Indomethacin, alone and combined with prochlorperazine and caffeine, but not sumatriptan, abolishes peripheral and central sensitization in in vivo models of migraine

Quantification of Caffeine Interactions in Choline Chloride Natural Deep Eutectic Solvents: Solubility Measurements and COSMO-RS-DARE Interpretation

Solubility of active pharmaceutical ingredients is an important aspect of drug processing and formulation. Although caffeine was a subject of many studies aiming to quantify saturated solutions, many applied solvents suffer from not being environmentally friendly. This work fills this gap by presenting the results of solubility measurements in choline chloride natural deep eutectic solvents, ccNADES, comprising one of seven of the following polyalcohols: glycerol, sorbitol, xylitol, glucose, sucrose, maltose and fructose. The ratio of ccNADES components was optimized for maximizing caffeine solubility at room temperature. Additionally, temperature dependent solubility was measured for the first four systems exhibiting the highest solubility potential, both in their neat forms and in mixtures with water. Results were used for intermolecular interactions assessments using the COSMO-RS-DARE approach, which led to a perfect match between experimental and computed solubility values. An important methodological discussion was provided for an appropriate definition of the systems. Surprising linear trends were observed between the values of fitting parameters and water-ccNADES composition. In addition, comments on selection of the values of the fusion thermodynamic parameters were provided, which led to the conclusion that COSMO-RS-DARE solubility computations can effectively compensate for the inaccuracies of these important physicochemical properties.

Mechanism of action of indomethacin in indomethacin-responsive headaches

Indomethacin, as a member of the non-steroidal anti-inflammatory drug class, plays a special role in the treatment of headaches. By definition, it is completely efficacious in the treatment of the primary headache disorders paroxysmal hemicrania and hemicrania continua. Therefore, indomethacin is also used as a tool for differential diagnosis in headache clinics. Indomethacin has a clear action as a cyclooxygenase inhibitor. Additional mechanisms and interactions with cell signaling pathways and inflammatory pathways are considered in this article. However, it is not known what mechanism or interaction with pathophysiological mechanisms is the key to indomethacin's specific pharmacology in headache therapy. Focusing on headache therapy, we summarize the current knowledge of pharmacology, treatment options, and recommendations for the use of indomethacin in primary headaches. New findings from the field of headache research, as well as from Alzheimer's disease and cancer research on the pharmacological actions of indomethacin and their potential implications on the pathophysiology of indomethacin sensitive headaches, are discussed.

Intranasal delivery of cyclobenzaprine hydrochloride-loaded thiolated chitosan nanoparticles for pain relief

The purpose of present investigation was to formulate and characterize the cyclobenzaprine HCl (CBZ)-loaded thiolated chitosan nanoparticles and assessment of in-vitro cell viability, trans-mucosal permeability on RPMI2650 cell monolayer, in-vivo pharmacokinetic and pharmacodynamic study of thiolated chitosan nanoparticles on Swiss albino mice after intranasal administration. A significant high permeation of drug was observed from thiolated chitosan nanoparticles with less toxicity on nasal epithelial cells. Brain uptake of the drug after (99m)Tc labeling was significantly enhanced after thiolation of chitosan. CBZ-loaded thiolated chitosan NPs significantly reverse the N-Methyl-.-Aspartate (NMDA)-induced hyperalgesia by intranasal administration than the CBZ solution. The studies of present investigation revealed that thiolation of chitosan significantly reduce trans-mucosal toxicity with enhanced trans-mucosal permeability via paracellular pathway and brain uptake of a hydrophilic drug (normally impermeable across blood brain barrier) and pain alleviation activity via intranasal route.

Spontaneous trigeminal allodynia in rats: a model of primary headache

Animal models are essential for studying the pathophysiology of headache disorders and as a screening tool for new therapies. Most animal models modify a normal animal in an attempt to mimic migraine symptoms. They require manipulation to activate the trigeminal nerve or dural nociceptors. At best, they are models of secondary headache. No existing model can address the fundamental question: How is a primary headache spontaneously initiated? In the process of obtaining baseline periorbital von Frey thresholds in a wild-type Sprague-Dawley rat, we discovered a rat with spontaneous episodic trigeminal allodynia (manifested by episodically changing periorbital pain threshold). Subsequent mating showed that the trait is inherited. Animals with spontaneous trigeminal allodynia allow us to study the pathophysiology of primary recurrent headache disorders. To validate this as a model for migraine, we tested the effects of clinically proven acute and preventive migraine treatments on spontaneous changes in rat periorbital sensitivity. Sumatriptan, ketorolac, and dihydroergotamine temporarily reversed the low periorbital pain thresholds. Thirty days of chronic valproic acid treatment prevented spontaneous changes in trigeminal allodynia. After discontinuation, the rats returned to their baseline of spontaneous episodic threshold changes. We also tested the effects of known chemical human migraine triggers. On days when the rats did not have allodynia and showed normal periorbital von Frey thresholds, glycerol trinitrate and calcitonin gene related peptide induced significant decreases in the periorbital pain threshold. This model can be used as a predictive model for drug development and for studies of putative biomarkers for headache diagnosis and treatment.

