Topical analgesics for acute and chronic pain in adults - an overview of Cochrane Reviews.

BACKGROUND: Topical analgesic drugs are used for a variety of painful conditions. Some are acute, typically strains or sprains, tendinopathy, or muscle aches. Others are chronic, typically osteoarthritis of hand or knee, or neuropathic pain. OBJECTIVES: To provide an overview of the analgesic efficacy and associated adverse events of topical analgesics (primarily nonsteroidal anti-inflammatory drugs (NSAIDs), salicylate rubefacients, capsaicin, and lidocaine) applied to intact skin for the treatment of acute and chronic pain in adults. METHODS: We identified systematic reviews in acute and chronic pain published to February 2017 in the Cochrane Database of Systematic Reviews (the Cochrane Library). The primary outcome was at least 50% pain relief (participant-reported) at an appropriate duration. We extracted the number needed to treat for one additional beneficial outcome (NNT) for efficacy outcomes for each topical analgesic or formulation, and the number needed to treat for one additional harmful outcome (NNH) for adverse events. We also extracted information on withdrawals due to lack of efficacy or adverse events, systemic and local adverse events, and serious adverse events. We required information from at least 200 participants, in at least two studies. We judged that there was potential for publication bias if the addition of four studies of typical size (400 participants) with zero effect increased NNT compared with placebo to 10 (minimal clinical utility). We extracted GRADE assessment in the original papers, and made our own GRADE assessment. MAIN RESULTS: Thirteen Cochrane Reviews (206 studies with around 30,700 participants) assessed the efficacy and harms from a range of topical analgesics applied to intact skin in a number of acute and chronic painful conditions. Reviews were overseen by several Review Groups, and concentrated on evidence comparing topical analgesic with topical placebo; comparisons of topical and oral analgesics were rare.For at least 50% pain relief, we considered evidence was moderate or high quality for several therapies, based on the underlying quality of studies and susceptibility to publication bias.In acute musculoskeletal pain (strains and sprains) with assessment at about seven days, therapies were diclofenac Emulgel (78% Emulgel, 20% placebo; 2 studies, 314 participants, NNT 1.8 (95% confidence interval 1.5 to 2.1)), ketoprofen gel (72% ketoprofen, 33% placebo, 5 studies, 348 participants, NNT 2.5 (2.0 to 3.4)), piroxicam gel (70% piroxicam, 47% placebo, 3 studies, 522 participants, NNT 4.4 (3.2 to 6.9)), diclofenac Flector plaster (63% Flector, 41% placebo, 4 studies, 1030 participants, NNT 4.7 (3.7 to 6.5)), and diclofenac other plaster (88% diclofenac plaster, 57% placebo, 3 studies, 474 participants, NNT 3.2 (2.6 to 4.2)).In chronic musculoskeletal pain (mainly hand and knee osteoarthritis) therapies were topical diclofenac preparations for less than six weeks (43% diclofenac, 23% placebo, 5 studies, 732 participants, NNT 5.0 (3.7 to 7.4)), ketoprofen over 6 to 12 weeks (63% ketoprofen, 48% placebo, 4 studies, 2573 participants, NNT 6.9 (5.4 to 9.3)), and topical diclofenac preparations over 6 to 12 weeks (60% diclofenac, 50% placebo, 4 studies, 2343 participants, NNT 9.8 (7.1 to 16)). In postherpetic neuralgia, topical high-concentration capsaicin had moderate-quality evidence of limited efficacy (33% capsaicin, 24% placebo, 2 studies, 571 participants, NNT 11 (6.1 to 62)).We judged evidence of efficacy for other therapies as low or very low quality. Limited evidence of efficacy, potentially subject to publication bias, existed for topical preparations of ibuprofen gels and creams, unspecified diclofenac formulations and diclofenac gel other than Emulgel, indomethacin, and ketoprofen plaster in acute pain conditions, and for salicylate rubefacients for chronic pain conditions. Evidence for other interventions (other topical NSAIDs, topical salicylate in acute pain conditions, low concentration capsaicin, lidocaine, clonidine for neuropathic pain, and herbal remedies for any condition) was very low quality and typically limited to single studies or comparisons with sparse data.We assessed the evidence on withdrawals as moderate or very low quality, because of small numbers of events. In chronic pain conditions lack of efficacy withdrawals were lower with topical diclofenac (6%) than placebo (9%) (11 studies, 3455 participants, number needed to treat to prevent (NNTp) 26, moderate-quality evidence), and topical salicylate (2% vs 7% for placebo) (5 studies, 501 participants, NNTp 21, very low-quality evidence). Adverse event withdrawals were higher with topical capsaicin low-concentration (15%) than placebo (3%) (4 studies, 477 participants, NNH 8, very low-quality evidence), topical salicylate (5% vs 1% for placebo) (7 studies, 735 participants, NNH 26, very low-quality evidence), and topical diclofenac (5% vs 4% for placebo) (12 studies, 3552 participants, NNH 51, very low-quality evidence).In acute pain, systemic or local adverse event rates with topical NSAIDs (4.3%) were no greater than with topical placebo (4.6%) (42 studies, 6740 participants, high quality evidence). In chronic pain local adverse events with topical capsaicin low concentration (63%) were higher than topical placebo (5 studies, 557 participants, number needed to treat for harm (NNH) 2.6), high quality evidence. Moderate-quality evidence indicated more local adverse events than placebo in chronic pain conditions with topical diclofenac (NNH 16) and local pain with topical capsaicin high-concentration (NNH 16). There was moderate-quality evidence of no additional local adverse events with topical ketoprofen over topical placebo in chronic pain. Serious adverse events were rare (very low-quality evidence).GRADE assessments of moderate or low quality in some of the reviews were considered by us to be very low because of small numbers of participants and events. AUTHORS' CONCLUSIONS: There is good evidence that some formulations of topical diclofenac and ketoprofen are useful in acute pain conditions such as sprains or strains, with low (good) NNT values. There is a strong message that the exact formulation used is critically important in acute conditions, and that might also apply to other pain conditions. In chronic musculoskeletal conditions with assessments over 6 to 12 weeks, topical diclofenac and ketoprofen had limited efficacy in hand and knee osteoarthritis, as did topical high-concentration capsaicin in postherpetic neuralgia. Though NNTs were higher, this still indicates that a small proportion of people had good pain relief.Use of GRADE in Cochrane Reviews with small numbers of participants and events requires attention.

