by use of a paw clamp technique as the end-tidal concentration of isoflurane halfway between the values that allowed or inhibited purposeful movement. Rectal temperature, end-tidal CO2 concentration, heart rate, oxygen saturation, and arterial blood pressure were measured to evaluate cardiopulmonary function. RESULTS: Mean +/- SE MAC(ISO) in saline (0.9% NaCl) solution-treated rabbits was 2.49 +/- 0.07% and was not significantly different from that associated with administration of meloxicam at 0.3 mg/kg (2.56 +/- 0.07%) or 1.5 mg/kg (2.66 +/- 0.07%). Butorphanol significantly reduced the MAC(ISO) to 2.30 +/- 0.07% when administered with saline solution alone, 2.27 +/- 0.07% when administered with 0.3 mg of meloxicam/kg, and 2.33 +/- 0.07% when administered with 1.5 mg of meloxicam/kg. The percentage reduction in MAC(ISO) was significantly greater for rabbits that received butorphanol and meloxicam at either dose, compared with butorphanol and saline solution. CONCLUSIONS AND CLINICAL RELEVANCE: Results indicated that meloxicam does not have a direct isoflurane-sparing effect and does not interfere with the anesthetic-sparing effect of butorphanol in rabbits.

Analgesics, Non-Narcotic↗

PubMed2006

Serum concentrations and analgesic effects of liposome-encapsulated and standard butorphanol tartrate in parrots.

OBJECTIVE: To compare serum concentrations of liposome-encapsulated butorphanol tartrate (LEBT) and standard butorphanol tartrate (STDBT) following SC and IM administration, respectively, and to evaluate analgesic effects of LEBT and STDBT after parenteral administration to Hispaniolan parrots. ANIMALS: 11 adult Hispaniolan parrots. PROCEDURE: The ability of LEBT to prolong the duration of analgesia in an avian species was tested. Blood samples were collected at serial time points after SC administration of LEBT (10 mg/kg or 15 mg/kg) or IM administration of STDBT (5 mg/kg). Serum concentrations of butorphanol tartrate were determined by use of a commercial immunoassay that measured parent drug and metabolites. Analgesic efficacy was evaluated in parrots exposed to electrical and thermal stimuli. Foot withdrawal thresholds were recorded at baseline and at serial time points after LEBT (15 mg/kg), liposome vehicle, STDBT (2 mg/kg), or physiologic saline (0.9% NaCl) solution administration. RESULTS: LEBT had a prolonged in vivo release for up to 5 days. Negligible serum butorphanol and butorphanol metabolite concentrations were obtained at 24 hours after IM administration of STDBT. Analgesic efficacy of LEBT as measured by foot withdrawal threshold to noxious thermal and electrical stimuli persisted for 3 to 5 days following SC administration of LEBT. CONCLUSIONS AND CLINICAL RELEVANCE: SC administration of LEBT provided analgesia and detectable serum butorphanol concentrations in Hispaniolan parrots for up to 5 days. The use of LEBT may allow for substantial improvement in long-term pain relief without subjecting birds to the stress of handling and multiple daily injections.

Amazona↗

PubMed2003

Postoperative hypoxemia and hypercarbia in healthy dogs undergoing routine ovariohysterectomy or castration and receiving butorphanol or hydromorphone for analgesia.

