Poisoning with Over-the-Counter Doxylamine Preparations: An Evaluation of 109 Cases

1987 ◽  
Vol 6 (5) ◽  
pp. 355-359 ◽  
Author(s):  
C. Köppel ◽  
J. Tenczer ◽  
K. Ibe

One hundred and nine cases of monointoxication with doxylamine were evaluated with respect to age distribution, amount ingested, plasma level, and clinical symptomatology. The age of 60% of the patients ranged between 16 and 30 years. In about 60% of the cases 10 to 40 times a single therapeutic dose (25 mg) was ingested. Doxylamine plasma concentrations exceeded the maximum plasma level after a therapeutic dose by a factor of 10 to 40 in two-thirds of cases. The most frequent symptoms included impaired consciousness, seizures, tachycardia, mydriasis and a 'psychosis' similar to that in catatonic stupor. A serious complication may be rhabdomyolysis with subsequent impairment of renal function and acute renal failure. No symptoms were observed in 39% of the patients. No correlation was found between the amount ingested or doxylamine plasma level and the clinical symptomatology. Primary detoxication included gastric lavage, administration of activated charcoal and sodium sulfate. Regarding the high frequency of doxylamine overdose and its possible complications the question arises as to whether doxylamine-containing preparations should be subjected to prescription.

2021 ◽  
Vol 19 (suplemento) ◽  
Author(s):  
A Anadón

The aim of this study was to evaluate the pharmacokinetic behaviour and the absolute bioavailability of marbofloxacin (MFX) in adult water buffaloes and to estimate the pharmacokinetic parameters for calculating the therapeutic dose in this animal species. Six adult buffaloes (3 males and 3 females) where treated by intravenous (IV) and subcutaneous (SC) route with a 10% experimental MFX injectable formulation at the dose of 2 mg/kg. After administration blood samples were drawn at pre-established times and MFX plasma concentrations where determined by microbiologic method. The pharmacokinetic analysis was made by compartmental analysis. After IV administration MFX presented a clearance of 198.4 ± 21.0 mL.kg.h and a half-life of elimination of 7.64 ± 3.29 h. After SC administration marbofloxacin presented a half-life of elimination of 8.5 ± 2.42 h, reaching it maximum plasma concentration (1.67 ± 0.516 μg/mL) at 1.69 ± 0.231 h, with a bioavailability of 80.8 ± 11.2 %. The estimated values of clearance and bioavailability will be employed in further studies for calculating the therapeutic dose of MFX in water buffaloes.    


1981 ◽  
Vol 96 (1) ◽  
pp. 141-144 ◽  
Author(s):  
Kjersti Sletholt

Abstract. Plasma concentrations of MAP during and after oral administration were measured by a radioimmunoassay technique capable of detecting 2 pg of MAP in 0.1 ml of unextracted plasma. Four ewes were individually subjected to treatment with 50 mg MAP orally per day in 10 days. The maximum plasma concentrations of MAP during the treatment varied considerably among the 4 ewes, the highest recorded was 3.5 ng/ml and the lowest 2.1 ng/ml. The plasma level of MAP declined to a non-detectable level 5 days after the last administrations in 2 ewes, in the other 2 ewes the level was non-detectable after 6 and 7 days, respectively.


2020 ◽  
Vol 9 (5) ◽  
pp. 1395
Author(s):  
Jan Matek ◽  
Stanislav Cernohorsky ◽  
Stanislav Trca ◽  
Zdenek Krska ◽  
David Hoskovec ◽  
...  

Background: The aim of this study was to compare plasma levobupivacaine concentrations in thoracic epidural and subpleural paravertebral analgesia. Methods: Forty-four patients indicated for open lung resection had an epidural catheter inserted preoperatively or a subpleural catheter surgically. A bolus of 0.25% levobupivacaine at a dosage of 0.5 mg × kg−1 was given after the thoracotomy closure. Plasma levobupivacaine level at 30 min was the primary outcome. Pharmacokinetic modeling was performed subsequently. Secondary outcomes included the quality of analgesia, complications, and patients’mobility. Results: Plasma concentrations were similar 30 min after application—0.389 mg × L−1 in the epidural and 0.318 mg × L−1 in the subpleural group (p = 0.33) and lower in the subpleural group at 120 min (p = 0.03). The areas under the curve but not maximum concentrations were lower in the subpleural group. The time to reach maximum plasma level was similar in both groups—27.6 vs. 24.2 min. No clinical symptoms of local anesthetic toxicity were recorded. Conclusions: Levobupivacaine systemic concentrations were low in both groups without the symptoms of toxicity. This dosage should be safe for postoperative analgesia after thoracotomy.


