QT time prolongation
Adverse drug events
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Explanations of the substances for patients
We have no additional warnings for the combination of sparfloxacin and abarelix. Please also consult the relevant specialist information.
The reported changes in exposure correspond to the changes in the plasma concentration-time curve [ AUC ]. We do not expect any change in exposure for sparfloxacin, when combined with abarelix (100%). We do not expect any change in exposure for abarelix, when combined with sparfloxacin (100%).
The pharmacokinetic parameters of the average population are used as the starting point for calculating the individual changes in exposure due to the interactions.
Sparfloxacin has a high oral bioavailability [ F ] of 92%, which is why the maximum plasma level [Cmax] tends to change little during an interaction. The terminal half-life [ t12 ] is 17.5 hours and constant plasma levels [ Css ] are reached after approximately 70 hours. Protein binding [ Pb ] is not known. The metabolism does not take place via the common cytochromes and the active transport takes place in particular via PGP.
The bioavailability of abarelix is unknown. The terminal half-life [ t12 ] is rather long at 316.8 hours and constant plasma levels [ Css ] are only reached after more than 1267.2 hours. The protein binding [ Pb ] is 97.5% strong. The metabolism via cytochromes is currently still being worked on.
|Serotonergic Effects a||0||Ø||Ø|
Rating: According to our knowledge, neither sparfloxacin nor abarelix increase serotonergic activity.
|Kiesel & Durán b||0||Ø||Ø|
Rating: According to our knowledge, neither sparfloxacin nor abarelix increase anticholinergic activity.
QT time prolongation
Rating: In combination, sparfloxacin and abarelix can potentially trigger ventricular arrhythmias of the torsades de pointes type.
General adverse effects
|Side effects||∑ frequency||spa||aba|
|Hypersensitivity reaction||0.0 %||0.01||n.a.|
|Aortic aneurysm||0.0 %||0.01||n.a.|
Based on your answers and scientific information, we assess the individual risk of undesirable side effects. These recommendations are intended to advise professionals and are not a substitute for consultation with a doctor. In the restricted test version (alpha), the risk of all substances has not yet been conclusively assessed.
Abstract: Sparfloxacin is a recently developed fluoroquinolone. The drug has shown potent antimicrobial activity against a wide range of Gram-positive and Gram-negative bacteria, glucose non-fermenters, anaerobes, Legionella spp., Mycoplasma spp., Chlamydia spp. and Mycobacterium spp. Methicillin-resistant Staphylococcus aureus is also susceptible to sparfloxacin. Plasma sparfloxacin concentrations reach a peak (Cmax) of approximately 0.7 mg/L at 3 to 5 hours after a 200mg oral dose. This is followed by a monophasic slow decrease, with an elimination half-life (t1/2) of 15 to 20 hours. The Cmax and area under the plasma concentration-time curve show dose-related increases. Food intake does not affect the absorption and pharmacokinetics of sparfloxacin. Sparfloxacin binds weakly to plasma protein (37%), and exhibits excellent tissue distribution and effective penetration into extracellular fluids. Concentrations of the drug in most tissues are similar to, or higher than, concomitant plasma concentrations. Sparfloxacin distributes slightly into cerebrospinal fluid. The drug is metabolised to a glucuronide. The urinary excretion of the unchanged drug accounts for 10 to 14% of the given dose. The ratio of Cmax values after multiple and single oral doses is 1.3 to 1.4, but other pharmacokinetic parameters of sparfloxacin are not influenced by multiple doses. Even in patients with severe renal failure, no significant prolongation of the half-life is observed after oral administration. Sparfloxacin appears unlikely to affect the pharmacokinetics of theophylline. Antacids containing aluminium hydroxide reduce the oral bioavailability of sparfloxacin by 25 to 35%. Probenecid does not affect sparfloxacin pharmacokinetics. The pharmacokinetic properties of sparfloxacin allow once-daily administration in the treatment of various infections.
Abstract: No Abstract available
Abstract: The mechanism of intestinal secretion of the difluorinated quinolone sparfloxacin was investigated with the epithelial cell line Caco-2 and was compared to that of the P-glycoprotein (P-gp) substrate vinblastine. The P-gp inhibitors verapamil and progesterone significantly increased the epithelial cell accumulation of both vinblastine and sparfloxacin. This increase is likely to result from an inhibition of drug secretion since both vinblastine uptake and sparfloxacin uptake are known to proceed through a passive transmembrane diffusion. The unidirectional fluxes across cell monlayers grown on permeable filters indicated that a net secretion of sparfloxacin and vinblastine occurred across Caco-2 cells. These secretions were significantly inhibited by the MDR-reversing agent verapamil. We conclude that the P-gp is likely to be involved in the intestinal elimination of the difluorinated quinolone sparfloxacin.
Abstract: Sparfloxacin, a fluoroquinolone antibacterial agent, prolongs cardiac repolarization, which may predispose to torsades de pointes. This study was designed to assess simultaneously the hemodynamic and electrophysiologic effects of sparfloxacin using the halothane-anesthetized, closed-chest in vivo canine model (n = 6). Sparfloxacin was intravenously administered in the following two doses with a pause of 20 min, a clinically relevant dose of 3.0 mg/kg/10 min and a 10 times higher dose of 30 mg/kg/10 min. After the low dose of sparfloxacin, cardiac output increased, heart rate decreased, and ventricular repolarization and refractory periods were prolonged. After the high dose, cardiac output increased, whereas heart rate and mean blood pressure decreased, and ventricular repolarization and effective refractory periods were prolonged. The increment was greater in repolarization than in refractoriness, indicating an increase of electrical vulnerability. Because sparfloxacin prolonged repolarization in a reverse use-dependent manner, its negative chronotropic effect may have potentiated the QT prolongation. Left ventricle preload, left ventricular contraction, and AV nodal as well as intraventricular conduction were minimally affected. These results suggest that caution should be used when administering sparfloxacin to patients having risk factors for QT prolongation.