Analgesic dose-response relationship of ibuprofen 50, 100, 200, and 400 mg after surgical removal of third molars: a single-dose, randomized, placebo-controlled, and double-blind study of 304 patients

Analgesic effect of oral ibuprofen 400, 600, and 800 mg; paracetamol 500 and 1000 mg; and paracetamol 1000 mg plus 60 mg codeine in acute postoperative pain: a single-dose, randomized, placebo-controlled, and double-blind study

PURPOSE

Effect size estimates of analgesic drugs can be misleading. Ibuprofen (400 mg, 600 mg, 800 mg), paracetamol (1000 mg, 500 mg), paracetamol 1000 mg/codeine 60 mg, and placebo were investigated to establish the multidimensional pharmacodynamic profiles of each drug on acute pain with calculated effect size estimates.

METHODS

A randomized, double-blind, single-dose, placebo-controlled, parallel-group, single-centre, outpatient, and single-dose study used 350 patients (mean age 25 year, range 18 to 30 years) of homogenous ethnicity after third molar surgery. Primary outcome was sum pain intensity over 6 h. Secondary outcomes were time to analgesic onset, duration of analgesia, time to rescue drug intake, number of patients taking rescue drug, sum pain intensity difference, maximum pain intensity difference, time to maximum pain intensity difference, number needed to treat values, adverse effects, overall drug assessment as patient-reported outcome measure (PROM), and the effect size estimates NNT and NNTp.

RESULTS

Ibuprofen doses above 400 mg do not significantly increase analgesic effect. Paracetamol has a very flat analgesic dose-response profile. Paracetamol 1000/codeine 60 mg gives similar analgesia as ibuprofen from 400 mg, but has a shorter time to analgesic onset. Active drugs show no significant difference in maximal analgesic effect. Other secondary outcomes support these findings. The frequencies of adverse effects were low, mild to moderate in all active groups. NNT and NTTp values did not coincide well with PROMs.

CONCLUSION

Ibuprofen doses above 400 mg for acute pain offer limited analgesic gain. Paracetamol 1000 mg/codeine 60 mg is comparable to ibuprofen doses from 400 mg. Calculated effect size estimates and PROM in our study seem not to relate well as clinical analgesic efficacy estimators.

TRIAL REGISTRATION

NCT00699114.

Clinical and pharmacological approaches to the choice of a drug for a tension-type headache relief

The article goes to describe clinical and pharmacological approaches to choosing a drug with an optimal efficacy/safety profile, providing the necessary analgesic effect in tension-type headache. TRPV1 brain receptors are considered the main action point of the mediator. Aim. The purpose of this study is a comparative analysis of the pharmacodynamic and pharmacokinetic parameters of ibuprofen and paracetamol as a part of fixed dose combination and as monotherapy in tension type headaches. Materials and methods. Comparative dissolution kinetics test; Comparative analysis of pharmacokinetic parameters using the PubMed/MEDLINE database. Results. The median Tmax of ibuprofen as a part of a fixed-dose combination and as a monotherapy is 75 minutes. The median Tmax of paracetamol is 30 min when taken in a fixed dose combination and 40 min as a monotherapy. In patients who received the fixed dose combination, the concentration of ibuprofen in the blood plasma after 10 minutes 6.64 g/ml-1; after 20 minutes 16.81 g/ml-1, while when taken in the same dose in as a monotherapy, respectively, 0.58 and 9.00 g/ml-1. The mean plasma concentrations of paracetamol after 10 and 20 minutes in patients receiving the fixed combination were 5.43 and 14.54 g/ml-1, respectively, compared with 0.33 and 9.19 g/ml-1 for paracetamol as monotherapy. dissolution kinetics test of the Paracytolgin: after 5 minutes, 20% of paracetamol passed into the solution in a system with a pH of 1.2; in a system with a pH of 4.5 36.4%; in a system with a pH of 6.8 33.5%; after 10 minutes, respectively 68.5, 98.0 and 89.6%. After 15 minutes, almost complete dissolution was noted in all systems: 98.5, 98.8 and 100.5%, respectively. Discussion. The combination of ibuprofen and paracetamol makes it possible to enhance the analgesic effect as a result of additive action by the help of central mechanisms. The fixed dose combination of ibuprofen and paracetamol significantly increases the rate of absorption of paracetamol, which has potential therapeutic benefits in terms of a faster analgesias onset. Conclusion. The fixed dose combination of ibuprofen and paracetamol provides faster and long-term anaesthesia with a comparatively lower dosage of each analgesic.

Application of the relationship between pharmacokinetics and pharmacodynamics in drug development and therapeutic equivalence: a PEARRL review

Objectives

The objective of this review was to provide an overview of pharmacokinetic/pharmacodynamic (PK/PD) models, focusing on drug-specific PK/PD models and highlighting their value added in drug development and regulatory decision-making.

Key findings

Many PK/PD models, with varying degrees of complexity and physiological understanding have been developed to evaluate the safety and efficacy of drug products. In special populations (e.g. paediatrics), in cases where there is genetic polymorphism and in other instances where therapeutic outcomes are not well described solely by PK metrics, the implementation of PK/PD models is crucial to assure the desired clinical outcome. Since dissociation between the pharmacokinetic and pharmacodynamic profiles is often observed, it is proposed that physiologically based pharmacokinetic and PK/PD models be given more weight by regulatory authorities when assessing the therapeutic equivalence of drug products.

Summary

Modelling and simulation approaches already play an important role in drug development. While slowly moving away from ‘one-size fits all’ PK methodologies to assess therapeutic outcomes, further work is required to increase confidence in PK/PD models in translatability and prediction of various clinical scenarios to encourage more widespread implementation in regulatory decision-making.