1986 ◽  
Vol 56 (01) ◽  
pp. 001-005 ◽  
Author(s):  
M Verstraete ◽  
C A P F Su ◽  
P Tanswell ◽  
W Feuerer ◽  
D Collen

SummaryPharmacokinetics and pharmacological effects of two intravenous doses of recombinant tissue-type plasminogen activator (rt-PA) (40 and 60 mg over 90 min) were determined in healthy volunteers. Mean maximum plasma concentrations were 1080 and 1560 ng/ml respectively. The steady state level during subsequent maintenance infusion of 30 mg over 6 h was 250 ng/ml. The pharmacokinetics of rt-PA showed a bi-exponential disappearance from plasma consistent with a 2-compartment model of t½α = 5.7 min, a t½β = 1.3 h and a total clearance of 380 ml/min.Mean fibrinogen levels at the end of the infusions of 40 mg or 60 mg rt-PA over 90 min, measured in thawed plasma samples collected on citrate/aprotinin, decreased to 74% and 57% of the preinfusion values respectively. Plasminogen fell to 55% and 48%, and α2-antiplasmin to 28% and 18% of initial values. No further decrease of these parameters was observed during the infusion of 30 mg rt-PA over 6 h. Only 2% of the preinfusion fibrinogen levels could be recovered as fibrinogen-fibrin degradation products. This moderate extent of systemic fibrinogenolysis is much less than that reported for therapeutic i.v. infusions of streptokinase.


2021 ◽  
Vol 134 (1) ◽  
pp. 95-101 ◽  
Author(s):  
R. Loch Macdonald ◽  
Daniel Hänggi ◽  
Poul Strange ◽  
Hans Jakob Steiger ◽  
J Mocco ◽  
...  

OBJECTIVEThe objective of this study was to measure the concentration of nimodipine in CSF and plasma after intraventricular injection of a sustained-release formulation of nimodipine (EG-1962) in patients with aneurysmal subarachnoid hemorrhage (SAH).METHODSPatients with SAH repaired by clip placement or coil embolization were randomized to EG-1962 or oral nimodipine. Patients were classified as grade 2–4 on the World Federation of Neurosurgical Societies grading scale for SAH and had an external ventricular drain inserted as part of their standard of care. Cohorts of 12 patients received 100–1200 mg of EG-1962 as a single intraventricular injection (9 per cohort) or they remained on oral nimodipine (3 per cohort). Plasma and CSF were collected from each patient for measurement of nimodipine concentrations and calculation of maximum plasma and CSF concentration, area under the concentration-time curve from day 0 to 14, and steady-state concentration.RESULTSFifty-four patients in North America were randomized to EG-1962 and 18 to oral nimodipine. Plasma concentrations increased with escalating doses of EG-1962, remained stable for 14 to 21 days, and were detectable at day 30. Plasma concentrations in the oral nimodipine group were more variable than for EG-1962 and were approximately equal to those occurring at the EG-1962 800-mg dose. CSF concentrations of nimodipine in the EG-1962 groups were 2–3 orders of magnitude higher than in the oral nimodipine group, in which nimodipine was only detected at low concentrations in 10% (21/213) of samples. In the EG-1962 groups, CSF nimodipine concentrations were 1000 times higher than plasma concentrations.CONCLUSIONSPlasma concentrations of nimodipine similar to those achieved with oral nimodipine and lasting for 21 days could be achieved after a single intraventricular injection of EG-1962. The CSF concentrations from EG-1962, however, were at least 2 orders of magnitude higher than those with oral nimodipine. These results supported a phase 3 study that demonstrated a favorable safety profile for EG-1962 but yielded inconclusive efficacy results due to notable differences in clinical outcome based on baseline disease severity.Clinical trial registration no.: NCT01893190 (ClinicalTrials.gov).


2019 ◽  
Vol 19 (1) ◽  
pp. 31-45
Author(s):  
Meena K. Yadav ◽  
Laxmi Tripathi

Background: N-{[3-(4-chlorophenyl)-4-oxo-3, 4-dihydroquinazolin-2-yl] methyl}, 2-[(2- isopropyl-5-methyl) 1-cyclohexylidene] hydrazinecarboxamide QS11 was designed by computational study. It possessed essential pharmacophoric features for anticonvulsant activity and showed good docking with iGluRs (Kainate) glutamate receptor. Methods: QSAR and ADMET screening results suggested that QS11 would possess good potency for anticonvulsant activity. QS11 was synthesised and evaluated for its anticonvulsant activity and neurotoxicity. QS11 showed protection in strychnine, thiosemicarbazide, 4-aminopyridine and scPTZ induced seizure models and MES seizure model. QS11 showed higher ED50, TD50 and PI values as compared to the standard drugs in both MES and scPTZ screen. A high safety profile (HD50/ED50 values) was noted and hypnosis, analgesia, and anaesthesia were only observed at higher doses. No considerable increase or decrease in the concentration of liver enzymes was observed. Optimized QS11 was subjected to preclinical (in-vivo) studies and the pharmacokinetic performance of the sample was investigated. The result revealed that the pharmacokinetic performance of QS11 achieved maximum plasma concentrations (Cmax) of 0.315 ± 0.011 µg/mL at Tmax of 2.0 ± 0.13 h, area under the curve (AUC0-∞) value 4.591 ± 0.163 µg/ml x h, elimination half-life (T1/2) 6.28 ± 0.71 h and elimination rate constant was found 0.110 ± 0.013 h-1. Results and Conclusion: Above evidences indicate that QS11 could serve as a lead for development of new antiepileptic drugs.


