Absorption and attachment of atropine to etafilcon A contact lenses.

PURPOSE: Myopia (short-sightedness) is a growing vision problem worldwide. Currently atropine eye drops are used to control the progression of myopia but these suffer from potential lack of bioavailability and low ocular residence time. Commercially available myopia control contact lenses are also used to limit myopia progression, but neither atropine nor contact lenses individually completely stop progression. Development of myopia control contact lenses which could deliver therapeutic doses of atropine is thus desirable and may provide increased efficacy. This study was designed to explore the feasibility of attaching atropine to etafilcon A contact lenses through an esterification reaction. METHODS: Carboxylic acid groups on etafilcon A contact lenses were quantified using Toluidine Blue O. The carboxylic acid groups in etafilcon A contact lenses were activated using 1-ethyl-3-(3-dimethylaminopropyl)carbodiimide (EDC-HCl) and N-hydroxysuccinimide (NHS) crosslinkers after which atropine was added to undergo potential binding via esterification. Atropine was released from lenses by alkaline hydrolysis. Reverse phase high performance liquid chromatography (HPLC) was used to detect and quantify the released atropine and its degradation products in solution. Contact lenses that had not been activated by EDC-NHS (controls) were also examined to determine the amount of atropine that could be absorbed rather than chemically bound to lenses. RESULTS: Each etafilcon A contact lens contained 741.1 ± 5.5 µg carboxylic acid groups which may be available for esterification. HPLC had a limit of detection for atropine of 0.38 µg/mL and for tropic acid, an atropine degradation product, of 0.80 µg/mL. The limits of quantification were 1.16 µg/mL for atropine and 2.41 µg/mL for tropic acid in NH4HCO3. The etafilcon A lenses adsorbed up to 7.69 µg atropine when incubated in a 5 mg/mL atropine solution for 24 h. However, there was no evidence that atropine could be chemically linked to the lenses, as washing in a high concentration of NaCl removed all the atropine from the contact lenses with no atropine being subsequently released from the lenses after incubating in 0.01 N NH4HCO3. CONCLUSIONS: Etafilcon A contact lenses contain free carboxylic acids which may be an appropriate option for attaching drugs such as atropine. Etafilcon A lenses adsorbed up to 7.69 µg atropine, which would be more than enough to deliver atropine to eyes to control myopia. However, atropine could not be chemically bound to the carboxylic acids of the etafilcon A lenses using this methodology.

Oculocardiac Reflex in a Patient With Maxillofacial Trauma: A Case Study and Literature Review.

Oculocardiac reflex (OCR), presenting as bradycardia and asystole, is a potential intraoperative complication that may occur during maxillofacial trauma surgery. Bradycardia is the most common symptom of this phenomenon. Surgeons should be aware of its long-term effects, such as arrhythmias and even cardiac arrest. We report the case of a 40-year-old male patient with a fracture of the floor of the orbit. During a surgical exploration of the orbital floor, the patient exhibited sudden symptoms of OCR. It was managed by withholding the surgery and administering atropine. The article also highlights the mechanism, types, incidence, and management of OCR in patients with maxillofacial trauma.

Enhanced ophthalmic bioavailability and stability of atropine sulfate via sustained release particles using polystyrene sulfonate resin.

Atropine sulfate (ATS) eye drops at low concentrations constitute a limited selection for myopia treatment, with challenges such as low ophthalmic bioavailability and inadequate stability. This study proposes a novel strategy by synthesizing ophthalmic sodium polystyrene sulfonate resin (SPSR) characterized by a spherical shape and uniform size for cationic exchange with ATS. The formulation of ATS@SPSR suspension eye drops incorporates xanthan gum and hydroxypropyl methylcellulose (HPMC) as suspending agents. In vitro studies demonstrated that ATS@SPSR suspension eye drops exhibited sustained release characteristics, and tropic acid, its degradation product, remained undetected for 30 days at 40 °C. The ATS levels in the tear fluids and aqueous humor of New Zealand rabbits indicated a significant increase in mean residence time (MRT) and area under the drug concentration-time curve (AUC0-12h) for ATS@SPSR suspension eye drops compared to conventional ATS eye drops. Moreover, safety assessment confirmed the non-irritating nature of ATS@SPSR suspension eye drops in rabbit eyes. In conclusion, the cation-responsive sustained-release ATS@SPSR suspension eye drops enhanced the bioavailability and stability of ATS, offering a promising avenue for myopia treatment.