Acetaminophen, ibuprofen, and tramadol analgesic interactions after adenotonsillectomy

BACKGROUND

The impact of tramadol in children given acetaminophen-ibuprofen combination therapy is uncertain in acute pediatric pain management. A model describing the interaction between these three drugs would be useful to understand the role of supplemental analgesic therapy.

METHODS

Children undergoing tonsillectomy were given oral paracetamol and ibuprofen perioperatively. Blood was taken for paracetamol and ibuprofen drug assay on up to six occasions over 6 h after the initial dose. Tramadol was administered by caregivers for unacceptable postoperative pain. Pain was measured using the Parent's Postoperative Pain Measurement rating two hourly on the first postoperative day. A first-order absorption, one-compartment linear model with first-order elimination was used to describe acetaminophen and ibuprofen disposition. Analgesia was described using an E_MAX model extended for three drugs, assuming additive effects. Curve fitting was performed using nonlinear mixed effects models.

RESULTS

Pharmacodynamic parameter estimates, expressed using fractional Hill equation, were maximum effect (E_MAX ) 0.65 (95%CI 0.54, 0.74), the concentration of acetaminophen associated with 50% of the maximal drug effect (C_50,ACET ) 7.06 (95%CI 7.03, 7.72) mg/L, and the ibuprofen C₅₀ (C_50,IBU ) 3.95 (95%CI 2.57, 7.53) mg/L. The Hill coefficient was 1.48 (95%CI 0.92, 2.62) and an interaction term was fixed at zero (additivity). The half-time (t_1/2 keo) for equilibration between the plasma and effect site was 0.34 hour (95%CI 0.23, 1.98) for acetaminophen and 1.04 hour (95%CI 0.75, 1.77) for ibuprofen. Tramadol had a C_50,TRAM of 0.07 (95%CI 0.048, 1.07) mg/L with a t_1/2 keo,_TRAM 1.78 hour (95%CI 1.06, 1.96).

CONCLUSION

Ibuprofen has an EC₅₀ for analgesia in children similar to that of adults (3.95 mg/L; 95%CI 2.57-7.53, vs 5-10 mg/L adults). The maximum effect from combination therapy (ie, 65% reduction in pain score) achieves satisfactory analgesia with commonly used doses but increased dose adds little additional benefit. The addition of tramadol to this analgesic mixture prolongs analgesia duration.

Effect of Nonsteroidal Anti-inflammatory Drug as an Oral Premedication on the Anesthetic Success of Inferior Alveolar Nerve Block in Treatment of Irreversible Pulpitis: A Systematic Review with Meta-analysis and Trial Sequential Analysis

INTRODUCTION

Successful anesthesia with an inferior alveolar nerve block (IANB) is imperative for treating patients with irreversible pulpitis in mandibular teeth. This systematic review assessed the efficacy of nonsteroidal anti-inflammatory drugs (NSAIDs) as oral premedications on the success of IANBs in irreversible pulpitis.

METHODS

Three databases were searched to identify randomized clinical trials (RCTs) published up until September 2017. Retrieved RCTs were evaluated using the revised Cochrane Risk of Bias Tool. The primary efficacy outcome of interest was the success rate of IANB anesthesia. Meta-analytic estimates (risk ratio [RR] with 95% confidence intervals [CIs]) performed using a random effects model and publication bias determined using funnel plot analysis were assessed. Random errors were evaluated with trial sequential analyses, and the quality of evidence was appraised using a Grading of Recommendations, Assessment, Development and Evaluation approach.

RESULTS

Thirteen RCTs (N = 1034) were included. Eight studies had low risk of bias. Statistical analysis of good-quality RCTs showed a significant beneficial effect of any NSAID in increasing the anesthetic success of IANBs compared with placebo (RR = 1.92; 95% CI, 1.55-2.38). Subgroup analyses showed a similar beneficial effect for ibuprofen, diclofenac, and ketorolac (RR = 1.83 [95% CI, 1.43-2.35], RR = 2.56 [95% CI, 1.46-4.50], and RR = 2.07 [95% CI, 1.47-2.90], respectively). Dose-dependent ibuprofen >400 mg/d (RR = 1.85; 95% CI, 1.39-2.45) was shown to be effective; however, ibuprofen ≤400 mg/d showed no association (RR = 1.78; 95% CI, 0.90-3.55). TSA confirmed conclusive evidence for a beneficial effect of NSAIDs for IANB premedication. The Grading of Recommendations, Assessment, Development and Evaluation approach did not reveal any concerns regarding the quality of the results.

CONCLUSIONS

Oral premedication with NSAIDs and ibuprofen (>400 mg/d) increased the anesthetic success of IANBs in patients with irreversible pulpitis.

