Thiamine and Cyanocobalamin Relieve Neuropathic Pain in Rats: Synergy with Dexamethasone

Dexamethasone attenuates neuropathic pain through spinal microglial expression of dynorphin A via the cAMP/PKA/p38 MAPK/CREB signaling pathway

This study aimed to elucidate the opioid mechanisms underlying dexamethasone-induced pain antihypersensitive effects in neuropathic rats. Dexamethasone (subcutaneous and intrathecal) and membrane-impermeable Dex-BSA (intrathecal) administration dose-dependently inhibited mechanical allodynia and thermal hyperalgesia in neuropathic rats. Dexamethasone and Dex-BSA treatments increased expression of dynorphin A in the spinal cords and primary cultured microglia. Dexamethasone specifically enhanced dynorphin A expression in microglia but not astrocytes or neurons. Intrathecal injection of the microglial metabolic inhibitor minocycline blocked dexamethasone-stimulated spinal dynorphin A expression; intrathecal minocycline, the glucocorticoid receptor antagonist Dex-21-mesylate, dynorphin A antiserum, and κ-opioid receptor antagonist GNTI completely blocked dexamethasone-induced mechanical antiallodynia and thermal antihyperalgesia. Additionally, dexamethasone elevated spinal intracellular cAMP levels, leading to enhanced phosphorylation of PKA, p38 MAPK and CREB. The specific adenylate cyclase inhibitor DDA, PKA inhibitor H89, p38 MAPK inhibitor SB203580 and CREB inhibitor KG-501 completely blocked dexamethasone-induced anti-neuropathic pain and increased microglial dynorphin A exprression. In conclusion, this study reveal that dexamethasone mitigateds neuropathic pain through upregulation of dynorphin A in spinal microglia, likely involving the membrane glucocorticoid receptor/cAMP/PKA/p38 MAPK/CREB signaling pathway.

Photobiomodulation and vitamin B treatment alleviate both thermal and mechanical orofacial pain in rats

PURPOSE

The present study investigates the efficacy of Photobiomodulation (PBM) and Vitamin B Complex (VBC) to relieve pain, both in separately and combined (PBM and VBC).

METHODS

Rats with chronic constriction injury of the right infraorbital nerve (CCI-IoN) or Sham surgery were used. PBM was administered at a wavelength of 904 nm and energy density of 6.23 J/cm2 and VBC (containing B1, B6 and B12) subcutaneously, both separately and combined. Behavioral tests were performed to assess mechanical and thermal hypersensitivity before and after CCI and after PBM, VBC, or PBM + VBC. The expression of inflammatory proteins in the trigeminal ganglion and the immunohistochemical alterations of Periaqueductal Gray (PAG) astrocytes and microglia were examined following CCI and treatments.

RESULTS

All testeds treatments reversed the painful behavior. The decrease in pain was accompanied by a decrease of Glial Fibrillary Acidic Protein (GFAP), a specific astrocytic marker, and Ionized calcium-binding adaptor molecule 1 (Iba-1), a marker of microglia, and decreased expression of Transient Receptor Potential Vanilloid 1 (TRPV1), Substance P, and Calcitonin Gene-Related Peptide (CGRP) induced by CCI-IoN in PAG and Trigeminal ganglion. Furthermore, both treatments showed a higher expression of Cannabinoid-type 1 (CB1) receptor in the trigeminal ganglion compared to CCI-IoN rats. Our results show that no difference was observed between groups.

CONCLUSION

We showed that PBM or VBC regulates neuroinflammation and reduces inflammatory protein expression. However, the combination of PBM and VBC did not enhance the effectiveness of both therapies alone.

Mechanisms of action of vitamin B1 (thiamine), B6 (pyridoxine), and B12 (cobalamin) in pain: a narrative review

Pain is a complex sensory and emotional experience with nociceptive, nociplastic, and neuropathic components. An involvement of neurotropic B vitamins (B1 - thiamine, B6 - pyridoxine, and B12 - cyanocobalamin) as modulators of inflammation and pain has been long discussed. New evidence suggests their therapeutic potential in different pain conditions. In this review, we discuss the main role of neurotropic B vitamins on different nociceptive pathways in the nervous system and to describe their analgesic action mechanisms. The performed literature review showed that, through different mechanisms, these vitamins regulate several inflammatory and neural mediators in nociceptive and neuropathic pain. Some of these processes include aiming the activation of the descending pain modulatory system and in specific intracellular pathways, anti-inflammatory, antioxidative and nerve regenerative effects. Moreover, recent data shows the antinociceptive, antiallodynic, and anti-hyperalgesic effects of the combination of these vitamins, as well as their synergistic effects with known analgesics. Understanding how vitamins B1, B6, and B12 affect several nociceptive mechanisms can therefore be of significance in the treatment of various pain conditions.