Effect of pH and temperature on tropane alkaloids within a processing strategy to provide safe infant cereal-based food.

Tropane alkaloids (TAs) are secondary metabolites from weeds that can contaminate cereals and vegetables during harvest. Due to their toxicity, the Regulation (EC) 2023/915 sets maximum levels for atropine and scopolamine in cereal-based foods for infants containing millet, sorghum, buckwheat or their derived products. The aim of this study was to evaluate the effect of pH and temperature on the stability of TAs, as possible parameters in thermal processing to mitigate this chemical hazard in cereal-based infant food. The effect of pH (4 and 7) and temperature (80 °C and 100 °C) was assessed in buffer solutions. Also, treatment at 180 °C was performed in spiked and naturally incurred millet flour to assess the effect of high temperature, simulating cooking or drying, on the stability of TAs in the cereal matrix. The fate of 24 TAs was assessed by UHPLC-MS/MS. TAs showed high thermostability, although it was variable depending on the specific compound, pH, temperature and treatment time. In buffer solutions, higher degradation was found at 100 °C and pH 7. In spiked millet flour at 180 °C for 10 min, scopolamine and atropine contents decreased by 25 % and 22 %, similarly to other TAs which also showed a slow thermal degradation. Atropine, scopolamine, anisodamine, norscopolamine, scopine and scopoline were found in naturally contaminated millet flour. Interestingly, naturally incurred atropine was more thermostable than when spiked, showing a protective effect of the cereal matrix on TAs degradation. The present results highlight the need for an accurate monitorization of TAs in raw materials, as this chemical hazard may remain in infant cereal-based food even after intense thermal processing.

Impact of salivary flow inhibition on masticatory behaviours in healthy individuals.

BACKGROUND: It remains unclear how the salivary flow and the fat content of food affect bolus formation during mastication. OBJECTIVES: We aimed to clarify: (1) how hyposalivation affects jaw-closing and hyoid-elevating muscle activities in bolus formation, and (2) if the effect of hyposalivation on muscle activity depends on the fat content of food. METHODS: Eighteen healthy male volunteers were instructed to freely ingest four test foods: Plain, Fat without seasoning, Fat with seasoning, and Soft rice crackers. Masseter and suprahyoid electromyographic activities were recorded before and 30 min after the administration of atropine sulfate, a muscarinic receptor antagonist that induces hyposalivation. RESULTS: Hyposalivation extended the masticatory duration significantly in all the test foods except Fat with seasoning. Masticatory cycle time was significantly longer with vs without hyposalivation for the Soft (p = .011). Suprahyoid activity/cycle was significantly greater with vs without hyposalivation (p = .013). Masticatory cycle time was significantly longer at the late stage with vs without hyposalivation for the Soft (p < .001). Suprahyoid activity/cycle was significantly greater at the middle (p = .045) and late stages (p = .002) with vs without hyposalivation for the Soft and greater at the late stage with vs without hyposalivation for the Plain (p = .043). Changes in masticatory cycle time and suprahyoid activity/cycle for these foods had significantly positive relationship (p < .001). CONCLUSION: Hyposalivation-induced changes in masticatory behaviours resulted from the middle and late stage suprahyoid activity. Fat content and seasoning compensate for salivary flow inhibition.

Atropine sulfate as a continuous intravenous infusion for the treatment of organophosphate toxicity in a cat.

Case summary: A 1-year-old male neutered domestic shorthair cat presented on an emergency basis with clinical signs suspected to be secondary to organophosphate (OP) toxicity. The control of clinical abnormalities (bradycardia, obtundation, tachypnea, anorexia) was achieved using high-dose continuous rate intravenous infusion (CRI) of atropine sulfate (maximum rate 0.1 mg/kg/h). After 5 days of hospitalization, the patient made a full clinical recovery without the development of atropine toxicity, intermediate syndrome or delayed polyneuropathy at 4 weeks after discharge. Relevance and novel information: Treatment of OP toxicity in cats is sparsely reported in veterinary literature. Current standards of treatment and published protocols recommend the use of atropine sulfate as intermittent boluses for the treatment of muscarinic signs of toxicity; however, there is a paucity of information regarding the safety and efficacy of atropine sulfate as a CRI for severe toxicosis as described in humans. This report includes the first published case using such a treatment protocol in a cat.

