Different fetal effects on fingers from exposure to phenytoin, phenobarbital, and carbamazepine.

Exposure at conception to phenytoin (PHT), phenobarbital (PB), and carbamazepine (CBZ) has been associated with several different effects on the fetus, including hypoplasia of the distal phalanges, dysmorphic facial features, and structural abnormalities such as oral clefts and neural tube defects. One question is whether each of these antiepileptic drugs (AEDs) has the same effects or just similar effects. A systematic examination of the fingers of children exposed at conception to PHT, PB, or CBZ, as monotherapy, has been used to address this question. The findings in the examinations of the fingers of 115 AED-exposed children (40, PHT; 34, PB; 41, CBZ) and their parents were compared to the findings in 111 age- and sex-matched children and their parents. The evaluations used were both subjective assessments and objective measurements. Shortening and narrowing of the fifth fingernail and an increased frequency of arch patterns in the dermal ridges were more common in PHT-exposed children. A significant decrease in the length of the nail, but not width, occurred in the PB-exposed children. Stiffness of the interphalangeal joints was more common in the CBZ-exposed children. The findings in children exposed to PHT, PB, or CBZ, as monotherapy, showed that all three exposures in early pregnancy affected the fingers, but the effects were not the same. The most striking effects were present in PHT-exposed children.

Facial dysmorphology in children exposed in pregnancy to anticonvulsant medications correlates with deficits in IQ.

Some children exposed at conception to the antiepileptic drugs (AEDs) phenytoin (PHT), phenobarbital (PB), and carbamazepine (CBZ) have changes in their midface and fingers. It has been suggested that the anticonvulsant-exposed child with these subtle changes in facial features (the "anticonvulsant face") has a greater likelihood of having deficits in IQ in comparison with children exposed to the same anticonvulsants who do not have these features. 115 AED-exposed children (40, PHT; 34, PB; and 41, CBZ) between 6.5 and 16 years of age and 111 unexposed children matched by sex, race, and year in school were evaluated. The evaluations were (WISC-III), physical examination with measurements of facial features and digits and photographs. The AED-exposed children had cephalometric radiographs, but not the unexposed. Each parent had a similar examination of face and hands plus tests of intelligence. These AED-exposed children showed an increased frequency of a short nose and anteverted nares, features of the "anticonvulsant face." Lateral skull radiographs showed a decrease in the angle between the anterior cranial base and nasal bone, which produces anteverted nares. Mean IQs were significantly lower on one or more IQ measures for the children with these facial features. Shortening of the distal phalanges and small fingernails correlated with the presence of a short nose in that child. The findings in 115 children exposed at conception to either phenytoin, phenobarbital, or carbamazepine, as monotherapy, confirmed the hypothesis that those with a short nose and anteverted nares had a lower IQ than exposed children without those features.

Pharmacological management of prolonged seizures in Dravet syndrome including intravenous phenytoin.

Dravet syndrome (DS) is an infantile onset developmental and epileptic encephalopathy. Sodium channel blockers are known to exacerbate seizures in this syndrome. Due to its high incidence, the management of prolonged seizures is crucial for DS patients. There is still ambiguity regarding the use of intravenous phenytoin for prolonged seizure in DS patients mainly due to the lack of data, raising concern about the safety of it use. We conducted a retrospective study (from January 2009 to January 2020) aiming to assess the management of prolonged seizures in DS with a focus on the use of intravenous phenytoin. Data were collected for patients admitted to our hospital for seizures lasting >5 min. Among 52 identified patients in our database, 23 experienced 59 prolonged seizures managed in our hospital. Only four seizures ceased without rescue medication. Notably, the use of intravenous phenytoin was not associated with discernible adverse effects and was effective in stopping status epilepticus in 71% of cases. This study suggests the safety and efficacy of intravenous phenytoin for prolonged seizure in DS. There is a need for broader investigations of emergency treatments for evidence-based recommendations for the emergency plan of each patient.

Phenytoin is associated with increased risk of osteoporosis and fragility fractures in adult epileptic patients.

