ALTERNATIVE MANAGEMENT OF CIRCUMSCRIBED CHOROIDAL HEMANGIOMA USING INTRAVITREAL METOPROLOL

Intravitreal bevacizumab plus propranolol for neovascular age-related macular degeneration (the BEVALOL study): a phase I clinical trial

BACKGROUND

Given the persistently large public health impact of neovascular age-related macular degeneration (nARMD) despite many years of anti-VEGF therapy as the first-line treatment and the demonstrated ability of b-blockers to reduce neovascularization, a synergistic effect between an anti-VEGF agent and an intravitreal beta-blocker is important to investigate in the quest for therapeutic alternatives that maximize efficacy and/or reduce costs. The main purpose of this study is to investigate the safety of a 0.1 ml intravitreal injection of a combination of bevacizumab (1.25 mg/0.05 ml) and propranolol (50 g/0.05 ml) to treat nARMD.

METHODS

Prospective phase I clinical trial that included patients with nARMD. Comprehensive ophthalmic evaluation was performed at baseline and included Early Treatment Diabetic Retinopathy Study (ETDRS) best-corrected visual acuity (BCVA), biomicroscopy of the anterior and posterior segments, binocular indirect ophthalmoscopy, color fundus photography, spectral domain optical coherence tomography (OCT), OCT angiography (OCT-A), fluorescein angiography (Spectralis, Heidelberg), and full-field electroretinography (ERG). All eyes were treated with a 0.1 ml intravitreal injection of a combination of bevacizumab (1.25 mg/0.05 ml) and propranolol (50 g/0.05 ml) within 1 week of baseline evaluation. The patients were reexamined at weeks 4, 8 and 12, and clinical evaluation and SD-OCT were performed at all follow-up visits. Additional injections of combination bevacizumab (1.25 mg/0.05 ml) and propranolol (50 g/0.05 ml) were administered at weeks 4 and 8. At the final study evaluation (week 12), color fundus photography, OCT-A, fluorescein angiography, and full-field ERG were repeated.

RESULTS

Eleven patients (11 eyes) completed all study visits of the 12 week study. Full field ERG b-waves did not show significant (p < 0.05) changes at week 12 compared to baseline. During the 12 week follow-up period, none of the study eyes developed intraocular inflammation, endophthalmitis or intraocular pressure elevation more than 4 mmHg over baseline. Mean ± SE BCVA (logMAR) was 0.79 ± 0.09 at baseline and was significantly (p < 0.05) improved to 0.61 ± 0.10 at week 4; 0.53 ± 0.10 at week 8; and 0.51 ± 0.09 at week 12. Mean ± SE central subfield thickness (CST) (μm) was 462 ± 45 at baseline and was significantly (p < 0.05) lower at 4, 8 and 12 weeks (385 ± 37; 356 ± 29 and 341 ± 24, respectively).

CONCLUSIONS

In this 12 week trial of a combination of intravitreal bevacizumab and propranolol for treatment of nARMD, no adverse events or signals of ocular toxicity were observed. Further studies using this combination therapy are warranted. Trial Registration Project registered in Plataforma Brasil with CAAE number 28108920.0.0000.5440 and approved in ethics committee of Clinics Hospital of Ribeirao Preto Medicine School of São Paulo University-Ribeirão Preto, São Paulo, Brazil (appreciation number 3.999.989 gave the approval).

β-Adrenoreceptors as Therapeutic Targets for Ocular Tumors and Other Eye Diseases-Historical Aspects and Nowadays Understanding

β-adrenoreceptors (ARs) are members of the superfamily of G-protein-coupled receptors (GPCRs), and are activated by catecholamines, such as epinephrine and norepinephrine. Three subtypes of β-ARs (β₁, β₂, and β₃) have been identified with different distributions among ocular tissues. Importantly, β-ARs are an established target in the treatment of glaucoma. Moreover, β-adrenergic signaling has been associated with the development and progression of various tumor types. Hence, β-ARs are a potential therapeutic target for ocular neoplasms, such as ocular hemangioma and uveal melanoma. This review aims to discuss the expression and function of individual β-AR subtypes in ocular structures, as well as their role in the treatment of ocular diseases, including ocular tumors.

