A cost analysis of orthopedic foot surgery: can outpatient continuous regional analgesia provide the same standard of care for postoperative pain control at home without shifting costs?

BACKGROUND AND OBJECTIVES

Same-day surgery is common for foot surgery. Continuous regional anesthesia for outpatients has been shown effective but the economic impact on the perioperative process-related healthcare costs remains unclear.

METHODS

One hundred twenty consecutive patients were included in this assessor-blinded, prospective cohort study and allocated according to inclusion criteria in the day-care or in the in-patient group. Standardized continuous popliteal sciatic nerve block was performed in both groups for 48 h using an elastomeric pump delivering ropivacaine 0.2 % at a rate of 5 ml/h with an additional 5 ml bolus every 60 min. Outpatients were discharged the day of surgery and followed with standardized telephone interviews. The total direct health costs of both groups were compared. Moreover, the difference in treatment costs and the difference in terms of quality of care and effectiveness between the groups were compared.

RESULTS

Total management costs were significantly reduced in the day-care group. There was no difference between the groups regarding pain at rest and with motion, persistent pain after catheter removal and the incidence of PONV. Persistent motor block and catheter inflammation/infection were comparable in both groups. There was neither a difference in the number of unscheduled ambulatory visits nor in the number of readmissions.

CONCLUSIONS

Day-care continuous regional analgesia leads to an overall positive impact on costs by decreasing the incidence of unplanned ambulatory visits and unscheduled readmissions, without compromising on the quality of analgesia, patients' satisfaction, and safety.

An adherence based cost-consequence model comparing bimatoprost 0.01% to bimatoprost 0.03%

OBJECTIVES

Estimate the long-term direct medical costs and clinical consequences of improved adherence with bimatoprost 0.01% compared to bimatoprost 0.03% in the treatment of glaucoma.

METHODS

A cost-consequence model was constructed from the perspective of a US healthcare payer. The model structure included three adherence levels (high, moderate, low) and four mean deviation (MD) defined health states (mild, moderate, severe glaucoma, blindness) for each adherence level. Clinical efficacy in terms of IOP reduction was obtained from the randomized controlled trial comparing bimatoprost 0.01% with bimatoprost 0.03%. Medication adherence was based on observed 12 month rates from an analysis of a nationally representative pharmacy claims database. Patients with high, moderate and low adherence were assumed to receive 100%, 50% and 0% of the IOP reduction observed in the clinical trial, respectively. Each 1 mmHg reduction in IOP was assumed to result in a 10% reduction in the risk of glaucoma progression. Worse glaucoma severity health states were associated with higher medical resource costs. Outcome measures were total costs, proportion of patients who progress and who become blind, and years of blindness. Deterministic sensitivity analyses were performed on uncertain model parameters.

RESULTS

The percentage of patients progressing, becoming blind, and the time spent blind slightly favored bimatoprost 0.01%. Improved adherence with bimatoprost 0.01% led to higher costs in the first 2 years; however, starting in year 3 bimatoprost 0.01% became less costly compared to bimatoprost 0.03% with a total reduction in costs reaching US$3433 over a lifetime time horizon. Deterministic sensitivity analyses demonstrated that results were robust, with the majority of analyses favoring bimatoprost 0.01%. Application of 1 year adherence and efficacy over the long term are limitations.

CONCLUSIONS

Modeling the effect of greater medication adherence with bimatoprost 0.01% compared with bimatoprost 0.03% suggests that differences may result in improved economic and patient outcomes.

Cost-offset analysis: bimatoprost versus other prostaglandin analogues in open-angle glaucoma

OBJECTIVES

To develop a cost-offset model from a US payer perspective comparing glaucomatous progression and costs among primary open-angle glaucoma (POAG) patients using bimatoprost, latanoprost, or travoprost.

STUDY DESIGN

Cost-offset model.