Human Plasma Butyrylcholinesterase Hydrolyzes Atropine: Kinetic and Molecular Modeling Studies.

The participation of butyrylcholinesterase (BChE) in the degradation of atropine has been recurrently addressed for more than 70 years. However, no conclusive answer has been provided for the human enzyme so far. In the present work, a steady-state kinetic analysis performed by spectrophotometry showed that highly purified human plasma BChE tetramer slowly hydrolyzes atropine at pH 7.0 and 25 °C. The affinity of atropine for the enzyme is weak, and the observed kinetic rates versus the atropine concentration was of the first order: the maximum atropine concentration in essays was much less than Km. Thus, the bimolecular rate constant was found to be kcat/Km = 7.7 × 104 M-1 min-1. Rough estimates of catalytic parameters provided slow kcat < 40 min-1 and high Km = 0.3-3.3 mM. Then, using a specific organophosphoryl agent, echothiophate, the time-dependent irreversible inhibition profiles of BChE for hydrolysis of atropine and the standard substrate butyrylthiocholine (BTC) were investigated. This established that both substrates are hydrolyzed at the same site, i.e., S198, as for all substrates of this enzyme. Lastly, molecular docking provided evidence that both atropine isomers bind to the active center of BChE. However, free energy perturbations yielded by the Bennett Acceptance Ratio method suggest that the L-atropine isomer is the most reactive enantiomer. In conclusion, the results provided evidence that plasma BChE slowly hydrolyzes atropine but should have no significant role in its metabolism under current conditions of medical use and even under administration of the highest possible doses of this antimuscarinic drug.

The efficacy of the use of atropine in children with reflex anoxic syncope during pallid breath-holding spells: can cardiac pacemaker implantation be avoided?

OBJECTIVES: Reflex anoxic syncope is the result of an overreaction of the vagal system, resulting in hypotension and bradycardia or brief cardiac arrest. Because of the benign character and the absence of complications in short or long term, treatment is only necessary in case of frequent or severe clinical presentation. Treatment options are anticholinergic drugs or cardiac pacemaker placement. We investigated atropine treatment and aimed to examine if pacemaker placement can be avoided. METHODS: We retrospectively reviewed patients treated with atropine for severe reflex anoxic syncope in our centre from January 2017 until May 2023, and compared our results to those in the literature. RESULTS: The study population consisted of 10 children, 70% female, with an age ranging from 5 months to 3 years (mean 14.5 months) when atropine treatment was started (dose 17-50 microg/kg/day). All patient's parents reported adequate symptom management during atropine treatment, with complete resolution in 10%. Minor side effects were reported in 60% (dry mucosa in 40%, obstipation in 20%, and nausea or blurry vision in 10%). DISCUSSION: We consider atropine a safe and effective treatment to manage reflex anoxic syncope with similar success rate to pacemaker implantation. However, pacemaker implantation entails substantial risk for complications (up to 25%) such as infection or technical problems and morbidity such as scar formation. This might be considered redundant for a benign and temporary condition, certainly given the possibility of other efficient treatment options. Consequently, we recommend atropine treatment over implantation of a cardiac pacemaker in children with severe reflex anoxic syncope.

Effect of 0.01% atropine combined with orthokeratology lens on axial elongation: a 2-year randomized, double-masked, placebo-controlled, cross-over trial.

Purpose: To evaluate the effect of 0.01% atropine combined with orthokeratology (OK) lens on axial elongation in schoolchildren with myopia. Methods: Sixty children aged 8-12 years with spherical equivalent refraction (SER) from -1.00D to -4.00D in both eyes were enrolled in this randomized, double-masked, placebo-controlled, cross-over trial. Children who had been wearing OK lenses for 2 months were randomly assigned into combination group (combination of OK lens and 0.01% atropine) for 1 year followed by control group (combination of OK lens and placebo) for another 1 year or vice versa. This trial was registered in the Chinese Clinical Trial Registry (Number: ChiCTR2000033904, 16/06/2020). The primary outcome was changes in axial length (AL). Data of right eyes were analyzed. Results: There were statistically significant differences in the changes in AL between combination and control groups after generalized estimating equation model adjusting for age and baseline SER (p = 0.001). The mean axial elongation difference between combination and control groups was 0.10 mm in the first year (0.10 ± 0.13 mm vs. 0.20 ±0.15 mm; p = 0.01), and 0.09 mm in the second year (0.22 ± 0.10 mm vs. 0.13 ± 0.14 mm; p = 0.01), respectively. The mean axial elongation difference of two groups in the first year was similar to that in the second year during the cross-over treatment. Conclusion: In central Mainland China in myopic children, the treatment of combination therapy is more effective than single OK lens in controlling axial elongation.