INTRODUCTION: Osteoporotic fractures lead to significant decreases in the quality of life with increases in morbidity, mortality, and disability. Treatment with a variety of anti-epileptic drugs, such as phenytoin, has been understood to cause a decrease in bone mineral density. MATERIALS AND METHODS: Cohort A was identified as patients that were 18-55 years old that had epilepsy and recurrent seizures that were also prescribed phenytoin. Cohort B was identified as patients that were 18-55 years old that had epilepsy and recurrent seizures but were not prescribed phenytoin or other anti-epileptic medications. Cohorts were matched for relevant confounding pathologies and demographic factors. Outcomes were evaluated from 1 day to 5 years after the indexed event. RESULTS: A total of 35,936 patients with epilepsy that were prescribed phenytoin were matched with 109,335 patients with epilepsy that were not prescribed phenytoin. Patients on phenytoin therapy were at significantly higher risk for osteoporosis without pathological fracture, fracture of metatarsal bone, fracture of shoulder and upper arm, fracture of distal radius, fracture of thoracic vertebra, fracture of cervical vertebra, fracture of lumbar vertebra, fracture of femoral head or neck, pertrochanteric fracture, femoral shaft fracture, and distal tibia fracture (all outcomes p < 0.001). CONCLUSION: Epileptic patients on phenytoin therapy that were 18-55 years old exhibited higher associated risk of osteoporosis and osteoporotic-fragility fractures of various regions. Patients that undergo phenytoin therapy for epilepsy treatment should be educated on the increased risk of bone fractures and have appropriate lifestyle and diet modifications.

Evaluation of Goal Phenytoin Levels After an Initial Intravenous Loading Dose at an Academic Medical Center.

BACKGROUND: Phenytoin intravenous loading doses are administered in status epilepticus to rapidly achieve therapeutic levels. Accurately assessing phenytoin levels after the initial load can be challenging because of its complex pharmacokinetic profile and nonstandardized weight-based loading doses. OBJECTIVES: The objectives of this analysis were to determine the incidence of patients achieving goal phenytoin levels after the initial loading dose and characterize factors that contribute to achieving the goal level. METHODS: This single-center, retrospective cohort analysis was approved by our institutional review board and included adult patients who received a phenytoin load from May 2016 to March 2021. Patients were excluded if no total phenytoin level was drawn within 24 hours of the load, if the maintenance dose was given before the first level was drawn, or if the patient was on phenytoin before the load. The major endpoint was the percentage of patients achieving a corrected goal phenytoin level of ≥10 mcg/mL after the initial load. Multivariate regression was used to determine predictors of achieving the goal phenytoin level. RESULTS: Of the 152 patients included, 139 patients (91.4%) achieved a corrected goal level after the first load. Patients at goal received a significantly higher median weight-based loading dose (19.1 mg/kg [15.0-20.0] vs 12.6 mg/kg [10.1-15.0], P < 0.01). The multivariate analysis identified weight-based dosing as a statistically significant predictor of achieving the corrected goal level (odds ratio, 1.30; 95% CI, 1.12-1.53; P < 0.01). CONCLUSION AND RELEVANCE: Most patients achieved a corrected goal phenytoin level after the initial load. A higher median weight-based loading dose was shown to be a predictor of achieving the goal level and should be encouraged for rapid seizure termination. Future studies are warranted to confirm patient-specific factors that affect rapid achievement of the goal phenytoin level.

Intranasal delivery of phenytoin loaded layered double hydroxide nanoparticles improves therapeutic effect on epileptic seizures.

Improving the efficiency of antiseizure medication entering the brain is the key to reducing its peripheral toxicity. A combination of intranasal administration and nanomedicine presents a practical approach for treating epileptic seizures via bypassing the blood-brain barrier. In this study, phenytoin (PHT) loaded layered double hydroxide nanoparticles (BSA-LDHs-PHT) were fabricated via a coprecipitation - hydrothermal method for epileptic seizure control. In this study, we expound on the preparation method and characterization of BSA-LDHs-PHT. In-vitro drug release experiment shows both rapid and continuous drug release from BSA-LDHs-PHT, which is crucial for acute seizure control and chronic epilepsy therapy. In-vivo biodistribution assays after intranasal administration indicate excellent brain targeting ability of BSA-LDHs. Compared to BSA-Cyanine5.5, BSA-LDHs-Cyanine5.5 were associated with a higher brain/peripheral ratio across all tested time points. Following intranasal delivery with small doses of BSA-LDHs-PHT, the latency of seizures in the pentylenetetrazole-induced mouse models was effectively improved. Collectively, the present study successfully designed and applied BSA-LDHs-PHT as a promising strategy for treating epileptic seizures with an enhanced therapeutic effect.