A Randomized Double-Blind Controlled Trial of Intravenous Meloxicam in the Treatment of Pain Following Dental Impaction Surgery

This randomized, controlled phase 2 study was conducted to evaluate the analgesic efficacy, safety, and tolerability of single intravenous (IV) doses of 15 mg, 30 mg, and 60 mg meloxicam compared with oral ibuprofen 400 mg and placebo after dental impaction surgery. The primary efficacy end point was the sum of time‐weighted pain intensity differences for 0‐24 hours postdose. Among 230 evaluable subjects, meloxicam IV 60 mg produced the greatest reduction in pain, followed by the 30‐mg and 15‐mg doses. Statistically significant differences in summed pain intensity differences over 24 hours were demonstrated for each active‐treatment group vs placebo (favoring active treatment) and for meloxicam IV 30 mg and 60 mg vs ibuprofen 400 mg (favoring meloxicam IV). Moreover, there was a statistically significant dose response for meloxicam IV 15 mg to 60 mg. The onset of action for meloxicam IV was rapid and sustained; significant differences in pain intensity differences were detected as early as 10 minutes postdose and lasted through the 24‐hour postdose period. Subjects in the meloxicam IV groups were more likely than placebo recipients to achieve perceptible and meaningful pain relief and were less likely to use rescue medication. Patient‐reported global evaluation showed that meloxicam IV 60 mg had the highest rating. There were no deaths, serious adverse events, or discontinuations due to adverse events. The incidence of subjects with ≥1 treatment‐emergent adverse event was greatest in the placebo group, followed by the groups that received ibuprofen, meloxicam IV 15 mg, 30 mg, and 60 mg. Nausea was the most commonly reported treatment‐emergent adverse event. Clinical trial registration number: NCT00945763.

Factors associated with efficacy of an ibuprofen/pseudoephedrine combination drug in pharmacy customers with common cold symptoms

AIM

The aim of this study was to explore factors affecting efficacy of treatment of common cold symptoms with an over-the-counter ibuprofen/pseudoephedrine combination product.

METHODS

Data from an anonymous survey among 1770 pharmacy customers purchasing the combination product for treatment of own common cold symptoms underwent post-hoc descriptive analysis. Scores of symptoms typically responsive to ibuprofen (headache, pharyngeal pain, joint pain and fever), typically responsive to pseudoephedrine (congested nose, congested sinus and runny nose), considered non-specific (sneezing, fatigue, dry cough, cough with expectoration) and comprising all 11 symptoms were analysed. Multiple regression analysis was applied to explore factors associated with greater reduction in symptom intensity or greater probability of experiencing a symptom reduction of at least 50%.

RESULTS

After intake of first dose of medication, typically ibuprofen-sensitive, pseudoephedrine-responsive, non-specific and total symptoms were reduced by 60.0%, 46.3%, 45.4% and 52.8%, respectively. A symptom reduction of at least 50% was reported by 73.6%, 55.1%, 50.9% and 61.6% of participants, respectively. A high baseline score was associated with greater reductions in symptom scores but smaller probability of achieving an improvement of at least 50%. Across both multiple regression approaches, two tablets at first dosing were more effective than one and (except for ibuprofen-sensitive symptoms) starting treatment later than day 2 of the cold was generally less effective.

DISCUSSION AND CONCLUSIONS

Efficacy of an ibuprofen/pseudoephedrine combination in the treatment of common cold symptoms was dose-dependent and greatest when treatment started within the first 2 days after onset of symptoms.

Acute Pain Management

Acute pain management is improving steadily over the past few years, but training and professional education are still lacking in many professions. Untreated or undertreated acute pain could have detrimental effects on the patient in terms of comfort and recovery from trauma or surgery. Acute undertreated pain can decrease a patient's vascular perfusion, increase oxygen demand, suppress the immune system, and possibly risk increased incidence of venous thrombosis. Although acute postoperative pain needs to be managed aggressively, patients are most vulnerable during this period for developing adverse effects, and therefore, patient assessment and careful drug therapy evaluation are necessary processes in therapeutic planning. Acute pain management requires careful and thorough initial assessment and follow-up reassessment in addition to frequent dosage adjustments, and managing analgesic induced side effects. Analgesic selection and dosing must be based on the patient's past and recent analgesic exposure. There is no single acute pain management regimen that is suitable for all patients. Analgesics must be tailored to the individual patient.

Combination paracetamol and ibuprofen for pain relief after oral surgery: a dose ranging study

PURPOSE

Combined paracetamol and ibuprofen has been shown to be more effective than either constituent alone for acute pain in adults, but the dose-response has not been confirmed. The aim of this study was to define the analgesic dose-response relationship of different potential doses of a fixed dose combination containing paracetamol and ibuprofen after third molar surgery.

METHODS

Patients aged 16 to 60 years with moderate or severe pain after the removal of at least two impacted third molars were randomised to receive double-blind study medication as two tablets every 6 h for 24 h of either of the following: two tablet, combination full dose (paracetamol 1000 mg and ibuprofen 300 mg); one tablet, combination half dose (paracetamol 500 mg and ibuprofen 150 mg); half a tablet, combination quarter dose (paracetamol 250 mg and ibuprofen 75 mg); or placebo. The primary outcome measure was the time-adjusted summed pain intensity difference over 24 h (SPID 24) calculated from the 100-mm VAS assessments collected over multiple time points for the study duration.

RESULTS

Data from 159 patients were included in the analysis. Mean (SD) time-adjusted SPID over 24 h were full-dose combination 20.1 (18.0), half dose combination 20.4 (20.8), quarter dose combination 19.3 (20.0) and placebo 6.6 (19.8). There was a significant overall effect of dose (p = 0.002) on the primary outcome. Planned pairwise comparisons showed that all combination dose groups were superior to placebo (full dose vs. placebo p = 0.004, half dose vs. placebo p = 0.002, quarter dose vs. placebo p = 0.002). The overall effect of dose was also significant for maximum VAS pain intensity score (p = 0.048), response rate (p = 0.0094), percentage of participants requiring rescue (p = 0.025) and amount of rescue (p < 0.001). No significant dose effect was found for time to peak reduction in VAS or time to meaningful pain relief. The majority of adverse events recorded were of mild (52.75%) or moderate (40.16%) severity and not related (30.7%) or unlikely related (57.5%) to the study medication.

CONCLUSION

All doses of the combination provide safe superior pain relief to placebo in adult patients following third molar removal surgery.

