Analgesic efficacy of dextropropoxyphene and dextropropoxyphene-containing combinations: a review

Comparative risk-benefit profiles of weak opioids in the treatment of osteoarthritis: a network meta-analysis of randomized controlled trials

BACKGROUND

Despite their poor tolerance, weak opioids are still the most commonly-prescribed medicine for osteoarthritis (OA)-related pain. The objective of this network meta-analysis was to comparatively examine the efficacy and safety of weak opioids in OA treatment.

METHODS

Databases including PubMed, Embase, Cochrane Library and Web of Science were searched from inception to August 5, 2020 to retrieve randomized controlled trials (RCTs) comparing weak opioids with placebo or between one another in OA patients. Bayesian network meta-analysis was performed on the following outcomes of interest, namely the change-from-baseline score in pain relief, gastrointestinal (GI) adverse events (AEs), central nervous system (CNS) AEs, and total number of AEs (i.e., the number of subjects experiencing any AE for at least once) during follow-up.

RESULTS

A total of 14 RCTs involving four types of weak opioids were included in this meta-analysis. Compared to placebo, tramadol (standardized mean difference [SMD] = -0.34, 95% credible interval [CrI]: -0.53 to -0.18) and codeine (SMD = -0.39, 95% CrI: -0.79 to -0.04) were effective for pain relief, but involved a higher risk of GI AEs, CNS AEs and total number of AEs. Dextropropoxyphene demonstrated a significantly lower risk of GI AEs (OR = 0.28, 95%CrI: 0.17 to 0.51), CNS AEs (OR = 0.29, 95%CrI: 0.11 to 0.78) and total number of AEs (OR = 0.35, 95%CrI: 0.15 to 0.82) compared to codeine. Dihydrocodeine had a better safety profile in CNS AEs (SUCRA = 64.8%) and total number of AEs (SUCRA = 66.6%).

CONCLUSIONS

The results of the present study confirmed that tramadol and codeine were effective drugs for the treatment of OA, but involved considerable safety issues. Dextropropoxyphene and dihydrocodeine exhibited a relatively good safety profile but their efficacy still warrant further investigation.

Dextropropoxyphene: safety and efficacy in older patients

Dextropropoxyphene, alone or in combination with acetaminophen (paracetamol), is among the most frequently prescribed opioid analgesics in the elderly in the US despite the American Geriatric Society recommendation that its use should be restricted. However, this recommendation is based on expert opinion in an apparent absence of data. Accordingly, we conducted a literature search which identified nine studies that reported efficacy and safety data for dextropropoxyphene in predominantly older patients (> or = 55 years of age). These studies were evaluated to assess the efficacy and safety of dextropropoxyphene compared with other opioids and to evaluate whether safety and tolerability differed in older versus younger patients. The efficacy of dextropropoxyphene appeared to be similar to that of other analgesics, and its safety was comparable to that of other opioid analgesics. Although the adverse event profile suggests that elderly patients might have more frequent gastrointestinal and CNS complaints than younger patients treated with dextropropoxyphene, the frequency of reports appears similar to that of other opioids. The incidences of dizziness and somnolence were not significantly greater in older patients (1-2% and 0-21%, respectively) than in younger patients (8% and 13%, respectively). The absence of clinical studies directly addressing the safety and tolerability of dextropropoxyphene in elderly patients (>65 years of age) versus younger patients encumbers assessment of the validity of restricting its use in the elderly. Careful outcomes research is needed to assess the effectiveness and safety of dextropropoxyphene in older patients and to develop evidence-based risk/benefit prescribing criteria for use of this drug in this age group.

Analgesia in piezoelectric SWL: comparative study of kidney and upper ureter treatments

BACKGROUND

The development of newer-generation lithotripters has reduced the pain associated with SWL, but many patients still require some form of sedation. We prospectively compared the analgesic requirements for kidney and upper ureteral treatments. Predictive factors for pain during piezoelectric SWL were also studied.

PATIENTS AND METHODS

A total of 102 consecutive patients without any previous experience of SWL were treated for renal (N = 70) or upper ureteral (N = 32) calculi using the EDAP LT02 lithotripter. The stones' largest diameter ranged from 4 to 30 mm (mean 9 mm). Patients were given an oral dose of 60 mg of dextropropoxyphene hydrochloride and 800 mg of paracetamol associated with 100 mg of ketoprofene per rectum 30 minutes before treatment. The SWL session was begun at low intensity and increased to the maximal range of energy as rapidly as could be tolerated by the patient. The amount of pain during treatment was recorded according to a visual analogue scale (VAS). Further analgesia using intravenous alfentanil was given as required by the severity of the pain. Visual analog pain scores, additional sedation requirements, and success rates after one session were analyzed.