Evaluation and comparison of the efficacy and safety of the combination of topical phenytoin and microneedling with microneedling alone in the treatment of atrophic acne scars: A controlled blinded randomized clinical trial.

INTRODUCTION: Severe acne breakouts often lead to atrophic acne scars, which affect millions of people worldwide and can significantly affect a person's self-confidence and self-image. Given the difficulty in treating atrophic acne scars, this study aims to investigate the efficacy of topical phenytoin in the treatment of atrophic acne scars. METHOD: This split face clinical trial on 25 patients between the ages of 18 and 40 involved the application of microneedling on one side of the face, with three sessions taking place over the course of a month. On the other side, a 1% phenytoin cream was administered three times daily for 1 week following the microneedling procedure. Baseline information was collected for all patients, and follow-up assessments were conducted during the treatment sessions and 2 months after the last session. The assessments included evaluating the number and area of pores and spots, determining scar severity, assessing patient satisfaction, and recording any potential complications. RESULTS: Among patients, 20 individuals (80%) were females, and the average age of the participants was 35.96 ± 9.23. In terms of the fine pore area, despite the fine pore count, both groups showed improvement over time (p: 0.03 vs. 0.06). Also, regarding large pore count and area, and the count and area of spots, both groups showed improvement over time (p: 0.001). However, there were no significant differences between the two groups (p > 0.05). On the other hand, when it comes to acne scar grade and patients' satisfaction, the phenytoin group outperformed the control group in all follow-up sessions and this difference was found to be significant (p: 0.001). It is worth noting that no complications were observed among any of the patients. CONCLUSION: It appears that combining phenytoin cream with microneedling has a more effective therapeutic outcome in enhancing atrophic acne scars, when compared to microneedling alone, and this method can be regarded as a viable alternative in treating these types of scars.

Guidelines for Seizure Prophylaxis in Adults Hospitalized with Moderate-Severe Traumatic Brain Injury: A Clinical Practice Guideline for Health Care Professionals from the Neurocritical Care Society.

BACKGROUND: There is practice heterogeneity in the use, type, and duration of prophylactic antiseizure medications (ASMs) in patients with moderate-severe traumatic brain injury (TBI). METHODS: We conducted a systematic review and meta-analysis of articles assessing ASM prophylaxis in adults with moderate-severe TBI (acute radiographic findings and requiring hospitalization). The population, intervention, comparator, and outcome (PICO) questions were as follows: (1) Should ASM versus no ASM be used in patients with moderate-severe TBI and no history of clinical or electrographic seizures? (2) If an ASM is used, should levetiracetam (LEV) or phenytoin/fosphenytoin (PHT/fPHT) be preferentially used? (3) If an ASM is used, should a long versus short (> 7 vs. ≤ 7 days) duration of prophylaxis be used? The main outcomes were early seizure, late seizure, adverse events, mortality, and functional outcomes. We used Grading of Recommendations Assessment, Development, and Evaluation (GRADE) methodology to generate recommendations. RESULTS: The initial literature search yielded 1998 articles, of which 33 formed the basis of the recommendations: PICO 1: We did not detect any significant positive or negative effect of ASM compared to no ASM on the outcomes of early seizure, late seizure, adverse events, or mortality. PICO 2: We did not detect any significant positive or negative effect of PHT/fPHT compared to LEV for early seizures or mortality, though point estimates suggest fewer late seizures and fewer adverse events with LEV. PICO 3: There were no significant differences in early or late seizures with longer versus shorter ASM use, though cognitive outcomes and adverse events appear worse with protracted use. CONCLUSIONS: Based on GRADE criteria, we suggest that ASM or no ASM may be used in patients hospitalized with moderate-severe TBI (weak recommendation, low quality of evidence). If used, we suggest LEV over PHT/fPHT (weak recommendation, very low quality of evidence) for a short duration (≤ 7 days, weak recommendation, low quality of evidence).

Comparative efficacy of Salix aegyptiaca's active compound versus phenytoin in healing full-thickness rat skin wounds: An animal model study.