Improved transnasal transport and brain uptake of tizanidine HCl-loaded thiolated chitosan nanoparticles for alleviation of pain

The aim of this study was to prepare and characterize thiolated chitosan (TC) nanoparticles (NPs) of tizanidine HCl (TZ) and to evaluate its transport across monolayer of RPMI 2650 cells (Human nasal septum carcinoma cell line) followed by assessment of their pharmacokinetic and pharmacodynamic attributes, after intranasal (i.n.) administration. Chitosan was thiolated by carbodiimide method and thiolation was confirmed qualitatively and quantitatively. NPs were prepared using ionotropic gelation and evaluated for mucoadhesion using sheep nasal mucosa for drug permeation and cytotoxicity using monolayer of RPMI 2650 cells. Drug biodistribution was evaluated after technetium-99m labeling, visualized using gamma camera, and evaluated pharmacodynamically by measuring antinociceptive activity in mice. High mucoadhesion and permeation of drug were observed for TC NPs with least toxicity to nasal epithelial cells. Brain uptake and antinociceptive effect of the drug were significantly enhanced after thiolation of chitosan. This concludes that TC NPs, after i.n. administration, show significant increase in the mucoadhesion, reduction in cytotoxicity, enhanced permeation across cells monolayer, higher TZ brain uptake, and considerable increase in antinociceptive activity of TZ in mice. These features make TC an interesting polymer for demonstrating appreciable improvement of transnasal permeation of hydrophilic drugs, such as TZ, known to have limited permeation across blood-brain barrier.

Indomethacin/prochlorperazine/caffeine: a review of its use in the acute treatment of migraine and in the treatment of episodic tension-type headache

The indomethacin/prochlorperazine/caffeine fixed combination (Difmetré®) combines the NSAID indomethacin with the phenothiazine antiemetic prochlorperazine and caffeine. It is currently available as two oral (effervescent tablet and coated tablet) and two rectal (suppository and low-dose suppository) formulations. Oral and rectal formulations of indomethacin/prochlorperazine/caffeine were effective and generally well tolerated in the treatment of migraine and episodic tension-type headache (TTH) in adult patients participating in randomized, multicentre, active-comparator controlled studies. For the most part, the efficacy of oral indomethacin/prochlorperazine/caffeine did not significantly differ from that of oral sumatriptan in patients with migraine and oral nimesulide in patients with episodic TTH. With rectal administration, indomethacin/prochlorperazine/caffeine was, in general, significantly more effective than sumatriptan in patients with migraine. Thus, oral and rectal formulations of indomethacin/prochlorperazine/caffeine provide a further option in the acute treatment of migraine and in the treatment of episodic TTH in adult patients.

Combined analgesics in (headache) pain therapy: shotgun approach or precise multi-target therapeutics?

BACKGROUND

Pain in general and headache in particular are characterized by a change in activity in brain areas involved in pain processing. The therapeutic challenge is to identify drugs with molecular targets that restore the healthy state, resulting in meaningful pain relief or even freedom from pain. Different aspects of pain perception, i.e. sensory and affective components, also explain why there is not just one single target structure for therapeutic approaches to pain. A network of brain areas ("pain matrix") are involved in pain perception and pain control. This diversification of the pain system explains why a wide range of molecularly different substances can be used in the treatment of different pain states and why in recent years more and more studies have described a superior efficacy of a precise multi-target combination therapy compared to therapy with monotherapeutics.

DISCUSSION

In this article, we discuss the available literature on the effects of several fixed-dose combinations in the treatment of headaches and discuss the evidence in support of the role of combination therapy in the pharmacotherapy of pain, particularly of headaches. The scientific rationale behind multi-target combinations is the therapeutic benefit that could not be achieved by the individual constituents and that the single substances of the combinations act together additively or even multiplicatively and cooperate to achieve a completeness of the desired therapeutic effect.As an example the fixed-dose combination of acetylsalicylic acid (ASA), paracetamol (acetaminophen) and caffeine is reviewed in detail. The major advantage of using such a fixed combination is that the active ingredients act on different but distinct molecular targets and thus are able to act on more signalling cascades involved in pain than most single analgesics without adding more side effects to the therapy.

