Use of a fixed combination of acetylsalicylic acid, acetaminophen and caffeine compared with acetaminophen alone in episodic tension-type headache: meta-analysis of four randomized, double-blind, placebo-controlled, crossover studies

Paracetamol Combination Therapy for Back Pain and Osteoarthritis: A Systematic Review and Meta-Analyses

BACKGROUND AND OBJECTIVE

Although paracetamol (acetaminophen) combined with other analgesics can reduce pain intensity in some pain conditions, its effectiveness in managing low back pain and osteoarthritis is unclear. This systematic review investigated whether paracetamol combination therapy is more effective and safer than monotherapy or placebo in low back pain and osteoarthritis.

METHODS

Online database searches were conducted for randomised trials that evaluated paracetamol combined with another analgesic compared to a placebo or the non-paracetamol ingredient in the combination (monotherapy) in low back pain and osteoarthritis. The primary outcome was a change in pain. Secondary outcomes were (serious) adverse events, changes in disability and quality of life. Follow-up was immediate (≤ 2 weeks), short (> 2 weeks but ≤ 3 months), intermediate (> 3 months but < 12 months) or long term (≥ 12 months). A random-effects meta-analysis was conducted. Risk of bias was assessed using the original Cochrane tool, and quality of evidence using Grading of Recommendations Assessment, Development and Evaluation (GRADE).

RESULTS

Twenty-two studies were included. Pain was reduced with oral paracetamol plus a non-steroidal anti-inflammatory drug (NSAID) at immediate term in low back pain (paracetamol plus ibuprofen vs ibuprofen [mean difference (MD) - 6.2, 95% confidence interval (CI) -10.4 to -2.0, moderate evidence]) and in osteoarthritis (paracetamol plus aceclofenac vs aceclofenac [MD - 4.7, 95% CI - 8.3 to - 1.2, moderate certainty evidence] and paracetamol plus etodolac vs etodolac [MD - 15.1, 95% CI - 18.5 to - 11.8; moderate certainty evidence]). Paracetamol plus oral tramadol reduced pain compared with placebo at intermediate term for low back pain (MD - 11.7, 95% CI - 19.2 to - 4.3; very low certainty evidence) and osteoarthritis (MD - 6.8, 95% CI - 12.7 to -0.9; moderate certainty evidence). Disability scores improved in half the comparisons. Quality of life was infrequently measured. All paracetamol plus NSAID combinations did not increase the risk of adverse events compared to NSAID monotherapy.

CONCLUSIONS

Low-to-moderate quality evidence supports the oral use of some paracetamol plus NSAID combinations for short-term pain relief with no increased risk of harm for low back pain and osteoarthritis compared to its non-paracetamol monotherapy comparator.

Paracetamol versus ibuprofen in treating episodic tension-type headache: a systematic review and network meta-analysis

Tension-type headache (TTH) is the most common type of headache worldwide. It is defined and classified according to the International Classification of Headache Disorders. TTH is treated with over-the-counter medications, mostly paracetamol or ibuprofen. The purpose was to assess the effectiveness of paracetamol versus ibuprofen in treating episodic tension-type headache (ETTH) through direct and indirect comparisons of randomized controlled trials (RCTs). We included RCTs comparing paracetamol with a placebo, ibuprofen with a placebo, or paracetamol with ibuprofen for acute ETTH treatment that were published between 1988 and 2022. We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, EMBASE, and the Web of Science. The Cochrane Collaboration risk of bias tool was used to assess the risk of bias. We identified 14 studies including 6521 people with ETTH. None of the studies had a low risk of bias for all domains; this was most likely due to inadequate reporting and a small sample size. Ibuprofen (odds ratio (OR): 1.73, 95% confidence interval (CI): 1.17-2.56) showed better efficacy than paracetamol (OR: 1.62, 95% CI 1.24-2.13) for pain-free status at 2 h, while paracetamol (OR: 1.42, 95% CI 0.87-2.30) showed better efficacy than ibuprofen (OR: 1.20, 95% CI 0.58-2.48) for pain-free status at 1 h. Paracetamol was associated with the lowest likelihood of rescue medication use (OR: 0.49, 95% CI 0.37-0.65). Ibuprofen was associated with a lower likelihood of the occurrence of any events and gastrointestinal adverse events compared with placebo and paracetamol (OR: 0.95, 95% CI 0.64-1.41 and OR: 0.81, 95% CI 0.44-1.50, respectively). Paracetamol and ibuprofen showed better efficacy than placebo in treating ETTH; there was no statistically significant difference in efficacy between the two drugs. For individuals at a higher risk (like renal insufficiency or risk of GI bleeding), paracetamol may be considered as a preferred option instead of Ibuprofen. Further meta-analyses of head-to-head trials are needed for direct comparisons in the future.PROSPERO registration number: CRD42022340936.