METHODS

A Markov cohort model was used to estimate glaucomatous progression for POAG patients over 7 years. The model assumed bimatoprost-treated patients had lower resulting intraocular pressure (IOP) (by 1 mm Hg) for all presenting IOP categories than latanoprost- or travoprost-treated patients. Patients with lower IOP were assumed to have lower probability of progression. Those that progressed were assumed to do so at a rate of -0.6 dB per year. Direct costs associated with mean deviation score categories were applied to each treatment cohort to calculate the expected 7-year costs of treating patients with each prostaglandin analogue (PGA). Literature was used to support assumptions. A budget impact analysis was conducted where all travoprost patients switched to generic latanoprost and where all bimatoprost patients switched to generic latanoprost. The base case market share was 22% bimatoprost, 23% travoprost, and 55% latanoprost.

RESULTS

Model results demonstrate that for a managed care plan with 9500 PGA-treated glaucoma patients, exclusive bimatoprost use would prevent progression in 136 additional individuals compared with exclusive travoprost or latanoprost treatment. Model results demonstrate that greater IOP reduction from bimatoprost is associated with increased cost savings compared with latanoprost or travoprost treatments.

CONCLUSIONS

Model results demonstrate that greater IOP reduction from bimatoprost could reduce managed care spending.

Cost-effectiveness of treating resistant hypertension with an implantable carotid body stimulator

The purposes of this study are to investigate the cost-effectiveness of an implantable carotid body stimulator (Rheos; CVRx, Inc, Minneapolis, MN) for treating resistant hypertension and determine the range of starting systolic blood pressure (SBP) values where the device remains cost-effective. A Markov model compared a 20-mm Hg drop in SBP from an initial level of 180 mm Hg with Rheos to failed medical management in a hypothetical 50-year-old cohort. Direct costs (2007$), utilities, and event rates for future myocardial infarction, stroke, heart failure, and end-stage renal disease were modeled. Sensitivity analyses tested the assumptions in the model. The incremental cost-effectiveness ratio (ICER) for Rheos was $64,400 per quality-adjusted life-years (QALYs) using Framingham-derived event probabilities. The ICER was <$100,000 per QALYs for SBPs > or =142 mm Hg. A probability of device removal of <1% per year or SBP reductions of > or =24 mm Hg were variables that decreased the ICER below $50,000 per QALY. For cohort characteristics similar to Anglo-Scandinavian Cardiac Outcomes Trial-Blood Pressure-Lowering Arm (ASCOT-BPLA) participants, the ICER became $26,700 per QALY. Two-way sensitivity analyses demonstrated that lowering SBP 12 mm Hg from 220 mm Hg or 21 mm Hg from 140 mm Hg were required. Rheos may be cost-effective, with an ICER between $50,000 and $100,000 per QALYs. Cohort characteristics and efficacy are key to the cost-effectiveness of new therapies for resistant hypertension .

First-year treatment patterns among new initiators of topical prostaglandin analogs

OBJECTIVE

To evaluate treatment patterns and costs among new initiators of topical prostaglandin analogs in a managed-care population.

RESEARCH DESIGN AND METHODS

Annual costs were modeled using multiple inputs. A retrospective cohort design was used to identify treatment patterns for pharmacotherapy. The study population was identified from pharmacy claims for patients who met study inclusion criteria (patients initiating prostaglandin analog monotherapy). Published studies were used to estimate visit-related resource use and costs were obtained from published and standard sources.

RESULTS

In the cohort analysis, a total of 12 202 patients met study criteria: 2275 received bimatoprost, 7347 received latanoprost and 2580 received travoprost (1808 used the original formulation and 772 used the newer preservative formulation). Of patients meeting study criteria, 50% stopped all glaucoma therapy, 6% switched from their initial prostaglandin therapy, and the remaining 44% stayed on their initial prostaglandin for 1 year. Of patients remaining on prostaglandin analog monotherapy for 1 year, 22.7% of bimatoprost patients, 19.8% of latanoprost patients and 17.9% of travoprost patients (19.7% for the original formulation and 13.7% for the new formulation) required adjunctive therapy. Of those requiring adjunctive therapy, the median number of days until starting adjunctive therapy was 53 days for bimatoprost patients, 63 days for latanoprost patients and 83 days for travoprost patients (70.5 days for the original formulation and 109 days for the new formulation). The resources used at each visit were estimated at $424 for an initial visit and $70 for follow-up visits. Estimated first-year costs were $1294, $1199, and $1186 for patients initiating therapy with bimatoprost, latanoprost, and travoprost, respectively. Estimated travoprost costs were higher for the original formulation ($1203) than for the new formulation ($1160). Sensitivity analyses suggested that the cost estimates are robust to changes in costs and use of adjunctive therapies.