Comparative study of intravenous Tramadol versus Ketorolac for preventing postoperative pain after third molar surgery--a prospective randomized study

The aim of this comparative, prospective, randomized, controlled study was to evaluate two different regimens of analgesics: a preoperative intravenous dose of either Tramadol or Ketorolac given 10 min prior to surgery to assess their impact on clinical recovery after third molar surgery. Forty patients requiring surgical extraction of unilateral impacted mandibular third molars similar in position were enrolled in the study. Patients were randomly divided into two groups based on permuting the numbers. Patients in Group 1 and Group 2 were administered either Tramadol 50 mg or Ketorolac 30 mg, intravenously, 10 min prior to surgery. The difference in postoperative pain was assessed by four primary points: pain intensity as measured by a 10 mm visual analogue scale hourly for 12 h, median time to rescue analgesics, number of analgesics consumed and patient's overall 5-point global assessment scale. Throughout the 12 h investigation period, patients treated with Ketorolac reported significantly lower pain intensity scores, significantly longer time to rescue analgesics (Acetaminophen 500 mg) and less intake of postoperative analgesics. In Group 2, 40% of the patient had good overall assessment as compared to Group 1 where only 25% of patients had good overall assessment. The current study shows that pre-emptive use of Inj. Ketorolac 30 mg intravenously can reduce the severity of the postoperative sequelae of asymptomatic impacted mandibular third molar surgery.

Surgical suture assembled with polymeric drug-delivery sheet for sustained, local pain relief

Surgical suture is a strand of biocompatible material designed for wound closure, and therefore can be a medical device potentially suitable for local drug delivery to treat pain at the surgical site. However, the preparation methods previously introduced for drug-delivery sutures adversely influenced the mechanical strength of the suture itself - strength that is essential for successful wound closure. Thus, it is not easy to control drug delivery with sutures, and the drug-delivery surgical sutures available for clinical use are now limited to anti-infection roles. Here, we demonstrate a surgical suture enabled to provide controlled delivery of a pain-relief drug and, more importantly, we demonstrate how it can be fabricated to maintain the mechanical strength of the suture itself. For this purpose, we separately prepare a drug-delivery sheet composed of a biocompatible polymer and a pain-relief drug, which is then physically assembled with a type of surgical suture that is already in clinical use. In this way, the drug release profiles can be tailored for the period of therapeutic need by modifying only the drug-loaded polymer sheet without adversely influencing the mechanical strength of the suture. The drug-delivery sutures in this work can effectively relieve the pain at the surgical site in a sustained manner during the period of wound healing, while showing biocompatibility and mechanical properties comparable to those of the original surgical suture in clinical use.

DUEXIS(®) (ibuprofen 800 mg, famotidine 26.6 mg): a new approach to gastroprotection for patients with chronic pain and inflammation who require treatment with a nonsteroidal anti-inflammatory drug

Chronic pain conditions affect at least 116 million US adults and more than one-third of adults worldwide. Nonsteroidal anti-inflammatory drugs (NSAIDs) are used extensively for the treatment of chronic pain due to their efficacy as anti-inflammatory and analgesic agents. Gastrointestinal toxicity is the most well known adverse effect of NSAID therapy and it may manifest as dyspepsia, ulcers, or bleeding. Current guidelines for the management of patients who require NSAIDs for chronic pain and inflammation recognize the potential toxicity associated with these drugs and the need for gastroprotection. DUEXIS(®) (ibuprofen 800 mg, famotidine 26.6 mg) is a proprietary combination, immediate release tablet containing 800 mg of ibuprofen and 26.6 mg of famotidine. The efficacy of DUEXIS(®) taken three times daily has been demonstrated in two large-scale controlled clinical trials (Registration Endoscopic Studies to Determine Ulcer Formation of HZT-501 Compared with Ibuprofen: Efficacy and Safety Studies (REDUCE) and REDUCE-2) which showed that this new formulation significantly reduced the risk of endoscopic upper gastrointestinal ulcers compared with ibuprofen alone (REDUCE-1, p < 0.0001, REDUCE-2, p <0.05). DUEXIS(®) was also superior to ibuprofen in decreasing the risk for gastric ulcers (REDUCE-1, p < 0.001, REDUCE-2, p < 0.05) as well as duodenal ulcers (REDUCE-1, p < 0.05, REDUCE-2, p < 0.05). Safety results from these two studies indicated that treatment-emergent adverse events occurred in 55% of patients treated with DUEXIS(®)versus 58.7% for ibuprofen, and serious adverse events were recorded for 3.2% of patients treated with DUEXIS(®)versus 3.3% of those on ibuprofen. Adverse events leading to discontinuation occurred in 6.7% of patients treated with DUEXIS(®) and 7.6% for ibuprofen. The combination of ibuprofen and famotidine in a single tablet has the potential to improve adherence to gastroprotective therapy in patients who require NSAID treatment and the use of a histamine type 2 receptor antagonist rather than a proton-pump inhibitor may decrease the risk for clinically significant drug interactions and adverse events (e.g. interaction with clopidogrel, fracture, pneumonia, Clostridium difficile infection).

Combined acetaminophen and ibuprofen for pain relief after oral surgery in adults: a randomized controlled trial

Background

Acetaminophen is often used with a non-steriodal anti-inflammatory drug for acute pain. Hitherto, these drugs have had to be given separately, typically at different time intervals. Maxigesic^® tablets combine acetaminophen and ibuprofen in clinically appropriate doses to simplify administration and dosage regimen. We compared this combination with each of the constituent drugs for the relief of pain after extraction of third molar teeth.