Debate: differences and similarities between tension-type headache and migraine

Tension-type headache (TTH) and migraine are two common primary headaches distinguished by clinical characteristics according to the 3^rd edition of the International Classification of Headache Disorders. Migraine is identified by specific features such as being more prevalent in females, being aggravated by physical activity, certain genetic factors, having photophobia, phonophobia, nausea, vomiting, or aura, and responding to specific drugs. Nonetheless, TTH and migraine share some common characteristics, such as onset occurring in the 20 s, and being triggered by psychological factors like stress, moderate pain severity, and mild nausea in chronic TTH. Both conditions involve the trigeminovascular system in their pathophysiology. However, distinguishing between TTH and migraine in clinical practice, research, and epidemiological studies can be challenging, as there is a lack of specific diagnostic tests and biomarkers. Moreover, both conditions may coexist, further complicating the diagnostic process. This review aims to explore the similarities and differences in the pathophysiology, epidemiology, burden and disability, comorbidities, and responses to pharmacological and non-pharmacological treatments of TTH and migraine. The review also discusses future research directions to address the diagnostic challenges and improve the understanding and management of these conditions.

Caffeine for Headaches: Helpful or Harmful? A Brief Review of the Literature

Consumption of caffeine in the diet, both daily and occasional, has a significant biological effect on the nervous system. Caffeine, through various and not yet fully investigated mechanisms, affects headaches. This is especially noticeable in migraine. In other headaches such as hypnic headache, post-dural puncture headache and spontaneous intracranial hypotension, caffeine is an important therapeutic agent. In turn, abrupt discontinuation of chronically used caffeine can cause caffeine-withdrawal headache. Caffeine can both relieve and trigger headaches.

The Effect of Coffee in the Prevention of Oral Mucositis Associated with Head and Neck Radiotherapy

AIM

This study investigates the effect of coffee on the management of oral mucositis associated with head and neck radiotherapy.

METHOD

Twenty-nine patients who underwent radiotherapy for the first time due to head and neck cancer between March 2019 and February 2020 were included in the experimental study. One cup/day of Turkish coffee (6 mg) was given to the patients in the intervention group every day for 3 weeks from the first day of radiotherapy. Data monitoring of both groups was performed once a week for 3 weeks.

RESULTS

Most of the patients participating in the study were at local stage (65.2%), and 72.4% underwent head and neck radiotherapy with the diagnosis of nasopharynx and larynx cancer. Although the development rate of oral mucositis was lower in the intervention group, no statistically significant difference was determined (p > 0.05). In the repeated follow-up, the quality of life scores was found to be similar in both groups.

CONCLUSION

We concluded that coffee application is not an effective approach in the prevention of oral mucositis associated with head and neck radiotherapy. Further studies with larger sample sizes are needed to determine the prophylactic effect of coffee in the management of oral mucositis.

Current Understanding of the Pathophysiology and Approach to Tension-Type Headache

PURPOSE OF REVIEW

Description of headache dates back thousands of years, and to date, tension-type headache (TTH) remains the most common form of headache. We will review the history and current understanding of the pathophysiology of TTH and discuss the recommended clinical evaluation and management for this syndrome.

RECENT FINDINGS

Despite being the most prevalent headache disorder, TTH pathophysiology remains poorly understood. Patients with TTH tend to have muscles that are harder, more tender to palpation, and may have more frequent trigger points of tenderness than patients without headache. However, cause and effect of these muscular findings are unclear. Studies support both peripheral and central mechanisms contributing to the pain of TTH. Diagnosis is based on clinical presentation, while the focus of evaluation is to rule out possible secondary causes of headache. Treatment options have remained similar over the course of the past decade, with some additional studies supportive of both pharmacological and non-pharmacological options. An approach to TTH has been outlined including historical context, evolution over time, and the best evidence regarding our current understanding of the complex pathophysiology and treatment of this disease.

