Gene/Protein Disease Symptom Drug Enzyme Compound
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Query: UMLS:C0595921 (intraocular pressure)
 11,750 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Ketanserin has been characterized as a relatively selective antagonist for serotonin (5-HT2) receptors. However, recent evidence suggests that ketanserin can also antagonize activity at alpha 1-adrenoceptors. Topically applied ketanserin lowered intraocular pressure (IOP) in rabbits, cats, and monkeys. Ketanserin also suppressed ocular hypertension induced by waterloading and the IOP recovery rate in response to hypertonic saline. In contrast, the ocular hypotensive activity of ketanserin was markedly attenuated in sympathectomized (SX) rabbits. In the cat nictitating membrane, ketanserin produced dose-related inhibition of contractions elicited by neuronal stimulation and by intra-arterial injection of norepinephrine. These data demonstrate that ketanserin: 1) lowers IOP more effectively in eyes with intact sympathetic innervation than in SX eyes, 2) appears to lower IOP by suppressing aqueous inflow, and 3) acts primarily by antagonizing the action of norepinephrine on alpha 1-adrenoceptors.
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PMID:Mechanism of the ocular hypotensive action of ketanserin. 388 71

The effect of topical ketanserin on intraocular pressure (IOP) in normotensive and hypertensive eyes was evaluated. The study was performed on 10 healthy volunteers and 10 glaucomatous patients. Systolic arterial blood pressure (SBP), diastolic arterial blood pressure (DBP), heart rate (HR), IOP, tonographic outflow facility, pupil diameter, corneal thickness, and tear secretion were recorded at baseline and at 1 hour intervals for 12 hours after topical administration of 0.5% ketanserin or placebo, given in a randomised, double masked, crossover fashion. The alternative treatment was given 1 week later. In all subjects ketanserin significantly lowered IOP, while no variations in SBP, DBP, HR, pupil diameter, corneal thickness, and tear secretion were found. When subjects received placebo no significant variations of IOP occurred. Total outflow facility, measured by conventional tonography, increased significantly after drug administration in all subjects. Ketanserin is effective up to 6 hours in control subjects and 9 hours in glaucomatous patients. The placebo did not induce any change in this component of the aqueous humour dynamic in normal or in glaucomatous eyes. The findings indicate that topical ketanserin might be added to the list of antiglaucomatous agents.
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PMID:Effect of topical ketanserin administration on intraocular pressure. 831 80

The authors investigated the effect of ketanserin 0.5% eye drops on intraocular pressure and orbital blood flow in some healthy volunteers. Ketanserin is a selective antagonist of serotonin S(2) receptors; moreover, it produces an alpha(1)-blocking effect. It causes a systemic reduction of blood pressure and capillary vasodilatation. Three hours after topical administration of ketanserin 0.5%, the intraocular pressure was decreased by about 14% from the baseline. At the same time, we observed by color Doppler imaging that the mean percent increase in the peak systolic velocity in the ophthalmic artery (OA) was 5.18% (p < 0.161) and 23.18% (p < 0.001) in the posterior ciliary arteries (PCAs). The mean resistance index of the OA was in contrast reduced by 1.16% (p < 0.669) and by 32.14% (p < 0.003) in the PCAs. These data show that ketanserin 0.5% eye drops may be useful not only to decrease intraocular pressure but also to improve blood flow in the PCAs that supply the optic nerve head.
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PMID:Color doppler imaging of ocular blood flow after topical ketanserin. 1051 15

The effects of fluoxetine, which is a selective inhibitor of serotonin reuptake (SSRI) have been studied on the intraocular pressure (IOP) in the rabbit. IOP was measured using a Perkins tonometer. Intravenous administration of fluoxetine (6.0 mg kg-1) significantly increased IOP by 7.2 +/- 1.3 mmHg (P < 0.001). Fluoxetine administration also reduced the amount of urine excreted during the 24 hr, and increased the urine concentration of 5-hydroxyindole acetic acid (5-HIAA). Topical preadministration of ketanserin prevented a rise in IOP, without there being any effects on the other parameters examined. These findings indicate that intravenous administration of fluoxetine is able to raise IOP, through increased plasma levels of serotonin, which is confirmed by elevated 5-HIAA urine excretion and reduction in diuresis. Ketanserin, a specific 5-HT2A antagonist, counteracts the IOP increase brought about by fluoxetine, thus emphasizing the role of serotonin in the regulation of IOP and stressing the importance of including ophthalmological examination in the protocol of depressed patients undergoing SSRI therapy.
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PMID:Effect of fluoxetine on intraocular pressure in the rabbit. 1087 May 12

Ketanserin, a hypotensive drug with 5-HT2 receptor antagonism, when administered by topical infusion of a 0.25% w/v solution by corneal and scleral applications, was found to lower intraocular pressure with four times more activity than its metabolite, ketanserinol. Drug and metabolite were measured periodically in the corneal epithelium, corneal stroma/endothelium, aqueous humor, iris/ciliary body, conjunctiva, sclera and lens during the infusion period (0-120 min) and the postinfusion period (120-240 min) using a fluorometric reversed-phase HPLC assay developed and verified for the research. The infusion results showed that drug entered the eye by both the corneal and scleral routes. Lateral diffusion occurred between the conjunctiva and corneal epithelium. Drug and metabolite were also detected in the untreated fellow eyes, suggesting contralateral systemic redistribution. In vitro metabolism was studied and found to occur in the corneal epithelium, iris/ciliary body and bulbar and palpebral conjunctiva but not in the corneal stroma/endothelium, aqueous humor and sclera. From noncompartmental analysis, zero-order infusion rate constants, first-order absorption constants, mean residence time, volumes of distribution at steady state (Vss) and clearance (Cle) were obtained using equations specific to the topical infusion method. Vss and Cle of aqueous humor (0.972 ml and 13.55 microl/min) were greater than aqueous humor volume (0.311 ml) and turnover rate (4.7 microl/min).
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PMID:The ocular pharmacokinetics of ketanserin and its metabolite, ketanserinol, in albino rabbits. 1111 40