• The Korean Journal of Pain
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• v.12 no.2
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• pp.242-245
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• 1999

Gabapentin is an oral antiepileptic agent with an unknown mechanism of action. There have been many proposed uses for gabapentin, including neuropathic pain, reflex sympathetic dystrophy, postherpetic neuralgia, midscapular pain secondary to radiation myelopathy and migraine prophylaxis. This report presents patients who were treated with gabapentin when other pharmacologic interventions failed to relieve neuropathic pain 3 patients with neuropathic pain were included among these cases. All patients were started on 200 mg gabapentin. The maximum dose required for pain relief was between 800 mg and 2400 mg. Gabapentin may be a useful adjunct for treating neuropathic pain with minimum of side effects.

• The Korean Journal of Pain
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• v.20 no.1
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• pp.8-14
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• 2007

Background: Anticonvulsants and antidepressants are adjuvant analgesic drugs that are used widely for treating chronic neuropathic pain syndromes. The combined analgesic effect of gabapentin and milnacipran was investigated with a rat neuropathic pain model. Methods: The rat neuropathic pain model was made by ligating the spinal nerves (L5 and L6). An intrathecal catheter was inserted into the subarachnoid space. Tactile allodynia was tested with the up-down method using von Frey hair. We determined the antiallodynic effect of intraperitoneal (I.P.) and intrathecal (I.T.) gabapentin. The combined effect of I.P. gabapentin (50 mg/kg) and milnacipran (0, 10 and 30 mg/kg) was investigated. Results: Intraperitoneal and intrathecal administration of gabapentin increased the threshold for tactile allodynia (the ED50 was 60.6 mg/kg and $45.5{\mu}g$, respectively). Co-administration of I.P. milnacipran increased the antiallodynic effect of I.P. gabapentin in a dose-dependent fashion. Conclusion: The combined administration of milnacipran and gabapentin may increase the total analgesic effect during treatment of neuropathic pain.

• Korean Journal of Psychosomatic Medicine
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• v.22 no.2
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• pp.138-142
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• 2014

Burning mouth syndrome is characterized by intra-oral burning sensation without any organic abnormalities. This syndrome is associated with various etiological factors such as neuropathy, malnutrition, menopause and depression. Several medications have been tried for the treatment. Those are analgesics, hormones, anticonvulsants and antidepressants. However, optimal effective pharmacologic treatment remains still unknown. The purpose of this case study is to report the clinical effectiveness of gabapentin in the treatment of burning mouth syndrome in postmenopausal women with comorbid depression. We report two menopausal women. Antidepressants were effective for improving depressive symptoms, but it had no effects on intra-oral burning sensation. Gabapentin reduced intra-oral burning sensation effectively for all two patients. One patient reported 55% reduction(a decrease from 9 to 4 on VAS), the other patient reported 35% reduction(from 8 to 5) of the intra-oral burning sensation during 16 weeks. The minimal effective daily dose of gabapentin was 300mg. This study suggests that gabapentin might be a useful, effective therapeutic option for treating burning mouth syndrome in postmenopausal women with comorbid depression. Further prospective clinical studies are needed to investigate the effectiveness of gabapentin in patients with burning mouth syndrome.

• Journal of Korean Neurosurgical Society
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• v.67 no.2
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• pp.202-208
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• 2024

Objective : Failed back surgery syndrome (FBSS) is a common long-term complication following spine surgeries characterized by chronic persistent pain; different strategies of management were employed to deal with it. This clinical trial aims to compare the efficacy of Pregabalin and Gabapentin in the management of this condition. Methods : A double-blind, randomized, comparative study (clinical trial registry NCT05324761 on 11th April 2022) with two parallel arms with Pregabalin and Gabapentin were used in arms one and two, respectively. Visual analog scale was used for basal and endpoint assessment of pain. T-test and analysis of covariance were used to deal with different variables. A pairwise test was used to compare pairs of means. Results : Of 66 patients referred to the trial, 64 were eligible, with 60 patients completing the 30 days trial. Both pregabalin and gabapentin effectively reduce pain, with significant p-values of 0.001 for each group. However, the pregabalin group was superior to gabapentin in pain reduction (p=0.001). Gender was an insignificant factor (p=0.574 and p=0.445 for the pregabalin and gabapentin groups, respectively, with a non-significant reduction (p=0.393) for both groups in total. Location of stenosis before surgery and type of surgery performed show non-significant effect on pain reduction for both groups. Conclusion : Both pregabalin and gabapentin effectively and safely relieve neuropathic pain associated with FBSS; pregabalin was significantly more effective irrespective of the patients' gender.