Impact of Various Concentrations of Low-Dose Atropine on Pupillary Diameter and Accommodative Amplitude in Children with Myopia.

Purpose: To assess over 2 weeks, the effect of 3 different low concentrations of atropine on pupillary diameter and accommodative amplitude in children with myopia. Methods: Fifty-eight children with myopia [spherical equivalent (SE) of -0.50 diopters (D) or worse, astigmatism of less than or equal to 2.00 D] were randomly allocated to 3 groups receiving 0.01%, 0.02%, or 0.03% atropine eye drops, once nightly for 2 weeks. The primary outcome was the change from baseline in pupillary diameter and accommodative amplitude with each of the concentrations. Results: Fifty-seven participants (114 eyes), aged between 6 and 12 years, completed the 2-week trial (mean age 9.3 ± 1.7 years and mean SE -3.53 ± 1.79 D). After 2 weeks of use, all the 3 concentrations were found to have a statistically significant effect on both the pupillary diameter and accommodative amplitude. Accommodative amplitude reduced by an average of 5.23 D, 9.28 D, and 9.32 D, and photopic pupil size increased by an average of 0.95 ± 1.05 mm, 1.65 ± 0.93 mm, and 2.16 ± 0.88 mm with 0.01%, 0.02%, and 0.03%, respectively. Of the eyes, a total of 5.3% and 5.9% of the eyes on 0.02% and 0.03% atropine had a mean residual accommodative amplitude of <5 D. The percentage of eyes having a pupillary dilation >3 mm were 4.8%, 10.5%, and 23.5% for 0.01%, 0.02%, and 0.03% atropine, respectively. Conclusions: Low-dose atropine had an effect on pupillary diameter and accommodative amplitude. With the highest concentration assessed, that is, 0.03% nearly 1 of 4 eyes had pupillary dilation of >3 mm. Clinical Trial Registration number: NCT03699423.

The effect of glycopyrrolate vs. atropine in combination with neostigmine on cardiovascular system for reversal of residual neuromuscular blockade in the elderly: a randomized controlled trial.

BACKGROUND: Glycopyrrolate-neostigmine (G/N) for reversing neuromuscular blockade (NMB) causes fewer changes in heart rate (HR) than atropine-neostigmine (A/N). This advantage may be especially beneficial for elderly patients. Therefore, this study aimed to compare the cardiovascular effects of G/N and A/N for the reversal of NMB in elderly patients. METHODS: Elderly patients aged 65-80 years who were scheduled for elective non-cardiac surgery under general anesthesia were randomly assigned to the glycopyrrolate group (group G) or the atropine group (group A). Following the last administration of muscle relaxants for more than 30 min, group G received 4 ug/kg glycopyrrolate and 20 ug/kg neostigmine, while group A received 10 ug/kg atropine and 20 ug/kg neostigmine. HR, mean arterial pressure (MAP), and ST segment in lead II (ST-II) were measured 1 min before administration and 1-15 min after administration. RESULTS: HR was significantly lower in group G compared to group A at 2-8 min after administration (P < 0.05). MAP was significantly lower in group G compared to group A at 1-4 min after administration (P < 0.05). ST-II was significantly depressed in group A compared to group G at 2, 3, 4, 5, 6, 7, 8, 9, 11, 13, 14, and 15 min after administration (P < 0.05). CONCLUSIONS: In comparison to A/N, G/N for reversing residual NMB in the elderly has a more stable HR, MAP, and ST-II within 15 min after administration.

Efficacy and Safety of Low-Dose Atropine on Myopia Prevention in Premyopic Children: Systematic Review and Meta-Analysis.