OBJECTIVE: To determine frequency and severity of postanesthetic hypoxemia and hypercarbia in healthy dogs undergoing elective ovariohysterectomy or castration and given butorphanol or hydromorphone for analgesia. DESIGN: Prospective trial. ANIMALS: 0 healthy dogs weighing > 10 kg (22 lb). PROCEDURE: Dogs were anesthestized with acepromazine, glycopyrrolate, thiopental, and isoflurane, and butorphanol (n = 10) or hydromorphone (10) was used for perioperative analgesia. Arterial blood gas analyses were performed 10 and 30 minutes and 1, 2, 3, and 4 hours after extubation. RESULTS: In dogs that received hydromorphone, mean PaCO2 was significantly higher, compared with the preoperative value, 10 and 30 minutes and 1, 2, and 3 hours after extubation. Mean PaCO2 was significantly higher in dogs given hydromorphone rather than butorphanol 10 and 30 minutes and 1 and 2 hours after extubation. Mean PaO2 was significantly lower, compared with preoperative values, 30 minutes and 1 and 2 hours after extubation in dogs given hydromorphone and 30 minutes after extubation in dogs given butorphanol. Mean PaO2 was significantly lower in dogs given hydromorphone rather than butorphanol 1 hour after extubation. Four dogs had PaO2 < 80 mm Hg 1 or more times after extubation. CONCLUSIONS AND CLINICAL RELEVANCE: Results suggest that administration of hydromorphone to healthy dogs undergoing elective ovariohysterectomy or castration may result in transient increases in PaCO2 postoperatively and that administration of hydromorphone or butorphanol may result in transient decreases in PaO2. However, increases in PaCO2 and decreases in PaO2 were mild, and mean PaCO2 and PaO2 remained within reference limits.

Analgesics, Opioid↗

PubMed1990

The use of butorphanol tartrate for the prevention of canine intussusception following renal transplantation.

Butorphanol tartrate (0.05 mg/kg, im) was included in the preanesthetic medication in 15 out of 29 conditioned female mongrel dogs (22.7-27.3 kg body wt) undergoing renal autotransplants as part of a 48-h kidney preservation study. Four postoperative intussusceptions were noted (3 jejunojejunal, 1 ileocolic) among the 14 dogs without butorphanol, whereas no intussusceptions developed in the 15 dogs receiving butorphanol as part of the preanesthetic protocol. In a prior study, 2 out of 18 dogs undergoing renal autotransplants without the use of butorphanol as part of a 24-h kidney preservation study developed intussusceptions (jejunojejunal). With the exception of butorphanol the anesthetic protocol was the same for all 47 dogs receiving transplants. Throughout these studies the surgical team remained constant, and all dogs were negative for parasites and systemic infectious disease pre- and postoperatively. The results indicate that the use of butorphanol tartrate as part of a preanesthetic protocol is effective in preventing canine intestinal intussusception following renal autotransplantation.

Animals↗

PubMed1999

The sedative and analgesic effects of detomidine-butorphanol and detomidine alone in donkeys.

Butorphanol and detomidine constitute an effective combination for sedation and analgesia in horses. This trial was undertaken to assess the effectiveness of this combination in donkeys. The detomidine and butorphanol were given intravenously one after the other. A dose of 10 microg/kg of detomidine and 25 microg/kg of butorphanol was used. Sedation is easily extended by additional doses of butorphanol. The average dose of detomidine was 11.24 microg/kg and that of butorphanol was 28.0 microg/kg. Four donkeys in the detomidine group required additional sedation and analgesia. Detomidine alone did not totally eliminate coronary band pain. Heart rates dropped significantly in the first minute after the injection of the combination. One donkey developed an atrioventricular block, while another developed a sino-atrial block. Four donkeys developed a Cheyne-Stokes respiratory pattern. The combination of detomidine and butorphanol is an effective combination for sedation and analgesia of donkeys for standing procedures.

Analgesics↗

PubMed1999

Analgesic effects of butorphanol and buprenorphine in conscious African grey parrots (Psittacus erithacus erithacus and Psittacus erithacus timneh).

