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American Journal of Veterinary Research Jun 1986The cardiopulmonary effects of 3 dosages of doxapram hydrochloride (0.275 mg/kg, 0.55 mg/kg, and 1.1 mg/kg, IV) were studied in 6 adult horses. Doxapram given IV...
The cardiopulmonary effects of 3 dosages of doxapram hydrochloride (0.275 mg/kg, 0.55 mg/kg, and 1.1 mg/kg, IV) were studied in 6 adult horses. Doxapram given IV significantly (P less than 0.05) decreased PaCO2 and increased respiratory rate, cardiac output arterial blood pressures (systolic, mean, and diastolic) arterial pH, and PaO2 at 1 minute after each dose was administered. Heart rate and mean and diastolic pulmonary arterial blood pressure were significantly (P less than 0.05) increased 1 minute after the 2 larger dosages of doxapram were given (0.55 mg/kg and 1.1 mg/kg, IV), but not after the smallest dosage was given. All measurements, except heart rate and cardiac output, had returned to base line by 5 minutes after each dosing. Heart rate remained significantly (P less than 0.05) increased 10 minutes after the 0.55 mg/kg dosage was given and 30 minutes after the 1.1 mg/kg dosage. Cardiac output remained significantly (P less than 0.05) increased at 10 minutes, 5 minutes, and 30 minutes after the 0.275, 0.55, and 1.1 mg/kg dosages, respectively, were given.
Topics: Animals; Blood Pressure; Cardiac Output; Doxapram; Female; Heart; Heart Rate; Hemodynamics; Horses; Male; Respiration
PubMed: 3729140
DOI: No ID Found -
Lancet (London, England) Aug 1991
Topics: Anesthesia; Body Temperature Regulation; Doxapram; Humans; Hypothermia; Intraoperative Complications; Shivering
PubMed: 1678807
DOI: No ID Found -
Journal of Veterinary Pharmacology and... Nov 2023Doxapram is marketed as a respiratory stimulant and is used by some veterinarians to help with neonatal apnoea, especially in puppies delivered by caesarean. There is a...
Doxapram is marketed as a respiratory stimulant and is used by some veterinarians to help with neonatal apnoea, especially in puppies delivered by caesarean. There is a lack of consensus as to whether the drug is effective and data on its safety are limited. Doxapram was compared to placebo (saline) in newborn puppies in a randomized, double-blinded clinical trial using two outcome measures: 7-day mortality rate and repeated APGAR score measurements. Higher APGAR scores have been positively correlated with survival and other health outcomes in newborns. Puppies were delivered by caesarean and a baseline APGAR score was measured. This was immediately followed by a randomly allocated intralingual injection of either doxapram or isotonic saline (of the same volume). Injection volumes were determined by the weight of the puppy and each injection was administered within a minute of birth. The mean dose of doxapram administered was 10.65 mg/kg. APGAR scores were measured again at 2, 5, 10 and 20 min. One hundred and seventy-one puppies from 45 elective caesareans were recruited into this study. Five out of 85 puppies died after receiving saline and 7 out of 86 died after receiving doxapram. Adjusting for the baseline APGAR score, the age of the mother and whether the puppy was a brachycephalic breed, there was insufficient evidence to conclude a difference in the odds of 7-day survival for puppies that received doxapram compared to those that received saline (p = .634). Adjusting for the baseline APGAR score, the weight of the mother, the litter size, the mother's parity number, the weight of the puppy and whether the puppy was a brachycephalic breed, there was insufficient evidence to conclude a difference in the probability of a puppy having an APGAR score of ten (the maximum APGAR score) between those that received doxapram compared to those that received saline (p = .631). Being a brachycephalic breed was not associated with an increased odds of 7-day mortality (p = .156) but the effect of the baseline APGAR score on the probability of having an APGAR score of ten was higher for brachycephalic than non-brachycephalic breeds (p = .01). There was insufficient evidence that intralingual doxapram provided an advantage (or disadvantage) compared to intralingual saline when used routinely in puppies delivered by elective caesarean and that were not apnoeic.
Topics: Pregnancy; Female; Animals; Dogs; Animals, Newborn; Doxapram; Apgar Score; Litter Size; Cesarean Section
PubMed: 37211671
DOI: 10.1111/jvp.13388 -
Veterinary Medicine and Science Mar 2021The present prospective randomized experimental study was designed to determine the effects of doxapram on haematological, serum biochemical and antioxidant status in...
