Preventive and therapeutic effects of magnesium sulfate on nikethamide-induced seizures: Implications for COVID-19 treatment

Abstract

BACKGROUND

Nikethamide, a respiratory stimulant, is used to treat hypoxemia caused by coronavirus disease 2019 (COVID-19), but it carries a risk of convulsions. Magnesium sulfate (MgSO₄), a seizure inhibitor, might serve as a rescue agent against nikethamide-induced seizures.

AIM

To investigate the therapeutic effect of MgSO₄ on nikethamide -induced seizures in COVID-19 patients through animal experiments, providing experimental support for the clinical application of MgSO₄ in preventing and treating seizures caused by nikethamide.

METHODS

Forty mice were randomly divided into four groups: (1) Physiological saline; (2) Low-dose MgSO₄ (50 mg/kg); (3) Medium-dose MgSO₄ (100 mg/kg); and (4) High-dose MgSO₄ (200 mg/kg). After 15 minutes of intraperitoneal injection of different doses of MgSO₄ or an equal volume of physiological saline, the mice were injected with nikethamide (250 mg/kg).

RESULTS

Compared to the normal saline group, all doses of MgSO₄ significantly prolonged the seizure latency and reduced the severity of convulsions. However, they also extended the duration of seizures and correspondingly increased survival time (P < 0.05). The incidence of seizures and mortality rate in the MgSO₄-treated groups were significantly lower than those in the normal saline group (P < 0.05).

CONCLUSION

MgSO₄ can prevent and treat seizures caused by nikethamide in mice. This finding has implications for the application of MgSO₄ in treating and preventing seizures caused by nikethamide in COVID-19 treatment.

Key Words: COVID-19; Drug discovery; Hypoxemia; Magnesium sulfate; Nikethamide; Seizures

Core Tip: Nikethamide is a respiratory stimulant used for the treatment of coronavirus disease 2019 (COVID-19); however, its use carries the risk of seizure induction. This study demonstrates that magnesium sulfate (MgSO₄) can effectively prevent and mitigate nikethamide-induced seizures in a dose-dependent manner. The results indicate that MgSO₄ prolongs seizure latency, reduces seizure severity, extends seizure duration, and decreases mortality in the experimental model. These findings provide important insights into the potential clinical application of MgSO₄ for managing nikethamide-associated seizure complications in COVID-19 patients.

INTRODUCTION

Nikethamide is a respiratory stimulant that primarily acts by stimulating the respiratory center in the brainstem[1,2]. It has historically been used to treat central respiratory and circulatory failure, as well as to counteract central nervous system (CNS) depression caused by sedatives. However, at high doses, nikethamide is known to cause serious side effects, including vomiting, convulsions, and seizure-like symptoms[3]. These convulsive effects are primarily attributed to its ability to induce the prolonged abnormal opening of sodium ions (Na⁺) channels, leading to excessive neuronal excitation[3,4].

In the context of coronavirus disease 2019 (COVID-19), nikethamide has been explored as a potential treatment for hypoxemia, particularly in critically ill patients[1]. Some studies suggest that nikethamide may improve oxygen saturation, enhance respiratory function, and reduce mortality[5]. However, there remains significant controversy regarding its efficacy in COVID-19 treatment, with conflicting reports on its clinical benefits[6]. Additionally, its use is limited due to the high risk of seizures, making it essential to identify effective strategies for preventing these adverse effects[7,8].

Magnesium sulfate (MgSO₄) is a well-established anticonvulsant widely used in conditions such as eclampsia[9]. It exerts its effects by inhibiting N-methyl-D-aspartate receptors (NMDARs) in a voltage-dependent manner[10,11]. Since excessive NMDAR activation is linked to seizure activity, MgSO₄ may serve as a potential rescue agent for nikethamide-induced seizures[12-14]. In addition to its anticonvulsant properties, MgSO₄ has been suggested to have potential benefits in COVID-19 treatment, including reducing hypoxia and inflammation[15]. However, its role in managing hypoxemia remains unclear, with inconsistent findings in clinical studies[16-18].

This study aimed to evaluate the preventive and therapeutic effects of MgSO₄ on nikethamide-induced seizures using an animal model. Specifically, we investigated whether MgSO₄ could prolong seizure latency, reduce convulsion severity, extend seizure duration, and improve the survival rate of mice treated with nikethamide. By elucidating its neuroprotective effects, the findings of this study may provide valuable insights for the clinical application of MgSO₄ in managing nikethamide-associated seizure complications in COVID-19 patients.