2002 ◽  
Vol 55 (1-2) ◽  
pp. 5-12 ◽  
Author(s):  
Kornelija Djakovic-Svajcer

Food can exert a significant influence on the effects of certain drugs. The interactions between food and drugs can be pharmacokinetic and pharmacodynamic. Pharmacokinetic interactions most often take place on absorption and drug metabolism levels. Absorption can be either accelerated or delayed, increased or decreased, while drug metabolism can be either stimulated or inhibited. The factors which influence food-drug interactions are as follows: composition and physic-chemical properties of drugs, the interval between a meal and drug intake and food composition. Food consistency is of lesser influence on drug bioavailability than food composition (proteins, fats, carbohydrates, cereals). Important interactions can occur during application of drugs with low therapeutic index, whereby the plasma level significantly varies due to changes in resorption or metabolism (e.g. digoxin, theophyllin, cyclosporin) and drugs such as antibiotics, whose proper therapeutic effect requires precise plasma concentrations.


Pharmaceutics ◽  
2021 ◽  
Vol 13 (6) ◽  
pp. 778
Author(s):  
Bettina Gerner ◽  
Oliver Scherf-Clavel

Cabozantinib (CAB) is a receptor tyrosine kinase inhibitor approved for the treatment of several cancer types. Enterohepatic recirculation (EHC) of the substance is assumed but has not been further investigated yet. CAB is mainly metabolized via CYP3A4 and is susceptible for drug–drug interactions (DDI). The goal of this work was to develop a physiologically based pharmacokinetic (PBPK) model to investigate EHC, to simulate DDI with Rifampin and to simulate subjects with hepatic impairment. The model was established using PK-Sim® and six human clinical studies. The inclusion of an EHC process into the model led to the most accurate description of the pharmacokinetic behavior of CAB. The model was able to predict plasma concentrations with low bias and good precision. Ninety-seven percent of all simulated plasma concentrations fell within 2-fold of the corresponding concentration observed. Maximum plasma concentration (Cmax) and area under the curve (AUC) were predicted correctly (predicted/observed ratio of 0.9–1.2 for AUC and 0.8–1.1 for Cmax). DDI with Rifampin led to a reduction in predicted AUC by 77%. Several physiological parameters were adapted to simulate hepatic impairment correctly. This is the first CAB model used to simulate DDI with Rifampin and hepatic impairment including EHC, which can serve as a starting point for further simulations with regard to special populations.


Cephalalgia ◽  
2009 ◽  
Vol 29 (2_suppl) ◽  
pp. 17-27 ◽  
Author(s):  
SD Silberstein ◽  
J Schoenen ◽  
H Göbel ◽  
HC Diener ◽  
AH Elkind ◽  
...  

Tonabersat is a novel benzopyran derivative that blocks the cortical spreading depression proposed to be associated with migraine attacks. The ability of single oral doses of 15, 25, 40 and 80 mg of tonabersat to relieve the symptoms of moderate to severe migraine was evaluated in 859 migraineurs enrolled in two dose-ranging, double-blind, randomized, placebo-controlled, parallel-group trials, one international and the other North American. In the international study, significantly more patients given tonabersat than given placebo experienced relief of headache pain at 2 h (15 mg, 36.8%; 40 mg, 40.7%), the principal efficacy variable, and at 4 h (40 mg, 63.0%) and complete abolition of headache at 4 h (40 mg, 34.3%). None of the primary or secondary efficacy variables indicated significant differences between tonabersat and placebo in the North American study. Tonabersat was generally well tolerated, with dizziness and nausea the most common side-effects. Serious adverse events were uncommon, and no patient withdrew from either study because of adverse events. These results suggest a possible interplay between tonabersat pharmacokinetics (the relatively long time required to reach maximum plasma concentrations) and patient characteristics (previous triptan exposure) in the management of acute migraine attacks. Based on the pharmacokinetics and actions on cortical spreading depression, tonabersat may have potential value in migraine prophylaxis.


2017 ◽  
Vol 20 (3) ◽  
pp. 535-538
Author(s):  
A. Di Salvo ◽  
M. Giorgi ◽  
H.K. Lee ◽  
C. Vercelli ◽  
F. Rueca ◽  
...  

Abstract Sheep are often subjected to painful procedures and thus they need to be treated with analgesics. Nevertheless, knowledges about pharmacokinetic features of these drugs in this species are poor. The aim of this study was to evaluate plasma behaviour of cimicoxib in sheep after a single oral administration at two different dose rates (4 and 6 mg/kg). Maximum plasma concentrations of cimicoxib were equal to 273.78 (median value; range 189.00-567.32) and 565.01 (range 308.27-822.59) ng/mL after treatment with 4 and 6 mg/kg, respectively. The time of maximum concentration (Tmax) was achieved between 4 and 10 hours following treatment at the lower dose, and between 6 and 10 hours after the administration of the higher dose, with one sheep achieving the concentration peak at 0.75 hours. The slow absorption and the great individual variability in plasma concentration, probably due to ruminal effects, suggest that cimicoxib is not suitable for oral treatment in sheep.


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