Azithromycin: An Assessment of Its Pharmacokinetics and Therapeutic Potential in CAPD

2001 ◽  
Vol 21 (4) ◽  
pp. 372-377 ◽  
Author(s):  
James R. Kent ◽  
Michael K. Almond ◽  
Soraya Dhillon

Background Azithromycin is an azalide antibiotic with a similar antibacterial spectrum to erythromycin but with greater gram-negative activity. Azithromycin displays a favorable pharmacokinetic profile, with improved absorption and higher sustained tissue concentrations compared with erythromycin. This results in a prolonged elimination half-life, suggesting a potential for treating continuous ambulatory peritoneal dialysis (CAPD) peritonitis. Objective This study aimed to define the potential role of azithromycin in treating CAPD peritonitis. Design The pharmacokinetics and peritoneal dialysis (PD) clearance of azithromycin were studied following a single 500-mg oral dose of azithromycin. Blood and dialysate samples were taken over a 10-day period and assayed using high-pressure liquid chromatography. Setting The study took place within the Renal Unit at Southend Hospital NHS Trust, a district general hospital in the United Kingdom. Patients Eight patients with oliguric end-stage renal failure without peritonitis maintained on CAPD (3 x 2 L/day). Results Peak plasma concentrations occurred at 2 -3 hours with 0.35 - 1.35 mg/mL (mean 0.75). The mean elimination half-life was 84.55 hrs, and plasma clearance was 21.93 L/hour. This compares with values of greater than 40 hours and 40.8 L/hour reported in healthy volunteers. After 8 hours, the mean dialysate concentration was 0.07 mg/mL; PD clearance was 0.06 L/hr. Conclusion Azithromycin is not substantially removed by CAPD in the absence of peritonitis and cannot be recommended for widespread use in this setting at present. However, the successful use of azithromycin in CAPD peritonitis, due possibly to an intracellular drug transport mechanism, has been reported. Future research should address this possibility.

PLoS ONE ◽  
2021 ◽  
Vol 16 (8) ◽  
pp. e0256862
Author(s):  
Michael Yaeger ◽  
Jonathan P. Mochel ◽  
Zuowei Wu ◽  
Paul Plummer ◽  
Orhan Sahin ◽  
...  

The purpose of this study was to evaluate the pharmacokinetics of tulathromycin in the plasma and maternal and fetal tissues of pregnant ewes when administered within 24 hours of a single, IV Campylobacter jejuni (C. jejuni) challenge. Twelve, pregnant ewes between 72–92 days of gestation were challenged IV with C. jejuni IA3902 and then treated with 1.1 ml/45.36 kg of tulathromycin subcutaneously 18 hours post-challenge. Ewes were bled at predetermined time points and euthanized either at a predetermined time point or following the observation of vaginal bleeding or abortion. Following euthanasia, tissues were collected for bacterial culture, pharmacokinetics and histologic examination. The maximum (geometric) mean tulathromycin plasma concentration was estimated at 0.302 μg/mL, with a peak level observed at around 1.2 hours. The apparent systemic clearance of tulathromycin was estimated at 16.6 L/h (or 0.28 L/kg/h) with an elimination half-life estimated at approximately 22 hours. The mean tissue concentrations were highest in the uterus (2.464 μg/g) and placentome (0.484 μg/g), and were lowest in fetal liver (0.11 μg/g) and fetal lung (0.03 μg/g). Compared to previous reports, results of this study demonstrate that prior IV administration of C. jejuni appeared to substantially alter the pharmacokinetics of tulathromycin, reducing both the peak plasma concentrations and elimination half-life. However, additional controlled trials are required to confirm those observations.


2017 ◽  
Vol 5 (1) ◽  
pp. 11 ◽  
Author(s):  
Mohamed Elbadawy ◽  
Mohamed Aboubakr