SUMMARY

Multitarget therapeutics like combined analgesics broaden the array of therapeutic options, enable the completeness of the therapeutic effect, and allow doctors (and, in self-medication with OTC medications, the patients themselves) to customize treatment to the patient's specific needs. There is substantial clinical evidence that such a multi-component therapy is more effective than mono-component therapies.

The central analgesia induced by antimigraine drugs is independent from Gi proteins: superiority of a fixed combination of indomethacin, prochlorperazine and caffeine, compared to sumatriptan, in an in vivo model

A hypofunctionality of Gi proteins has been found in migraine patients. The fixed combination of indomethacin, prochlorperazine and caffeine (Indoprocaf) is a drug of well-established use in the acute treatment of migraine and tension-type headache. The aim of this study was to investigate if Indoprocaf was able to exert its central antinociceptive action when Gi proteins activity is abolished by pertussis toxin (PTX), compared to its single active ingredients and to sumatriptan. The mice model of abdominal constriction test induced by an i.p. injection of a 0.6% solution of acetic acid was used. The study showed that Indoprocaf (a fixed combination of indomethacin 1 mg/kg, prochlorperazine 1 mg/kg and caffeine 3 mg/kg, s.c.) and sumatriptan (20 mg/kg, s.c.) exert their central antinociceptive action independently from the Gi proteins. In addition, the antinociceptive efficacy of Indoprocaf in this study was statistically superior to that of sumatriptan. This study also showed that the single active ingredients of Indoprocaf, indomethacin (1 mg/kg, s.c.), prochlorperazine (1 mg/kg, s.c.) and caffeine (3 mg/kg, s.c.), were able to exert their central antinociceptive action independently from the Gi proteins. However, Indoprocaf at analgesic doses was able to abolish almost completely the abdominal constrictions, with a statistically higher efficacy compared to the single active ingredients, showing an important synergic effect of Indoprocaf. This synergic effect was evident not only when Gi proteins activity was abolished by PTX, but also under control condition, when Gi proteins were active. This study suggests that the central antinociceptive action induced by antimigraine drugs is independent from Gi proteins.

Almotriptan and Its Combination with Aceclofenac For Migraine Attacks: A Study of Efficacy and The Influence of Auto-Evaluated Brush Allodynia

Early treatment and combining a triptan with a non-steroidal anti-inflammatory drug (NSAID) are thought to improve outcome during migraine attacks, possibly by counteracting the negative influence of cutaneous allodynia. The aim of this multicentre, double-blind pilot study was to evaluate the prevalence of brush allodynia and its relative influence on the efficacy of a triptan-NSAID combination compared with headache intensity at the time of treatment. In a randomized, cross-over design, 112 migraineurs treated two moderate or severe attacks with almotriptan 12.5 mg combined with either aceclofenac 100 mg or placebo. Patients used a 2-cm brush to assess cutaneous allodynia. Allodynia was reported in 34.4± of attacks. The almotriptan-aceclofenac combination was numerically superior to triptan-placebo on 2-24-h sustained pain-free ( P = 0.07), 2-h pain-free ( P = 0.07) and headache recurrence ( P = 0.05) rates, but not on 1-h headache relief. Allodynia numerically reduced treatment success overall, but this effect was not significant for the primary outcome measures. Headache intensity had a significant negative influence on 1-h relief in both attacks ( P = 0.0001 and 0.0008, X2) and on 2-24-h sustained pain-free rates in triptanplacebo-treated attacks ( P = 0.013). Multivariate logistic regression analysis confirmed that headache intensity at treatment intake, rather than allodynia, significantly influenced most outcome measures, predominantly so in attacks treated with almotriptan and aceclofenac. In the latter, severe compared with moderate headache intensity reduced the likelihood of achieving the primary efficacy end-points [odds ratios (OR) 0.12 and 0.33], whereas allodynia was not a significant explanatory variable (OR 0.76 and 0.65). The results apply to the protocol used here and need to be confirmed in larger studies using quantitative sensory testing.

Efficacy of dosing and re-dosing of two oral fixed combinations of indomethacin, prochlorperazine and caffeine compared with oral sumatriptan in the acute treatment of multiple migraine attacks: a double-blind, double-dummy, randomised, parallel group, multicentre study

AIMS AND METHODS

In this double-blind, double-dummy, randomised, parallel group, multicentre study, the efficacy of dosing and re-dosing of a fixed combination of indomethacin, prochlorperazine and caffeine (Indoprocaf) was compared with encapsulated sumatriptan in the acute treatment of two migraine attacks. Additionally, in the group taking Indoprocaf, two different oral formulations were tested: effervescent tablets and encapsulated coated tablets.