MATERIALS AND METHODS

Ethics approval

This study was conducted following the ethical guidelines for animal research and was approved by the Ethics Committee of Taizhou University.

Experimental animals

Forty pathogen-free Kunming mice, both male and female, weighing between 16 g and 18 g, were obtained from Zhejiang Weitong Lihua Laboratory Animal Technology Co., Ltd. (located in Jiaxing City, Zhejiang Province, China). The company holds the license number SYXK (Zhejiang Province) 2021-0013 and the production license number SCXK (Zhejiang Province) 2019-0001. Three days prior to the experiment, the mice were allowed to acclimate to the laboratory environment and had free access to food and water. To prevent potential behavioral differences among the mice from influencing the research results, all the experiments were conducted at the same time each day.

Drugs

The reagents utilized in this study included MgSO₄ produced by Tianjin Jinyao Pharmaceutical Co., Ltd. (Tianjin, China), with a batch number of H12020994 and a specification of 10 mL/2.5 g. Additionally, the experiment utilized nikethamide injection manufactured by Shanghai Hyundai Hasen Pharmaceutical Co., Ltd. (Shangqiu City, Henan Province, China), with a batch number of H20053727 and a specification of 1.5 mL/0.375 g. Furthermore, sodium chloride injection was provided by Shanghai Baxter Medical Products Co., Ltd. (Shanghai, China), with a batch number of H19983149 and a specification of 1000 mL/9 g.

Grouping and processing

Using a random number table, the mice were evenly and randomly allocated to four groups, namely, the saline control, low-dose MgSO₄ (50 mg/kg), medium-dose MgSO₄ (100 mg/kg), and high-dose MgSO₄ (200 mg/kg) groups, with 10 mice in each group. The mice were administered different doses of MgSO₄ or an equal volume of normal saline via intraperitoneal injection. After 15 minutes, each group of mice received an injection of nikethamide solution (250 mg/kg).

Observation indicators

The incubation period of convulsions (in seconds), duration of convulsions (in minutes), number of convulsions, and number of deaths among the mice in each group were observed and recorded. Compared to those prior to administration, convulsions were judged based on increased activity, such as walking, jumping, and irritability. The time from nikethamide injection to the appearance of convulsions was considered the incubation period of convulsions. The duration of convulsions was measured from the onset of convulsions to a state of silence in the mice. The time until death was calculated from the start of nikethamide injection to the moment of death.

Statistical analysis

The statistical analysis was performed using Statistical Package for the Social Sciences 26.0 (IBM Corp., Armonk, NY, United States), Excel 2019 (Microsoft Corporation, Redmond, WA, United States), and GraphPad Prism 8 (GraphPad Prism v8.0; GraphPad Software). The convulsion latency, convulsion duration, and time until death is expressed as the mean ± SD. Continuous quantitative data were compared among multiple groups using one-way analysis of variance (ANOVA), and Dunnett's t test was used for post hoc testing. Convulsion rates and mortality were expressed as percentages, and differences were compared using the rank sum test. A P value < 0.05 indicated a statistically significant difference.

RESULTS

Seizure latency

MgSO₄ significantly prolonged the incubation period to seizure onset in a dose-dependent manner. The control group exhibited a shortest latency of 80.30 seconds ± 22.32 seconds, whereas magnesium-treated groups showed progressively longer mean latencies: (1) 192.70 seconds ± 73.57 seconds at low dose; (2) 380.20 seconds ± 63.40 seconds at mid dose; and (3) 1129.50 seconds ± 252.51 seconds at high dose. Medium-dose and high-dose MgSO₄ groups had a significantly delayed seizure onset compared to control (P < 0.01 for each). Notably, the high-dose MgSO₄ group’s latency was about 17 minutes longer than control (P < 0.001), with a mean difference of 1049.2 seconds (95%CI: 900.35–1198.05). An overall one-way ANOVA confirmed a significant effect of treatment on seizure latency (F-statistic = 121.12, P < 0.001). These findings demonstrate a clear dose–response relationship, as higher MgSO₄ doses yielded greater delays in seizure initiation, indicating that MgSO₄ effectively prolongs seizure onset in this model (Figure 1 and Table 1).

Figure 1 Comparison of incubation period, duration time, and death time among different groups. The figure presents the comparison of three variables—incubation period, duration time, and death time—among the control, low dose, medium dose, and high dose groups. Each dot represents an individual data point, and the error bars indicate the standard deviation. Statistical significance is marked with asterisks: (1) ^aP < 0.05; (2) ^bP < 0.01; (3) ^cP < 0.001; and (4) ^dP < 0.0001. Horizontal lines with asterisks above bars denote significant differences between the two connected groups, while asterisks directly above bars indicate significant differences compared to the control group.