• The Korean Journal of Pain
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• v.12 no.2
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• pp.188-190
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• 1999

Background: The goal of this study was to evaluate the effects of gabapentin on postherpetic neuralgia. Gabapentin is a known anti-seizure medication, whose cellular mechanism of action is not well understood. Unlike other anticonvulsant, gabapentin has the advantage of a low toxicity and favorable side effect profile. If has been recently recommended for use in treatment of neuropathic pain. Methods: Twelve patients with a diagnosis of postherpetic neuralgia were prescribed gabapentin after failure of routine therapeutic regimens. The dose of gabapentin ranged 300~1800 mg per day, in three divided doses. If initial dose was ineffective and no side effects were noted, the dosages was increased by 300 mg a day in divided doses, to the maximum level for 2 weeks. Patients were evaluated for analgesia using visual analogue scale (VAS) pain score (0; no pain, 10; worst possible pain) and possible side effects. Results: A significant decrease in pain scores with gabapentin were noted. There were several mild side effects such as dizziness, somnolence, dry mouth, constipation and facial edema, without need of special treatment. Conclusions: Gabapentin may be a useful adjunct for treating intractable postherpetic neuralgia with a minimal side effects.

• The Korean Journal of Pain
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• v.13 no.2
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• pp.137-142
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• 2000

Background: Systemic or intrathecal administration of gabapentin has been shown to reverse various pain states. However, until now, the effect of intracerebroventricular (ICV) gabapentin to noxious stimuli has not been reported. The authors' aim of this study was to determine the effect of ICV gabapentin on the inflammatory nociceptive model, formalin test, in rats. Methods: ICV catheters were implanted under halothane anesthesia. For the nociceptive test, $50{\mu}l$ of 5% formalin was subcutaneously injected into the hindpaw. The effect of ICV gabapentin, administered 10 min before formalin injection, were examined on flinching, mean arterial pressure and heart rate evoked by a injection of formalin. Results: Injection of formalin into the paw resulted in a biphasic flinching and cardiovascular response. ICV gabapentin produced a dose-dependent suppression of the flinching and mean arterial pressure response during phase 1. In contrast, in phase 2, ICV gabapentin did not attenuate the pain behavior. ICV gabapentin did not affect on the baseline mean arterial pressure and heart rate. Conclusions: ICV gbapentin was effective for the acute noxious stimulus but it had no effect on the facilitated states induced by tissue injury.

• Journal of Yeungnam Medical Science
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• v.21 no.1
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• pp.82-90
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• 2004

Background: Gabapentin is widely used for the relief of neuropathic pain. But, there is no study of gabapentin in relation to traumatic neuropathic pain. The aim of this study is to assess the efficacy and effectiveness of gabapentin for the various clinical symptoms of traumatic neuropathic pain Materials and Methods: 50 patients with traumatic nerve injury were assigned to receive gabapentin, titrated to 900 mg/day over 9 days, followed by further increases to a maximum of 2400 mg/day. Continuous pain, paroxysmal pain, allodynia and thermal evoked pain were measured in mean daily pain scores, based on the 11-point Likert scale. The primary efficacy parameter was compared from the baseline to the final study week. Results: Over the 4.5 week study, this pain score decreased by 2.6 points in the continuous pain, 3.6 points in the paroxysmal pain, 3.1 points in the allodynia, and 2.5 points in the thermal evoked pain. The percentage of patients with over 50% improvement in pain scores was 33% in the continuous pain, 67% in the paroxysmal pain, 53% in the allodynia and 36% in the thermal evoked pain. There was no significant correlation between the effect of gabapentin and the time difference of the onset of symptoms and start of medication. Conclusions: This study shows that gabapentin reduced neuropathic pain in patients with traumatic peripheral nerve injury. Among the various characteristics of neuropathic pain, the reduction of paroxysmal pain and allodynia was greatest.