LIMITATIONS

The use of a claims database without compliance data or clinical outcomes and the selection of new initiators of topical prostaglandin analogs limits the findings and does not allow projecting outcomes to all glaucoma patients.

CONCLUSIONS

Use of adjunctive therapy in glaucoma is an important driver of glaucoma management costs. Based on the results of this study, it is possible that longer duration of monotherapy with prostaglandin analogs may be associated with lower annual costs. Further study should be conducted to validate these findings.

A cost-effectiveness analysis of fixed-combination therapies in patients with open-angle glaucoma: a European perspective

OBJECTIVE

To compare the efficacy and cost implications of the use of the intraocular pressure-lowering prostaglandin analogues bimatoprost, travoprost, and latanoprost as fixed-combination therapies with timolol, a beta-adrenergic receptor antagonist.

METHODS

A decision analytic cost-effectiveness model was constructed. Since no head-to-head studies comparing the three treatment options exist, the analysis was based on an indirect comparison. Hence, the model was based on efficacy data from five randomized, controlled, clinical studies. The studies were comparable with respect to study design, time horizon, patient population and type of end point presented. The measure of effectiveness was the percentage reduction of the intraocular pressure level from baseline. The cost evaluated was the cost of medication and clinical visits to the ophthalmologist. All drug costs were market prices inclusive of value-added tax, and visit costs were priced using official physician fees. Cost-effectiveness analyses were carried out in five European countries: Spain, Italy, United Kingdom, Norway and Sweden. The time horizon for the analyses was 3 months.

RESULTS

The analysis showed that fixed-combination bimatoprost/timolol was more effective and less costly than fixed-combination travoprost/timolol and fixed-combination latanoprost/timolol in three out of the five countries analyzed. In two countries, bimatoprost/timolol was less costly than latanoprost/timolol, and cost the same as travoprost/timolol.

CONCLUSIONS

This cost-effectiveness analysis showed that the fixed combination of bimatoprost 0.03%/timolol 0.5% administered once daily was a cost-effective treatment option for patients with primary open-angle glaucoma. This study was limited by available clinical data: without a head-to-head trial, indirect comparisons were necessary. In the United Kingdom, Sweden, Norway, Italy, and Spain, from a health service viewpoint, bimatoprost/timolol was a slightly more effective as well as less costly treatment strategy when compared to both travoprost/timolol and latanoprost/timolol.

Pharmacoeconomic analysis of prostaglandin and prostamide therapy for patients with glaucoma or ocular hypertension

BACKGROUND

To determine monthly cost and cost effectiveness of bilateral prostaglandin/prostamide therapy for lowering intraocular pressure (IOP) in patients taking bimatoprost 0.03% (Lumigan, Allergan, Inc.), latanoprost 0.005% (Xalatan, Pfizer, Inc.), or travoprost 0.004% (Travatan, Alcon Laboratories, Inc.).

METHODS

Drops in five new 2.5-mL bottles were counted and then averaged for each drug. Average retail price was determined by surveys of pharmacies. Drop count, average retail price, average wholesale price, and IOP reduction data were used to compute annual cost, and cost effectiveness (annual cost-per-mm Hg of IOP reduction) of the three drugs.

RESULTS

Drops per 2.5-mL bottle averaged 113 for bimatoprost 0.03%, 84 for latanoprost 0.005%, and 83 for travoprost 0.004%. Average retail cost (2005) per bottle was $69.99 for bimatoprost 0.03%, $61.69 for latanoprost 0.005%, and $66.37 for travoprost 0.004%. The monthly retail cost of bilateral therapy was $37.92 for bimatoprost 0.03%, $44.75 for latanoprost 0.005%, and $49.25 for travoprost 0.004%. Cost effectiveness ranges were $57 to $65 per mm Hg reduction in IOP per year for bimatoprost, 0.03%, $67 to $90 per mm Hg for latanoprost 0.005%, and $74 to $84 per mm Hg for travoprost 0.004%.