Why is the therapeutic effect of acute antimigraine drugs delayed? A review of controlled trials and hypotheses about the delay of effect

In randomised controlled trials (RCTs) of oral drug treatment of migraine attacks, efficacy is evaluated after 2 hours. The effect of oral naratriptan 2.5 mg with a maximum blood concentration (Tmax ) at 2 hours increases from 2 to 4 hours in RCTs. To check whether such a delayed effect is also present for other oral antimigraine drugs, we hand-searched the literature for publications on RCTs reporting efficacy. Two triptans, 3 nonsteroidal anti-inflammatory drugs (NSAIDs), a triptan combined with an NSAID and a calcitonin gene-related peptide receptor antagonist were evaluated for their therapeutic gain with determination of time to maximum effect (Emax ). Emax was compared with known Tmax from pharmacokinetic studies to estimate the delay to pain-free. The delay in therapeutic gain varied from 1-2 hours for zolmitriptan 5 mg to 7 hours for naproxen 500 mg. An increase in effect from 2 to 4 hours was observed after eletriptan 40 mg, frovatriptan 2.5 mg and lasmiditan 200 mg, and after rizatriptan 10 mg (Tmax  = 1 h) from 1 to 2 hours. This strongly indicates a general delay of effect in oral antimigraine drugs. A review of 5 possible effects of triptans on the trigemino-vascular system did not yield a simple explanation for the delay. In addition, Emax for triptans probably depends partly on the rise in plasma levels and not only on its maximum. The most likely explanation for the delay in effect is that a complex antimigraine system with more than 1 site of action is involved.

Administration of Micronized Caffeine Using a Novel Oral Delivery Film Results in Rapid Absorption and Electroencephalogram Suppression

Route of administration is well-known to impact factors ranging from absorption and distribution, up through the subjective effects of active ingredients. Different routes of administration confer specific advantages, such as more rapid absorption resulting from intravenous injection, or increased convenience with oral administration, but a combination of both rapid and convenient delivery is highly desirable. QuickStrip™ was designed as a rapidly dissolving thin film matrix that contains active ingredients, which may be promising for rapid and convenient delivery via the oral mucosa. To assess the delivery of QuickStrip™, we administered the well-characterized active ingredient caffeine to mice and compared QuickStrip™ to standard oral gavage delivery at an equivalent dose of 20 mg kg^-1. Using HPLC assessment of serum concentrations of caffeine, we found that QuickStrip™ delivery resulted in higher serum levels of caffeine at 1, 10, and 30 min following administration compared to gavage. QuickStrip™ also produced greater bioavailability compared to gavage, as demonstrated by area under the curve analysis. Caffeine delivered by QuickStrip™ produced robust behavioral activation of locomotion, consistent with gavage caffeine. Electroencephalographic (EEG) assessment of central nervous system effects demonstrated that both gavage and QuickStrip™ caffeine produced suppression of delta and theta, consistent with prior literature on the effects of caffeine. In addition, QuickStrip™ produced a more rapid onset of EEG suppression, supporting the more rapid absorption demonstrated in the serum studies. Collectively, these studies suggest that QuickStrip™ may provide a balance between convenience and rapid onset, offering new options for delivery of therapeutics.

Results from a pharmacy-based patient survey on the use of a fixed combination analgesic containing acetylsalicylic acid, paracetamol and caffeine by self-diagnosing and self-treating patients

Background

Patients suffering from migraine or tension-type headache (TTH) often treat their complaints with over-the-counter (OTC) medications. Fixed dose combinations of acetylsalicylic acid, paracetamol and caffeine (APC) are among the most commonly used analgesics, and their efficacy for treating acute headache pain has been well demonstrated. This investigation was run to better characterize patients who treat their headache with OTC APC combinations, as well as treatment effects.

Methods

A pharmacy-based patient survey in 164 German pharmacies was performed. Patients (age ≥18 years) who purchased APC analgesics (of the brand Thomapyrin^®) were handed a questionnaire, which had to be filled out at patients own discretion after taking the medication. Demographics, pain characteristics and perceived efficacy and tolerability data were analysed with descriptive statistics.