The aim of present study was to determine the pharmacokinetics and tissue residues of tilmicosin phosphate (tilmicoral®) as well as its in vitro and in vivo evaluation for control of Mycoplasma gallisepticum (MG) infection in broiler chickens. Pharmacokinetics (single oral dose) and tissues residues (daily for five days) of tilmicosin (25 mg/kg b.wt) in broilers were investigated. Peak plasma concentration of tilmicosin was 1.25±0.0.09 μg/mL and achieved at 3.15±0.34 h. Elimination half-life was long (44.3±7.22 h) and Vdarea was large (1.25±0.082 L/kg). Residue study revealed a good distribution and penetration of tilmicosine in lung, liver, kidney and muscles. Tilmicosin could not be detected in all tested tissues (except in lung) at 6 days after last administration. The MIC of tilmicosin and tylosin against MG were 0.054 and 0.319 μg/mL, respectively. MG infected chickens and treated by tilmicosin or tylosin showed a significant (p<0.05) improvement in mean body weights gain and a significant (p<0.05) decline in mean clinical signs score, air sac lesion score and mortality rate, however tilmicosin was a superior drug. In conclusion, timicoral® was a very effective medication for controlling MG infection in broiler chickens due to its rapid absorption, long elimination half-life, rapid and extensive penetration from blood into tissues especially lungs and air sacs. Additionally, tilmicoral® had a short withdrawal time. Moreover, its superior efficacy (in vitro and in vivo) against MG.


2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
J G Diness ◽  
J E Kirchhoff ◽  
L Abildgaard ◽  
N Edvardsson ◽  
U S Soerensen ◽  
...  

Abstract Background Small conductance Ca2+-activated K+-channels (SK-channels) are a promising new atrial selective target for treatment of atrial fibrillation (AF). AP30663 is a small molecule inhibitor of SK-channels that is currently undergoing clinical trials for treatment of AF. Here we present preclinical data from conscious pigs with persistent AF treated with AP30663. Purpose To examine the pharmakokintetics (PK) of AP30663 in anaesthetized pigs and to test whether AP30663 could cardiovert AF that was resistant to treatment by 4 mg/kg vernakalant in pigs. Methods A total of 12 Danish landrace pigs (gilts) were used for the experiments (2 for PK and 10 for cardioversion of AF). Ten conscious pigs with implanted neurostimulators were tachypaced in the right atrium for 17±5 days until persistent AF that did not respond to treatment with 4 mg/kg vernakalant was obtained. After 3±2 days of vernakalant-resistant AF, the pigs received an infusion of 20 mg/kg AP30663 over 60 minutes. During the infusion the pigs remained conscious and the ECG was monitored. If AF reverted within this period, burst pacing with 50 Hz was applied thrice. Cardioversion was considered successful if sustained AF was reverted. Protection against reinduction of AF was considered successful if no episodes of AF lasting for more than 10 minutes could be reinduced by burst pacing. Results Six out of ten pigs with vernakalant-resistant AF cardioverted during infusion of 20 mg/kg AP30663 over 60 minutes. Four out of six pigs were protected against re-induction of AF by burst pacing. The average time to cardioversion was 29±18 minutes corresponding to calculated free plasma concentrations of 1.0–1.4 μM AP30663. In all the conscious pigs AP30663 was well tolerated with no adverse events. The maximal plasma concentration (Cmax) of AP30663 observed at the end of infusion was 4532±844 ng/ml corresponding to an unbound concentration of 1.54±0.29 μM. The plasma concentrations during infusion were described well by first-order kinetics with a half-time of 5.2 minutes, whereas the plasma concentrations after infusion followed Michaeilis-Menten kinetics with a fast half-life of 6.8 minutes and a slow half-life of 93.7 minutes. Thus, it seems that there is a fast distribution to other tissues and an elimination half-life of approximately 90 minutes. The plasma concentration during infusion reached 90% of the steady state concentration after 17 minutes. Conclusion In an advanced pig model of persistent AF where clinically relevant doses of vernakalant could no longer convert the AF to SR, AP30663 able to convert the pigs to sinus rhythm and protect against reinduction of AF. No signs of adverse events were observed during or after infusion of AP30663. The SK channel inhibitor AP30663 had a fast distribution and an elimination half-life of approximately 90 minutes. The results support the development of AP30663 for treatment of AF in man.


2017 ◽  
Vol 2017 ◽  
pp. 1-11 ◽  
Author(s):  
Md. Akil Hossain ◽  
Hae-chul Park ◽  
Kyunghun Jeong ◽  
Yang ho Jang ◽  
Dae Gyun Kim ◽  
...  