The present prospective randomized experimental study was designed to determine the effects of doxapram on haematological, serum biochemical and antioxidant status in dogs after propofol anaesthesia. Twenty-four healthy male mixed breed dogs, aged 1-2 years, weighing 20.4 ± 2.6 kg was studied. Each dog was anaesthetized twice, with at least one week for washout. Animals were sedated with acepromazine (0.1 mg/kg) intramuscularly. Forty minutes later, anaesthesia was induced using intravenous (IV) propofol (4 mg/kg) titration and maintained for 30 min by propofol (0.2 mg kg min ). After propofol was discontinued, doxapram (2 mg/kg) hydrochloride was administrated IV in PD treatment while an equal volume of saline was administrated in PS treatment. Blood parameters were analysed in four times: immediately before sedation (T1), after treatment (T2), after complete recovery (T3) and 24 hr later (T4). Haematological assessments revealed no significant difference between treatments except in haematocrit which was significantly reduced at T4 (24 hr later) in PD. A decreasing trend of all haematological variables was observed after doxapram administration until recovery, except monocyte, mean corpuscular haemoglobin, red blood cell distribution width and platelet count. Serum urea, creatinine, glucose, cholesterol, direct bilirubin concentration and alanine aminotransferase activity were not changed following doxapram administration compared to the PS treatment. After doxapram administration, Creatinine (T3), Albumin (T2) and Protein (T2 & T3) decreased while Glucose (T2 & T3) and BT (T3) increased. Antioxidant parameters measured showed no difference between treatments or time. Doxapram (2 mg/kg) IV did not induce any major negative effects on haematological, serum biochemical variables and oxidant/antioxidant status in dogs after propofol anaesthesia.
Topics: Anesthetics; Animals; Antioxidants; Blood Chemical Analysis; Central Nervous System Stimulants; Dogs; Doxapram; Erythrocytes; Hematologic Tests; Oxidants; Propofol
PubMed: 33210449
DOI: 10.1002/vms3.398 -
The American Journal of Emergency... Mar 2017
Topics: Adjuvants, Anesthesia; Administration, Intravenous; Aged; Central Nervous System Stimulants; Coma; Doxapram; Humans; Male; Sodium Oxybate
PubMed: 27641247
DOI: 10.1016/j.ajem.2016.09.010 -
Comparative Biochemistry and... Jan 2023The resting membrane potential of most cells is maintained by potassium K2p channels. The pharmacological profile and distribution of various K2p channel subtypes in...
The resting membrane potential of most cells is maintained by potassium K2p channels. The pharmacological profile and distribution of various K2p channel subtypes in organisms are still being investigated. The Drosophila genome contains 11 subtypes; however, their function and expression profiles have not yet been determined. Doxapram is clinically used to enhance respiration in humans and blocks the acid-sensitive K2p TASK subtype in mammals. The resting membrane potential of larval Drosophila muscle and synaptic transmission at the neuromuscular junction are pH sensitive. The present study investigated the effects of doxapram on membrane potential and synaptic transmission using intracellular recordings of larval Drosophila muscles. Doxapram (1 mM and 10 mM) depolarizes the muscle and appears to depolarize motor neurons, causing an increase in the frequency of spontaneous quantal events and evoked excitatory junction potentials. Verapamil (1 and 10 mM) paralleled the action of doxapram. These changes were matched by an extracellular increase in KCl (50 mM) and blocked by Cd. It is assumed that the motor nerve depolarizes to open voltage-gated Ca channels in presynaptic nerve terminals because of exposure to doxapram. These findings are significant for building models to better understand the function of pharmacological agents that affect K2p channels and how K2p channels contribute to the physiology of tissues. Drosophila offers a genetically amenable model that can alter the tissue-specific expression of K2p channel subtypes to simulate known human diseases related to this family of channels.
Topics: Animals; Humans; Membrane Potentials; Drosophila; Doxapram; Neuromuscular Junction; Synaptic Transmission; Potassium Channels; Mammals
PubMed: 36306997
DOI: 10.1016/j.cbpc.2022.109497 -
Veterinary Surgery : VS Oct 2021To compare the effects of two doses of doxapram intravenous injection and carbon dioxide inhalation on the cardiovascular and laryngeal functions of anesthetized hounds.