Synergistic interaction between amitriptyline and paracetamol in persistent and neuropathic pain models: An isobolografic analysis

The current study was designed to evaluate the transient antinociceptive interaction between amitriptyline and paracetamol in the formalin test. In addition, considering other long-term neuroprotective mechanisms of these drugs, we hypothesized that this combination might exert some synergistic effects on neuropathic pain linked with its possible ability to prevent Wallerian degeneration (WD). The effects of individual and fixed-ratio of 1:1 combinations of orally administered amitriptyline and paracetamol were assayed in the two phases of the formalin test and in the chronic constriction injury (CCI) model in rats. Isobolographic analysis was employed to characterize the synergism produced by the combinations. Amitriptyline, paracetamol, and fixed-ratio amitriptyline-paracetamol combinations produced dose-dependent antinociceptive effects mainly on the inflammatory tonic phase. Repeated doses of individual drugs and their combination decreased CCI-induced mechanical allodynia in a dose-dependent manner. ED₃₀ (formalin) and ED₅₀ (CCI) values were estimated for the individual drugs, and isobolograms were constructed. Theoretical ED_30/50 values for the combination estimated from the isobolograms were 16.5 ± 3.9 mg/kg and 26.0 ± 7.2 mg/kg for the single and repeated doses in persistent and neuropathic pain models, respectively. These values were significantly higher than the actually observed ED_30/50 values, which were 0.39 ± 0.1 mg/kg and 8.2 ± 0.8 mg/kg in each model, respectively, indicating a synergistic interaction. Remarkably, CCI-induced sciatic nerve WD-related histopathological changes were prevented by this combination compared to either drug administered alone.

Co-Administered Low Doses Of Ibuprofen And Dexamethasone Produce Synergistic Antinociceptive Effects On Neuropathic Mechanical Allodynia In Rats

Background

The traditional analgesics used to treat neuropathic pain such as anticonvulsants, opioids, and nonsteroidal anti-inflammatory drugs (NSAIDs) lack efficacy and/or carry unpleasant side effects. The present study aimed to investigate the synergistic antinociceptive effects of co-administered low doses of ibuprofen and dexamethasone in rats with trigeminal neuropathic pain.

Materials and methods

A Sprague-Dawley rat model for trigeminal neuropathic pain was produced using mal-positioned dental implants. The left mandibular second molar was extracted under anesthesia and replaced with a miniature dental implant to induce injury to the inferior alveolar nerve.

Results

Monotherapy with intraperitoneal injection of high-dose ibuprofen (30 mg/kg) or dexamethasone (10 mg/kg) but not low-dose ibuprofen (1, 5, 10 mg/kg) or dexamethasone (0.01, 1 mg/kg) attenuated the neuropathic mechanical allodynia in the rats with inferior alveolar nerve injury. We examined the synergistic antinociceptive effects of co-administered ibuprofen (5 mg/kg) and dexamethasone (0.01, 0.1, 1 mg/kg). The early co-administration of ibuprofen (5 mg/kg) with dexamethasone (0.1, 1 mg/kg) on postoperative days (POD) 1–3 significantly inhibited mechanical allodynia before the pain had been established. We also observed the synergistic antinociceptive effects of the same doses the combined treatment on mechanical allodynia on POD 7–9, when the pain had already been established. The attenuation of c-fos immuno-positive cells in the ipsilateral trigeminal subnucleus caudalis after the intraperitoneal co-administration of ibuprofen (5 mg/kg) with dexamethasone (1 mg/kg) confirmed these synergistic antinociceptive effects. Moreover, the magnitude of the effects of this co-administration was comparable with that of gabapentin both before and after the pain had been established.

Conclusion

These results suggest that a combination of ibuprofen and dexamethasone at low doses is an alternative therapeutic strategy for neuropathic pain and provide a rationale for the use of such drug combinations in patients who are unable to tolerate high-dose monotherapy.

[The efficacy of cocarnit in diabetic neuropathy]

AIM

To study the efficacy of the complex therapy, including cocarnit (group B vitamins, triphosadenine and nicotinamide), of diabetic neuropathy.