Background: Early-onset myopia increases the risk of irreversible high myopia. Methods: This study systematically evaluated the efficacy and safety of low-dose atropine for myopia control in children with premyopia through meta-analysis using random-effects models. Effect sizes were calculated using risk ratios (RRs) with 95% confidence intervals (CIs). Comprehensive searches of PubMed, EMBASE, Cochrane CENTRAL, and ClinicalTrials.gov were conducted until 20 December 2023, without language restrictions. Results: Four studies involving 644 children with premyopia aged 4-12 years were identified, with atropine concentrations ranging from 0.01% to 0.05%. The analysis focused on myopia incidence and atropine-related adverse events. Lower myopia incidence (RR, 0.62; 95% CI, 0.40-0.97 D/y; p = 0.03) and reduction in rapid myopia shift (≥0.5 D/1y) (RR, 0.50; 95% CI, 0.26-0.96 D/y; p < 0.01) were observed in the 12-24-month period. Spherical equivalent and axial length exhibited attenuated progression in the atropine group. No major adverse events were detected in either group, whereas the incidence of photophobia and allergic conjunctivitis did not vary in the 12-24-month period. Conclusions: Our meta-analysis supports atropine's efficacy and safety for delaying myopia incidence and controlling progression in children with premyopia. However, further investigation is warranted due to limited studies.

Evaluation of curcumin-based ophthalmic nano-emulsion on atropine-induced dry eye in mice.

Background: One of the most efficient treatments for dry eye syndrome (DES) is to use nanocarriers as a potential delivery system. We aim to evaluate curcumin in a nano emulsion formulation. Methods: A new formulation containing 5.5% curcuminoid was used. DLS, Zeta potential, TEM, and HPLC tests were performed to determine the size and morphology. First, 30 mice were selected as atropine-induced dry eye models. Next, 25 mice in 5 groups were treated with the nano emulsion at different doses, and corneal tissues were separated for evaluation. Results: The DLS test results were indicative of the particles' stability. Nano curcumin appeared to be thoroughly effective in all groups, with the highest dose showing the most similarity to the healthy control group. Conclusions: Curcumin-based nano emulsion eye drop is a promising candidate for DES management. However, further investigation is required to evaluate the possible risks in humans.

Increase of Intraocular Pressure after Application of 0.125% Atropine Eye Drops in Children Using Ortho-K Contact Lenses.

Introduction: This report describes a case of elevated intraocular pressure following the use of 0.125% atropine eye drops in a child wearing orthokeratology lenses. Case Presentation: A 9-year-old boy presented to our clinic with myopia, and he had been wearing orthokeratology lenses overnight for 23 months. He was treated previously with a once-daily administration of topical 0.125% atropine eye drops to reduce myopic progression. Three days after treatment, his intraocular pressure was 36 mm Hg in the right eye and 32 mm Hg in the left eye. Two days after the discontinuation of atropine eye drops and overnight orthokeratology lenses, the intraocular pressure was 18/20 mm Hg in both eyes. Conclusion: Low-dose atropine eye drops can cause intraocular pressure elevation in patients wearing overnight orthokeratology lenses. Although it may resolve promptly, short-term follow-up with intraocular pressure checks may be necessary for the early diagnosis and treatment of this complication.

Sublingual administration of atropine eye drops for treating organophosphorus poisoning.

An 89-year-old patient with fenitrothion toxicity received sublingual atropine eye drops, reducing the intravenous atropine requirement. This alternative method enabled rapid rehabilitation, and he walked unaided, leading to discharge.

Hypertensive emergency secondary to atropine / Emergencia hipertensiva secundaria a atropina

Atropine, a competitive antagonist of acetylcholine muscarinic receptors, is commonly used to treat severe bradycardia by blocking parasympathetic activity. We present a rare case of hypertensive emergency following atropine administration, with only one previous report in the literature. A 78-year-old woman with essential hypertension and hypercholesterolemia was admitted to the cardiac intensive care unit for non-ST segment elevation myocardial infarction. During coronary angiography, an occlusion of the right coronary artery was identified. While removing the diagnostic catheter through the right radial artery, the patient experienced intense pain and discomfort, accompanied by a vasovagal reflex characterized by bradycardia and hypotension. Intravenous atropine (0.5mg) was administered, leading to a rapid rise in heart rate with frequent ventricular ectopy. Subsequently, a progressive and exaggerated elevation in arterial blood pressure occurred, peaking at 294/121mmHg approximately 10min after atropine administration. The patient developed hypertensive acute pulmonary edema, successfully treated with intravenous nitroglycerine (10mg) and furosemide (60mg). Blood pressure normalized after approximately 14min. The exact mechanism of atropine-induced hypertensive emergency remains unknown. While hypertensive emergencies with atropine are exceedingly rare, healthcare professionals should be aware of this potential effect and be prepared for prompt intervention.(AU)

