Pharmacokinetics of diclofenac after oral administration of its potassium salt in sachet and tablet formulations

Identifying and Characterizing Stress Pathways of Concern for Consumer Safety in Next-Generation Risk Assessment

Many substances for which consumer safety risk assessments need to be conducted are not associated with specific toxicity modes of action, but rather exhibit nonspecific toxicity leading to cell stress. In this work, a cellular stress panel is described, consisting of 36 biomarkers representing mitochondrial toxicity, cell stress, and cell health, measured predominantly using high content imaging. To evaluate the panel, data were generated for 13 substances at exposures consistent with typical use-case scenarios. These included some that have been shown to cause adverse effects in a proportion of exposed humans and have a toxicological mode-of-action associated with cellular stress (eg, doxorubicin, troglitazone, and diclofenac), and some that are not associated with adverse effects due to cellular stress at human-relevant exposures (eg, caffeine, niacinamide, and phenoxyethanol). For each substance, concentration response data were generated for each biomarker at 3 timepoints. A Bayesian model was then developed to quantify the evidence for a biological response, and if present, a credibility range for the estimated point of departure (PoD) was determined. PoDs were compared with the plasma Cmax associated with the typical substance exposures, and indicated a clear differentiation between "low" risk and "high" risk chemical exposure scenarios. Developing robust methods to characterize the in vitro bioactivity of xenobiotics is an important part of non-animal safety assessment. The results presented in this work show that the cellular stress panel can be used, together with other new approach methodologies, to identify chemical exposures that are protective of consumer health.

Population scale retrospective analysis reveals distinctive antidepressant and anxiolytic effects of diclofenac, ketoprofen and naproxen in patients with pain

Currently approved monoamine modulating antidepressant and anxiolytic pharmaceutics fail in over one third of patients due to delayed and variable therapeutic effect, adverse reactions preceding the therapeutic action, and adherence issues. Even with adequate adherence to the regimen and tolerability, one third of the patients do not respond to any class of antidepressants. There is a strong correlation between treatment resistant depression and increase in inflammatory cytokines in plasma and cerebrospinal fluid. Furthermore, epidemiological studies suggest that depression and anxiety are commonly comorbid with pain and inflammation. While a link between pain, inflammation and depression has been suggested it remains unclear which anti-inflammatory treatment may be beneficial to patients with depression and anxiety due to pain. Here, we analyzed 430,783 FDA adverse effect reports of patients treated for pain to identify potential antidepressant and anxiolytic effects of various anti-inflammatory medications. Patients treated for depression or patients taking any known antidepressants were excluded. The odds ratio analysis of 139,072 NSAID reports revealed that ketoprofen was associated with decreased reports of depression by a factor of 2.32 (OR 0.43 and 95% Confidence Interval [0.31, 0.59]) and decreased reports of anxiety by a factor of 2.86 (OR 0.35 [0.22, 0.56]), diclofenac with decreased depression reports by a factor of 2.22 (OR 0.45 [0.40, 0.49]) and anxiety by a factor of 2.13 (OR 0.47 [0.41, 0.54]), while naproxen decreased depression reports by a factor of 1.92 (OR 0.52 [0.49, 0.57]) and anxiety by a factor of 1.23 (OR 0.81 [0.75, 0.88]). Other NSAIDs did not exhibit any noticeable antidepressant and/or anxiolytic effect.

Post Hoc Subanalysis of Two Randomized, Controlled Phase 3 Trials Evaluating Diclofenac Potassium for Oral Solution: Impact of Migraine-Associated Nausea and Prior Triptan Use on Efficacy

Objective

To determine whether baseline nausea or prior triptan treatment for migraine impact the effectiveness of diclofenac potassium for oral solution in treating acute migraine.

Background

A great deal of variability exists in patients' response to migraine medications. Migraine‐associated nausea is common and debilitating and can reduce the effectiveness of oral medications. It may cause patients to delay taking oral medications, which is known to diminish therapeutic outcomes, or to avoid taking them altogether. Gastroparesis, which may be associated with nausea, also inhibits drug absorption, resulting in lower bioavailability. Studies have shown that having nausea at the time of drug administration predicts a poorer response to triptan treatment. It is of interest to understand how effective other migraine medications are in patients with a poor response to triptans.

Methods

Data from two randomized, double‐blind, placebo controlled trials were pooled and post hoc subgroup analyses were performed in patients with and without nausea at baseline, and in patients with and without prior triptan treatment. Efficacy assessments included the percentage of patients who, at 2 hours postdosing, were headache pain‐free (2hPF, primary endpoint), without photophobia, without phonophobia, without nausea, or without a severe degree of disability. A Cochran–Mantel–Haenszel test, stratified by analysis center was used to evaluate treatment effect. Effects of nausea or prior triptan use were determined using logistic regression with factors of treatment group, analysis center, nausea or prior triptan use at time of dosing, and interaction of treatment group by nausea or prior triptan use at time of dosing.

Results

The modified intent to treat population consisted of 1272 patients, 644 on active drug and 628 on placebo. The majority of patients (85%) were female. At the time of dosing, 783 (62%) patients reported nausea with the treated attack. Prior triptan use was recorded in 570 (45%). For headache pain, nausea, photophobia, and phonophobia, patients in the active treatment group had a statistically significantly better response than those receiving placebo, regardless of whether they had nausea at baseline. In logistic regression analysis only treatment group predicted a response for these parameters with no detectable group interaction. Baseline nausea, as well as treatment group, predicted whether patients recorded severe disability at 2 hours. While patients in the active treatment group were significantly more likely to be headache pain‐free at 2 hours after dosing, whether or not they had previously been treated with triptan, more triptan‐naïve patients (30%) than triptan‐experienced patients (20%) were headache pain‐free. Interestingly, in the placebo groups, triptan‐naïve patients were also more likely to be PF (14% vs 7%). In the logistic regression analysis, treatment group predicted a headache pain response, triptan use predicted a lack of response, and there was no interaction between the two. Prior triptan use did not predict any of the other outcome measures.