The pharmacokinetics of marbofloxacin in pigs after intravenous (i.v.), intramuscular (i.m.), and peroral (p.o.) administration and pharmacokinetic/pharmacodynamic indices of this drug against Korean local isolates ofActinobacillus pleuropneumoniaewere determined in this study. Marbofloxacin (2.50 mg/kg of body weight) was administered, and blood samples were collected with designated time intervals. Plasma-extracted marbofloxacin was injected into the LC-MS/MS system. The in vitro and ex vivo antibacterial activities of marbofloxacin were evaluated against 20 isolates ofA. pleuropneumoniae. The mean peak plasma concentrations (Cmax) after i.v., i.m., and p.o administration were2.60±0.10,2.59±0.12, and2.34±0.12 µg/mL at0.25±0.00,0.44±0.10, and1.58±0.40 h, respectively. The area under the plasma concentration-time curves (AUC0–24) and elimination half-lives were24.80±0.90,25.80±1.40, and23.40±5.00 h·μg/mL and8.60±0.30,12.80±1.10, and8.60±0.00 h, for i.v., i.m., and p.o. administration, correspondingly. The AUC0–24/MICs of marbofloxacin after i.v., i.m., and p.o. administration were253.86±179.91,264.1±187.16, and239.53±169.75 h, respectively. TheCmax/MIC values were26.58±18.84,26.48±18.77, and23.94±16.97, and T>MICs were42.80±1.01,36.40±1.24, and38.60±1.18 h, after i.v., i.m., and p.o. administration, respectively. Thus, marbofloxacin dosage of 2.50 mg/kg of body weight by i.v., i.m., and p.o. administration with 24 h dosing interval will provide effective treatment for the infection of pig byA. pleuropneumonia.


1992 ◽  
Vol 26 (1) ◽  
pp. 8-10 ◽  
Author(s):  
David E. Nix ◽  
J. Michael Spivey ◽  
Allyn Norman ◽  
Jerome J. Schentag

OBJECTIVE: To assess the pharmacokinetics and tolerance of ciprofloxacin after the administration of single intravenous doses of 200, 300, and 400 mg. DESIGN: Double-blind, three-period, randomized, crossover trial. SETTING: Private, university-affiliated, hospital-based, clinical research center. PATIENTS: Normal healthy male volunteers, 18–40 years of age. INTERVENTIONS: Subjects received 200-, 300-, and 400-mg single intravenous doses of ciprofloxacin via 30-minute infusions in random sequence. MAIN OUTCOME MEASURES: Serum ciprofloxacin concentrations were determined by HPLC after each dose and the results were used to derive pharmacokinetic parameters. Tolerance was assessed by reported and observed adverse events, urine microscopic examinations for crystals, and examination of intravenous infusion sites. RESULTS: The mean area under the time curve (AUC) values displayed linearity with respect to the administered dose. No statistical differences were observed in total body clearance, steady-state volume of distribution, or elimination half-life with respect to dose administered. The mean total body clearance, steady-state volume of distribution, or elimination half-life ranged from 36 to 41 L/h, 146 to 169 L, and 3.5 to 3.7 h for the 200-, 300-, and 400-mg doses, respectively. Adverse effects, including venous irritation (four subjects) and crystalluria (two subjects), were mild and did not require withdrawal of any subject from the study. CONCLUSIONS: Intravenous ciprofloxacin in doses ranging from 200 to 400 mg demonstrated linear pharmacokinetics. These single doses were well tolerated, although cases of transient venous irritation and crystalluria were observed.


1988 ◽  
Vol 16 (4) ◽  
pp. 396-404 ◽  
Author(s):  
C. Aun ◽  
I. T. Houghton ◽  
K. Chan ◽  
R. H. Carley ◽  
N. P. Salmon ◽  
...  

Alfentanil requirements were compared in thirty-six Asian and forty-three European patients during general anaesthesia with muscle relaxants. Alfentanil infusion at 5 μg/kg/min was started immediately after induction with thiopentone and alcuronium. The infusion rate was reduced to 0.5 μg/kg/min after ten minutes. An incremental dose of 5 μg/kg/min for five minutes was given on each occasion when anaesthesia was clinically judged to be inadequate. Recovery parameters were recorded. Pharmacokinetics were also studied in five Europeans, four Chinese and four Nepalese. The dosage of alfentanil required was comparable in both Asian and European patients, but recovery was slower in the Asian patients. The elimination half-life in the Chinese and the Nepalese were both significantly shorter than that of the Europeans (P < 0.05), but at the time of recovery of spontaneous ventilation, the mean plasma concentrations were not significantly different.


