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Respiratory, endocrine, cardiac, and renal topics
Published in Evelyne Jacqz-Aigrain, Imti Choonara, Paediatric Clinical Pharmacology, 2021
Evelyne Jacqz-Aigrain, Imti Choonara
Carbonic anhydrase inhibitors are weak diuretics, at best producing the excretion of 5% of the Na+ and water filtered load. The action of carbonic anhydrase inhibitors is self-limiting. The excretion of decreases in parallel, with the development of metabolic acidosis in response to carbonic anhydrase inhibition.
Main Classes of Drugs
Published in Jerome Z. Litt, Neil H. Shear, Litt's Drug Eruption & Reaction Manual, 2017
Carbonic anhydrase inhibitorAcetazolamideBrinzolamideDichlorphenamideDorzolamideEthoxzolamideMethazolamide
Medical Therapy for Glaucoma
Published in Neil T. Choplin, Carlo E. Traverso, Atlas of Glaucoma, 2014
Jennifer E. Williamson, Janet B. Serle
Carbonic anhydrase is an enzyme found predominantly in the ciliary epithelium, the kidney, the central nervous system, and the red blood cells. It catalyzes the combination of water and carbon dioxide to form bicarbonate and hydrogen ions. Within the ciliary epithelium, hydrogen ions are exchanged for sodium ions, some bicarbonate is exchanged for chloride, and bicarbonate and/or chloride are actively transported into the aqueous with sodium and water passively following. The enzyme carbonic anhydrase must be inhibited at least 99% in order to decrease aqueous formation. This degree of inhibition results in reductions in aqueous humor formation of up to 30% with maximum doses of oral carbonic anhydrase inhibitors (CAI) and up to 19% with maximum doses of topical CAIs.
Synthesis, biological evaluation and theoretical studies of (E)-1-(4-sulfamoyl-phenylethyl)-3-arylidene-5-aryl-1H-pyrrol-2(3H)-ones as human carbonic anhydrase inhibitors
Published in Journal of Enzyme Inhibition and Medicinal Chemistry, 2023
Farhat Ramzan, Syed Ayaz Nabi, Mehak Saba Lone, Alessandro Bonardi, Aabid Hamid, Sameena Bano, Kalicharan Sharma, Syed Shafi, Mohammed Samim, Kalim Javed, Claudiu T. Supuran
In the present study, 20 new hybrid molecules incorporating pyrrolone nucleus with ethyl benzenesulphonamide moiety 3a-t were synthesised. Spectroscopic data and elemental analysis support the structures proposed for the synthesised compounds. These compounds along with acetazolamide, were tested as inhibitors of the physiologically relevant hCA isoforms, that is, hCAI, II, IX and XII. The potency of all compounds ranged from low nanomolar to high nanomolar. The compound 3b behaved as more effective inhibitor against the human cytosolic isoforms hCA I and II having Ki values (368.7 and 81.4 nM) respectively, while 3n behaved as more effective inhibitor against the membrane bound cancer related isozyme hCA IX and XII, having Ki values (41.3 and 39.1 nM) respectively. The results of ADMET studies provided a clear picture that all compounds have acceptable pharmacokinetic range and physicochemical characteristics. Density Functional Theory (DFT) calculations of 3n were carried to gain more understanding about the stability of the E and Z isomers. The energy values clearly indicate the stability of E-isomer over Z-isomer by −8.2 kJ mol−1 which is further supported by Frontier Molecular Orbital (FMO) analysis of these isomers. Results of our investigation suggest another possible class of carbonic anhydrase inhibitors of medicinal importance, hence making these molecules as promising candidates for the discovery of new and effective inhibitor of carbonic anhydrase.
Contemporary management of the pseudotumor cerebri syndrome
Published in Expert Review of Neurotherapeutics, 2019
Carbonic anhydrase is a metalloenzyme which catalyzes the reversible hydration and dehydration of carbon dioxide and bicarbonate [23]. The human brain and choroid plexus contain many carbonic anhydrase isoforms. The secretion of CSF involves the transport of Na+, Cl- and HCO3- from the blood to the brain ventricles which is driven by an osmotic gradient [24]. Carbonic anhydrase inhibitors maintain pH and bicarbonate homeostasis and most of them incorporate a sulfonamide as a zinc binding group and act systemically, leading to off-target side effects (e.g. nausea, fatigue, depression). The inhibitory effect of acetazolamide on CSF secretion and flow was demonstrated in 1954 by Tschirigi et al. and confirmed in a cat model by Kister, who infused intravenous acetazolamide at various doses into cats and recorded CSF flow [25]. He found a decline in CSF flow to about 30% of control rates which occurred within 5 min, reached a maximum in 30 min and persisted for several hours, independent of the dose infused. Methazolamide is a lipophilic, methylated analogue of acetazolamide and an equally potent carbonic anhydrase inhibitor. Acetazolamide is more likely to cause metabolic acidosis, has greater urinary secretion and a longer duration of action in the proximal tubule than methazolamide [26]. The most common side effects of acetazolamide are paresthesias, weight loss, diarrhea, dyspepsia, nausea, and vomiting [20].
Evaluation of Diurnal Fluctuation in Parafoveal and Peripapillary Vascular Density Using Optical Coherence Tomography Angiography in Patients with Exfoliative Glaucoma and Primary Open-Angle Glaucoma
Published in Current Eye Research, 2021
Atılım Armağan Demirtaş, Mine Karahan, Sedat Ava, Çağla Çilem Han, Uğur Keklikçi
This research has some limitations. It was limited by its small sample size. IOP and retinal VD measurements were made only during the daytime, instead of considering examinations during both the evening and night. For this reason, the absent pattern of variation demonstrated by IOP and retinal VD recorded in this study may not indicate the complete diurnal variation. Also, the use of medicine, such as topical antiglaucoma therapy, was permitted during the examinations. This raises the possibility that the diurnal changes in VD readings could have been affected by the antiglaucoma therapy. Previous studies have shown that diurnal fluctuation is decreased by ocular hypotensive medication.29–31 Hence, the real magnitude of diurnal IOP and retinal VD variation might have been computed incorrectly during this research. Takasagawa et al.15 reported that the use of beta-blocker eye drops was associated with reduced VD of the macular superficial macular layer. This could be because beta-blockers demonstrate a vasoconstrictive action, thereby reducing the VD. Moreover, patients prescribed oral carbonic anhydrase inhibitors were excluded from this research. A subgroup analysis could not be performed in this research because of the small sample size used. Lastly, ocular haemodynamic changes and variations in systemic haemodynamics relevant to retinal blood vessels in the POAG and XFG groups were not taken into consideration. However, because individuals with systemic hypertension or diabetes mellitus were not included in this study, it can be stated that systemic haemodynamic fluctuation was not present in these subjects.