RESULTS

The VAS scores and intravenous sedation requirements were significantly lower for patients with upper ureteral stones than for those with renal calculi (P < 0.01). The stone-free rates after one session were, respectively, 90% and 73% (P < 0.05). On the other hand, SWL tolerance was significantly lower for women presenting with renal stones (P < 0.05).

CONCLUSION

Piezoelectric SWL without intravenous sedation is suitable for the treatment of upper ureteral calculi. However, such an approach is less efficient in the management of kidney stones, especially for female patients.

High-risk drugs in the elderly population

Drug therapy in elderly patients is affected by age-related changes in distribution and elimination and is further complicated by the increased sensitivity aged persons have to many of the effects of medications. Medications are often necessary in the elderly population, but care should be made to properly monitor these patients, especially those taking multiple drugs. Nurses, who are at the front lines of health care in all areas of practice, should be aware of drugs that may be high risk for use in the elderly and monitor these patients carefully for signs and symptoms of toxicity.

Lack of analgesic effect of 50 and 100 mg oral tramadol after orthopaedic surgery: a randomized, double-blind, placebo and standard active drug comparison

Tramadol hydrochloride is a synthetic mu-opioid agonist with additional monoaminergic activity. Tramadol's analgesic effect has been equated with that of pethidine, with a more favourable side-effect profile. Tramadol has been the most-selling prescription analgesic in Germany for several years, and it is now available in many other European countries, but still there is a lack of adequately controlled clinical studies of its analgesic properties. The purpose of this study was to compare the analgesic efficacy of 50 and 100 mg oral tramadol with our standard analgesic for postoperative pain treatment, 1000 mg paracetamol + 60 mg codeine, and placebo. A single-dose, parallel group, double-blind design was used. One hundred forty-four patients were enrolled the day after total hip replacement if they had a pain intensity of 60 mm or more on a 0-100 mm visual analogue scale. Treatments were compared on the basis of pain intensity and derived variables (pain intensity difference, and summed pain intensity differences), the need of rescue medication, and a global evaluation. Serum concentrations confirmed rapid and good absorption comparable with that reported in healthy volunteers. The active drug control, paracetamol+codeine, was significantly superior to placebo for all efficacy variable (P = 0.0002-0.004), confirming good assay sensitivity. Paracetamol+codeine was also significantly superior to both 50 mg tramadol (P = 0.002-0.03) and 100 mg tramadol (P = 0.002-0.02). There was no difference between placebo and 50 and 100 mg tramadol for any of the efficacy variables.(ABSTRACT TRUNCATED AT 250 WORDS)

Acceptability and efficacy of two associations of paracetamol with a central analgesic (dextropropoxyphene or codeine): comparison in osteoarthritis

A double-blind randomized parallel group trial was undertaken to compare the acceptability and efficacy of 2 forms of analgesic treatment, DI-Antalvic (Houde Laboratories, Puteaux, France) (30 mg dextropropoxyphene and 400 mg paracetamol per capsule) and Efferalgan-Codeine (UPSA Laboratories, Rueil Malmaison, France) (30 mg codeine and 500 mg paracetamol per tablet) prescribed for 1 week at doses of 6 capsules/day and 6 tablets/day, respectively, in 141 outpatients with active osteoarthritis of the knee or hip. The principal aim of the trial was concerned with acceptability, with efficacy as its secondary aim. The principal trial criterion was defined as overall assessment of acceptability by the patient at the end of the trial (success or failure) or by treatment dropouts because of an adverse effect (failure). Comparability of the groups was confirmed before any treatment regarding the physical characteristics of the patients, characteristics of osteoarthritis, and the initial level of pain and functional consequences of pain. Results show that the analgesic efficacy of the treatment was similar, but that the acceptability of Efferalgan-Codeine was significantly worse than that of DI-Antalvic: 53% failure with Efferalgan-Codeine versus 29% failure with DI-Antalvic (P = .005). Other trials of the same type would seem necessary (comparison of lower doses, other types of pain) before being able to generally extrapolate such findings.