OBJECTIVE: To evaluate effects of butorphanol tartrate and buprenorphine hydrochloride on withdrawal threshold to a noxious stimulus in conscious African grey parrots. ANIMALS: 29 African grey parrots (Psittacus erithacus erithacus and Psittacus erithacus timneh). PROCEDURE: Birds were fitted with an electrode on the medial metatarsal region of the right leg, placed into a test box, and allowed to acclimate. An electrical stimulus (range, 0.0 to 1.46 mA) was delivered to each bird's foot through an aluminum perch. A withdrawal response was recorded when the bird lifted its foot from the perch or vigorously flinched its wings. Baseline threshold to a noxious electrical stimulus was determined. Birds then were randomly assigned to receive an i.m. injection of saline (0.9% NaCl) solution, butorphanol (1.0 mg/kg of body weight), or buprenorphine (0.1 mg/kg), and threshold values were determined again. RESULTS: Butorphanol significantly increased threshold value, but saline solution or buprenorphine did not significantly change threshold values. CONCLUSIONS AND CLINICAL RELEVANCE: Butorphanol had an analgesic effect, significantly increasing the threshold to electrical stimuli in African grey parrots. Buprenorphine at the dosage used did not change the threshold to electrical stimulus. Butorphanol provided an analgesic response in half of the birds tested. Butorphanol would be expected to provide analgesia to African grey parrots in a clinical setting.

Analgesia↗

PubMed2003

Preliminary study of the effects of xylazine or detomidine with or without butorphanol for standing sedation in dairy cattle.

The sedative effect induced by administering xylazine hydrochloride or detomidine hydrochloride with or without butorphanol tartrate to standing dairy cattle was compared in two groups of six adult, healthy Holstein cows. One group received xylazine (0.02 mg/kg i.v.) followed by xylazine (0.02 mg/kg) and butorphanol (0.05 mg/kg i.v.) 1 week later. Cows in Group B received detomidine (0.01 mg/kg i.v.) followed by detomidine (0.01 mg/kg i.v.) and butorphanol (0.05 mg/kg i.v.) 1 week later. Heart rate, respiratory rate, and arterial blood pressure were monitored and recorded before drugs were administered and every 10 minutes for 1 hour after drug administration. The degree of sedation was evaluated and graded. Cows in each treatment group had significant decreases in heart rate and respiratory rate after test drugs were given. Durations of sedation were 49.0 +/- 12.7 minutes (xylazine), 36.0 +/- 14.1 (xylazine with butorphanol), 47.0 +/- 8.1 minutes (detomidine), and 43.0 +/- 14.0 minutes (detomidine with butorphanol). Ptosis and salivation were observed in cows of all groups following drug administration. Slow horizontal nystagmus was observed from three cows following administration of detomidine and butorphanol. All cows remained standing while sedated. The degree of sedation seemed to be most profound in cows receiving detomidine and least profound in cows receiving xylazine.

Animals↗

PubMed1986

Double-blind comparison of intravenous doses of dezocine, butorphanol, and placebo for relief of postoperative pain.

The safety and efficacy of intravenous doses of dezocine (5 or 10 mg), butorphanol (1 mg), and placebo were compared in a double-blind study in 160 patients with moderate to severe postoperative pain. Analgesic efficacy was assessed for 6 hours after each dose. Mean pain relief scores were consistently higher, indicating greater pain relief, for the three active treatment groups than for the placebo group. The 10-mg dezocine dose was the most effective treatment, and 5 mg of dezocine was comparable to 1 mg of butorphanol. In the 2 hours after the first dose, 32% of the 10-mg dezocine group, 53% of the 5-mg dezocine group, 65% of the butorphanol group, and 88% of the placebo group withdrew from the study because of unsatisfactory pain relief. The differences in these percentages were statistically significant (P less than 0.05) between each active therapy group and the placebo group, and between the 10-mg dezocine group and the butorphanol group. Changes in degree of sedation were similar in the three active therapy groups. Adverse reactions were rare, mild, and equally distributed among the four treatment groups. We conclude that 10 mg of dezocine is superior to 1 mg of butorphanol, and that 5 mg of dezocine is as effective as 1 mg of butorphanol for the relief of moderate to severe postoperative pain.

Adolescent↗

PubMed1988

Urological applications of butorphanol tartrate: postoperative pain and renal colic.