BACKGROUND: Wound healing poses a challenging therapeutic scenario, requiring diverse clinical approaches. OBJECTIVES: This study aims to assess the wound-healing potential of Salix aegyptiaca's flower ointment compared to phenytoin, considering the active constituents of S. aegyptiaca and its traditional usage. METHODS: Initially, the active components of S. aegyptiaca were isolated and identified through the GC-MS technique. Subsequently, for the experimental intervention, thirty-five rats were divided into five distinct groups: control (C), phenytoin (F), and three S. aegyptiaca ointment groups at different concentrations (5 % - S5, 25 % - S25, and 50 % - S50). Anesthesia was administered, and wounds were induced on the animals' necks following a standard procedure. These wounds were then treated for a duration of 21 days. Wound healing progress was quantified, and histopathological assessments were conducted using hematoxylin and eosin staining and Mason's trichrome staining. RESULTS: The main active compounds of S. aegyptiaca, namely n-hexadecanoic acid and oleic acid, were identified via GC-MS analysis. Although the initial group weights did not show a significant difference (P = 0.271), a significant variation was observed in the final weights (P = 0.003). The S50 group exhibited a lower wound healing rate than the S25 group on the 7th and 14th days but surpassed it on the 21st day (C < F < S5≈S25

Determination of phenytoin at trace levels in domestic wastewater and synthetic urine samples by gas chromatography-mass spectrometry after its preconcentration by simple liquid-phase microextraction.

This work presents a sensitive and accurate analytical method for the determination of phenytoin at trace levels in domestic wastewater and synthetic urine samples by gas chromatography-mass spectrometry (GC-MS) after the metal sieve-linked double syringe liquid-phase microextraction (MSLDS-LPME) method. A metal sieve was produced in our laboratory in order to disperse water-immiscible extraction solvents into aqueous media. Univariate optimization studies for the selection of proper extraction solvent, extraction solvent volume, mixing cycle, and initial sample volume were carried out. Under the optimum MSLDS-LPME conditions, mass-based dynamic range, limit of quantitation (LOQ), limit of detection (LOD), and percent relative standard deviation (%RSD) for the lowest concentration in calibration plot were figured out to be 100.5-10964.2 µg kg-1, 150.6 µg kg-1, 45.2 µg kg-1, and 9.4%, respectively. Detection power was improved as 187.7-folds by the developed MSLDS-LPME-GC-MS system while enhancement in calibration sensitivity was recorded as 188.0-folds. In the final step of this study, the accuracy and applicability of the proposed system were tested by matrix matching calibration strategy. Percent recovery results for domestic wastewater and synthetic urine samples were calculated as 95.6-110.3% and 91.7-106.6%, respectively. These results proved the accuracy and applicability of the proposed preconcentration method, and the obtained analytical results showed the efficiency of the lab-made metal sieve apparatus.

Phenytoin Induced Purple Glove Syndrome: An Effective Management Technique.

Background: Purple glove syndrome (PGS) is a rare condition characterized by limb edema, discoloration, and pain associated with intravenous and oral phenytoin administration. The pathophysiology is poorly understood, and there is no established treatment. Simple cases have previously been managed with hyaluronidase subcutaneous injections, with more severe cases resulting in compartment syndrome, debridement, or even amputation. Methods/Results: In this case report, a 2-year-old boy with status epilepticus developed PGS after receiving intravenous phenytoin via a cannula on the dorsum of the right hand. The patient was successfully managed by locally infiltrating subcutaneous hyaluronidase diffusely to the affected area, titrating its dose to effect, rather than aiming to adhere to any specific dosing limitation. The child was reviewed daily by the Plastic Surgery team until being discharged, and focal lesions began to demarcate after 48 hours, with epidermal loss but no deeper trauma. The epidermis peeled within one month, with healthy underlying skin found underlying when followed up in clinic. Conclusions: This case illustrates that subcutaneous administration of hyaluronidase and titrating to effect provides an effective and safe treatment for treating distal cases of early PGS in children.

Calcium Phosphate-Based Nanoformulation Selectively Abolishes Phenytoin Resistance in Epileptic Neurons for Ceasing Seizures.