MATERIAL AND METHODS

Forty-one patients with diabetes mellitus type 2 and distal symmetric sensorimotor polyneuropathy were examined. Patients were divided into 2 groups. Patients of the main group (n=26) received complex therapy, including cocarnit, and patients of the comparison group (n=15) received standard treatment.

RESULTS AND CONCLUSION

The positive dynamics based on the VAS (р=0.0001), TSS (р=0.0001), NSS (р=0.001), NDS (р=0.0431), SF-36 (р=0.0008), electroneuromyographic results and glycated hemoglobin levels was observed in the main group. In patients of the comparison group, the positive dynamics was instable; the scores of clinical scales did not reach statistical significance. The results suggest the use of cocarnit in the complex treatment of patients with diabetic neuropathy.

New approach to peripheral nerve injury: nutritional therapy

Purpose of review: There is no review in the literature on the effect of nutrition-related factors on peripheral nerve injuries. Therefore, it is aimed to evaluate the effect of nutritional factors on nerve injuries in this compilation. Recent findings: Although there are several fundamental mechanisms by which nutrients and nutritional factors influence individuals, their exact impacts on neurogenesis have not been clearly identified. Recently, some studies showed that some nutrients have an important role in nerve injuries due to their neuroprotective properties. In addition to surgical treatment, in peripheral nerve injuries, these nutrients also may play a role in preserving nerve function and health, as well as in the recovery of an injured nerve tissue. Omega 3 and omega 6 fatty acids, group B vitamins, antioxidants, several minerals, phenolic compounds, and alpha lipoic acid are thought to have impacts on the nervous system. In addition to all of these, gut microbiota has effects on the nervous system, and some nutrient-related factors can also affect neurogenesis via gut microbiota. Summary: Peripheral nerve injury is a condition in which the nerves in the peripheral nervous system become damaged. After the trauma, the peripheral nerve is hardly repaired due to the following reasons; the disability of the regeneration of motor neurons, the lack of a survival environment for Schwann cells, and the poor ability of the nerves to regenerate. Nutrition-related factors, the effects of which were described in recent years, should be more taken into account more.

Vitamin B12 for herpetic neuralgia: A meta-analysis of randomised controlled trials

BACKGROUND

Postherpetic neuralgia (PHN) is the most distressful complication of herpes zoster. PHN results in an impaired quality of life and higher healthcare utilization. Vitamin B12 has been proven to be effective in pain relief for various conditions.

OBJECTIVE

We conducted a systematic review and a meta-analysis to evaluate the efficacy of vitamin B12 supplementation in PHN patients.

METHODS

PubMed, Embase, Cochrane Library, CINAHL, and ClinicalTrials.gov registry were searched. Randomised control trials evaluating the efficacy and safety of vitamin B12 in PHN patients were selected. Eligible trials were abstracted and assessed for the risk of bias by two reviewers, and the results of pain indicators in the selected trials were analysed.

RESULTS

Four trials including 383 participants were published between 2013 and 2016. Compared with the placebo group, the Vitamin B12 group exhibited a significant decrease in the Numeric Rating Scale score, with a mean difference of -4.01 (95% confidence interval = -4.70 to -3.33). Vitamin B12 administration improved the quality of life of PHN patients with moderate quality evidence and significantly decreased the number of patients using analgesics.

CONCLUSION

Vitamin B12 appears to be an attractive complementary therapy for PHN patients. Further investigation is needed before conclusive recommendations can be made.

Vitamin B complex and vitamin B12 levels after peripheral nerve injury

The aim of the present study was to evaluate whether tissue levels of vitamin B complex and vitamin B12 were altered after crush-induced peripheral nerve injury in an experimental rat model. A total of 80 male Wistar rats were randomized into one control (n = 8) and six study groups (1, 6, 12, 24 hours, 3, and 7 days after experimental nerve injury; n = 12 for each group). Crush-induced peripheral nerve injury was performed on the sciatic nerves of rats in six study groups. Tissue samples from the sites of peripheral nerve injury were obtained at 1, 6, 12, 24 hours, 3 and 7 days after experimental nerve injury. Enzyme-linked immunosorbent assay results showed that tissue levels of vitamin B complex and vitamin B12 in the injured sciatic nerve were significantly greater at 1 and 12 hours after experimental nerve injury, while they were significantly lower at 7 days than in control group. Tissue level of vitamin B12 in the injured sciatic nerve was significantly lower at 1, 6, 12 and 24 hours than in the control group. These results suggest that tissue levels of vitamin B complex and vitamin B12 vary with progression of crush-induced peripheral nerve injury, and supplementation of these vitamins in the acute period may be beneficial for acceleration of nerve regeneration.