Results

Questionnaires from 1298 patients were analysed, of whom 71.9 % were females and 28.1 % were males. Headache patients were assigned to TTH or migraine according to diagnosis criteria of the International Headache Classification-II (ICHD-II), with 828 patients for TTH and 206 for migraine. About one third of patients in the subgroup migraine did not report their pain as migraine. Nausea, photophobia/phonophobia turned out to be the most distinguishing feature between migraine and TTH. The main reasons for purchasing the product were recommendation by the pharmacists (40.5 %) and/or friends or relatives (24.4 %). 74 % of TTH and 55 % of migraine patients reported onset of pain relief within the first 30 min. More than 90 % rated efficacy as well as tolerability to be “good” or “very good”.

Conclusions

The main reason for purchasing APC products in the pharmacy are TTH or migraine. About a third of patients fulfilling the IHCD-II criteria for migraine failed to recognize their headache as migraine. This could be explained e.g. by patients’ misconceptions about their pain. Patients’ assessments of efficacy and tolerability showed that the investigated APC combinations are valuable for the treatment of TTH and migraine headache. These data complement those of randomized clinical studies on such preparations.

Paracetamol (acetaminophen) 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 headaches per month), and chronic TTH (15 headache days a month or more). Paracetamol (acetaminophen) is one of a number of analgesics suggested for acute treatment of headaches in frequent episodic TTH.

OBJECTIVES

To assess the efficacy and safety of paracetamol for the acute treatment of frequent episodic TTH in adults.

SEARCH METHODS

We searched the Cochrane Central Register of Controlled Trials (CENTRAL) (CRSO), MEDLINE, EMBASE, and the Oxford Pain Relief Database to October 2015, 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 paracetamol 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. We used the numbers of participants achieving each outcome to calculate the risk ratio (RR) and number needed to treat for one additional beneficial outcome (NNT) or one additional harmful outcome (NNH) for oral paracetamol compared to placebo or an active intervention for a range of outcomes, predominantly those recommended by the International Headache Society (IHS).We assessed the evidence using GRADE (Grading of Recommendations Assessment, Development and Evaluation) and created 'Summary of findings' tables.

MAIN RESULTS

We included 23 studies, all of which enrolled adults with frequent episodic TTH. Twelve studies used the IHS diagnostic criteria or similar, six used the older classification of the Ad Hoc Committee, and five did not describe specific diagnostic criteria but generally excluded participants with migraines. Participants had moderate or severe pain at the start of treatment. While 8079 people with TTH participated in these studies, the numbers available for any analysis were lower than this because outcomes were inconsistently reported and because many participants received active comparators.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 five studies to be at high risk of bias for incomplete outcome reporting, and seven due to small size.For the IHS preferred outcome of being pain free at two hours the NNT for paracetamol 1000 mg compared with placebo was 22 (95% confidence interval (CI) 15 to 40) in eight studies (5890 participants; high quality evidence), with no significant difference from placebo at one hour. The NNT was 10 (7.9 to 14) for pain-free or mild pain at two hours in five studies (5238 participants; high quality evidence). The use of rescue medication was lower with paracetamol 1000 mg than with placebo, with an NNTp to prevent an event of 7.8 (6.0 to 11) in six studies (1856 participants; moderate quality evidence). On limited data, the efficacy of paracetamol 500 mg to 650 mg was not superior to placebo, and paracetamol 1000 mg was not different from either ketoprofen 25 mg or ibuprofen 400 mg (low quality evidence).Adverse events were not different between paracetamol 1000 mg and placebo (RR 1.1 (0.94 to 1.3); 5605 participants; 11 studies; high quality evidence). Studies reported no serious adverse events.The quality of the evidence using GRADE comparing paracetamol 1000 mg with placebo was moderate to high. Where evidence was downgraded it was because a minority of studies reported the outcome. For comparisons of paracetamol 500 mg to 650 mg with placebo, and of paracetamol 1000 mg with active comparators, we downgraded the evidence to low quality or very low quality because of the small number of studies and events.

AUTHORS' CONCLUSIONS

Paracetamol 1000 mg provided a small benefit in terms of being pain free at two hours for people with frequent episodic TTH who have an acute headache of moderate or severe intensity.