CONCLUSION

Bimatoprost 0.03% had the lowest monthly and annual costs and the greatest cost effectiveness for lowering IOP compared with latanoprost 0.005% and travoprost 0.004%.

Efficiency of Instillation Methods for Prostaglandin Medications

PURPOSE

The aim of this study was to determine the most efficient methods for instillation of prostaglandin analogs.

METHODS

Drops were dispensed at room temperature from 2.5-mL bottles of bimatoprost, travoprost, and latanoprost. Two determinations of drop count were each made from bottles held vertically, at a 45-degree angle, and horizontally. The total volumes of medication dispensed from each bottle were measured.

RESULTS

The mean number of drops dispensed was 111.0, 105.1, and 76.1 drops for bimatoprost bottles; 81.4, 101.1, and 85.3 drops for travoprost bottles; and 94.3, 88.4, and 67.1 drops for latanoprost bottles, held vertically, at 45 degrees, and horizontally, respectively. The mean volume of medication dispensed per 2.5-mL bottle was 3.17 mL for bimatoprost, 2.54 mL for travoprost, and 3.02 mL for latanoprost. The most efficient instillation methods provided 56 days of bilateral therapy per 2.5-mL bottle for bimatoprost, 51 days for travoprost, and 47 days for latanoprost, with corresponding yearly medication costs of $408 for bimatoprost, $449 for travoprost, and $475 for latanoprost. Yearly savings of $109 to $192 could be achieved by using the most efficient instillation methods, representing 5.6 months of medication saved for patients using bimatoprost, 3.0 months for patients using travoprost, and 4.9 months for patients using latanoprost.

CONCLUSIONS

Health care providers are urged to instruct glaucoma patients in the most efficient method of instillation. For bimatoprost and latanoprost, vertical instillation is recommended, with 45 degrees nearly as efficient, and for travoprost, instillation at 45 degrees is recommended.

The cost-effectiveness of bimatoprost, latanoprost and timolol in treatment of primary open angle glaucoma in five European countries

OBJECTIVE

The objective of this cost-effectiveness analysis is to evaluate cost-effectiveness ratios of the intraocular pressure (IOP)-lowering agents bimatoprost, latanoprost and timolol in five major European countries: France, Germany, Italy, Spain and the UK.

METHODS

The cost-effectiveness analysis is based on achievement of IOP targets between 13 and 18 mm Hg. Thus, the cost-effectiveness ratios express the costs of having one patient successfully achieving IOP target. The perspective of the analysis is that of the health care sector payer, including costs of medicine and costs of ophthalmologist visits. The time frame is first year of glaucoma treatment. Four treatment strategies are analysed: Timolol as first line with add-on latanoprost or bimatoprost if IOP targets are not met, and latanoprost and bimatoprost as first line with add-on timolol.

RESULTS

In the UK, Spain, Italy and Germany the timolol first with add-on of bimatoprost is the least expensive treatment. This strategy dominates both strategies involving latanoprost (as add-on to timolol or as first line) in these four countries. The incremental cost-effectiveness ratio of bimatoprost first-line therapy versus timolol with add-on bimatoprost varies from each country and target (from 305 pounds sterlings to 43,720 euros per patient). In France the timolol first line and latanoprost add-on is not dominated and is the cheapest alternative. The incremental cost-effectiveness ratio of timolol with add-on bimatoprost versus add-on latanoprost lies between 71 euros and 355 euros per patient depending on target (18 and 13 mm Hg, respectively).

CONCLUSION

First-line treatment of latanoprost is dominated in all countries. In four out of five countries the timolol first-line therapy with add-on latanoprost is also dominated. Based on this pharmacoeconomic analysis, the most cost-effective strategy seems to be timolol first line with add-on bimatoprost if target is not met after 3 months.

An economic evaluation of bupivacaine plus fentanyl versus ropivacaine alone for patient-controlled epidural analgesia after total-knee replacement procedure: a double-blinded randomized study

BACKGROUND AND OBJECTIVES

Total-knee replacement (TKR) surgery is one of the most painful orthopedic procedures after surgery. Opioid has been commonly combined with a local anesthetic to improve the quality of pain relief, but the treatment has opioid-related side effects. This study compared the cost effectiveness of patient-controlled epidural analgesia (PCEA) with 0.0625% bupivacaine plus fentanyl (BF) 3 microg/mL versus 0.15% ropivacaine alone (R) during the first 48 hours after TKR procedure.