OBJECTIVE
To compare the effects of two doses of doxapram intravenous injection and carbon dioxide inhalation on the cardiovascular and laryngeal functions of anesthetized hounds.
STUDY DESIGN
Experimental study.
ANIMALS
Six healthy adult dogs.
METHODS
In a Latin-square design, the mean arterial blood pressure (MABP) and heart rate (HR) were recorded continuously. The inspiratory normalized glottic gap areas (iNGGA) were measured before and after each stimulation with 0.55 mg/kg of doxapram (L-DOX), 2.2 mg/kg of doxapram (H-DOX), or 90 s of inhalation of 10% carbon dioxide in oxygen (I-CO ). The stimulations were tested in duplicate or triplicate. Video clips of the laryngeal movement were scored by board-certified surgeons masked to the treatment.
RESULTS
The MABP increased with L-DOX and H-DOX up to 81% (both p < .001 compared to I-CO ), and persisted during the other stimulations (both p < .001). An intermittent tachycardic effect of up to 79% increase in HR was observed with doxapram. The HR following H-DOX was higher than L-DOX and I-CO (both p < .016). Neither hypertension nor tachycardia was observed with I-CO . The iNGGA increased with all treatments (p < .001). The iNGGA was greater with H-DOX than L-DOX and I-CO (both p < .007). All treatments received higher scores (all p < .001) with acceptable inter- and intra-observers Krippendorff's alphas.
CONCLUSION
All treatments were effective respiratory stimulants in anesthetized dogs; however, doxapram caused hypertension and tachycardia.
CLINICAL SIGNIFICANCE
Carbon dioxide inhalation might improve arytenoid motion without cardiovascular effects in dogs during clinical airway examinations.
Topics: Animals; Arytenoid Cartilage; Carbon Dioxide; Dogs; Doxapram; Glottis; Larynx
PubMed: 34355421
DOI: 10.1111/vsu.13709 -
Experimental Neurology Dec 2013Doxapram is a respiratory stimulant used to treat hypoventilation. Here we investigated whether doxapram could also trigger respiratory neuroplasticity. Specifically, we...
Doxapram is a respiratory stimulant used to treat hypoventilation. Here we investigated whether doxapram could also trigger respiratory neuroplasticity. Specifically, we hypothesized that intermittent delivery of doxapram at low doses would lead to long-lasting increases (i.e., facilitation) of phrenic motor output in anesthetized, vagotomized, and mechanically-ventilated rats. Doxapram was delivered intravenously in a single bolus (2 or 6mg/kg) or as a series of 3 injections (2mg/kg) at 5min intervals. Control groups received pH-matched saline injections (vehicle) or no treatment (anesthesia time control). Doxapram evoked an immediate increase in phrenic output in all groups, but a persistent increase in burst amplitude only occurred after repeated dosing with 2mg/kg. At 60min following the last injection, phrenic burst amplitude was 168±24% of baseline (%BL) in the group receiving 3 injections (P<0.05 vs. controls), but was 103±8%BL and 112±4%BL in the groups receiving a single dose of 2 or 6mg/kg, respectively. Following bilateral section of the carotid sinus nerves, the acute phrenic response to doxapram (2mg/kg) was reduced by 68% suggesting that at low doses the drug was acting primarily via the carotid chemoreceptors. We conclude that intermittent application of doxapram can trigger phrenic neuroplasticity, and this approach might be of use in the context of respiratory rehabilitation following neurologic injury.
Topics: Administration, Intravenous; Animals; Axotomy; Carotid Sinus; Diaphragm; Doxapram; Male; Neuronal Plasticity; Phrenic Nerve; Rats; Rats, Sprague-Dawley; Respiratory System Agents
PubMed: 24013015
DOI: 10.1016/j.expneurol.2013.08.016 -
The Journal of Pediatrics Aug 2002
Topics: Canada; Central Nervous System; Central Nervous System Stimulants; Doxapram; Humans; Infant Welfare; Infant, Newborn; United States
PubMed: 12183737
DOI: 10.1067/mpd.2002.126008 -
Archives of Disease in Childhood Sep 1984
Topics: Apnea; Doxapram; Dyskinesia, Drug-Induced; Humans; Infant, Newborn
PubMed: 6486873
DOI: 10.1136/adc.59.9.903-a