The analgesic efficacy and safety of butorphanol tartrate are discussed in 2 groups of patients who underwent urological procedures. The first group of 83 patients is presented as a retrospective review of the postoperative use of butorphanol. The second group of patients was involved in a double-blind, randomized comparative trial of butorphanol (2 or 4 mg) and meperidine (80 mg) for the relief of moderate to severe pain due to renal colic. Eighty-three patients with documented upper urinary tract calculi were evaluated for efficacy; 120 patients were evaluated for safety. Butorphanol 4 mg (i.m.) was more effective than butorphanol 2 mg (i.m.) and equivalent to meperidine 80 mg (i.m.). There were no statistically significant differences among the three treatment groups in regard to side effects. Overall, in the urology patients studied, butorphanol was found to be an effective and well tolerated agent that possesses important safety advantages when compared with the narcotic analgesics.

Adolescent↗

PubMed1979

Drug therapy reviews: evaluation of butorphanol tartrate.

The chemistry, pharmacology, uses, side effects, pharmacokinetics and dosage of butorphanol tartrate, a narcotic analgesic with antagonist properties, are reviewed. When administered intramuscularly or intravenously, butorphanol tartrate appears to be as effective for relieving moderate to severe pain as are pentazocine, meperidine and morphine. Butorphanol produces sedation more commonly and, at therapeutic dosages, depresses respiration as much as these other narcotic analgesics. A limited number of long-term clinical studies suggest a lower physical dependence liability with butorphanol than with other narcotic analgesics. Butorphanol is more expensive than morphine and, for most patients, offers no significant advantages over morphine for short-term use. Because butorphanol's cardiovascular effects are not completely understood, morphine also remains the drug of choice for pain associated with myocardial infarction.

Butorphanol↗

PubMed1984

Analgesic effects of butorphanol in horses: dose-response studies.

The analgesic effects of butorphanol (0.05, 0.1, 0.2, and 0.4 mg/kg), pentazocine (2.2 mg/kg), and butorphanol vehicle (0.04 ml/kg) were observed in 6 horses. These horses were instrumented to measure response objectively to painful superficial and visceral stimuli. The tested drugs were given IV according to a Latin square design. After preinjection base-line measurements were made, the analgesic effects were observed at 15 and 30 minutes and then at 30-minute intervals until postinjection minute 240. Analgesic effects of butorphanol were dose-related, with durations between 15 and 90 minutes. Duration of analgesia after pentazocine (2.2 mg/kg) was given was between 15 and 30 minutes. When compared with pentazocine, the 0.4 mg/kg dose of butorphanol provided a more intense and longer period of analgesia. A butorphanol dose of 0.2 mg/kg IV appears optimal. On a dose-body weight basis, the potency of butorphanol was 10 to 17 times that of pentazocine. Behavioral side effects were noted with both agents and were dose-related.

Analgesia↗

PubMed1996

A comparison of ketorolac with flunixin, butorphanol, and oxymorphone in controlling postoperative pain in dogs.

Ketorolac tromethamine, a nonsteroidal anti-inflammatory analgesic, was compared with flunixin and butorphanol for its analgesic efficacy and potential side effects after laparotomy or shoulder arthrotomy in dogs. Sixty-four dogs were randomly assigned to receive butorphanol 0.4 mg/kg body weight (BW) (n = 21), flunixin 1.0 mg/kg BW (n = 21), or ketorolac 0.5 mg/kg BW (n = 22), in a double blind fashion. The analgesic efficacy was rated from 1 to 4 (1 = inadequate, 4 = excellent) for each dog. The average scores after laparotomy were ketorolac, 3.4; flunixin, 2.7; and butorphanol, 1.6. After shoulder arthrotomy, the average scores were ketorolac, 3.5; flunixin, 3.0; and butorphanol, 1.4 (5/11 dogs). As butorphanol was unable to control pain after shoulder arthrotomy, oxymorphone, 0.05 mg/kg BW, replaced butorphanol in a subsequent group of dogs and had a score of 2.0 (6/11 dogs). Serum alanine aminotransferase and creatinine were significantly elevated above baseline at 24 hours postoperatively in dogs receiving flunixin. One dog in each group developed melena or hematochezia. One dog receiving ketorolac had histological evidence of gastric ulceration. We concluded that ketorolac is a good analgesic for postoperative pain in dogs.