METHODS

This prospective randomized double-blinded study was performed on 70 patients who underwent unilateral TKR procedure and received either BF or R after surgery. Visual analog scale (VAS) pain score at rest and upon movement, side effects, and cost of treatment were compared.

RESULTS

Overall pain at rest and upon movement between groups was not significantly different (P = 0.58, 95% CI = 4.4 to -7.8 and P = 0.8, 95% CI = 6.4 to -8.2, respectively). Patients in the BF group experienced more pruritus and had more vomiting episodes than those in the R group (P = .015), whereas no difference occurred in other side effects. Nevertheless, patient satisfaction with pain management was higher in the BF group compared with that in the R group. In addition, pain treatment with bupivacaine and fentanyl was 18% less costly compared with ropivacaine alone.

CONCLUSIONS

Considering the economic evaluation, we conclude that PCEA with 0.0625% bupivacaine plus fentanyl 3 microg/mL is more cost effective and provides more patient satisfaction than PCEA with ropivacaine alone. However, use of epidural ropivacaine alone causes fewer opioid-related side effects, particularly pruritus and vomiting.

Estimated Comparative Costs of Achieving a 20% Reduction in Intraocular Pressure with Bimatoprost or Latanoprost in Patients with Glaucoma or Ocular Hypertension

BACKGROUND

Although the probability of treatment success should be the primary factor guiding the choice of an intraocular pressure (IOP)-lowering medication, treatment cost is also important to physicians, patients and third-party payers. The objective of the present study was to compare the cost effectiveness of bimatoprost with that of latanoprost in the treatment of glaucoma and ocular hypertension.

METHODS

Estimated yearly costs and cost per treatment success for bimatoprost ophthalmic solution 0.03% once daily (Lumigan), Allergan, Inc., Irvine, CA, USA) were compared with those for latanoprost ophthalmic solution 0.005% once daily (Xalatan), Pfizer, Inc., New York, NY, USA). The pharmacoeconomic model was based on medical resource costs and the percentage of patients achieving > or =20% decrease in IOP from baseline at 8:00 am, 12:00 pm and 4:00 pm after 6 months of treatment (clinical success rate). Calculations were also made using the average success rate throughout the day and the average success rate minus the percentage of patients who withdrew from treatment as a result of adverse events.

RESULTS

After 6 months of treatment, the clinical success rates were significantly higher with bimatoprost than with latanoprost (p < or = 0.003). The average expected yearly cost per patient was similar for bimatoprost (US1151 dollars) and latanoprost (US1193 dollars). The cost per treatment success, however, averaged US568 dollars less with bimatoprost (US1501 dollars/success) than with latanoprost (US2069 dollars/success). This was true even when the percentage of patients who withdrew from treatment as a result of adverse events was subtracted from the clinical success rate.

CONCLUSION

The greater efficacy of bimatoprost resulted in a lower cost per treatment success than was seen with latanoprost. This remained true even when responder rates were adjusted by subtracting the percentage of patients who withdrew from treatment as a result of adverse events.

Cost analyses of remifentanil, mivacurium and ropivacaine - a systematic review

Remifentanil, mivacurium and ropivacaine are the latest innovations in clinical anaesthesia and have gained increasing importance in daily practise due to their unique pharmacodynamic and pharmacokinetic properties. However, drug acquisition costs for these agents are considerably higher in most countries than for comparable substances. This review provides a systematic, critical appraisal of pharmacoeconomic studies with remifentanil, mivacurium and ropivacaine, primarily based on prospective, randomised trials. Results from analyses using cost-minimising techniques stress the issue of the higher drug acquisition costs. However, studies using a more sophisticated method (e.g., cost-effectiveness analysis) indicate comparable costs or even financial advantage in favour of the newer investigative drugs remifentanil, mivacurium and ropivacaine.