Aspirin for acute treatment of episodic tension-type headache in adults.

BACKGROUND: Tension-type headache (TTH) affects about 1 person in 5 worldwide. It is divided into infrequent episodic TTH (fewer than one headache per month), frequent episodic TTH (two to 14 headache days per month), and chronic TTH (15 headache days per month or more). Aspirin is one of a number of analgesics suggested for acute treatment of episodic TTH. OBJECTIVES: To assess the efficacy and safety of aspirin for acute treatment of episodic tension-type headache (TTH) in adults compared with placebo or any active comparator. SEARCH METHODS: We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, Embase, and the Oxford Pain Relief Database from inception to September 2016, and also reference lists of relevant published studies and reviews. We sought unpublished studies by asking personal contacts and searching online clinical trial registers and manufacturers' websites. SELECTION CRITERIA: We included randomised, double-blind, placebo-controlled studies (parallel-group or cross-over) using oral aspirin for symptomatic relief of an acute episode of TTH. Studies had to be prospective, with participants aged 18 years or over, and include at least 10 participants per treatment arm. DATA COLLECTION AND ANALYSIS: Two review authors independently assessed studies for inclusion and extracted data. For various outcomes (predominantly those recommended by the International Headache Society (IHS)), we calculated the risk ratio (RR) and number needed to treat for one additional beneficial outcome (NNT), one additional harmful outcome (NNH), or to prevent one event (NNTp) for oral aspirin compared to placebo or an active intervention.We assessed the evidence using GRADE and created a 'Summary of findings' table. MAIN RESULTS: We included five studies enrolling adults with frequent episodic TTH; 1812 participants took medication, of which 767 were included in comparisons of aspirin 1000 mg with placebo, and 405 in comparisons of aspirin 500 mg or 650 mg with placebo. Not all of these participants provided data for outcomes of interest in this review. Four studies specified using IHS diagnostic criteria; one predated commonly recognised criteria, but described comparable characteristics and excluded migraine. All participants treated headaches of at least moderate pain intensity.None of the included studies were at low risk of bias across all domains considered, although for most studies and domains this was likely to be due to inadequate reporting rather than poor methods. We judged one study to be at high risk of bias due to small size.There were no data for aspirin at any dose for the IHS preferred outcome of being pain free at two hours, or for being pain free at any other time, and only one study provided data equivalent to having no or mild pain at two hours (very low quality evidence). Use of rescue medication was lower with aspirin 1000 mg than with placebo (2 studies, 397 participants); 14% of participants used rescue medication with aspirin 1000 mg compared with 31% with placebo (NNTp 6.0, 95% confidence interval (CI) 4.1 to 12) (low quality evidence). Two studies (397 participants) reported a Patient Global Evaluation at the end of the study; we combined the top two categories for both studies to determine the number of participants who were 'satisfied' with treatment. Aspirin 1000 mg produced more satisfied participants (55%) than did placebo (37%) (NNT 5.7, 95% CI 3.7 to 12) (very low quality evidence).Adverse events were not different between aspirin 1000 mg and placebo (RR 1.1, 95% CI 0.8 to 1.5), or aspirin 500 mg or 650 mg and placebo (RR 1.3, 95% CI 0.8 to 2.0) (low quality evidence). Studies reported no serious adverse events.The quality of the evidence using GRADE comparing aspirin doses between 500 mg and 1000 mg with placebo was low or very low. Evidence was downgraded because of the small number of studies and events, and because the most important measures of efficacy were not reported.There were insufficient data to compare aspirin with any active comparator (paracetamol alone, paracetamol plus codeine, peppermint oil, or metamizole) at any of the doses tested. AUTHORS' CONCLUSIONS: A single dose of aspirin between 500 mg and 1000 mg provided some benefit in terms of less frequent use of rescue medication and more participants satisfied with treatment compared with placebo in adults with frequent episodic TTH who have an acute headache of moderate or severe intensity. There was no difference between a single dose of aspirin and placebo for the number of people experiencing adverse events. The amount and quality of the evidence was very limited and should be interpreted with caution.