Alanine Transaminase↗

PubMed1997

Nor-binaltorphimine precipitates withdrawal and excitatory amino acid release in the locus ceruleus of butorphanol--but not morphine-dependent rats.

The relative involvement of kappa opioid receptors in the mediation of behavioral and neurochemical responses to withdrawal from chronic drug treatment with the opioid analgesic butorphanol was studied using in vivo microdialysis to detail extracellular fluid concentrations of glutamate and aspartate within the locus ceruleus. Sprague-Dawley rats were rendered opioid dependent after 3 days of intracerebroventricular (i.c.v.) infusion of butorphanol (26 nmol/microl/hr) or morphine (26 nmol/microl/hr) and after i.c.v. infusion of saline vehicle (1 microl/hr). Acute withdrawal was precipitated by i.c.v. injection of the selective kappa opioid receptor antagonist nor-binaltorphimine (48 nmol/5 microl) after the 3-day period of infusion. Behavioral signs of withdrawal were detected after nor-binaltorphimine only in butorphanol-dependent rats. Basal levels of glutamate and aspartate were not different between treatment groups. Nor-binaltorphimine in the butorphanol-dependent rats increased glutamate to 227% and aspartate to 158% in the initial 15-min sample (P < 0.01). Nor-binaltorphimine did not increase glutamate or aspartate concentrations in the morphine-dependent or saline-treated groups. These results indicate a significantly greater participation of kappa opioid receptors in the development of butorphanol, rather than morphine, dependence and identify a differential neurochemical response to butorphanol withdrawal within a defined brain region, the locus ceruleus.

Animals↗

PubMed1994

Effects of morphine, naloxone, buprenorphine, butorphanol, haloperidol and imipramine on morphine withdrawal signs in cynomolgus monkeys.

This study was conducted to characterize the opiate dependence potential of a number of opiate and non-opiate psychoactive drugs in morphine-dependent cynomolgus monkeys (Macaca fascicularis). In addition, the agonist/antagonist profiles of buprenorphine and butorphanol were directly compared. Six male cynomolgus monkeys were maintained on morphine (3.0 mg/kg, q.i.d.) for 6 months. On evaluation days, monkeys were scored for opiate withdrawal signs 18 h after the last dose of morphine. Single dose suppression studies were conducted by giving subcutaneous injections of morphine (3 or 6 mg/kg), naloxone (0.01, 0.05 or 0.1 mg/kg), buprenorphine (1, 3, 10, 30 or 100 micrograms/kg), butorphanol (0.01, 0.1, 1.0 or 3.2 mg/kg), haloperidol (0.01, 0.05 or 0.1 mg/kg), imipramine (2, 5 or 10 mg/kg) or saline and measuring the number and frequency of withdrawal signs that appeared over a 2-h period. In a separate precipitation experiment either saline or 0.01 or 0.1 mg/kg butorphanol was administered 2 h after the last maintenance dose of morphine. In the single dose suppression test, morphine completely suppressed most withdrawal signs while naloxone increased the severity of withdrawal. All doses of buprenorphine increased many withdrawal signs such as backward gait, rearing, chafing face, chain biting, vomiting, masturbation, and vocalizations after intimidation. Only a few signs were reduced, but the overall withdrawal scores were not significantly increased. Low doses of butorphanol suppressed some signs while the highest dose almost completely eliminated all withdrawal signs. Butorphanol also failed to precipitate opiate withdrawal, and actually reversed the signs present in the saline-treated monkeys. Imipramine and haloperidol had little effect on the morphine withdrawal syndrome.(ABSTRACT TRUNCATED AT 250 WORDS)

Animals↗

PubMed2006

Efficacy of caudal butorphanol.