PEDIATRICS ◽  
1989 ◽  
Vol 84 (2) ◽  
pp. 262-265
Author(s):  
William J. Lewander ◽  
Peter G. Lacouture ◽  
J. Enrique Silva ◽  
Frederick H. Lovejoy

During a 1-year period, 15 cases of acute thyroxine (T4) overdose with documented serum T4 concentrations were studied. All patients were &lt;5 years of age and 80% were boys. All were examined within 1 to 6 hours of ingestion and all were asymptomatic. Estimated dose ingested in 10 patients ranged from 1.5 to 8.8 mg (0.1 to 0.73 mg/kg). Three patients with initial T4 serum concentrations &gt;75 µg/dL manifested signs of toxicity within 12 to 48 hours (fever, tachycardia, hypertension, and/or agitation) that resolved within 24 to 60 hours. The mean elimination half-life of T4 in 7 patients with multiple serum concentrations was 2.8 ± 0.4 days, whereas the mean elimination half-life of triiodothyronine was 6 ± 1.7 days. It was concluded that (1) the majority of acute pediatric T4 overdoses are not severe and may be managed on an outpatient basis, (2) the absence of early clinical manifestations does not preclude delayed onset of toxicity that may be better predicted by initial T4 concentrations, and (3) the elimination half-life of T4 is shorter and the elimination half-life of triiodothyromine is longer than with therapeutic doses.


Author(s):  
Chiadi U. Onyike

Stimulants are typically prescribed for their positive effects on mood, motivation, alertness, arousal, and energy. They are believed to exert their pharmacologic effects by increasing synaptic release of endogenous catecholamines (norepinephrine and dopamine) while simultaneously blocking catecholamine reuptake at the nerve terminals. Themost commonly used ‘‘traditional’’ agents are methylphenidate and dextroamphetamine. Methylphenidate reaches peak blood levels in 1 to 3 hours and has an elimination half-life of 2 to 3 hours. Dextroamphetamine reaches peak levels in 2 to 4 hours and has an elimination half-life of 3 to 6 hours. Controlled-release formulations are available, allowing for dosing once daily. Dextroamphetamine is excreted primarily in the urine in unchanged form, whereas methylphenidate is excreted mainly as ritalinic acid. The newer generation stimulant modafinil has been marketed in the United States since 1998. Initially used in the treatment of narcolepsy, it is now prescribed for a wider range of conditions because of its positive effects on wakefulness, vigilance, cognitive performance, and mood. Its pharmacologic effects are thought to result primarily from the stimulation of wakefulness-promoting orexinergic neurons in the anterior hypothalamus. Inhibition of norepinephrine reuptake in the ventrolateral preoptic nucleus and of dopamine reuptake (by binding to the transporter) may contribute to its action. Modafinil is administered orally, achieves peak plasma concentrations in 2 to 4 hours, and has an elimination half-life of 12 to 15 hours. It is 90% metabolized in the liver, and its metabolites are excreted in the urine. The ergot alkaloids bromocriptine and pergolide are familiar to most neurologists in their use in the treatment of Parkinson’s disease (PD) and migraine headache. These dopamine receptor agonists are also used in neuropsychiatry in the treatment of apathetic states in patients recovering from brain trauma, cerebral anoxia, and strokes. Amantadine is another familiar agent used in the treatment of PD and drug-induced parkinsonism. In addition to other effects in the central nervous system (CNS), amantadine facilitates dopamine release and inhibits its reuptake. It thus has modest ‘‘stimulant-like’’ effects useful in the treatment of executive dysfunction syndromes, particularly in patients with dementia. Bupropion is a dopamine and norepinephrine reuptake inhibitor. It usually is prescribed as a ‘‘nonsedating’’ antidepressant, but its potentiation of catecholamine neurotransmission results in modest stimulant-like clinical effects.


2012 ◽  
Vol 30 (15_suppl) ◽  
pp. 8025-8025
Author(s):  
Niels Murawski ◽  
Gerhard Held ◽  
Samira Zeynalova ◽  
Carsten Mueller ◽  
Viola Poeschel ◽  
...  