Non-prescription (OTC) oral analgesics for acute pain - an overview of Cochrane reviews.

BACKGROUND: Non-prescription (over-the-counter, or OTC) analgesics (painkillers) are used frequently. They are available in various brands, package sizes, formulations, and dose. They can be used for a range of different types of pain, but this overview reports on how well they work for acute pain (pain of short duration, usually with rapid onset). Thirty-nine Cochrane reviews of randomised trials have examined the analgesic efficacy of individual drug interventions in acute postoperative pain. OBJECTIVES: To examine published Cochrane reviews for information about the efficacy of pain medicines available without prescription using data from acute postoperative pain. METHODS: We identified OTC analgesics available in the UK, Australia, Canada, and the USA by examining online pharmacy websites. We also included some analgesics (diclofenac potassium, dexketoprofen, dipyrone) of importance in parts of the world, but not currently available in these jurisdictions.We identified systematic reviews by searching the Cochrane Database of Systematic Reviews (CDSR) on The Cochrane Library through a simple search strategy. All reviews were overseen by a single review group, had a standard title, and had as their primary outcome numbers of participants with at least 50% pain relief over four to six hours compared with placebo. From individual reviews we extracted the number needed to treat for an additional beneficial outcome (NNT) for this outcome for each drug/dose combination, and also calculated the success rate to achieve at least 50% of maximum pain relief. We also examined the number of participants experiencing any adverse event, and whether the incidence was different from placebo. MAIN RESULTS: We found information on 21 different OTC analgesic drugs, doses, and formulations, using information from 10 Cochrane reviews, supplemented by information from one non-Cochrane review with additional information on ibuprofen formulations (high quality evidence). The lowest (best) NNT values were for combinations of ibuprofen plus paracetamol, with NNT values below 2. Analgesics with values close to 2 included fast acting formulations of ibuprofen 200 mg and 400 mg, ibuprofen 200 mg plus caffeine 100 mg, and diclofenac potassium 50 mg. Combinations of ibuprofen plus paracetamol had success rates of almost 70%, with dipyrone 500 mg, fast acting ibuprofen formulations 200 mg and 400 mg, ibuprofen 200 mg plus caffeine 100 mg, and diclofenac potassium 50 mg having success rates above 50%. Paracetamol and aspirin at various doses had NNT values of 3 or above, and success rates of 11% to 43%. We found no information on many of the commonly available low dose codeine combinations.The proportion of participants experiencing an adverse event were generally not different from placebo, except for aspirin 1000 mg and (barely) ibuprofen 200 mg plus caffeine 100 mg. For ibuprofen plus paracetamol, adverse event rates were lower than with placebo. AUTHORS' CONCLUSIONS: There is a body of reliable evidence about the efficacy of some of the most commonly available drugs and doses widely available without prescription. The postoperative pain model is predominantly pain after third molar extraction, which is used as the industry model for everyday pain. The proportion of people with acute pain who get good pain relief with any of them ranges from around 70% at best to less than 20% at worst; low doses of some drugs in fast acting formulations were among the best. Adverse events were generally no different from placebo. Consumers can make an informed choice based on this knowledge, together with availability and price. Headache and migraine were not included in this overview.

Interventions for treating persistent and intractable hiccups in adults.