Methods

Adults (more than 16 yr) having one or more wisdom teeth removed under general or local anaesthesia were instructed to take two tablets before operation, then two tablets every 6 h for up to 48 h of: (i) a combination of acetaminophen 500 mg and ibuprofen 150 mg per tablet (Maxigesic^®); (ii) acetaminophen 500 mg per tablet alone; or (iii) ibuprofen 150 mg per tablet alone. The primary outcome measure was the area under the curve (AUC) of the 100 mm visual analogue scale pain measurements taken for up to 48 h after surgery, divided by time, at rest and on activity. Pharmacokinetic data were collected in a subset of patients.

Results

The mean (sem) time-corrected AUC on rest and activity, respectively, were: combination group 22.3 (3.2) and 28.4 (3.4); acetaminophen group 33.0 (3.1) and 40.4 (3.3); and ibuprofen group 34.8 (3.2) and 40.2 (3.4); P<0.01 for each of the four comparisons of combination vs constituent drug. There was no pharmacokinetic interaction between acetaminophen and ibuprofen administered together.

Conclusions

Maxigesic^® tablets provide superior pain relief after oral surgery to acetaminophen or ibuprofen alone.

Single dose oral ibuprofen for acute postoperative pain in adults

BACKGROUND

This review updates a 1999 Cochrane review showing that ibuprofen at various doses was effective in postoperative pain in single dose studies designed to demonstrate analgesic efficacy. New studies have since been published. Ibuprofen is one of the most widely used non-steroidal anti-inflammatory (NSAID) analgesics both by prescription and as an over-the-counter medicine. Ibuprofen is used for acute and chronic painful conditions.

OBJECTIVES

To assess analgesic efficacy of ibuprofen in single oral doses for moderate and severe postoperative pain in adults.

SEARCH STRATEGY

We searched Cochrane CENTRAL, MEDLINE, EMBASE and the Oxford Pain Relief Database for studies to May 2009.

SELECTION CRITERIA

Randomised, double blind, placebo-controlled trials of single dose orally administered ibuprofen (any formulation) in adults with moderate to severe acute postoperative pain.

DATA COLLECTION AND ANALYSIS

Two review authors independently assessed trial quality and extracted data. Pain relief or pain intensity data were extracted and converted into the dichotomous outcome of number of participants with at least 50% pain relief over 4 to 6 hours, from which relative risk and number-needed-to-treat-to-benefit (NNT) were calculated. Numbers of participants using rescue medication over specified time periods, and time to use of rescue medication, were sought as additional measures of efficacy. Information on adverse events and withdrawals were collected.

MAIN RESULTS

Seventy-two studies compared ibuprofen and placebo (9186 participants). Studies were predominantly of high reporting quality, and the bulk of the information concerned ibuprofen 200 mg and 400 mg. For at least 50% pain relief compared with placebo the NNT for ibuprofen 200 mg (2690 participants) was 2.7 (2.5 to 3.0) and for ibuprofen 400 mg (6475 participants) it was 2.5 (2.4 to 2.6). The proportion with at least 50% pain relief was 46% with 200 mg and 54% with 400 mg. Remedication within 6 hours was less frequent with higher doses, with 48% remedicating with 200 mg and 42% with 400 mg. The median time to remedication was 4.7 hours with 200 mg and 5.4 hours with 400 mg. Sensitivity analysis indicated that pain model and ibuprofen formulation may both affect the result, with dental impaction models and soluble ibuprofen salts producing better efficacy estimates. Adverse events were uncommon, and not different from placebo.

AUTHORS' CONCLUSIONS

The very substantial amount of high quality evidence demonstrates that ibuprofen is an effective analgesic in treating postoperative pain. NNTs for 200 mg and 400 mg ibuprofen did not change significantly from the previous review even when a substantial amount of new information was added. New information is provided on remedication.

Articaine and mepivacaine efficacy in postoperative analgesia for lower third molar removal: a double-blind, randomized, crossover study

OBJECTIVE

Comparison of the clinical efficacy of 4% articaine in relation to 2% mepivacaine, both with 1:100,000 epinephrine, in the prevention of postoperative pain after lower third molar removal.

STUDY DESIGN

Twenty patients underwent removal of bilateral lower third molars under local anesthesia (articaine or mepivacaine) in 2 separate appointments, in a double-blind, randomized, and crossed manner. Objective and subjective parameters were recorded for paired comparison of postoperative courses.

RESULTS

Duration of analgesia provided by articaine and mepivacaine was 198.00 +/- 25.86, and 125.40 +/- 13.96 min, respectively (P = .02), whereas the duration of anesthesia was 273.80 +/- 15.94 and 216.85 +/- 20.15 min, respectively (P = .06). Both solutions exerted no important effects upon arterial pressure, heart rate, or oxygen saturation (P > .05).

CONCLUSIONS

Articaine provides a longer period of analgesic effect and a tendency for a longer period of anesthesia as compared to mepivacaine. The presence of a vasoconstrictor agent in local anesthetic solutions does not seem to influence hemodynamic parameters during lower third molar removal in healthy subjects.

Efficacy and safety of over-the-counter analgesics in the treatment of common cold and flu

RATIONALE

Common cold and flu are the most common human illnesses, and over-the-counter (OTC) analgesics are widely used to treat the pain and fever symptoms. Despite the every day use of these analgesic there is little information available in the literature on the efficacy and safety of these medicines in treating colds and flu symptoms. The aim of this review was to determine the safety and efficacy of the analgesics, aspirin, paracetamol and aspirin for the treatment of colds and flu.

METHODS

Electronic databases and a personal database were searched and the information retrieved together with information from relevant textbooks has been integrated in the review.