Table 1 Comparison of incubation period, duration and time until death of mice in each group.

Groups (n = 10)	Variable group	Time (mean ± SD)	95%CI	P value
Normal saline control group	1	80.30 ± 22.32	64.33-96.27	-
Low-dose MgSO4 group	1	192.70 ± 73.57	140.07-245.33	0.174
Medium-dose MgSO4 group	1	380.20 ± 63.40b	334.85-425.55	< 0.01
High-dose MgSO4 group	1	1129.50 ± 252.51b	948.86-1310.14	< 0.01
Normal saline control group	2	25.80 ± 3.58	23.24-28.36	-
Low-dose MgSO4 group	2	81.10 ± 6.33b	76.57-85.63	< 0.01
Medium-dose MgSO4 group	2	70.20 ± 18.03b	57.30-83.10	< 0.01
High-dose MgSO4 group	2	75.20 ± 10.68b	67.56-82.84	< 0.01
Normal saline control group	3	30.10 ± 5.90	25.88-34.32	-
Low-dose MgSO4 group	3	83.10 ± 5.53b	79.15-87.05	< 0.01
Medium-dose MgSO4 group	3	86.50 ± 19.60b	72.48-100.52	< 0.01
High-dose MgSO4 group	3	111.70 ± 17.23b	99.37-124.03	< 0.01

^bP < 0.01, statistical differences are highly significant.

1: Incubation period (second); 2: Duration time (minute); 3: Survival time (minute). MgSO₄: Magnesium sulfate.

Seizure duration

In contrast to its effect on latency, MgSO₄ treatment led to longer seizure durations compared to control animals. The mean duration of seizure activity in the control group was 25.80 minutes ± 3.58 minutes, whereas animals receiving MgSO₄ experienced extended seizure episodes (low dose: 81.10 minutes ± 6.33 minutes; mid dose: 70.20 minutes ± 18.03 minutes; high dose: 75.20 minutes ± 10.68 minutes). All magnesium-treated groups had significantly increased seizure durations relative to control. Specifically, the high-dose group had a seizure duration approximately 3 times longer than control (P < 0.01), and even the low-dose group showed a notable increase (P < 0.01 vs control). Statistical analysis (ANOVA with post hoc comparisons) confirmed these differences, with P values < 0.01 for each group (vs control). This result suggests that while MgSO₄ delays the onset of seizures, once seizures begin, they persist longer in treated animals. One explanation is that magnesium’s protective effects prevent early mortality or catastrophic seizure termination, thereby allowing seizures to continue for a prolonged period compared to the untreated controls (Figure 1 and Table 1).

Survival time

MgSO₄ markedly improved survival time following seizure induction, with higher doses conferring greater benefit. Control animals succumbed quickly, with a mean survival time of only 30.10 minutes ± 5.90 minutes post-seizure onset. In contrast, MgSO₄-treated groups survived substantially longer on average: (1) 83.10 minutes ± 5.53 minutes for the low-dose group; (2) 86.50 minutes ± 19.60 minutes for the mid-dose group; and (3) 111.70 minutes ± 17.23 minutes for the high-dose group. Collectively, the data indicate that MgSO₄ treatment improved overall survival in a dose-validated manner. The extended survival times in MgSO₄ groups highlight its neuroprotective role, as treated animals were able to withstand seizure activity longer without succumbing. This suggests that higher doses of MgSO₄ confer significant protection against lethal seizure consequences, underlining its potential therapeutic value in mitigating seizure-induced mortality (Figure 1 and Table 1).

Convulsion rate and mortality analysis

MgSO₄ exhibited a dose-dependent protective effect by reducing both convulsion incidence and mortality rates (Table 2). The low-dose group showed a convulsion rate of 90% and a mortality rate of 70%, with no significant difference from the control group (P > 0.99). The medium-dose group exhibited a moderate reduction in convulsion rate (60%) and mortality rate (30%), though the differences remained statistically non-significant (P > 0.05). In contrast, the high-dose group demonstrated a significant decrease in both convulsion incidence (20%, P = 0.045) and mortality (10%, P < 0.01), indicating a substantial neuroprotective effect. These results suggest that higher doses of MgSO₄ effectively mitigate seizure severity and significantly improve survival outcomes, whereas lower doses may be insufficient to confer full protection. The findings highlight the importance of dose optimization in clinical applications, reinforcing the potential of MgSO₄ as a therapeutic strategy for managing pharmacologically induced seizures.