The efficacy and tolerability of controlled-release dihydrocodeine tablets and combination dextropropoxyphene/paracetamol tablets in patients with severe osteoarthritis of the hips

A double-blind, parallel group study was undertaken in general practice to compare the efficacy of and tolerability to controlled-release (CR) dihydrocodeine tablets and combination dextropropoxyphene/paracetamol tablets in patients with severe osteoarthritis of the hip(s). Eighty-six patients were randomly allocated to receive either CR dihydrocodeine (60 mg) tablets (1 tablet twice daily to 2 tablets daily) or combination dextropropoxyphene (32.5 mg)/paracetamol (325 mg) tablets (2 tablets 3-times daily to 2 tablets 4-times daily) for a period of 2 weeks. Patients recorded in a diary card 4 times a day the severity of their pain and each morning whether or not they woke during the night due to pain in their hip(s). On entry to the study, after the first week's treatment and at the final visit another week later, the investigator assessed the patient's severity of pain on passive movement of the hip and also noted the severity of any volunteered symptoms or side-effects. After 2-weeks' treatment, pain on passive movement of the hip joint was statistically significantly less severe on CR dihydrocodeine than on dextropropoxyphene/paracetamol (p = 0.02). Nausea and vomiting were more pronounced in the dihydrocodeine than in the dextropropoxyphene/paracetamol group after the first week's treatment but by the end of the study there was no significant treatment difference in any of the volunteered side-effects. Patients on CR dihydrocodeine developed some constipation as expected and the dextropropoxyphene/paracetamol patients suffered from impaired concentration. More patients withdrew on CR dihydrocodeine than on dextropropoxyphene/paracetamol but these withdrawals tended to occur early in the trial just after initiating therapy. Tolerance in terms of withdrawals or side-effect profile did not appear to the dosage of each preparation administered. It is concluded that after 2-weeks' treatment CR dihydrocodeine provided superior analgesia to dextropropoxyphene/paracetamol with no difference in side-effects. Furthermore, CR dihydrocodeine has the advantage of twice rather than 3 or 4-times daily dosing.

Codeine plus paracetamol versus paracetamol in longer-term treatment of chronic pain due to osteoarthritis of the hip. A randomised, double-blind, multi-centre study

This randomized, double-blind, multi-centre study was undertaken to evaluate the efficacy and safety of treatment for 4 weeks with codeine plus paracetamol versus paracetamol in relieving chronic pain due to osteoarthritis of the hip. A total of 158 outclinic patients entered the study. Eighty-three patients (mean age 66 years) were treated with codeine 60 mg plus paracetamol 1 g 3 times daily, and 75 patients (mean age 67 years) with paracetamol 1 g 3 times daily. Ibuprofen 400 mg was prescribed as rescue medication. Due to an unexpected high rate of adverse drug reactions, the study was closed before the planned 400 patients had entered. Over weeks 1-4, 87%, 64%, 61% and 52% of patients in the codeine plus paracetamol group, and 38%, 31%, 22% and 29% of patients in the paracetamol group had one or more adverse drug reactions. Significantly more patients in the codeine plus paracetamol group had adverse drug reactions in each of the 4 weeks. Nausea, dizziness, vomiting and constipation were predominant adverse reactions in the codeine plus paracetamol group. During the first week of treatment, 30 patients (36%) in the codeine plus paracetamol group and 9 (12%) in the paracetamol group dropped out. As evaluated from patients completing the first week of treatment, the pain intensity during that week compared to their baseline pain was significantly lower in the codeine plus paracetamol group than in the paracetamol group. Moreover, during the first week the paracetamol group received rescue medicine significantly more frequently. In conclusion, when evaluated after 7 days of treatment, the daily addition of codeine 180 mg to paracetamol 3 g significantly reduced the intensity of chronic pain due to osteoarthritis of the hip joint. However, several adverse drug reactions, mainly of the gastrointestinal tract, and the larger number of patients withdrawing from treatment means that the addition of such doses of codeine cannot be recommended for longer-term treatment of chronic pain in elderly patients.

Ibuprofen and acetaminophen in the relief of postpartum episiotomy pain

A single-dose, double-blind, randomized clinical trial was conducted to examine the relative analgesic efficacy of ibuprofen 400 mg (n = 36), acetaminophen 1000 mg (n = 37), and placebo (n = 38) in postpartum patients who had moderate to severe pain after episiotomy. At regular intervals over 4 hours, patients evaluated pain severity and relief on categorical scales and completed a categorical overall evaluation at the end of the trial. Both active agents were effective compared with placebo (P less than .05). Ibuprofen 400 mg was more effective than acetaminophen 1000 mg for the sum of pain intensity difference, total pain relief, and reduction of pain by more than 50% (P less than .05), suggesting a more rapid onset of action and a more prolonged effect by ibuprofen 400 mg. No adverse effects were reported. Based on the results of this conventional postpartum episiotomy pain model, both agents are considered efficacious and ibuprofen 400 mg is a more effective analgesic for the relief of acute pain than acetaminophen 1000 mg.