RESULTS

The literature search established that there is relatively little information on the use of analgesics in treating colds and flu and that much of the safety and efficacy data must be related to other pain and fever models. The review establishes that aspirin, paracetamol and ibuprofen are safe in OTC doses and that there is no evidence for any difference between the medicines as regards efficacy and safety for treatment of colds and flu (except in certain cases such as the use of aspirin in feverish children). There is also no evidence that these medicines prolong the course of colds and flu by any effect on the immune system or by reducing fever.

CONCLUSION

Despite the lack of clinical data on the safety and efficacy of analgesics for the treatment of colds and flu symptoms a case can be made that these medicines are safe and effective for treatment of these common illnesses.

Dose-response in direct comparisons of different doses of aspirin, ibuprofen and paracetamol (acetaminophen) in analgesic studies

AIMS

Establishing the dose-response relationship for clinically useful doses of aspirin, ibuprofen and paracetamol has been difficult. Indirect comparison from meta-analysis is compromised by too little information at some doses.

METHODS

A systematic review of randomized, double-blind trials in acute pain comparing different doses of aspirin, ibuprofen and paracetamol was therefore undertaken.

RESULTS

Fifty trials were found. Numerical superiority of higher over lower dose was found by the original authors in 37/50 trials (74%) and statistical superiority in 11/50 (22%). Twenty-eight trials had design, quality and data reporting characteristics to allow pooling of common doses; in 3/28 (11%) of the individual trials our calculations showed statistical superiority of higher over lower dose. Pooled comparison of 1000/1200 mg aspirin over 500/600 mg was statistically superior, with a number-needed-to-treat (NNT) for higher over lower dose of 16 (8 to > 100). Pooled comparison of 400 mg ibuprofen over 200 mg was statistically superior, with an NNT for higher over lower dose of 10 (6-23). Pooled comparison of 1000 mg paracetamol over 500 mg was statistically superior, with an NNT for higher over lower dose of 9 (6-20).

CONCLUSIONS

Use of trials making direct comparison of two different doses of target drugs revealed the underlying dose-response curve for clinical analgesia.

[Study of the extent and rate of bioavailability of ibuprofen tablets]

The extent and rate of bioavailability of ibuprofen tablets were determined in a crossover clinical trial in 18 healthy subjects of both sexes. The study was approved by the local ethical committee and was authorized by the Spanish Medicines Agency. Volunteers signed an informed consent form and were included in accordance with the standard procedures for this type of study. In two distinct sessions participants received a single 600 mg ibuprofen dose as Gelofeno(®) 600 mg tablets (Laboratorios Gelos S.L.), or as the reference formulation, Neobrufen(®) 600 mg tablets. Ibuprofen concentrations in plasma were determined immediately before (0 h) and 0.25, 0.5, 0.75, 1, 1.5, 2, 2.5, 3, 4, 6, 8, 10, 12 and 24 h after drug administration. The pharmacokinetic parameters were then calculated. In all subjects, Gelofeno(®) 600 mg tablets produced plasma concentrations above the quantification limit between 15 and 30 minutes after administration, and in 9 (50%) of these subjects maximal plasma concentrations were reached at 1 h. The median t(max) was 1.25 h, and the average maximal plasma concentration was 40.7 mg/l. Gelofeno(®) 600 mg tablets were bioequivalent both in extent and in rate of bioavailability compared with the reference drug. The formulation showed good tolerability and no medication-related adverse effects were observed.

COX-dependent mechanisms involved in the antinociceptive action of NSAIDs at central and peripheral sites

Despite the diverse chemical structure of aspirin-like drugs, the antinociceptive effect of NSAIDs is mainly due to their common property of inhibiting cyclooxygenases involved in the formation of prostaglandins. Prostaglandins are potent hyperalgesic mediators which modulate multiple sites along the nociceptive pathway and enhance both transduction (peripheral sensitizing effect) and transmission (central sensitizing effect) of nociceptive information. Inhibition of the formation of prostaglandins at peripheral and central sites by NSAIDs thus leads to the normalisation of the increased pain threshold associated with inflammation. The contribution of peripheral and central mechanisms to the overall antinociceptive action of NSAIDs depends on several factors including the location of the targets of drug action, the site of drug delivery and the uptake and distribution to the site of action. The present work reviews the data on the regulation and location of cyclooxygenases at central and peripheral sites of the nociceptive pathway and focuses on the role of COX in the generation and maintenance of pain hypersensitivity. Experimental and clinical evidences are used to evaluate the significance of the peripheral and central antihyperalgesic effects of NSAIDs.

Addition of ibuprofen to pseudoephedrine and chlorpheniramine in the treatment of seasonal allergic rhinitis

BACKGROUND

Patients with seasonal allergic rhinitis experience many nasal and concomitant nonnasal symptoms. Many patients also experience headaches and facial pain, pressure, or discomfort. Standard over-the-counter therapy with antihistamines and nasal decongestants often does not completely relieve all symptoms associated with allergic rhinitis.

OBJECTIVE

To establish the contribution of ibuprofen when used with pseudoephedrine and chlorpheniramine, a standard over-the-counter regimen, to relieve the symptoms of seasonal allergic rhinitis.

METHODS

In this 7-day, multicenter, randomized, placebo-controlled, double-blind, double-dummy, parallel-group trial, qualified subjects were randomly assigned to 1 of 4 treatment groups that received combined ibuprofen/pseudoephedrine/chlorpheniramine (200/30/2 mg or 400/60/4 mg), combined pseudoephedrine/chlorpheniramine (30/2 mg), or placebo. Therapy began when the subject experienced a minimum of moderate allergy-associated pain, and it continued 3 times a day for 7 consecutive days.