Table 2 Comparison of convulsion rate and mortality of mice in each group.

Group	Convulsion rate (%)	H value	P value	Mortality rate (%)	H value	P value
Low-dose MgSO4 group	90	0.00	> 0.99	70	0.471	> 0.99
Medium-dose MgSO4 group	60	0.668	> 0.99	30	5.051	0.356
High-dose MgSO4 group	20	2.670	0.045a	10	9.899	< 0.01b

^aP < 0.05, differences are statistically significant.

^bP < 0.01, statistical differences are highly significant.

Control group: The control group in this study was the saline control group, in which mice received an equal volume of saline solution without magnesium sulfate. MgSO₄: Magnesium sulfate.

DISCUSSION

In this study, we demonstrated that MgSO₄ significantly protects against nikethamide-induced seizures in mice. All doses of MgSO₄ prolonged the seizure latency and increased post-seizure survival time compared to saline, with medium (100 mg/kg) and high (200 mg/kg) doses producing especially strong effects. These doses also significantly reduced the intensity of convulsions and prolonged the duration of seizures. Compared with the control group, the incidence of seizures and mortality rate were significantly lower in the high-dose group. Notably, the anticonvulsant efficacy of MgSO₄ was dose-dependent. However, animals receiving the high dose exhibited signs of CNS depression (lethargy and even brief loss of consciousness in some cases), indicating that while seizures were well-controlled, excessive sedation occurred at the highest dose. Only one mouse in the high-dose group succumbed during the experiment, suggesting that 200 mg/kg, though sedating, did not reach a lethal threshold in this model. In summary, MgSO₄ dose-dependently prevented or mitigated the convulsive effects of nikethamide—prolonging the seizure-free interval, reducing seizure severity, extending seizure duration, improving survival, and lowering seizure frequency and mortality—albeit with observable sedation at high doses. These findings confirm our hypothesis that MgSO₄ can serve as an effective anticonvulsant countermeasure to nikethamide in vivo.

Comparison with previous studies

Our results align with and extend the existing literature on respiratory stimulants and anticonvulsant therapies. Nikethamide (also known as coramine) has historically been used to stimulate respiration in acute respiratory failure[3]. However, it is well documented that at high doses or with prolonged use, nikethamide and similar analeptics can provoke adverse effects such as tachypnea, convulsions, and even life-threatening respiratory paralysis[19-21]. The convulsive side effects we observed in control mice given high-dose nikethamide are consistent with these earlier reports. Previous animal studies have begun to elucidate nikethamide’s neural effects: For instance, Qian et al[2] demonstrated that nikethamide’s enhancement of respiratory rhythm in neonatal rat brainstems involves activation of 5-hydroxytryptamine (5-HT) 2A receptors, and additional work implicates gamma-aminobutyric acid(A)_A receptor modulation in nikethamide-induced respiratory changes[4]. These findings support the notion that nikethamide can broadly increase excitatory neurotransmission, which may underlie its seizure-inducing potential.

MgSO₄’s efficacy as an anticonvulsant, on the other hand, is well established in certain clinical contexts. It is the treatment of choice for eclamptic seizures in obstetric practice[7,8] and has been reported to exhibit anticonvulsant and neuroprotective properties in various models[5]. Our observation that MgSO₄ suppresses seizures is in line with these known anticonvulsant effects. To our knowledge, however, no prior studies have specifically examined MgSO₄ for preventing drug-induced convulsions from respiratory stimulants like nikethamide. Thus, our study fills an important gap by demonstrating that magnesium’s protective action can be extended to this unique scenario. In contrast to some reports that magnesium therapy can ameliorate respiratory symptoms in COVID-19 patients (an effect that remains somewhat controversial)[13,14], our work focuses on magnesium’s role in managing a serious side effect of a COVID-19 therapeutic. This distinct perspective underscores the innovative nature of our findings while remaining consistent with the general understanding that MgSO₄ is a broad-spectrum anticonvulsant agent.