Conclusions

Nausea at the time of dosing does not diminish the effectiveness of diclofenac potassium for oral solution. The rapid absorption profile may enhance the effectiveness in patients with nausea. Prior triptan use predicted poorer headache response at 2 hours postdose, suggesting the possibility of a subset of patients who are more likely to be refractory to both triptans and diclofenac. Diclofenac potassium for oral solution is effective in triptan‐naïve patients but no reliable inference can be made from this study as to about how to order treatment.

Diclofenac potassium for oral solution (CAMBIA®) in the acute management of a migraine attack: clinical evidence and practical experience

Migraine headache affects about 12% of Western populations and is the third most common disease worldwide (sixth in terms of disability). In 1993, triptans were introduced in the United States as a new treatment for managing migraine attacks, but their use is limited by lack of response and safety concerns in some patients. Treatment options for patients with migraine who fail or cannot tolerate triptans include switching to another medication or adding an adjunctive medication. Desirable characteristics reported by patients for acute treatment of migraine attacks include complete pain relief, fast onset of action, and no pain recurrence. Diclofenac is a nonsteroidal anti-inflammatory medication that has been established as effective for acute treatment of migraine by the American Headache Society based on available evidence. Diclofenac potassium for oral solution is rapidly absorbed, achieving maximal plasma concentrations in 15 min, which coincides with a rapid onset of effect. In a comparison of diclofenac potassium for oral solution with diclofenac potassium tablets, the solution achieved a significant reduction in headache intensity beginning at 15 min compared with 60 min for the tablet. Across randomized clinical trials, approximately 25% of patients were pain free 2 h after administration of diclofenac oral solution and the effects were maintained over a 24-h period. Diclofenac potassium for oral solution is well tolerated; the most common adverse events are dizziness and gastrointestinal complaints, with incidences similar to placebo. No serious adverse events have been reported in clinical trials of diclofenac potassium for oral solution in the acute treatment of migraine. Diclofenac oral solution may offer rapid and sustained pain relief for patients who do not achieve pain resolution with other medications. In addition, patients who experience central sensitization with allodynia may benefit from the cyclooxygenase-blocking activity of diclofenac, which is needed in this advanced phase of migraine.

Advances in NSAID development: evolution of diclofenac products using pharmaceutical technology

Diclofenac is a nonsteroidal anti-inflammatory drug (NSAID) of the phenylacetic acid class with anti-inflammatory, analgesic, and antipyretic properties. Contrary to the action of many traditional NSAIDs, diclofenac inhibits cyclooxygenase (COX)-2 enzyme with greater potency than it does COX-1. Similar to other NSAIDs, diclofenac is associated with serious dose-dependent gastrointestinal, cardiovascular, and renal adverse effects. Since its introduction in 1973, a number of different diclofenac-containing drug products have been developed with the goal of improving efficacy, tolerability, and patient convenience. Delayed- and extended-release forms of diclofenac sodium were initially developed with the goal of improving the safety profile of diclofenac and providing convenient, once-daily dosing for the treatment of patients with chronic pain. New drug products consisting of diclofenac potassium salt were associated with faster absorption and rapid onset of pain relief. These include diclofenac potassium immediate-release tablets, diclofenac potassium liquid-filled soft gel capsules, and diclofenac potassium powder for oral solution. The advent of topical formulations of diclofenac enabled local treatment of pain and inflammation while minimizing systemic absorption of diclofenac. SoluMatrix diclofenac, consisting of submicron particles of diclofenac free acid and a proprietary combination of excipients, was developed to provide analgesic efficacy at reduced doses associated with lower systemic absorption. This review illustrates how pharmaceutical technology has been used to modify the pharmacokinetic properties of diclofenac, leading to the creation of novel drug products with improved clinical utility.

Bioavailability of diclofenac potassium at low doses

AIM

Diclofenac-K has been recently launched at low oral doses in different countries for over-the-counter use. However, given the considerable first-pass metabolism of diclofenac, the degree of absorption of diclofenac-K at low doses remained to be determined. The aim of this study was to determine the bioavailability of low-dose diclofenac-K.

METHODS

A randomized, three-way, cross-over study was performed in 10 subjects. Each received diclofenac-K, 22.5 mg via short-term i.v. infusion and orally at single doses of 12.5 mg and 25 mg.

RESULTS

Mean (+/- SD) times to maximal plasma concentration (t(max)) of diclofenac were 0.48 +/- 0.28 h (12.5 mg) and 0.93 +/- 0.96 h (25 mg). The absolute bioavailability of diclofenac-K after oral administration did not differ significantly in the 12.5-mg and 25-mg dose group (63.1 +/- 12.6%vs. 65.1 +/- 19.4%, respectively). The 90% confidence intervals for the AUC(infinity) and AUC(t) ratios for the two oral regimes were 82.6, 103.4% (point estimate 92.4%) and 86.2, 112.9% (point estimate 98.6%), respectively. These values were within the acceptance criteria for bioequivalence (80-125%).

CONCLUSIONS

Our data indicate that diclofenac-K is rapidly and well absorbed at low dose, and are consistent with a rapid onset of action of the drug. Abbreviations AUC, area under plasma concentration-time curve; C(max), peak plasma concentration; CI, confidence interval; COX, cyclooxygenase; D, dose; F, absolute bioavailability; t(max), time to reach C(max).