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Results for “Timolol”

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At least 883 records · Page 49Linked to original sources

PubMed1980

Effects of timolol maleate on tear flow in human eyes.

Lacrimal function was studied in 30 patients treated for glaucoma, with 0.25% timolol eye drops. Rose bengal and fluorescein staining disclosed punctate epithelial defects in 11 eyes after one week. During the following weeks there defects disappeared spontaneously in most eyes. Schirmer tests (I and II), tear lysozyme and pre-corneal film break-up time were significantly decreased by the treatment, while tear immunoglobulins were unimpaired. The authors conclude that topical timolol treatment decreases tear production. This effect is quantitatively limited and does not appear dangerous for normal eyes, although it may become so for eyes with an originally low lacrimal secretion.

Administration, Topical↗

PubMedDate not supplied

Prospective comparative switch study from timolol 0.5% and latanoprost 0.005% to bimatoprost 0.03%.

This prospective study compared intraocular pressure (IOP) control, cardiorespiratory function, and adverse effects in 50 patients with glaucoma and ocular hypertension. Patients on topical combination timolol-latanoprost therapy were recruited. After they had used this combination for at least 2 months, they were switched to bimatoprost monotherapy. Full ocular examination and spirometric testing were performed; a questionnaire concerned with ocular symptoms was completed, and pulse rate was recorded. Two months later, mean IOP was similar with the combination (17.2 mm Hg) and with bimatoprost (16.4 mm Hg), but mean peak expiratory flow rate, ratio of forced expiratory volume in 1 second to forced vital capacity, and heart rate had increased significantly after the switch was made to bimatoprost. Adverse effects generally were similar with these regimens; however, the incidence of hyperemia doubled after the switch had been made. Bimatoprost and the timolol-latanoprost combination were equally efficacious in lowering IOP; bimatoprost had less of an effect on cardiorespiratory function.

Adult↗

PubMed1983

Effect of timolol on aqueous humor protein concentration in humans.

Short-term topical application of timolol, in a prospective, randomized, double-masked study of 32 human eyes, was associated with an average aqueous humor protein concentration of 38 mg/100 ml, compared to 13 mg/100 ml in control subjects (P less than .001). This apparent influence of timolol on aqueous protein levels probably resulted from reduced aqueous production. It did not affect the course of intraocular surgery.

Aged↗

PubMed1986

Adverse respiratory and cardiovascular events attributed to timolol ophthalmic solution, 1978-1985.

Between September 1978 and December 1985, 450 case reports of serious respiratory and cardiovascular events and 32 case reports of death attributed to ophthalmic timolol were received by the United States Food and Drug Administration and the National Registry of Drug-Induced Ocular Side Effects. Two hundred sixty-seven patients (55%) experienced a cardiac arrhythmia or a bronchospasm-related event. The median age was 68 years (n = 365). Fifty-five percent of the patients were women and 45% were men (n = 41). Of the 212 persons for whom medical history was provided, 129 (61%) had respiratory disease, 65 (31%) had cardiovascular disease, 13 (6%) had other illnesses, and five (2%) had no underlying illness. Of the 318 patients for whom data on duration of drug use were available 106 (33%) experienced their adverse event within one week of beginning timolol therapy: 73 (23%) had their events on the first day of therapy. Of 192 patients for whom information was available 177 (92%) improved after the drug was discontinued.

Heart Diseases↗

PubMedDate not supplied

The additive effect of timolol on open angle glaucoma patients on maximal medical therapy.

Thirty-one eyes of 20 glaucomatous patients on maximum medication were treated with timolol drops for a mean period of 9 months. Adequate levels of control of intraocular pressures were obtained in 21 eyes. No significant ocular or systemic side effects were noted. Timolol has an additive effect in further lowering intraocular pressures in patients being treated with a combination of carbonic anhydrase inhibitors, pilocarpine, epinephrine, and the anticholinesterases.

Adult↗

PubMedDate not supplied

Timolol plus maximum tolerated antiglaucoma therapy: a one-year followup study.

Thirty-three eyes of 22 patients with primary open-angle glaucoma or severe ocular hypertension had topical timolol maleate added to their maximally tolerated medical regimens. With minimal side effects, 25 eyes (76%) could be treated medically for one year, and only eight eyes (24%) required filtering surgery. Thirteen (39%) of the medically treated eyes achieved intraocular pressures of 21 mm Hg or less. After the addition of timolol, 17 of the 33 eyes (52%) completed the one-year protocol with final mean intraocular pressure decreases of 5 mm Hg or more on medical therapy.