RESULTS

Of 297 patients randomised (150 assigned to Indoprocaf and 147 to sumatriptan), 281 were included in the intention-to-treat efficacy analysis. The initial dosing of Indoprocaf and sumatriptan was similarly effective with pain-free rates higher than 30% (95% CI of odds-ratio: 0.57-1.28) and headache relief rates of about 60% (95% CI of odds-ratio: 0.82-1.84) with both the drugs. The efficacy of re-dosing of Indoprocaf as rescue medication was more effective than that of sumatriptan with pain-free values of 47% vs. 27% in the total attacks with a statistically significant difference in the first migraine attack in favour of Indoprocaf. The efficacy of re-dosing to treat a recurrence/relapse was very high without differences between the drugs (pain-free: 60% with Indoprocaf and 50% with sumatriptan in the total attacks). Indoprocaf and sumatriptan were well-tolerated.

CONCLUSION

The study demonstrated that the efficacy of the initial dosing of Indoprocaf was not higher than that of sumatriptan, but that the strategy to use the lowest effective dose as soon as the headache occurred, followed by a second dose if the headache has not relieved or to treat a relapse, was very effective, especially with Indoprocaf.

Effect of modulation of serotonergic, cholinergic, and nitrergic pathways on murine fundic size and compliance measured by ultrasonomicrometry

Reduced fasting or postprandial gastric volumes have been implicated in the pathophysiology of functional dyspepsia. The mechanisms that underlie the control of gastric fundic volume are incompletely understood, partly because of an inability to accurately measure fundic volume in vivo in small animals. Small animals are useful models to evaluate mechanisms, e.g., in knockout animals. The aim of this study was to determine whether an ultrasonometric technique accurately monitors fundic contraction and relaxation in mice in vivo and to determine the effect of modulation of cholinergic, nitrergic, and serotonergic pathways on fundic size and compliance in the intact mouse innervated stomach. Two to four piezoelectric crystals (diameter 1 mm, 24-microm resolution) were glued to the serosal side of fundus and used to measure distance. Validation studies showed excellent correlation between measured changes and actual changes in distances between crystals and excellent reproducibility. The expected responses to pharmacological modulation with bethanechol and nitroglycerin were demonstrated. Atropine increased the distance between the crystals, suggesting a baseline cholinergic regulation of fundic volume. Bethanechol, Nomega-nitro-L-arginine, and the 5-HT1B/D agonist sumatriptan decreased the distance between the crystals, suggesting fundic contraction. Atropine, nitroglycerin, and buspirone caused an increase in intercrystal distance consistent with fundic relaxation. Fundic compliance was investigated by changing intragastric pressure via an implanted catheter. Sumatriptan increased compliance, whereas buspirone increased the distance between crystals but did not change compliance. The data suggest that ultrasonomicrometry is a useful tool that can reproducibly and accurately measure changes in fundic size and the response to pharmacological agents.

Efficacy of a fixed combination of indomethacin, prochlorperazine, and caffeine in the treatment of episodic tension-type headache: a double-blind, randomized, nimesulide-controlled, parallel group, multicentre trial

In this double-blind, randomized, parallel group, multicentre study the efficacy of a fixed combination of indomethacin, prochlorperazine, and caffeine (IndoProCaf) and nimesulide were compared over an 8-h period in the treatment of two consecutive episodes of tension-type headache (TTH). Both drugs were administered orally. Of 54 randomized patients, 40 were compliant to the protocol. More patients on IndoProCaf than on nimesulide were pain-free at 2 h post-dose (45% vs. 10%; P<0.05), reached a pain reduction of at least 50% at 2 (75% vs. 30%; P<0.05) and 4 h post-dose (90% vs. 58%; P<0.05), and had a statistically significant lower mean time to a 50 and 100% pain reduction in the second TTH episode. A higher percentage of patients reached a 50 or 100% pain reduction at 2 h post-dose with IndoProCaf compared with nimesulide, in two of two treated TTH episodes. A clinically and statistically significant change within each treatment group over time was found for the severity of pain, the headache intensity difference (HID), the sum of headache intensity difference (SHID), the maximum headache intensity difference (MAXHID), the headache relief (HER), the sum of total headache relief (TOTHER) and the maximum headache relief (MAXHER). In conclusion, IndoProCaf showed to be superior, but globally not statistically different from nimesulide in the treatment of episodic TTH. Both drugs were very effective and well tolerated.