8025 Background: 6xCHOP-14 with 8xR given over an extended period improved 3-year EFS (67% vs. 54%; p=0.030) and OS (80% vs. 67%, p=0.034) of poor-prognosis patients (IPI=3-5) in the SMARTE-R trial compared to the RICOVER-60 trial where patients received 8xR every 2 weeks. Because we had recently shown (Mueller et al., Blood 2012) that elderly male patients have a faster R clearance (12.68 ml/h vs. 8.21 ml/h; p=0.003) and shorter serum elimination half life (t1/2ß=24.7 vs. t1/2ß=30.7 days; p=0.003) than females, we analyzed whether these differences translated into different outcomes by comparing the results achieved by elderly female and male patients in the RICOVER-60 and SMARTE-R trials. Methods: In SMARTE-R, 189 evaluable elderly (61-80 y) pts. with DLBCL received 6 cycles of 2-weekly CHOP-14 combined with 8xR on days -4, -1, 10, 29, 57, 99, 155, and 239. The primary endpoint was event-free survival (EFS). 306 pts treated within the RICOVER-60 trial with 6xCHOP-14 + 8 R given on days 1, 15, 29, 43, 57, 71, 85 and 99 served as controls. Results: The 3-year EFS of 51 poor-prognosis male patients in SMARTE-R was 67% compared to 47% of 66 poor-prognosis male patients treated in RICOVER-60 (p=0.037); the respective figures were 71% vs. 53% (p=0.051) for PFS and 80% vs. 60% (p=0.027) for OS. In contrast, female poor-risk patients had only a small benefit from the extended rituximab exposure in SMARTE-R (n=48) compared to RICOVER-60 (n=57): 67% vs. 61% (p=0.354) for EFS; 71% vs. 67% (p=0.489) for PFS; and 80% vs. 76% (p=0.528) for OS. Conclusions: Elderly male patients with poor-prognosis DLBCL who have a faster R clearance and shorter R serum elimination half life than female patients, benefit significantly from the longer R exposure in SMARTE-R with a gain of 20% in 3-year OS, while the outcome of female patients was only slightly improved. Even though R maintenance has failed to demonstrate any benefit in the primary treatment of DLBCL to date, these results underline the importance of a minimum exposure time of R in order to exploit its full therapeutic potential in DLBCL. Supported by Deutsche Krebshilfe.


2013 ◽  
Vol 57 (7) ◽  
pp. 3208-3213 ◽  
Author(s):  
Alma Tostmann ◽  
Charles M. Mtabho ◽  
Hadija H. Semvua ◽  
Jossy van den Boogaard ◽  
Gibson S. Kibiki ◽  
...  

ABSTRACTEast Africa has a high tuberculosis (TB) incidence and mortality, yet there are very limited data on exposure to TB drugs in patients from this region. We therefore determined the pharmacokinetic characteristics of first-line TB drugs in Tanzanian patients using intensive pharmacokinetic sampling. In 20 adult TB patients, plasma concentrations were determined just before and at 1, 2, 3, 4, 6, 8, 10, and 24 h after observed drug intake with food to estimate the areas under the curve from 0 to 24 h (AUC0–24) and peak plasma concentrations (Cmax) of isoniazid, rifampin, pyrazinamide, and ethambutol. Acetylator status for isoniazid was assessed phenotypically using the isoniazid elimination half-life and the acetylisoniazid/isoniazid metabolic ratio at 3 h postdose. The geometric mean AUC0–24s were as follows: isoniazid, 11.0 h · mg/liter; rifampin, 39.9 h · mg/liter; pyrazinamide, 344 h · mg/liter; and ethambutol, 20.2 h · mg/liter. TheCmaxwas below the reference range for isoniazid in 10/19 patients and for rifampin in 7/20 patients. In none of the patients were theCmaxs for pyrazinamide and ethambutol below the reference range. Elimination half-life and metabolic ratio of isoniazid gave discordant phenotyping results in only 2/19 patients. A substantial proportion of patients had an isoniazid and/or rifampinCmaxbelow the reference range. Intake of TB drugs with food may partly explain these low drug levels, but such a drug intake reflects common practice. The finding of low TB drug concentrations is concerning because low concentrations have been associated with worse treatment outcome in several other studies.


Sign in / Sign up

Export Citation Format

Share Document