Phenytoin (PHT) is a first-line antiepileptic drug in clinics, which could decrease neuronal bioelectric activity by blocking the voltage-operated sodium channels. However, the intrinsically low blood-brain-barrier (BBB)-crossing capability of PHT and upregulated expression level of the efflux transporter p-glycoprotein (P-gp) coded by the gene Abcb1 in epileptic neurons limit its efficacy in vivo. Herein, a nanointegrated strategy to overcome PHT resistance mechanisms for enhanced antiepileptic efficacy is reported. Specifically, PHT is first incorporated into calcium phosphate (CaP) nanoparticles through biomineralization, followed by the surface modification of the PEGylated BBB-penetrating TAT peptide. The CaP@PHT-PEG-TAT nanoformulation could effectively cross the BBB to be taken in by epileptic neurons. Afterward, the acidic lysosomal environment would trigger their complete degradation to release Ca2+ and PHT into the cytosol. Ca2+ ions would inhibit mitochondrial oxidative phosphorylation to reverse cellular hypoxia to block hypoxia-inducible factor-1α (Hif1α)-Abcb1-axis, as well as disrupt adenosine triphosphate generation, leading to simultaneous suppression of the expression and drug efflux capacity of P-gp to enhance PHT retention. This study offers an approach for effective therapeutic intervention against drug-resistant epilepsy.

Tacrolimus toxicity due to enzyme inhibition from ritonavir.

Tacrolimus is commonly used for immunosuppression in patients following solid organ transplantation. For transplant patients with COVID-19 infection, early treatment is indicated due to the risk of progression to severe disease. However, the first line agent, nirmatrelvir/ritonavir, has multiple drug-drug interactions. We report a case of tacrolimus toxicity in a patient with a history of renal transplant due to enzyme inhibition related to nirmatrelvir/ritonavir. An 85-year-old woman with a history of multiple comorbidities presented to the emergency department (ED) with weakness, increasing confusion, poor oral intake, and inability to walk. She had been recently diagnosed with COVID-19 infection and was prescribed nirmatrelvir/ritonavir due to her underlying comorbidities and immune suppression. In the ED, she was dehydrated and had an acute kidney injury (creatinine 2.1 mg/dL, up from a baseline of 0.8 mg/dL). The tacrolimus concentration on initial labs was 143 ng/mL (5-20 ng/mL) and it continued to rise despite being held, to a peak of 189 ng/mL on hospital day 3. The patient was treated with phenytoin for enzyme induction and the tacrolimus concentration began to fall. She was discharged to a rehabilitation facility after a 17 day hospitalization. ED physicians must be cognizant of drug-drug interactions when prescribing nirmatrelvir/ritonavir and evaluating patients recently treated with the drug to identify toxicity due to these interactions.

Drug-induced cutaneous pseudolymphoma: A systematic review of the literature.

Drug-induced cutaneous pseudolymphoma (CPL) is a common form of pseudolymphoma and there are numerous drugs associated with it. In this study, we performed a systematic review of the literature by searching PubMed/Medline and Embase databases to determine the most common drugs responsible for CPL and to define the demographic, clinical, histopathological and immunopathological characteristics of patients (updated on 30 December 2020). From 883 initially found articles, 56 studies (89 reported cases) were included. The mean age of patients was 54.4 ± 17.7 (ranging 8-86) years, and 46 (51.7%) were men. The median time interval between drug intake and CPL occurrence was 120 days (range 1-7300 days). The shortest median time interval between taking the drug and the onset of the disease was observed among patients taking antidepressants (60 days) (range 7-540) and the longest median time interval was observed in individuals using immunomodulators (300 days) (range 3-7300). The most-reported drug categories causing CPL were anti-hypertensives (17.9%), anticonvulsants (14.6%), monoclonal antibodies (13.4%) and antidepressants (11.2%). Moreover, the most common drugs were phenytoin (6.7%), amlodipine (5.6%), fluoxetine (5.6%) and carbamazepine (4.4%). Histopathological evaluation of 76 cases revealed 62 (81.5%) reports of T-cell infiltrations. Furthermore, positive reports of CD4 (94.0%), CD8 (93.0%) and CD30 (87.5%) were noted. The lowest prevalence of CD30-positive reports was observed among monoclonal antibodies. In conclusion, anti-hypertensives, anti-convulsants, monoclonal antibodies and anti-depressants are the most common drugs responsible for CPL. It mostly presents in middle-aged patients with almost no gender difference as pruritic papules, nodules and plaques.

Comparison of Efficacy and Safety of Levetiracetam Versus Phenytoin for Post-craniotomy Seizure Prophylaxis.