Local Administration of Methylcobalamin and Lidocaine for Acute Ophthalmic Herpetic Neuralgia: A Single-Center Randomized Controlled Trial

OBJECTIVES

To determine the therapeutic efficacy of combined methylcobalamin and lidocaine for acute ophthalmic herpetic neuralgia (AOHN).

METHODS

Based on the onset, patients with AOHN (n = 98) were randomly allocated into groups A (≤ 3 days) and B (4 to 7 days) and then subdivided into control (A0, B0; received intramuscular methylcobalamin in addition to local lidocaine injection) and treatment (A1, B1; received local injection of the methylcobalamin and lidocaine combination for 14 days) groups. Treatment efficacy was assessed based on rash healing time, alteration of pain intensity, and interference with quality of life. Multilevel modeling and survival analysis were performed.

RESULTS

The time (hours) to start and full opening of the affected eye and the time (hours) to start and full crusting were significantly reduced in both treatment groups (P < 0.05 vs. controls). The mean pain scores in A1 (2.6 ± 0.7) and B1 (1.2 ± 0.8) decreased significantly compared with those in A0 (7.0 ± 1.7) and B0 (5.6 ± 1.9), and the difference between the two therapeutic strategies significantly increased over time. The median minimum intervention time was 6 days in B1 and 11 days in A1. The incidence of postherpetic neuralgia (PHN) was 2.04% at 3 months.

CONCLUSIONS

Methylcobalamin combined with lidocaine mediated detumescence and improved cutaneous healing of the affected area, as well as a significant and sustained analgesic effect on AOHN. The incidence of PHN was also significantly decreased. Local methylcobalamin intervention within 4 to 7 days of onset may be an effective therapeutic option for AOHN.

Vitamin B complex attenuated heat hyperalgesia following infraorbital nerve constriction in rats and reduced capsaicin in vivo and in vitro effects

Vitamins of the B complex attenuate some neuropathic pain sensory aspects in various animal models and in patients, but the mechanisms underlying their effects remain to be elucidated. Herein it was investigated if the treatment with a vitamin B complex (VBC) reduces heat hyperalgesia in rats submitted to infraorbital nerve constriction and the possibility that TRPV1 receptors represent a target for B vitamins. In the present study, the VBC refers to a combination of vitamins B1, B6 and B12 at low- (18, 18 and 1.8mg/kg, respectively) or high- (180, 180 and 18mg/kg, respectively) doses. Acute treatment of rats with either the low- or the high-doses combination reduced heat hyperalgesia after nerve injury, but the high-doses combination resulted in a long-lasting effect. Repeated treatment with the low-dose combination reduced heat hyperalgesia on day four after nerve injury and showed a synergist effect with a single injection of carbamazepine (3 or 10mg/kg), which per se failed to modify the heat threshold. In naïve rats, acute treatment with the high-dose of VBC or B1 and B12 vitamins independently reduced heat hyperalgesia evoked by capsaicin (3µg into the upper lip). Moreover, the VBC, as well as, each one of the B vitamins independently reduced the capsaicin-induced calcium responses in HEK 293 cells transiently transfected with the human TRPV1 channels. Altogether, these results indicate that B vitamins can be useful to control heat hyperalgesia associated with trigeminal neuropathic pain and that modulation of TRPV1 receptors may contribute to their anti-hyperalgesic effects.

Treatment of idiopathic headshaking in horses with pulsed high-dose dexamethasone

BACKGROUND

Treatment of idiopathic headshaking in horses is complicated by an incomplete understanding of underlying pathophysiology and partially effective treatments. If an inflammatory etiology exists, corticosteroids could be beneficial.

HYPOTHESIS

An anti-inflammatory dose of dexamethasone reduces the signs of idiopathic headshaking in a field setting.

ANIMALS

Convenience sample of 20 adult horses with idiopathic headshaking syndrome. Cases were recruited from the general population and diagnosed by attending veterinarians.

METHODS

Prospective, blinded clinical trial. Pulsed dosing was with oral dexamethasone (60 mg PO Q24h × 4 days, q3 weeks for 4 months) or placebo (inert paste). Owners were blinded and asked to score the headshaking from 0 to 4 (4 = most severe) 3 days per week. The change in headshaking scores (HS) over each treatment pulse was compared between groups by ordinal logistic regression.