RESULTS

Mean pain intensity reduction in both ibuprofen/pseudoephedrine/chlorpheniramine treatment groups was 40% greater than in the placebo group and 33% greater than in the pseudoephedrine/chlorpheniramine treatment group (P < .001). Mean changes from baseline in total and nonpain symptom scores for both ibuprofen/pseudoephedrine/chlorpheniramine doses were significantly greater than for placebo (P < .001) and pseudoephedrine/chlorpheniramine (P < .001-.05) but were not different from each other. Ibuprofen enhanced the chlorpheniramine and pseudoephedrine effects, resulting in incremental 33% to 34% pain relief and 17% to 22% allergy symptom relief compared with pseudoephedrine/chlorpheniramine.

CONCLUSIONS

In both doses of the triple combination, ibuprofen added to the effects of chlorpheniramine and pseudoephedrine, resulting in superior relief of pain and all nonpain allergy symptoms compared with pseudoephedrine/chlorpheniramine treatment. Furthermore, the superior efficacy of the lower dose of the triple combination allowed for a decrease in the incidence of adverse effects.

Efficacy and tolerability of nonprescription ibuprofen versus celecoxib for dental pain

Many clinicians appear confused about the purported clinical advantages of the new generation COX-2 inhibitors compared to both over-the-counter and prescription nonsteroidal anti-inflammatory analgesic agents (NSAIDs). Infact, there is a paucity of published information comparing the safety and efficacy of these two classes of drugs when used to treat acute pain. This study was designed to compare the safety and analgesic efficacy of an over-the-counter (OTC) analgesic, ibuprofen (Advil Liqui-Gels), to the leading prescription COX-2 inhibitor celecoxib (Celebrex). Ibuprofen liquigel is an encapsulated, solubilized potassium salt of ibuprofen that has a higher Cmax and shorter tmax than traditional ibuprofen solid-dosage formulations. This trial evaluated the maximum approved OTC dosing regimen (400 mg x 3, q4-6h) of ibuprofen liquigels compared to a single dose of celecoxib (200 mg) and placebo in 174 patients with moderate orsevere pain following surgical extraction of impacted third molars. The study design was multiple dose, randomized (stratified by baseline pain and gender), placebo controlled, double blind, double dummy, and parallel group. The onset of pain relief was determined using a two-stopwatch procedure. Treatments were also compared using standard indices of pain intensity and pain relief. The study demonstrated assay sensitivity in that both active medications were significantly more effective than placebo for all efficacy measures. In comparing the two active medications, the time to meaningful relief was significantly shorter, and the mean 4-, 8-, and 12-hour summed pain relief combined with pain intensity difference scores were significantly higher for ibuprofen liquigels compared with celecoxib (p < 0.001). Analyses of other key efficacy variables, including the time to rescue medication and the patients' overall assessment of study medication, confirmed the superior efficacy of ibuprofen liquigels over celecoxib. Both active treatments were well tolerated, with no differences in incidence or severity of adverse events. Of particular interest, there were no differences in gastrointestinal-related side effects when comparing these doses of ibuprofen liquigels to celecoxib. In conclusion, ibuprofen liquigels were a significantly more effective analgesic and provided relief significantly faster compared with celecoxib in the treatment of postsurgical pain.

Ibuprofen liquigel for oral surgery pain

BACKGROUND

Ibuprofen liquigel is a solubilized potassium ibuprofen 200-mg gelatin capsule formulation that was approved for over-the-counter use in 1995.

OBJECTIVE

This study compared the analgesic efficacy and tolerability of ibuprofen liquigel 200 mg, ibuprofen liquigel 400 mg, acetaminophen caplets 1000 mg, and placebo in patients experiencing moderate or severe pain after surgical removal of impacted third molars.

METHODS

This randomized, double-blind, parallel-group, 6-hour study was conducted in 210 patients experiencing moderate or severe postoperative pain. Ratings of pain intensity and pain relief were recorded every 15 minutes for the first hour, at 90 and 120 minutes, and then hourly through hour 6. The onsets of first perceptible relief and meaningful relief were recorded using 2 stopwatches. An analysis of variance model was employed to test for significant differences (P < or = 0.05) between treatment groups with respect to pain relief, pain intensity difference, total pain relief (TOTPAR), and summed pain intensity difference (SPID). Stopwatch measures were analyzed using the Cox proportional hazards model. Drug tolerability was assessed by monitoring the occurrence of adverse events.

RESULTS

During the first 2 hours of the study (TOTPAR 2 and SPID 2), all active treatments were significantly more efficacious than placebo (P < 0.001), with ibuprofen liquigel 200 and 400 mg significantly more efficacious than acetaminophen 1000 mg (P < 0.05 and P < 0.01, respectively). For the entire duration of the study (TOTPAR 6 and SPID 6), only the 2 doses of ibuprofen liquigel were significantly more efficacious than placebo (P < 0.001). Ibuprofen liquigel 200 and 400 mg were also significantly more efficacious than acetaminophen 1000 mg on the summary measures TOTPAR 6 and SPID 6 (P < 0.01 and P < 0.001, respectively). Analysis of the stopwatch data revealed that all active treatments displayed significantly more rapid onsets to confirmed first perceptible relief (P < 0.001 to < 0.05) and meaningful relief (P < 0.001 to < 0.01) than did placebo, with ibuprofen liquigel 400 mg displaying a significantly more rapid onset to meaningful relief than acetaminophen 1000 mg (P < 0.05) and a significantly more rapid onset to confirmed first perceptible relief than acetaminophen 1000 mg (P < 0.001) and ibuprofen liquigel 200 mg (P < 0.01). All adverse events were considered mild or moderate, with an overall incidence of 11.5% in the ibuprofen liquigel 200-mg group, 6.8% in the ibuprofen liquigel 400-mg group, 19.0% in the acetaminophen 1000-mg group, and 25.9% in the placebo group.