Background: Superiority of levetiracetam over phenytoin for postcraniotomy seizure prophylaxis in patients with a supratentorial brain tumor is controversial. We aimed to evaluate the efficacy of levetiracetam versus phenytoin for postcraniotomy seizure prophylaxis in supratentorial brain tumor. Methods: In a randomized controlled trial study, 80 patients with a supratentorial brain tumor who underwent craniotomy were allocated to levetiracetam or phenytoin group, 40 patients each. Seizure prophylaxis was started 5 days before the surgery and continued until 90 days after surgery. Phenytoin group received 100 mg oral phenytoin 3 times a day. The levetiracetam group received 500 mg oral levetiracetam 2 times a day. The primary outcome was the incidence of postcraniotomy seizures. The secondary outcome measure was the safety profile of the drugs. Results: All patients of the phenytoin group and 39 patients of levetiracetam completed the study. Two seizures developed in the study population, 1 in the phenytoin group (2.5%) and 1 in the levetiracetam group (2.6%) (P = 0.710). Renal or hepatic dysfunction was not observed in any patients. Wound hematoma was seen in 5 patients (12.5%) of the phenytoin and 6 patients (15.4%) of the levetiracetam group (P = 0.481). Skin rash developed in 3 patients (7.5%) of the phenytoin group and no patient of the levetiracetam group (P = 0.132). Thrombocytopenia was detected in 1 patient of the phenytoin group (2.5%) and no patient of the levetiracetam group (P = 0.511). None of the adverse events led to drug withdrawal. Conclusion: These results reveal no superiority of levetiracetam over phenytoin for postcraniotomy seizure prophylaxis in supratentorial brain tumor.

Connectivity and Neuronal Synchrony during Seizures.

There is uncertainty regarding when and which groups of neurons fire synchronously during seizures. While several studies found heterogeneous firing during seizures, others suggested synchronous neuronal firing in the seizure core. We tested whether neuronal activity during seizures is orderly in the direction of the excitatory neuronal connections in the circuit. There are strong excitatory connections laterally within the septotemporally organized lamella and inhibitory trans-lamellar connections in the hippocampus, which allow testing of the connectivity hypothesis. We further tested whether epileptogenesis enhances synchrony and antiseizure drug administration disrupts it. We recorded local field potentials from CA1 pyramidal neurons using a small microelectrode array and kindled rats by a rapid, recurrent hippocampal stimulation protocol. We compared cross-correlation, theta phase synchronization, entropy, and event synchronization. These analyses revealed that the firing pattern was correlated along the lamellar, but not the septotemporal, axis during evoked seizures. During kindling, neuronal synchrony increased along the lamellar axis, while synchrony along the septotemporal axis remained relatively low. Additionally, the theta phase distribution demonstrated that CA1 pyramidal cell firing became preferential for theta oscillation negative peak as kindling progressed in the lamellar direction but not in the trans-lamellar direction. Last, event synchronization demonstrated that neuronal firings along the lamellar axis were more synchronized than those along the septotemporal axis. There was a marked decrease in synchronization and phase preference after treatment with phenytoin and levetiracetam. The synchrony structure of CA1 pyramidal neurons during seizures and epileptogenesis depends on anatomic connectivity and plasticity.SIGNIFICANCE STATEMENT We could improve the efficacy of brain stimulation to treat seizures by understanding the structure of synchrony. Electrical stimulation may disrupt seizures by desynchronizing neurons, but there is an uncertainty on which groups of neurons fire synchronously or chaotically during seizures. Here, we demonstrate that neurons linked by excitatory connections fire synchronously during seizures, and this synchrony is modulated by epileptogenesis and antiseizure drugs. Closed-loop brain stimulation carefully targeted to disrupt synchrony may improve the treatment of seizures.

Mechanistic Insights on the Mechanosynthesis of Phenytoin, a WHO Essential Medicine.

In recent years, mechanochemistry has enriched the toolbox of synthetic chemists, enabling faster and more sustainable access to new materials and existing products, including active pharmaceutical ingredients (APIs). However, molecular-level understanding of most mechanochemical reactions remains limited, delaying the implementation of mechanochemistry in industrial applications. Herein, we have applied in situ monitoring by Raman spectroscopy to the mechanosynthesis of phenytoin, a World Health Organization (WHO) Essential Medicine, enabling the observation, isolation, and characterization of key molecular-migration intermediates involved in the single-step transformation of benzil, urea, and KOH into phenytoin. This work contributes to the elucidation of a reaction mechanism that has been subjected to a number of interpretations over time and paints a clear picture of how mechanosynthesis can be applied and optimized for the preparation of added-value molecules.