• Journal of Pharmaceutical Investigation
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• v.35 no.3
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• pp.193-199
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• 2005

Gabapentin is an antiepileptic drug that is structurally similar to ${\gamma}-aminobutyric$ acid (GABA), but does not interact with the GABA receptor. It does not bind significantly to plasma proteins, and is excreted to unchanged form in the urine. The purpose of the present study was to evaluate the bioequivalence of two gabapentin capsules, $Neurontin^{TM}$ capsule 300 mg (Pfizer Pharm. Co., Ltd.) and Kuhnil $Gabapentin^{TM}$ capsule 300 mg (Kuhnil Pharm. Co., Ltd), according to the guidelines of the Korea Food and Drug Administration (KFDA). The release of gabapentin from the two gabapentin formulations in vitro was tested using KP VIII Apparatus II method with various dissolution media (pH 1.2, 4.0, 6.8 buffer solution and water). Twenty six healthy male subjects, $22.46{\pm}1.86$ years in age and $67.64{\pm}7.24$ kg in body weight, were divided into two groups and a randomized $2{\times}2$ cross-over study was employed. After a single capsule containing 300 mg as gabapentin was orally administered, blood samples were taken at predetermined time intervals and the concentrations of gabapentin in serum were determined using HPLC with fluorescence detector. The dissolution profiles of two formulations were similar at all dissolution media. In addition, the pharmacokinetic parameters such as $AUC_t$, $C_{max}$ and $T_{max}$ were calculated and ANOVA test was utilized for the statistical analysis of the parameters using logarithmically transformed $AUC_t$, $C_{max}$ and untransformed $T_{max}$. The results showed that the differences between two formulations based on the reference drug, $Neurontin^{TM}$ capsule 300 mg, were -2.03, -0.43 and 4.29% for $AUC_t$, $C_{max}$ and $T_{max}$, respectively. There were no sequence effects between two formulations in these parameters. The 90% confidence intervals using logarithmically transformed data were within the acceptance range of log 0.8 to log 1.25 $(e.g.,\;log\;0.89{\sim}log\;1.09\;and\;log\;0.91{\sim}log\;1.09$ for $AUC_t$ and $C_{max}$, respectively). Thus, the criteria of the KFDA bioequivalence guideline were satisfied, indicating Kuhnil $Gabapentin^{TM}$ capsule 300 mg was bioequivalent to $Neurontin^{TM}$ capsule 300 mg.

• International Journal of Oral Biology
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• v.37 no.3
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• pp.121-129
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• 2012

Previous clinical studies have demonstrated that gabapentin, a drug that binds to the voltage-gated calcium channel ${\alpha}2{\delta}1$ subunit proteins, is effective in the management of neuropathic pain, but there is limited evidence that addresses the participation of glial cells in the antiallodynic effects of this drug. The present study investigated the participation of glial cells in the anti-nociceptive effects of gabapentin in rats with trigeminal neuropathic pain produced by mal-positioned dental implants. Under anesthesia, the left mandibular second molar was extracted and replaced by a miniature dental implant to induce injury to the inferior alveolar nerve. Mal-positioned dental implants significantly decreased the air-puff thresholds both ipsilateral and contralateral to the injury site. Gabapentin was administered intracisternally beginning on postoperative day (POD) 1 or on POD 7 for three days. Early or late treatment with 0.3, 3, or 30 ${\mu}g$ of gabapentin produced significant anti-allodynic effect in the rats with mal-positioned dental implants. On POD 9, in the mal-positioned dental implants group, OX-42, a microglia marker, and GFAP, an astrocyte marker, were found to be up-regulated in the medullary dorsal horn, compared with the naive group. However, the intracisternal administration of gabapentin (30 ${\mu}g$) failed to reduce the number of activated microglia or astrocytes in the medullary dorsal horn. These findings suggest that gabapentin produces significant antinociceptive effects, which are not mediated by the inhibition of glial cell function in the medullary dorsal horn, in a rat model of trigeminal neuropathic pain.

• Journal of The Korean Dental Society of Anesthesiology
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• v.3 no.2 s.5
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• pp.92-97
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• 2003

Background: Gabapentin is a novel anti-epileptic drug, which is used in clinical practice to treat epilepsy. This drug is also used as an analgesic in pain patients. The antinociceptive effect of this drug was assessed using the formalin test in the rat. Methods: In order to investigate the effects of gabapentin on the trigeminal nerve territory, we injected 0.5% formalin into the upper lip. Adult, male, Sprague-Dawley rats received a $50{\mu}l$ subcutaneous injection of 5% formalin into one vibrissal pad and the consequent, facial grooming behavior was monitored. Consistent with previous investigations using tile formalin model, animals exhibited biphasic nocifensive grooming (phase 1, 0-12 min; phase 2, 12-60 min). Results: The intraperitoneal administration gabapentin 5 minutes prior to the formalin injection led to a significant, dose-dependent reduction in grooming time during phase 2. In high doses, gabapentin also reduced the time of grooming during phase 1. Conclusions: The Intraperitoneal injection of gabapentin has an analgesic effect in the facial formalin rat model and this analgesic effect increases dose-dependently.