Safety of intravitreal metoprolol in eyes with central serous chorioretinopathy

PURPOSE

To investigate ocular safety of intravitreal metoprolol in eyes with central serous chorioretinopathy.

METHODS

Five eyes of five patients diagnosed with chronic central serous chorioretinopathy (cCSC) previously treated unsuccessfully with oral spironolactone, micropulse laser and intravitreal anti-vascular endothelial growth factor agents were enrolled and received off-label intravitreal metoprolol (50 µg/0.05 ml). Baseline and follow-up examinations included measurement of best-corrected visual acuity (BCVA), intraocular pressure, anterior chamber cellular/flare scores, vitritis classification, fluorescein and indocyanine green angiography, spectral domain optical coherence tomography and electroretinography (ERG), recorded by means of DTL electrodes and following the standard suggested by the International Society for Clinical Electrophysiology of Vision (ISCEV). The total follow-up period was 4 weeks.

RESULTS

There were no significant differences between baseline and follow-up ERG parameters: scotopic or photopic, a- and b-wave amplitude and implicit time, nor oscillatory potentials amplitude, or whatsoever. No intraocular inflammation sign was observed. In addition, BCVA showed small improvement in 4 or kept baseline values in 1 patient. The subretinal and/or intraretinal fluid volume reduced in all patients at 1 month after treatment.

CONCLUSION

Patients with refractory cCSC treated with intravitreal 50 µg/0.05 ml metoprolol showed no signs of acute ocular toxicity, along with intraretinal fluid reduction and slight BCVA improvement 1 month after injection. This data suggest that intravitreal metoprolol may be a safe alternative for cCSC.

Alternative management of central serous chorioretinopathy using intravitreal metoprolol

Background

Beta-blockers may counteract the effect of catecholamines on central serous chorioretinopathy (CSC) pathology and accelerate the improvement of neurosensory retinal detachment. Oral propranolol has been associated with decreased duration of CSC in some studies. We describe two patients with visually symptomatic chronic CSC (cCSC) treated successfully with intravitreal metoprolol.

Case presentations

After obtaining the patients’ informed consent, two eyes of two 43-year-old men diagnosed with cCSC treated unsuccessfully with oral spirolactone, micropulse laser and intravitreal anti‐vascular endothelial growth factor (anti-VEGF) agents were treated with one off-label intravitreal injection of metoprolol (50 µg/0.05 ml). Baseline (pre-injection) and follow-up examinations (at 1 month post-injection) included best-corrected visual acuity (BCVA), anterior and posterior segment biomicroscopy, fundus autofluorescence, spectral domain optical coherence tomography (Spectralis, Heidelberg), and electroretinogaphy (ERG) according to International Society for Clinical Electrophysiology of Vision (ISCEV) full-field scotopic and photopic standard protocols. ERG results at baseline (pre-injection) and at 1 month post-injection were compared using paired t-tests.

Results

There was no significant difference in any of the ISCEV recommended ERG parameters with respect to a- and b-wave amplitude and implicit time, and oscillatory potentials maximal amplitude. BCVA improved in both patients. Neither patient developed clinical evidence of intraocular inflammation. Subretinal and/or intraretinal fluid had improved in both patients at 1 month after the metoprolol injection.

Conclusion

These preliminary findings suggest that intravitreal metoprolol may be a safe alternative therapy for patients with cCSC.

Clinical Pharmacokinetics of Metoprolol: A Systematic Review

BACKGROUND

Metoprolol is recommended for therapeutic use in multiple cardiovascular conditions, thyroid crisis, and circumscribed choroidal hemangioma. A detailed systematic review on the metoprolol literature would be beneficial to assess all pharmacokinetic parameters in humans and their respective effects on patients with hepatic, renal, and cardiovascular diseases. This review combines all the pharmacokinetic data on metoprolol from various accessible studies, which may assist in clinical decision making.

METHODOLOGY

The Google Scholar and PubMed databases were searched to screen articles associated with the clinical pharmacokinetics of metoprolol. The comprehensive literature search retrieved 41 articles including data on plasma concentration-time profiles after intravenous and oral (immediate-release, controlled-release, slow-release, or extended-release) routes of administration, and at least one pharmacokinetic parameter was reported in all studies included.