Impact of non-narcotic oral analgesics on pain management

Of the four categories of oral analgesics, three have been available since the 19th century. Although adequate doses of the more potent oral opioids such as morphine and methadone are effective even in severe pain, the commonly used "weak" narcotics such as codeine and propoxyphene are no more effective than usual doses of aspirin or acetaminophen. Furthermore, the opioids produce gastrointestinal and central nervous system adverse effects, and, during long-term administration, tolerance may develop and there is a risk of drug dependence. Aspirin and acetaminophen are the traditional agents of choice for oral analgesic therapy; until 10 years ago, there were no single-entity, oral analgesics--with the exception of large doses of oral narcotics--that were more effective than usual doses of aspirin or acetaminophen. However, there is a ceiling on the analgesic effect attainable with safe doses of these drugs, which may in part be overcome through the use of the third category of oral analgesics, combinations of aspirin or acetaminophen with oral opioids. The fourth category of oral analgesics constitutes the most important recent development in pain management with analgesic drugs: the newer peripherally acting, nonsteroidal anti-inflammatory analgesics, some of which are clearly more efficacious than aspirin or acetaminophen and compare favorably not only with full doses of narcotic combination products but even, in some cases, with strong injectable opioids. On repeated dosing, some nonsteroidal anti-inflammatory drugs are better tolerated than aspirin and some have a much longer duration of analgesic effect than aspirin or acetaminophen. Further study is needed to compare nonsteroidal anti-inflammatory drugs among themselves and to determine their value in chronic pain and in combination therapy.

Poisoning with dextropropoxyphene in Denmark

The sale of dextropropoxyphene is rising in Denmark, and the number of both fatal and non-fatal cases of poisoning with dextropropoxyphene is similarly rising. A total of 124 fatal and 297 non-fatal hospitalized cases of poisoning caused by dextropropoxyphene were reported to the National Board of Health in 1984. These figures are judged to be minimum figures. There is an accumulation of cases in the municipality of Copenhagen as compared to the remainder of the country. Cases of poisoning with dextropropoxyphene occur more frequently in socially and mentally encumbered groups. It is often difficult to determine with certainty the method of poisoning, but it is considered that the distribution is roughly one-third suicide or attempted suicide, about the same from accidental or simple over-dosage, while the remainder are uncertain. It is judged that the number of suicides or attempted suicides in normal persons is small, while the numbers in persons not entirely normal or carried out as an impulsive act are considerably higher. Other intoxicants, most frequently alcohol, have in more than one half of the cases been consumed together with dextropropoxyphene. The mortality rate for those cases reaching medical aid has been found to be 3.6% which is lower than the figure reported in other investigations. Very many of the cases of poisoning, however, are fatal at the time of discovery. Serious sequelae after non-fatal cases of poisoning are extremely rare. The steps being taken by the National Board of Health to reduce the number of cases of poisoning are mentioned, and the possibilities of reducing the number of cases are also discussed.

Analgesic efficacy of paracetamol/codeine and paracetamol/dextropropoxyphene in pain after episiotomy and ruptures in connection with childbirth

Pain after episiotomy and/or perineal/vaginal rupture in childbirth is severe in many patients and in most cases it can be treated with oral analgesics. In this trial the efficacy and side-effect profile of two combination analgesics, paracetamol/codeine and paracetamol/dextropropoxyphene hydrochloride, were compared in post-partum pain after episiotomy and/or rupture of the perineum. Eighty-five patients were analysed for efficacy and 96 were included in an analysis of side-effects. Paracetamol/codeine was shown to give faster and more efficient pain relief while not causing constipation or other troublesome side-effects.

A treatment for the acute migraine attack

A compound analgesic/anti-emetic formulation was significantly effective in reducing the severity of acute attacks of migraine, in a double-blind, randomized, crossover trial of 34 patients referred to a migraine clinic. The preparation contained paracetamol (acetaminophen) 500 mg, codeine phosphate 8 mg, buclizine hydrochloride 6.25 mg and dioctyl sodium sulphosuccinate 10 mg. The dosage was two tablets taken as early as possible in the acute attack. No specific factors could be identified which influenced response to treatment. Patients with a long history of migraine (more than 10 years) responded as well as those with a recent onset of the condition.