La atropina, un antagonista competitivo de los receptores muscarínicos de acetilcolina, se utiliza comúnmente para tratar la bradicardia severa al bloquear la actividad parasimpática. Presentamos un caso raro de emergencia hipertensiva después de la administración de atropina, con solo un informe previo en la literatura. Una mujer de 78 años con hipertensión esencial e hipercolesterolemia fue ingresada en la unidad de cuidados intensivos cardíacos por infarto agudo de miocardio sin elevación del segmento ST. Durante la angiografía coronaria, se identificó una oclusión de la arteria coronaria derecha. Mientras se retiraba el catéter diagnóstico a través de la arteria radial derecha, la paciente experimentó un intenso dolor y malestar, acompañado de un reflejo vasovagal caracterizado por bradicardia e hipotensión. Se administró atropina intravenosa (0,5 mg), lo que provocó un rápido aumento de la frecuencia cardíaca con frecuente ectopia ventricular. Posteriormente, ocurrió una elevación progresiva y exagerada de la presión arterial, alcanzando un máximo de 294/121 mmHg aproximadamente 10 minutos después de la administración de atropina. La paciente desarrolló edema pulmonar agudo hipertensivo, tratado con éxito con nitroglicerina intravenosa (10 mg) y furosemida (60 mg). La presión arterial se normalizó después de aproximadamente 14 minutos. El mecanismo exacto de la emergencia hipertensiva inducida por atropina sigue siendo desconocido. Aunque las emergencias hipertensivas con atropina son excepcionalmente raras, los profesionales de la salud deben estar al tanto de este efecto potencial y estar preparados para intervenir rápidamente.(AU)

Successful management of pylorospasm with atropine in a failure-to-thrive neonate case report.

Pylorospasm is an elusive diagnosis that can mimic the presentation of pyloric stenosis. There is limited discussion regarding its management in neonates with few case reports describing the use of antispasmodic agents. The following case reviews this management in a unique neonate. A 2-month-old female presented with persistent nonbilious, nonbloody emesis and failure-to-thrive. A thorough workup was performed due to its pronounced persistence while inpatient. Pyloric ultrasounds remained negative for pyloric stenosis; however, an upper gastrointestinal (GI) study was significant for pylorospasm. The workup also revealed hypothyroidism. Antispasmodic therapy with atropine was pursued as she was not a surgical candidate. Patient tolerated IV atropine therapy well with quick resolution of emesis and successfully transitioned to oral atropine therapy, displaying continued weight gain with exclusive oral feeds. This case displays a unique presentation of pylorospasm with successful management utilizing IV and oral atropine therapy in a neonate with failure-to-thrive and concomitant hypothyroidism.

Comparing Effectiveness and Safety of Intravenous Atropine with Topical Tetracaine in Preventing and Relieving Oculocardiac Reflex in Patients Undergoing Strabismus Surgery: A Randomized Clinical Trial.

Background: Oculocardiac reflex (OCR) is one of the serious complications following surgical therapeutic procedures for strabismus. Various medications have been tested to prevent or mitigate this complication. We aimed to compare the effect of intravenous atropine and topical tetracaine on the incidence and severity of OCR in strabismus surgery. Materials and Methods: In this triple-blind randomized clinical trial study, 120 patients who were candidates for strabismus surgery were randomly assigned to receive intravenous atropine, topical tetracaine, or artificial tears as the control. The incidence of OCR and its severity along with the changes in hemodynamic conditions were compared across the groups. Results: The incidence rate of OCR in the groups receiving atropine, tetracaine, and the control was found to be 17.5%, 25.0%, and 32.5% in the releasing phase without any difference, respectively (P = 0.303); however, it was 2.5%, 7.5%, and 25.0%, respectively, in the cutting phase, indicating a lower rate in the group receiving tetracaine (P = 0.004). Similarly, there was no difference in the severity of OCR across the three study groups in the releasing phase (P = 0.666); however, in the cutting phase, OCR was revealed to be milder in the group receiving atropine as compared to other groups (P = 0.033). Prescribing atropine led to higher mean systolic blood pressure and mean arterial pressure during surgery. Conclusion: The injection of atropine can effectively reduce the incidence of OCR during strabismus surgery and reduce its severity if this reflex occurs.