CONCLUSIONS

Ibuprofen liquigel provided greater peak and overall analgesic effects and a more rapid onset to analgesia than did acetaminophen 1000 mg.

Over-the-counter analgesics and antipyretics: a critical assessment

BACKGROUND

It is just 100 years since the introduction of aspirin to medicine. Since then, aspirin and its derivatives have been joined by acetaminophen, and the nonsteroidal anti-inflammatory drugs--ibuprofen, naproxen sodium, and ketoprofen--as the only over-the-counter (OTC) agents approved by the US Food and Drug Administration for the short-term treatment of pain, headache, dysmenorrhea, and fever. Recently the prescription use of aspirin has expanded to include a number of antiplatelet indications.

OBJECTIVE

The purpose of this paper is to review critically the history, mechanisms of action, efficacy, and tolerability of OTC analgesic and antipyretic products. Relatively new and potential future indications for these drugs are also discussed.

CONCLUSION

Although all of the OTC analgesic/antipyretic agents seem to share a common mechanism of prostaglandin inhibition, there are important differences in their pharmacology, efficacy, and side-effect profiles. Considering their often-unsupervised use, the risk-benefit ratio of this class of drugs has been extremely favorable. However, when used inappropriately, even these drugs pose significant risks to certain patient populations.

Distributions of individual susceptibility among humans for toxic effects. How much protection does the traditional tenfold factor provide for what fraction of which kinds of chemicals and effects?

A significant data base has been assembled on human variability in parameters representing a series of steps in the pathway from external exposure to the production of biological responses: contact rate (e.g., breathing rates/body weight, fish consumption/body weight); uptake or absorption (mg/kg)/intake or contact rate; general systemic availability net of first pass elimination and dilution; systemic elimination or half-life; active site availability/general systemic availability; physiological parameter change/active site availability; functional reserve capacity--change in baseline physiological parameter needed to pass a criterion of abnormal function or exhibit a response. This paper discusses the current results of analyzing these data to derive estimates for distributions of human susceptibility to different routes of exposure and types of adverse effects. The degree of protection is tentatively evaluated by projecting the incidences of effects that would be expected for a tenfold lowering of exposure from a 5% incidence level if the population distribution of susceptibility were truly log-normal out to the extreme tails, and if the populations, chemicals, and responses that gave rise to the underlying data were representative of the cases to which traditional uncertainty factor is applied. The results indicate that, acting by itself, a tenfold reduction in dose from a 5% effect level is associated with effect incidences ranging from slightly less than one in ten thousand, for a median chemical/response, to a few per thousand, for chemicals and responses that have greater human interindividual variability than 19 out of 20 typical chemicals/responses. In practice, for many of the cases where the traditional tenfold factor is applied, additional protection is provided by other uncertainty factors. Nevertheless, the results generate some reason for concern that current application of traditional safety or uncertainty factor approaches may allow appreciable incidences of responses in some cases.

Single dose oral ibuprofen and diclofenac for postoperative pain

BACKGROUND

Ibuprofen and diclofenac are two widely used non-steroidal anti-inflammatory (NSAID) analgesics. It is therefore important to know which drug should be recommended for postoperative pain relief. This review seeks to compare the relative efficacy of the two drugs, and also considers the issues of safety and cost.

OBJECTIVES

To assess the analgesic efficacy of ibuprofen and diclofenac in single oral doses for moderate to severe postoperative pain.

SEARCH STRATEGY

Randomised trials were identified by searching Medline (1966 to December 1996), Embase (1980 to January 1997), the Cochrane Library (Issue 3 1996), Biological Abstracts (January 1985 to December 1996) and the Oxford Pain Relief Database (1950 to 1994). Date of the most recent searches: July 1998.

SELECTION CRITERIA

The inclusion criteria used were: full journal publication, postoperative pain, postoperative oral administration, adult patients, baseline pain of moderate to severe intensity, double-blind design, and random allocation to treatment groups which compared either ibuprofen or diclofenac with placebo.

DATA COLLECTION AND ANALYSIS

Data were extracted by two independent reviewers, and trials were quality scored. Summed pain relief or pain intensity difference over four to six hours was extracted, and converted into dichotomous information yielding the number of patients with at least 50% pain relief. This was then used to calculate the relative benefit and the number-needed-to-treat (NNT) for one patient to achieve at least 50% pain relief.

MAIN RESULTS

Thirty-four trials compared ibuprofen and placebo (3,591 patients), six compared diclofenac with placebo (840 patients) and there were two direct comparisons of diclofenac 50 mg and ibuprofen 400 mg (130 patients). In postoperative pain the NNTs for ibuprofen 200 mg were 3.3 (95% confidence interval 2.8 to 4.0) compared with placebo, for ibuprofen 400 mg 2.7 (2.5 to 3.0), for ibuprofen 600 mg 2.4 (1.9 to 3.3), for diclofenac 50 mg 2.3 (2.0 to 2.7) and for diclofenac 100 mg 1.8 (1.5 to 2.1). Direct comparisons of diclofenac 50 mg with ibuprofen 400 mg showed no significant difference between the two.

REVIEWER'S CONCLUSIONS

Both drugs work well. Choosing between them is an issue of dose, safety and cost.