Mechanistic interpretation

The protective effects of MgSO₄ observed in our study can be explained by known neurophysiological mechanisms. Nikethamide exerts its respiratory stimulant action by enhancing CNS excitatory pathways, but this same action can tip into pathological excitation at high doses. Pharmacologically, nikethamide is known to prolong the open state of neuronal sodium channels and to activate NMDARs in the brain. Excessive sodium influx and NMDAR activation lead to a cascade of neuronal hyperexcitation: Increased intracellular Ca²⁺ entry through NMDAR-associated channels triggers downstream effects such as the overproduction of nitric oxide (a potent vasodilator and neuromodulator), ultimately resulting in aberrant neural firing and convulsions[22-25]. This mechanism explains why an overdose of nikethamide can induce seizures even as it stimulates respiration.

The respiratory rhythm control center in the pre-Bötzinger complex (Figure 2) is modulated by multiple neurotransmitters, with 5-HT being the most important neurotransmitter[26,27]. Endogenous activation of 5-HT2A[28] receptors is necessary for the production of respiratory rhythm in vitro. Protein kinase C can antagonize the blockade of the endogenous activation network of 5-HT2A receptors. Endogenously activated 5-HT2A receptors regulate Na⁺ conduction through the protein kinase C pathway to maintain this process[22,23]. Nikethamide alters the conformation of sodium ion channels and keeps them open for a long time, thereby altering the sodium ion current and affecting sodium ion distribution, leading to the induction of epilepsy and convulsions[24,25].

Figure 2 The position of the pre-Bötzinger complex. The pre-Bötzinger complex is located in the ventrolateral medulla oblongata.

Magnesium ions is a natural noncompetitive antagonist of NMDARs that mainly blocks calcium ions (Ca²⁺) influx through voltage-gated channels (Figure 3). By regulating the activity of Na⁺-Ca²⁺ channels in neurons, MgSO₄ injection has a good antagonistic effect on seizures induced by nikethamide[12-14]. By limiting calcium entry and stabilizing neuronal membranes, magnesium can prevent the excitotoxic escalation that leads to seizures. Additionally, Mg²⁺ has a general inhibitory influence on neurotransmission—for example, it can dampen excessive release of excitatory transmitters and interfere with the sodium-calcium exchange cycle that sustains high-frequency neuronal firing. In our experiment, these properties of magnesium almost certainly underlie the prolonged seizure latency, reduced seizure severity, and extended seizure duration observed in the treated mice. Essentially, MgSO₄ raises the seizure threshold by inhibiting the neuronal hyperexcitation induced by nikethamide. This mechanistic interpretation is supported by the observed dose-response: Higher doses of magnesium produced deeper CNS depression (e.g. sedation and decreased locomotor activity), indicating a stronger blockade of excitatory neural activity[29,30]. However, this also reflects the drug’s narrow therapeutic window–the same mechanisms that quell seizures can, in excess, suppress normal neural function (leading to respiratory and circulatory depression at very high levels of magnesium). Overall, the interplay between nikethamide and magnesium in our study highlights a classic excitatory-inhibitory counterbalance in neuropharmacology: Nikethamide drives neural activity up, while magnesium pushes it down, and at appropriate dosing, magnesium successfully restrains nikethamide’s overstimulation of the CNS.

Figure 3 The molecular mechanism of the respiratory rhythm control center in the pre-Bötzinger complex. The 5-hydroxytryptamine (5-HT) is an important neurotransmitter, can activate protein kinase C (PKC) by binding to the 5-HT2A receptor. PKC further regulates the conduction of sodium ions, which is essential for maintaining respiratory rhythm. The activation of N-methyl-D-aspartate receptors (NMDARs) leads to the influx of calcium ions (Ca²⁺) into neurons. Calmodulin is a calcium-binding protein, forms a complex with intracellular Ca²⁺ and further activates nitric oxide (NO) synthase to generate large amounts of NO. Magnesium ions (Mg²⁺) is a natural antagonist of NMDARs, can block Ca²⁺ influx through voltage-gated channels and thus antagonize NMDAR activation. Therefore, Mg²⁺ can be used as an antagonist to treat seizures caused by glutamate. Ca²⁺: Calcium ions; Mg²⁺: Magnesium ions; Na⁺: Sodium ions; NO: Nitric oxide; PKC: Protein kinase C; 5-HT: 5-hydroxytryptamine.