LC-MS/MS determination of atropine toxicity: Pre-analytical effect of blood collection tube and analytical matrix.

Atropine (ATR) intoxication is a recurrent case in emergency departments. The diagnosis is dependent on clinical evaluation and is supported by analytical assessment. The assay is limited by the rapid degradation/metabolism of ATR into TRP as well as the preanalytical factors impairing correct detection and diagnosis. In this study, an HPLC-MS/MS method was optimized for the simultaneous determination of ATR and TRP. The effect of analytical matrix and the impact of blood-collection tube type on the ATR analytical signal were investigated. Separation was achieved using water: 0.01% formic acid acidified methanol (40: 60, v/v) as a mobile phase and Inertsil® C18 column (5 µm; 4.6*150 mm) as a stationary phase. The retention-times were 2.6 and 6.5 min for ATR and TRP, respectively. A chromatographic shift (0.4 min) in ATR peak, but not TRP, was observed in biological samples from neat ones. The best analytical signal was observed when heparinized blood collection tubes were employed. The method was linear, accurate and precise in the ATR toxicity range enabling the detection of ATR intoxication down to a concentration of 0.1 ng/mL by applying a simple sample clean-up procedure. In conclusion, an HPLC-MS/MS method for the simultaneous determination of ATR and TRP is presented. The method highlights the chromatographic shift of ATR peak in biological samples that may induce false-negative detection and poses TRP as an alternative toxicological marker for ATR toxicity. Meanwhile the study recommends heparin tubes for blood-sample collection.

Five-Year Clinical Trial of the Low-Concentration Atropine for Myopia Progression (LAMP) Study: Phase 4 Report.

PURPOSE: To evaluate (1) the long-term efficacy of low-concentration atropine over 5 years, (2) the proportion of children requiring re-treatment and associated factors, and (3) the efficacy of pro re nata (PRN) re-treatment using 0.05% atropine from years 3 to 5. DESIGN: Randomized, double-masked extended trial. PARTICIPANTS: Children 4 to 12 years of age originally from the Low-Concentration Atropine for Myopia Progression (LAMP) study. METHODS: Children 4 to 12 years of age originally from the LAMP study were followed up for 5 years. During the third year, children in each group originally receiving 0.05%, 0.025%, and 0.01% atropine were randomized to continued treatment and treatment cessation. During years 4 and 5, all continued treatment subgroups were switched to 0.05% atropine for continued treatment, whereas all treatment cessation subgroups followed a PRN re-treatment protocol to resume 0.05% atropine for children with myopic progressions of 0.5 diopter (D) or more over 1 year. Generalized estimating equations were used to compare the changes in spherical equivalent (SE) progression and axial length (AL) elongation among groups. MAIN OUTCOMES MEASURES: (1) Changes in SE and AL in different groups over 5 years, (2) the proportion of children who needed re-treatment, and (3) changes in SE and AL in the continued treatment and PRN re-treatment groups from years 3 to 5. RESULTS: Two hundred seventy (82.8%) of 326 children (82.5%) from the third year completed 5 years of follow-up. Over 5 years, the cumulative mean SE progressions were -1.34 ± 1.40 D, -1.97 ± 1.03 D, and -2.34 ± 1.71 D for the continued treatment groups with initial 0.05%, 0.025%, and 0.01% atropine, respectively (P = 0.02). Similar trends were observed in AL elongation (P = 0.01). Among the PRN re-treatment group, 87.9% of children (94/107) needed re-treatment. The proportion of re-treatment across all studied concentrations was similar (P = 0.76). The SE progressions for continued treatment and PRN re-treatment groups from years 3 to 5 were -0.97 ± 0.82 D and -1.00 ± 0.74 D (P = 0.55) and the AL elongations were 0.51 ± 0.34 mm and 0.49 ± 0.32 mm (P = 0.84), respectively. CONCLUSIONS: Over 5 years, the continued 0.05% atropine treatment demonstrated good efficacy for myopia control. Most children needed to restart treatment after atropine cessation at year 3. Restarted treatment with 0.05% atropine achieved similar efficacy as continued treatment. Children should be considered for re-treatment if myopia progresses after treatment cessation. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.