Aged↗

PubMedDate not supplied

Effects of iris pigmentation on response of ocular pressure to timolol.

Timolol ophthalmic solution effectively reduced mean intraocular pressure (IOP) in Negro and Caucasian patients with chronic open angle glaucoma and untreated IOP of 22 mm Hg or higher. No differences in pressure lowering response were observed among the races although the Negroes required somewhat higher timolol concentrations to produce similar reductions from baseline IOP. Negro patients also appeared to have a more severe disease as indicated by the number of prior antiglaucoma drugs required and the untreated (baseline) pressures. An unexpected finding was the significantly greater number of Caucasians with dark irides who were discontinued from therapy because of inadequate pressure reduction.

Adult↗

PubMed1983

Safety and efficacy of timolol in pediatric glaucoma.

We reviewed the effect of timolol in 89 eyes (50 patients) with various types of pediatric glaucoma. Systemic side effects were observed in two patients (4%). Intraocular pressure (IOP) effect of timolol could only be observed in 18 eyes of 11 patients. The average decrease of IOP was 30.7% at the last follow-up.

Adolescent↗

PubMed1983

Timolol in the management of secondary glaucomas.

The mechanisms of the secondary glaucomas and the actions and side effects of antiglaucoma drugs are reviewed. Based on these observations, the advantages of timolol, as compared to other medications, in the management of secondary glaucomas are discussed. To illustrate some of these advantages, a study is reported in which timolol is evaluated for control of the early intraocular pressure elevation after routine cataract surgery.

Carbonic Anhydrase Inhibitors↗

PubMed1987

Influence of some beta blockers (pindolol, atenolol, timolol and metoprolol) on aggregation and arachidonic acid metabolism in human platelets.

The effects of four beta-adrenoceptor blocking agents on platelet aggregation, formation of thromboxane from exogenous arachidonic acid (AA) in platelets, on AA incorporation in platelet phospholipids, and on platelet phospholipase activity were studied. Of the four drugs pindolol inhibited thromboxane formation in a dose-related (0.25-1.0 mM) manner apparently by exerting its influence at the cyclooxygenase (CO) level. This drug also inhibited aggregation induced by AA, collagen, epinephrine and ADP. Atenolol and metoprolol though not showing inhibition of AA-induced aggregation did inhibit collagen- and ADP-induced aggregation; metoprolol reversed ADP-induced aggregation, and abolished second phase of epinephrine-induced aggregation. Timolol did not inhibit aggregation induced by all the aggregating agents. Atenolol inhibited (by ca. 10%) TxB2 formation in platelets from exogenous as well as endogenous AA at rather high concentrations (1.0 mM). Metoprolol and timolol did not do so. The observations reported here can be best explained by taking into account the membrane stabilizing effects and lipophilic properties of the drugs.

Adenosine Diphosphate↗

PubMed1993

Evidence for a synergistic interaction between isoprenaline and timolol on intraocular pressure in conscious rabbits.

1. Interaction between topical isoprenaline and timolol on intraocular pressure was studied in conscious rabbits through changes of the dose-response curves. 2. Both drugs caused a dose-dependent fall of intraocular pressure mainly by reducing the aqueous humour formation. 3. When combined, timolol increased the response to submaximal concentrations of isoprenaline as well as EC50 (from 2.06 x 10(-3) M to 3.63 x 10(-3) M) and slope (from 1.21 to 1.89), but peak response to isoprenaline remained unchanged. 4. Discordance between experimental and theoretical additive curves as well as an interaction index smaller than 1 show that the interaction between both drugs is synergistic.

Animals↗

PubMed1995

Determination of the optical purity of timolol maleate by proton nuclear magnetic resonance spectroscopy with a chiral Pr(III) shift reagent.

A 1H NMR spectroscopic method with chiral shift chelate is presented for the determination of the optical purity of timolol maleate. Optimum experimental conditions were established by studying the interactions of solvents (CCl4, CDCl3), substrate concentration, and the type and concentration of chiral lanthanide chelate (Pr(hfc)3, Eu(hfc)3). Larger induced shift (delta delta) and enantiomeric shift difference (delta delta delta) values, and more detailed spectral differences were obtained with Pr(hfc)3 than with Eu(hfc)3. By monitoring the spectral changes of the resonance signals for the enantiomeric -C(CH3)3 protons, suitable conditions for quantitative determinations were found when 0.1 molar equivalents of Pr(hfc)3 were complexed with 0.074 M of substrate. Enantiomeric compositions were calculated from the relative intensities of the enantiomeric -C(CH3)3 proton resonances. Based on the analysis of six synthetic enantiomeric mixtures, the mean +/- SD recovery of (R)-(+)-timolol by the proposed method was 99.5 +/- 1.17% of the amount added.