BACKGROUND: Persistent and intractable hiccups (typically defined as lasting for more than 48 hours and one month respectively) can be of serious detriment to a patient's quality of life, although they are relatively uncommon. A wide range of pharmacological and non-pharmacological interventions have been used for the treatment of persistent and intractable hiccups. However, there is little evidence as to which interventions are effective or harmful. OBJECTIVES: The objective of this review was to evaluate the effectiveness of pharmacological and non-pharmacological interventions used in the treatment of persistent and intractable hiccups of any aetiology in adults. SEARCH METHODS: Studies were identified from the following databases: CENTRAL, CDSR, DARE, MEDLINE, EMBASE, CINAHL, PsychINFO and SIGLE (last search March 2012). The search strategy for all the databases searched was based on the MEDLINE search strategy presented in Appendix 1. No additional handsearching of journals was undertaken. Investigators who are known to be carrying out research in this area were contacted for unpublished data or knowledge of the grey literature. SELECTION CRITERIA: Studies eligible for inclusion in this review were randomised controlled trials (RCTs) or controlled clinical trials (CCTs). INCLUSION CRITERIA: adults (over 18 years old) diagnosed with persistent or intractable hiccups (hiccups lasting more than 48 hours), treated with any pharmacological or non-pharmacological intervention. EXCLUSION CRITERIA: less than ten participants; no assessment of change in hiccup frequency or intensity in outcome measures. DATA COLLECTION AND ANALYSIS: Two independent review authors assessed each abstract and title for relevance. Disagreement on eligibility was resolved by discussion. Where no abstract was available the full paper was obtained and assessed. We obtained full copies of the studies which met the inclusion criteria for further assessment. Two review authors independently collected data from each appropriate study and entered them into the software Review Manager 5. Two independent review authors assessed the risk of bias using the RevMan 5 'Risk of bias' table following guidance from the Cochrane Handbook of Systematic Reviews of Interventions (Higgins 2009). MAIN RESULTS: A total of four studies (305 participants) met the inclusion criteria. All of these studies sought to determine the effectiveness of different acupuncture techniques in the treatment of persistent and intractable hiccups. All four studies had a high risk of bias, did not compare the intervention with placebo, and failed to report side effects or adverse events for either the treatment or control groups. Due to methodological differences we were unable to perform a meta-analysis of the results. No studies investigating pharmacological interventions for persistent and intractable hiccups met the inclusion criteria. AUTHORS' CONCLUSIONS: There is insufficient evidence to guide the treatment of persistent or intractable hiccups with either pharmacological or non-pharmacological interventions.The paucity of high quality studies indicate a need for randomised placebo-controlled trials of both pharmacological and non-pharmacological treatments. As the symptom is relatively rare, trials would need to be multi-centred and possibly multi-national.

Evidence-Based Pain Management and Palliative Care in Issue Three for 2007 of The Cochrane Library.

The Cochrane Library of Systematic Reviews is published quarterly. Issue 3 2007 contains 3197 complete reviews, 1744 protocols for reviews in production and 6312 one-page summaries of systematic reviews published in the general medical literature. In addition there are citations of 503,000 randomized controlled trials, and 9628 cited papers in the Cochrane methodology register. The health technology assessment database contains 6817 citations. This edition of the Library contains 103 new reviews of which 11 have potential relevance for practitioners in pain and palliative medicine.

Evidence-Based Pain Management and Palliative Care in Issue Two for 2006 of The Cochrane Library.

The Cochrane Library of Systematic Reviews is published quarterly. It now contains 2674 complete reviews, 1686 protocols for reviews in production and 6019 one page summaries of systematic reviews published in the general medical literature. In addition there are citations of 473,442 randomized controlled trials, 22 methodology reviews and 8255 cited papers in the Cochrane methodology register. The health technology assessment database contains 5648 citations. This edition of the Library contains 66 new reviews of which 4 have potential relevance for practitioners in pain and palliative medicine.

Evidence-based pain management and palliative care in Issue One for 2006 of The Cochrane Library.

The Cochrane Library of Systematic Reviews is published quarterly. It now contains 2608 complete reviews, 1592 protocols of reviews and 5859 one page summaries of systematic reviews published in the general medical literature. In addition there are citations of over 470,000 randomised controlled trials, 20 methodology reviews and 7615 cited papers in the Cochrane methodology register. The health technology assessment database contains 5378 citations. This edition of the Library contains 83 new reviews of which the three have potential relevance for practitioners in pain and palliative medicine. These address opioids for the management of breakthrough (episodic) pain in cancer patients, perioperative ketamine for acute postoperative pain, and superficial heat or cold for low back pain.

Evidence-based pain management and palliative care in issue two for 2004 of the Cochrane Library.

The Cochrane Library of Systematic Reviews is published quarterly. Issue two for 2004 of the library was published in April 2004. The Cochrane Library now contains 1,999 complete reviews, 1,441 protocols of reviews, and 4,645 one-page summaries of systematic reviews published in the general (non-Cochrane) medical literature. In addition there are citations of 405,580 randomized controlled trials, 18 methodology reviews and 5,414 cited papers in the Cochrane methodology register. The health technology assessment database now contains 3,848 citations. This edition of the Library contains the results of an extensive search for randomized controlled trials (RCTs) on EMBASE. The latest library contains 78 new reviews, 10 of which are considered relevant to practitioners in pain and palliative care. References are published in the same format as the citation for Cochrane reviews.