Clinical implications

Our findings have direct implications for improving the safety of COVID-19 treatments involving respiratory stimulants. Severe COVID-19 pneumonia[15-18] often leads to acute hypoxemic respiratory failure, partly due to dysregulated pulmonary vascular function and inflammation in the lungs (e.g. impaired hypoxic pulmonary vasoconstriction and widespread alveolar damage)[31-33]. In such cases, respiratory stimulants like nikethamide have been employed to drive ventilation in an attempt to counter profound hypoxia[3,34]. Nikethamide may offer transient benefits when respiratory muscle function remains partly intact[34,35], but its utility is severely limited by the risk of precipitating convulsions at higher doses or prolonged use. Our study suggests a solution to this dilemma: Co-administering MgSO₄ could prevent or attenuate nikethamide-induced seizures, thereby enabling the therapeutic use of nikethamide in critical COVID-19 patients who might otherwise be prone to drug-provoked convulsions. In practical terms, MgSO₄ could be considered as a prophylactic adjunct in COVID-19 cases where nikethamide or similar respiratory analeptics are indicated for refractory hypoxemia.

Several factors make MgSO₄ an attractive option in this context. It is inexpensive, widely available, and familiar to clinicians due to its long-standing use in conditions like preeclampsia, where it is valued for both efficacy and safety when used within the proper dose range[6,36]. Importantly, magnesium’s mode of action (sedation and seizure prevention) addresses exactly the side effect that limits nikethamide’s application. By mitigating convulsions, magnesium might expand the viable dosing range of nikethamide, potentially improving oxygenation in COVID-19 patients without inducing neurological complications. However, clinicians must also be mindful of MgSO₄’s narrow therapeutic window[37]. The sedative effects we observed at high doses in mice parallel known risks in humans–excessive magnesium can cause respiratory depression, loss of deep tendon reflexes, and cardiac arrhythmias or arrest if levels become toxic[7]. Thus, any clinical protocol emerging from this research would need to balance efficacy with careful monitoring (e.g. frequent reflex checks and magnesium level measurements) to avoid iatrogenic harm. In summary, incorporating MgSO₄ as a countermeasure could substantially enhance the safety profile of nikethamide therapy for COVID-19-related respiratory failure, but it would require judicious dosing and monitoring in the clinical setting.

Limitations and future directions

While promising, these results should be interpreted in light of several limitations. First, our study was conducted in a mouse model, and the extent to which the findings translate to humans remains uncertain. Mice were administered acute doses of nikethamide and MgSO₄; this controlled scenario may not capture the full complexity of COVID-19 patients who could have co-morbidities, ongoing inflammation, and concurrent medications. The number of animals per group was limited, which, despite yielding statistically significant outcomes, suggests that further studies with larger sample sizes are warranted to confirm the robustness of the protective effect. Additionally, we focused on short-term outcomes (seizure latency, duration, and survival in the acute phase after nikethamide exposure). We did not assess longer-term neurological status or potential cumulative toxicity, which could be relevant if MgSO₄ were to be used repeatedly or continuously in a clinical setting.

Mechanistically, we inferred magnesium’s site of action (NMDAR blockade and general CNS depression) from existing knowledge, but we did not directly measure neural activity markers in our experiments. Future research could include electrophysiological studies or neurochemical assays (for example, measuring glutamate release, calcium influx in neurons, or electroencephalogram monitoring during seizures) to directly validate the proposed mechanism of seizure suppression by magnesium in the context of nikethamide. It would also be valuable to explore optimal dosing strategies–for instance, whether a moderate dose of MgSO₄ might suffice to prevent seizures without causing undue sedation, or if fractionated dosing could maintain protection with lower peak magnesium levels.

Another important direction is to evaluate MgSO₄ in more clinically relevant models. This could include studies in larger animals or in rodent models that mimic COVID-19 pneumonia (e.g. using viral infection or inflammatory agents to induce lung injury and hypoxemia) to see if magnesium retains its protective effect against nikethamide-induced seizures under those conditions. Ultimately, a carefully controlled clinical trial in COVID-19 patients receiving nikethamide (or analogous respiratory stimulants) could be conducted to determine safety, optimal dosing, and efficacy of magnesium co-therapy. Such trials should closely monitor not only respiratory parameters and seizure occurrence but also potential side effects of magnesium, ensuring patient safety.

CONCLUSION

In conclusion, our work provides a proof-of-concept for using MgSO₄ to broaden the therapeutic utility of nikethamide by mitigating its most serious side effect. Further research and development are needed to transition these findings from bench to bedside, but the therapeutic implications are significant: If successful, this strategy could enhance treatment options for severe COVID-19 and improve outcomes by safely addressing refractory hypoxemia without added risk of seizures. The balance of efficacy and safety will be the guiding principle in these future investigations.

ACKNOWLEDGEMENTS

All the authors express their gratitude to the ethics committee of the medical college of Taizhou University for their help. We also express our gratitude to our colleague for the data support provided for this experiment.