Adrenergic beta-Antagonists↗

PubMed1983

The effect of timolol on the concentrations of albumin and IgG in the aqueous humor of the human eye.

We investigated albumin and IgG concentrations in the aqueous humor of 41 patients before intracapsular cataract extraction (primary samples) and at the end of surgery (secondary samples). Albumin and IgG concentrations were determined in all samples by means of a quantitative fluoroimmunoassay. A short-term topical application of timolol in 24 eyes was associated with a significant increase in both proteins in the primary aqueous humor samples compared with 17 control samples (P less than .005). The ratios of albumin to IgG--even when corrected for serum levels--were not significantly different in the two groups. Timolol did not affect the change in these ratios in the secondary aqueous humor samples. Thus, we concluded that these findings were not caused by a breakdown of the blood-aqueous barrier, but rather resulted from reduced aqueous humor flow and undisturbed protein filtration.

Aged↗

PubMed1990

Effects and interactions of epinephrine, norepinephrine, timolol, and betaxolol on outflow facility in the cynomolgus monkey.

Total outflow facility was determined in cynomolgus monkeys by two-level constant pressure perfusion. Topical epinephrine increased facility by 30% to 35% three to four hours after dosing, whether given as a single 600-micrograms dose or as twice daily 600-micrograms doses for three days. A single 5.5-micrograms intracameral dose of epinephrine or norepinephrine increased facility by 65% to 70% three to four hours after dosing. A single 180-micrograms topical dose of timolol or betaxolol had no effect on facility three to four hours later. Timolol pretreatment prevented the facility-increasing effect of both topical epinephrine and intracameral norepinephrine, but betaxolol pretreatment prevented neither. These findings indicate that no cumulative facility-increasing effect of epinephrine, beyond the acute (three hour) facility-increasing effect, develops within three days; there may be a facility-decreasing effect of large topical epinephrine doses on the vascular structures external to the trabecular meshwork; there is no, or only subthreshold, facility-affecting ambient beta-adrenergic tone in the meshwork; and the facility-increasing effect of both epinephrine and norepinephrine is mediated by beta 2-adrenergic receptors in the trabecular endothelium.

Administration, Topical↗

PubMed1985

Effect of topical indomethacin and timolol maleate on intraocular pressure in normal subjects.

In a prospective randomized double-masked crossover study in ten healthy volunteers, conducted to determine if the intraocular hypotensive effect of timolol eyedrops was significantly affected by the concomitant use of the topically administered prostaglandin inhibitor, indomethacin, we found that significant ocular hypotension was achieved with timolol alone. This was not changed by the concurrent administration of indomethacin. The results provide further evidence that prostaglandins are not involved in the control of normal intraocular pressure.

Double-Blind Method↗

PubMed1990

Direct separation and optimization of timolol enantiomers on a cellulose tris-3,5-dimethylphenylcarbamate high-performance liquid chromatographic chiral stationary phase.

A high-performance liquid chromatographic method was developed for the direct resolution and optimization of the separation of timolol enantiomers. The method involves the use of a cellulose tris-3,5-dimethylphenylcarbamate chiral stationary phase (OD-Chiralcel) column. The effects of concentration of 2-propanol, various aliphatic alcohols and diethylamine in the mobile phase and column temperature on the retention and enantioselectivity of timolol enantiomers were studied. The maximum resolution factor obtained was 4.00 when using the solvent system hexane-2-propanol (95:5) containing 0.4% (v/v) diethylamine at 5 degrees C.

1-Propanol↗

PubMed1979

Timolol--further observations.

Data from clinical records of patients using timolol confirm the ocular hypotensive effect of the drug in secondary glaucoma, aphakic glaucoma, ocular hypertension, and when used in combination with various other forms of glaucoma therapy. No serious local or systemic side effects were noted. Although many adrenergic agents ultimately produce tachyphylaxis, this effect is infrequent in timolol therapy.

Carbonic Anhydrase Inhibitors↗

PubMed1979

Effect of timolol on the permeability of corneal endothelium.

The effect of short-term administration of timolol on the permeability of the corneal endothelium to fluorescein was measured in normal subjects (single drop) and in a small group of glaucoma patients (one week's treatment). No effect on the endothelium was found in the normal eyes. In the glaucomatous eyes, endothelial permeability was higher than normal when measured after one week without topical medications and normal when measured after one week on timolol treatment. No evidence was found that short-term administration of this drug disturbs the barrier function of the endothelium.

Adult↗