RESULTS

Twelve horses completed the trial. There was no significant difference between treated or placebo horses (P = .987). Sun (P ≤ .001), wind (P = .028), and exercise (P ≤ .045) significantly increased HS.

CONCLUSIONS AND CLINICAL IMPORTANCE

No benefit of dexamethasone treatment was detected for idiopathic headshaking. The results confirmed previous reports of common triggers for headshaking behavior

Systematic administration of B vitamins attenuates neuropathic hyperalgesia and reduces spinal neuron injury following temporary spinal cord ischaemia in rats

BACKGROUND

B vitamins have been demonstrated to be effective in treating chronic pain due to peripheral nerve injury. We investigated whether B vitamins could alleviate neuropathic pain and reduce neuron injury following temporary ischaemia in a rat model of spinal cord ischaemia-reperfusion injury (SCII).

METHODS

SCII was produced by transiently blocking the unilateral lumbar arteries in adult male Sprague-Dawley rats. Behavioural and neurochemical signs of neuropathic pain and spinal neuron injury were analysed with and without B vitamin treatment.

RESULTS

SCII caused behavioural thermal hyperalgesia and mechanical allodynia and neurochemical alterations, including increased expression of the vanilloid receptor 1 (VR1) and induction of c-Fos, as well as activation of the astrocytes and microglial cells in the spinal cord. Repetitive systemic administration of vitamin B complex (B1/B6/B12 at 33/33/0.5 mg/kg, i.p., daily, for 7-14 consecutive days) significantly reduced thermal hyperalgesia and the increased expression of VR1 and c-Fos, as well as activation of the astrocytes and microglial cells. SCII caused a dramatic decrease of the expression of the rate-limiting enzyme glutamic acid decarboxylase-65 (GAD65), which synthesizes γ-aminobutyric acid (GABA) in the axonal terminals, and β-III-tubulin, and also caused loss of Nissl bodies in the spinal cord. These alterations were largely prevented and rescued by the B vitamin treatment.

CONCLUSIONS

These findings support the idea that the B vitamins are capable of neuroprotection and antinociception during spinal cord injury due to temporary ischaemia. Rescuing the loss of inhibitory GABAergic tone may reduce spinal central sensitization and contribute to B vitamin-induced analgesia.

B vitamins relieve neuropathic pain behaviors induced by infraorbital nerve constriction in rats

AIMS

There is mounting evidence that use of B vitamins can help control neuropathic pain. This study investigated if treatment with B1, B6 and B12 vitamins, alone or in combination with carbamazepine, can ameliorate distinct nociceptive behaviors in a model of trigeminal neuropathic pain.

MAIN METHODS

Male Wistar rats were submitted to infraorbital nerve constriction or sham surgery and received a 5-day treatment with one of the B vitamins, a single carbamazepine injection or the association of both treatments and were tested for facial thermal and mechanical hyperalgesia at different time intervals.

KEY FINDINGS

Repeated treatment with B1 (thiamine), B6 (pyridoxine) and B12 (cyanocobalamin) vitamins (at 180, 180 and 18 mg/kg/day, respectively, for 5 days) prevented the development of heat hyperalgesia after infraorbital nerve injury, but only B12 and B6 treatments attenuated cold and mechanical hyperalgesia, respectively. A single injection of carbamazepine (30 mg/kg) significantly reduced thermal, but not mechanical, hyperalgesia after nerve injury. Combinations of lower doses of each B vitamin (B1 and B6 at 18 mg/kg/day and B12 at 1.8 mg/kg/day for 5 days) with carbamazepine (10mg/kg) markedly reduced heat hyperalgesia after infraorbital nerve injury. Treatment with B12 (1.8 mg/kg/day) combined with carbamazepine (10mg/kg) also synergized to attenuate cold hyperalgesia at some time points, but combination of B6 (18 mg/kg/day) with carbamazepine (30 mg/kg) failed to modify mechanical hyperalgesia.

SIGNIFICANCE

We suggest that B vitamins might constitute a relevant adjuvant to control some aspects of the pain afflicting patients suffering from trigeminal neuropathic pain.