RESULTS

Out of 41 retrieved articles, six were after intravenous and 12 were after oral administration in healthy individuals. The oral studies depict a dose-dependent increase in maximum plasma concentration (C_max), time to reach maximum plasma concentration (T_max), and area under the concentration-time curve (AUC). Two studies were conducted in R- and S-enantiomers, in which one study reported the gender differences, depicting greater C_max and AUC among women, whereas in another study S-metoprolol was found to have higher values of C_max, T_max, and AUC in comparison with R-metoprolol. Results in different diseases depicted that after IV administration of 20 mg, patients with renal impairment showed an increase in clearance (CL) (60 L/h vs 48 L/h) compared with healthy subjects, whereas a decrease in CL (36.6 ± 7.8 L/h vs 48 ± 6.6 L/h) was seen in patients with hepatic cirrhosis at a similar dose. In comparison with a single oral dose following administration of 15 mg IV in three divided doses, patients having an acute myocardial infarction (AMI) showed an increase in C_max (823 nmol/L vs 248 nmol/L) at a steady state. Twenty different studies have reported significant changes in CL, C_max, and AUC of metoprolol when it is co-administered with other drugs. One study has reported a drug-food interaction for metoprolol but no significant changes were seen in the C_max and AUC.

CONCLUSION

This review summarizes all the pharmacokinetic parameters of metoprolol after pooling up-to-date data from all the studies available. The summarized pharmacokinetic data presented in this review can assist in developing and evaluating pharmacokinetic models of metoprolol. Moreover, this data can provide practitioners with an insight into dosage adjustments among the diseased populations and can assist in preventing potential adverse drug reactions. This review can also help avoid side effects and drug-drug interactions.

Intravitreal metoprolol for circumscribed choroidal hemangiomas: a phase I clinical trial

BACKGROUND

Choroidal hemangioma is a visual threatening condition for which treatments is neither uniform nor widely available. New management options are necessary. The purpose of this study is to assess the safety and early outcome of intravitreal metoprolol tartrate in five patients with CCH.

METHODS

Five eyes of five patients diagnosed with subfoveal or peripapillary CCH and unsuccessfully treated with intravitreal anti-VEGF agents were enrolled and received off-label intravitreal injections of metoprolol (50μg/0.05 ml). Baseline and follow-up evaluations included best-corrected visual acuity, intraocular pressure measurement, assessment of anterior chamber cellular score/flare and vitritis, retinography, fundus autofluorescence, and ERG. Patients were followed for a period of 30 days. Statistical analysis involved comparison of pre- and post-treatment findings using a paired t-test.

RESULTS

There was no significant difference in all ERG parameters regarding a- and b-wave amplitude and implicit time, and oscillatory potentials' maximal amplitude. There were no significant changes in visual acuity. None of the patients developed clinical signs of intraocular inflammation. The subretinal and/or intraretinal fluid improved in 3 out of 5 patients 4 weeks after the metoprolol injection.

CONCLUSIONS

Patients with CCH treated with a single injection of 50μg/0.05ml intravitreal metoprolol injections showed no signs of acute ocular toxicity. This pilot study did not assess long-term retinal toxicity, different concentrations, drug resistance, and complications from repeated-intravitreal injections.

Assessment of the safety of intravitreal injection of metoprolol tartrate in rabbits

PURPOSE

To verify the safety of different doses of intravitreal metoprolol tartrate (MT) after intravitreal injection in rabbit eyes.

METHODS

Animals were randomly assigned into 2 groups: group I received 50 µg of MT and group II 100 µg of MT. A volume of 0.05 mL of the drug solution was administered through an intravitreal injection, while the control eyes received an equal volume of saline solution. Safety was assessed by clinical observation, electroretinography (ERG) and histological evaluation.

RESULTS

No evidence of clinical toxicity was observed. ERG waveforms from the MT treated eyes were similar to those recorded from the control eyes in dark-adapted state, amplitude and the implicit time are similar between the groups in light-adapted state, and their retinas had no signs of toxicity by histological evaluation 7 days after intravitreal injection.

CONCLUSIONS

The intravitreal use of metoprolol at 50 and 100 µg dosages does not cause short-term retinal toxicity in rabbits.