Intravenous fosphenytoin as treatment for acute exacerbation of trigeminal neuralgia: A prospective systematic study of 15 patients.

INTRODUCTION: Intravenous fosphenytoin is widely used for acute exacerbation of trigeminal neuralgia, however, few studies have investigated this treatment. We aimed to examine the efficacy and side effects of initial intravenous fosphenytoin plus oral tapering of phenytoin for exacerbation of trigeminal neuralgia. METHODS: Consecutive patients with primary trigeminal neuralgia were included in this prospective observational 90-days follow-up study. Data were collected using standardized interviews before, at 24 hours, day 7, 30 and 90 post loading dose. The primary outcome was the proportion of responders defined as a 50% reduction in pain intensity 24 hours post loading dose. RESULTS: We included 15 patients. Nine patients (60%) were responders. Pain intensity 24 hours post loading dose was reduced by 5.00 points on the numerical rating scale (p < 0.001), and at day 7 by 5.5 points (p < 0.001). The most common side effects were hypotension and dizziness. CONCLUSION: Intravenous fosphenytoin relieves trigeminal neuralgia pain in most patients and provides a window for titrating prophylactic trigeminal neuralgia medications or planning neurosurgery. The decision to administer intravenous fosphenytoin should be taken with support from trigeminal neuralgia experts and involves considerations of co-morbidities and other treatment options for acute exacerbation of trigeminal neuralgia.Clinical Trial: Preregistered (ClinicalTrials.gov Identifier: NCT03712254.

Intravenous lacosamide and phenytoin for the treatment of acute exacerbations of trigeminal neuralgia: A retrospective analysis of 144 cases.

BACKGROUND: Scant evidence is available on the use of intravenous pain treatment in acute exacerbations of trigeminal neuralgia. The aim of this descriptive study was to evaluate the effectiveness and security of intravenous lacosamide and phenytoin in the treatment of acute trigeminal neuralgia pain. METHODS: We reviewed patients who attended the emergency department of a tertiary hospital between 2012 and 2020 for exacerbations of trigeminal neuralgia pain and were treated with either intravenous phenytoin or lacosamide for the first time. Primary endpoints were pain relief and adverse effects during the hospital stay. A comparative analysis between both treatment groups was performed. RESULTS: We studied 144 episodes in 121 patients (median age 61 years, 66.1% women). Trigeminal neuralgia etiology was secondary in 9.9%. Pain relief was observed in 77.8% of 63 patients receiving lacosamide infusions, and adverse effects in 1.6%. Pain relief was observed in 72.8% of 81 phenytoin infusions and adverse effects in 12.3%, all mild. No difference was observed in pain relief between groups, but the proportion of adverse effects was significantly different (p = 0.023). Statistically significant differences were also detected in readmissions within six months, time to readmission, and pain relief status at first follow-up visit. CONCLUSION: Intravenous lacosamide and phenytoin can be effective and safe treatments for acute pain in trigeminal neuralgia. According to our series, lacosamide might be better tolerated than phenytoin and lead to lower readmissions and sustained pain relief.

Pseudotumour cerebri due to phenytoin in a child.

Pseudotumour cerebri is a manifestation of intracranial hypertension in an otherwise normal individual. We hereby report phenytoin-induced pseudotumour cerebri in a 9-year-old boy who received phenytoin as a prophylactic anticonvulsant following surgical removal of unifocal Langerhans cell histiocytosis involving the right frontal bone. The child was evaluated for headache and diplopia after starting phenytoin and on evaluation was found to have bilateral sixth nerve palsy. The only abnormality detected was an elevated cerebrospinal fluid pressure. Withdrawal of phenytoin resulted in complete resolution of symptoms. Despite meticulous literature search, we found only 1 other report of phenytoin induced pseudotumour cerebri. We report this case to highlight the need to consider this entity whenever a patient presents with new onset or persistent headache and visual symptoms soon after starting a medication since a high degree of suspicion is needed to arrive at the diagnosis and to take appropriate steps before it progresses to harmful complications such as vision loss.