Analgesic efficacy and side-effect profile of paracetamol/codeine and paracetamol/dextropropoxyphene after surgical removal of a lower wisdom tooth

A double-blind randomized analgesic trial was carried out on 180 patients undergoing surgical removal of an impacted lower wisdom tooth. The patients took their first dose of either 1000 mg paracetamol plus 60 mg codeine or 650 mg paracetamol plus 65 mg dextropropoxyphene when pain appeared after the decline of the local anaesthesia. If needed, another two doses were available during the observation period (less than or equal to 10 h). The analgesic efficacy of paracetamol/codeine was overall superior to paracetamol/dextropropoxyphene in all variables. Sufficient pain relief was obtained in most patients. The pain reduction after the first dose was 64% in the group receiving paracetamol/codeine compared with 53% in the group receiving paracetamol/dextropropoxyphene and the mean durations of effect of the first dose were 6.6 and 5.8 h, respectively. Side-effects appeared in all patient groups but were most frequent in women taking paracetamol/codeine.

Evaluation of tilidine for morphine-like subjective effects and euphoria

Tilidine is an opioid analgesic that has been abused predominantly by the oral route. Studies of parenterally administered tilidine in animals did not clearly indicate a dependence potential of the morphine type. In this study we examined the abuse potential of orally and parenterally administered tilidine in humans. Both orally and intramuscularly given tilidine produced miosis and morphine-like subjective effects in non-dependent subjects. Oral tilidine was 1/8-1/10 as potent and intramuscular tilidine was 1/22 as potent as parenteral morphine in producing morphine-like subjective and miotic effects. Intramuscular tilidine suppressed and did not precipitate signs of abstinence in morphine-dependent subjects. However, intramuscularly given tilidine produced toxic effects not seen with morphine. Meperidine, codeine and d-propoxyphene produced morphine-like subjective and miotic effects, but also produced toxic effects at the highest doses tested. The results suggest that tilidine has a potential to be abused, that this potential is less than that of parenteral morphine and that tilidine is more likely to be abused orally than by the intramuscular route.

Analgesic sensitivity of two post-partum pain models

Post-partum uterine cramping and episiotomy pain are established, frequently used, clinical pain models for efficacy trials of investigational new analgesic agents. To determine the respective assay sensitivity of these two models in assessing relative efficacy, we reviewed data from 6 phase II, randomized, stratified, parallel, placebo-controlled, double-blind, single-dose studies involving hospitalized women with moderate or severe post-partum uterine cramping (332 patients) or episiotomy pain (434 patients). Using subjective reports as indices of response, patients rated pain intensity and relief at periodic interviews for 6-7 h. Post-partum uterine cramping showed excellent assay sensitivity for detecting differences among peripherally acting analgesics. In the same clinical trial this model could discriminate between a new drug and aspirin 650 mg, a standard reference analgesic, and between 2 graded doses of the new active agent (i.e., good upside sensitivity). In addition the uterine cramp model showed separation between placebo and all active agents (i.e., good downside sensitivity). Episiotomy pain demonstrated similar upside and downside discrimination in clinical trials of several weak centrally acting drugs. These data suggest that post-partum cramping is an excellent pain model for analgesic investigation of new non-steroidal anti-inflammatory drugs, and episiotomy pain for new weak narcotic and opioid analgesics.

Severe acute propoxyphene overdose: plasma concentrations of propoxyphene and norpropoxyphene and the effect of dopamine on circulatory failure

Twelve patients with cardiovascular failure because of propoxyphene self-poisoning were treated with dopamine. The patients responded favourably to dopamine infusion (2-17 micrograms/kg/min) with a dose-dependent rise in systolic arterial blood pressure and a fall in central venous pressure and copious urinary output. Side effects during infusion were few, and in periods where dopamine infusion exceeded 10 micrograms/kg/min no tachyarrhythmias were seen. Eleven of the patients were treated on a respirator. Two patients were discharged from the ICU with signs of hypoxic brain damage, one of whom recovered completely after 2 weeks. Serum propoxyphene and norpropoxyphene were measured in nine patients. All but one patient had either propoxyphene or norpropoxyphene concentrations above 3 mumol/l.

Combination analgesics

Six rationales for using combination analgesics are identified, but most combinations are formulated with two rationales in mind: enhancement of analgesia and reduction of adverse effects by combining two analgesics with different mechanisms of action. Acetaminophen and aspirin are the mainstays of oral analgesic combinations. There is substantial evidence that combining an optimal dose of acetaminophen or aspirin with an oral opioid such as codeine, hydrocodone, or oxycodone produces an additive analgesic effect greater than that obtained by doubling the dose of either constituent administered alone. There is also some evidence that the adverse effects produced by such combinations are less than would be produced by an equi-analgesic dose of a single constituent. The physician need not be confined to existing fixed-ratio combinations; he or she may extemporize to the patient's advantage by co-administering acetaminophen, aspirin, or other nonsteroidal anti-inflammatory drugs with available oral opioids and, in select situations, co-administering oral or injectable analgesics with psychoactive drugs.