OBJECTIVE: To evaluate the efficacy of butorphanol with or without bupivacaine for caudal epidural anesthesia in children undergoing infraumbilical surgery. METHODS: Sixty ASA physical status I and II patients of either sex aged 1-10 yr were randomized to one of three groups. Group L received 1 ml/kg of 0.25% bupivacaine; Group B received 1 ml/kg of 25 microg/kg butorphanol diluted in normal saline; and Group LB received 1 ml/kg of 25 microg/kg butorphanol in combination with 0.25% bupivacaine, in caudal epidural anesthesia. Hemodynamic variables (HR and MAP) and respiratory rate were monitored in all patients. Sedation score, pain score and requirement of rescue analgesia were recorded at preset time intervals alongwith post-operative complications. RESULTS: There was no difference among the groups regarding sedation scores, requirement of rescue analgesia and post-operative complications. Mean duration of analgesia was maximum in group BL (14.5 +/- 3.5 hr, P<0.001), than in group L (8.8 +/- 4.8 hr) and group B (6.8 +/- 2.9 hr). CONCLUSION: The addition of 25 microg/kg butorphanol to bupivacaine resulted in superior analgesia with a longer period compared with caudal bupivacaine and butorphanol alone, without an increase of side effects.

Analgesics, Opioid↗

PubMed1987

Comparison of fentanyl and butorphanol for outpatient anaesthesia.

Equianalgesic doses of butorphanol (40 micrograms X kg-1) and fentanyl (2.0 micrograms X kg-1) were compared as supplements to balanced general anaesthesia for outpatient laparoscopic procedures. Thirty-six adult female patients (ASA physical status I or II) participated in the study. The study drugs (butorphanol or fentanyl) were given just prior to induction of anaesthesia in a double-blind fashion. Following induction with a standard dose of thiopentone and tracheal intubation using succinylcholine, nitrous oxide in oxygen and a succinylcholine infusion were used for maintenance of anaesthesia. Seventeen of the 18 patients in the butorphanol group and 14 of the 18 patients in the fentanyl group showed signs of light anaesthesia and required supplementation with isoflurane. Induction, maintenance and recovery characteristics were not different in the two groups except that the post-intubation arterial pressure and heart rate in the fentanyl group were significantly higher than the base line values and the patients receiving butorphanol were more drowsy and also more pain-free in the postoperative period. The incidence of nausea and vomiting was high in both groups. Overall, butorphanol (40 micrograms X kg-1) used as part of a standard balanced general anaesthetic for a standard outpatient procedure was not superior to fentanyl (2 micrograms X kg-1) used in the same fashion.

Adult↗

PubMed1994

Double-blind comparison of intravenous butorphanol (Stadol) and fentanyl (Sublimaze) for analgesia during labor.

OBJECTIVE: Our purpose was to compare the analgesic properties, effect on labor, and maternal-fetal side effects of intravenous butorphanol and fentanyl. STUDY DESIGN: One hundred patients with uncomplicated term pregnancies were enrolled during early active labor. Each patient received standard doses of either fentanyl (50 to 100 micrograms) or butorphanol (1 to 2 mg) hourly on request in a double-blind manner. Pain was scored independently by the nurse and patient with a 10-point visual analog scale. Categoric and measurement data were collected for comparison of the effects on uterine activity, maternal and fetal well-being, and neonatal outcomes. RESULTS: The fentanyl (n = 50) and butorphanol (n = 50) groups were identical with respect to maternal age, race, parity, and weight. Greater improvement in pain relief was found after the first dose of butorphanol than after fentanyl (p < 0.05). When fentanyl was given, either more doses were necessary (3.2 +/- 1.3 vs 2.1 +/- 1.1, p < 0.01) or epidural analgesia was requested more often (16%, 32% vs 9%, 18%, p < 0.05). Uterine contraction patterns for the first hour after dosing were unchanged, and the duration of the first and second stages of labor were not different between the two groups. No differences in maternal or newborn adverse effects were observed. CONCLUSIONS: Both drugs were equally safe and without effect on active labor. Butorphanol provided better initial analgesia than fentanyl with fewer patient requests for more medication or epidural analgesia.

Adolescent↗