Behavioral evidence for the differential regulation of p-p38 MAPK and p-NF-κB in rats with trigeminal neuropathic pain

BACKGROUND

We investigated the differential regulation of p-p38 MAPK or p-NF-κB in male Sprague-Dawley rats with inferior alveolar nerve injury resulting from mal-positioned dental implants. For this purpose, we characterized the temporal expression of p-p38 MAPK or p-NF-κB in the medullary dorsal horn and examined changes in nociceptive behavior after a blockade of p-p38 MAPK or p-NF-κB pathways in rats with trigeminal neuropathic pain.

RESULTS

Under anesthesia, the left lower second molar was extracted and replaced with a mini dental implant to intentionally injure the inferior alveolar nerve. Western and immunofluorescence analysis revealed that p-p38 MAPK is upregulated in microglia following nerve injury and that this expression peaked on postoperative day (POD) 3 through 7. However, the activation of p-NF-κB in astrocyte peaked on POD 7 through 21. The intracisternal administration of SB203580 (1 or 10 μg), a p38 MAPK inhibitor, on POD 3 but not on POD 21 markedly inhibits mechanical allodynia and the p-p38 MAPK expression. However, the intracisternal administration of SN50 (0.2 or 2 ng), an NF-κB inhibitor, on POD 21 but not on POD 3 attenuates mechanical allodynia and p-NF-κB expression. Dexamethasone (25 mg/kg) decreases not only the activation of p38 MAPK but also that of NF-κB on POD 7.

CONCLUSIONS

These results suggest that early expression of p-p38 MAPK in the microglia and late induction of p-NF-κB in astrocyte play an important role in trigeminal neuropathic pain and that a blockade of p-p38 MAPK at an early stage and p-NF-κB at a late stage might be a potential therapeutic strategy for treatment of trigeminal neuropathic pain.

Early dexamethasone relieves trigeminal neuropathic pain

The analgesic effects of dexamethasone on neuropathic pain have been controversial. The present study investigated the effects of dexamethasone on mechanical allodynia in rats with mal-positioned dental implants. Under anesthesia, the left mandibular second molar was extracted and replaced by a miniature dental implant to injure the inferior alveolar nerve. Nociceptive behavior was examined on each designated day after surgery. Mal-positioned dental implants significantly decreased air-puff thresholds both ipsilateral and contralateral to the injury site. Distinct mechanical hyperalgesia and cold and thermal hypersensitivity were also observed bilaterally. Daily administration of dexamethasone produced prolonged anti-allodynic effects (25 or 50 mg/kg, i.p.), but failed to reduce mechanical allodynia when it had already been established. Therefore, our findings provide that early treatment with dexamethasone is important in the treatment of nociceptive behavior suggestive of trigeminal neuropathic pain.

Diclofenac plus B vitamins versus diclofenac monotherapy in lumbago: the DOLOR study

OBJECTIVES

To assess the influence of vitamins B1, B6 and B12 on the analgesia success achieved by diclofenac in subjects with acute lumbago.

RESEARCH DESIGN AND METHODS

A randomised, double blind controlled clinical study in parallel groups, in which subjects received twice-daily oral administration of either the combination therapy, Group DB (50 mg diclofenac plus 50 mg thiamine, 50 mg pyridoxine and 1 mg cyanocobalamin) or diclofenac monotherapy, Group D (50mg diclofenac). The study period lasted a maximum of 7 days. If sufficient pain reduction was achieved (defined as Visual Analogue Scale <20 mm and patient's satisfaction), subjects could withdraw from the treatment after 3 or 5 days. All subjects gave written informed consent to participate in the study.

MAIN OUTCOME MEASURES

The primary confirmatory study objective was to determine the number of patients with sufficient pain reduction after 3 days of treatment.

RESULTS

Three hundred and seventy-two subjects were allocated at random to either treatment group: Group DB - 187 subjects and Group D - 185 subjects. After 3 days of treatment, a statistically significant higher proportion of subjects in Group DB (n = 87; 46.5%) than in Group D (n = 55; 29%) terminated the study due to treatment success (chi(2): 12.06; p = 0.0005). Furthermore, the combination therapy yielded superior results in pain reduction, improvement of mobility and functionality. Drug safety monitoring profile throughout the trial was within the expected safety profile of diclofenac.

CONCLUSIONS

The combination of diclofenac with B vitamins was superior to diclofenac monotherapy in lumbago relief after 3 days of treatment. As a study drawback, daily VAS measurements were only recorded until subject withdrawal from treatment, whether after 3, 5, or 7 days. There were no differences in safety profile between the two study groups.