Benefit-Risk Assessment of Ropivacaine in the Management of Postoperative Pain

Ropivacaine is a long-acting amide-type local anaesthetic, released for clinical use in 1996. In comparison with bupivacaine, ropivacaine is equally effective for subcutaneous infiltration, epidural and peripheral nerve block for surgery, obstetric procedures and postoperative analgesia. Nevertheless, ropivacaine differs from bupivacaine in several aspects: firstly, it is marketed as a pure S(-)-enantiomer and not as a racemate, and secondly, its lipid solubility is markedly lower. These features have been suggested to significantly improve the safety profile of ropivacaine, and indeed, numerous studies have shown that ropivacaine has less cardiovascular and CNS toxicity than racemic bupivacaine in healthy volunteers. Extensive clinical data have demonstrated that epidural 0.2% ropivacaine is nearly identical to 0.2% bupivacaine with regard to onset, quality and duration of sensory blockade for initiation and maintenance of labour analgesia. Ropivacaine also provides effective pain relief after abdominal or orthopaedic surgery, especially when given in conjunction with opioids or other adjuvants. Nevertheless, epidurally administered ropivacaine causes significantly less motor blockade at low concentrations. Whether the greater degree of blockade of nerve fibres involved in pain transmission (Adelta- and C-fibres) than of those controlling motor function (Aalpha- and Abeta-fibres) is due to a lower relative potency compared with bupivacaine or whether other physicochemical properties or stereoselectivity are involved, is still a matter of intense debate. Recommended epidural doses for postoperative or labour pain are 20-40 mg as bolus with 20-30 mg as top-up dose, with an interval of >or=30 minutes. Alternatively, 0.2% ropivacaine can be given as continuous epidural infusion at a rate of 6-14 mL/h (lumbar route) or 4-10 mL/h (thoracic route). Preoperative or postoperative subcutaneous wound infiltration, during cholecystectomy or inguinal hernia repair, with ropivacaine 100-175 mg has been shown to be more effective than placebo and as effective as bupivacaine in reducing wound pain, whereby the vasoconstrictive potency of ropivacaine may be involved. Similar results were found in peripheral blockades on upper and lower limbs. Ropivacaine shows an identical efficacy and potency to that of bupivacaine, with similar analgesic duration over hours using single shot or continuous catheter techniques. In summary, ropivacaine, a newer long-acting local anaesthetic, has an efficacy generally similar to that of the same dose of bupivacaine with regard to postoperative pain relief, but causes less motor blockade and stronger vasoconstriction at low concentrations. Despite a significantly better safety profile of the pure S(-)-isomer of ropivacaine, the increased cost of ropivacaine may presently limit its clinical utility in postoperative pain therapy.

New local anesthetics. Are they worth the cost?

Epidural analgesia that uses dilute concentrations of bupivacaine with fentanyl or sufentanil provides excellent analgesia, good sensory-motor discrimination, and minimal toxicity and is inexpensive. The new local anesthetic agents, ropivacaine and levobupivacaine, offer potential improvements in the risk of toxicity when administered in large doses but probably no important clinical difference when used in dilute concentrations for labor analgesia. After accounting for the potency difference, ropivacaine offers little or no motor-sparing advantage over bupivacaine. Currently, epidural anesthesia with concentrated bupivacaine is rarely used for cesarean section, so there is little indication for the newer anesthetic agents in this setting either. The authors believe that large difference in cost cannot be justified on the basis of currently available data.

Prolonged epidural infusions of ropivacaine (2 mg/mL) after colonic surgery: the impact of adding fentanyl

We evaluated the safety and efficacy of a 72-h epidural infusion of ropivacaine and measured the impact of adding fentanyl 2 microg/mL to the required infusion rate, on the quality of postoperative pain relief and the incidence of side effects, after colonic surgery. One hundred fifty-five patients scheduled for elective colonic surgery were randomized in this trial. Epidural infusions of ropivacaine 2 mg/mL with fentanyl 2 microg/mL (R + F) and without fentanyl (R) were commenced during surgery and continued for 72 h postoperatively. This was a prospective, randomized, double-blinded, multi-center trial. The median infusion rate required was less in the R + F group (9.3 vs 11.5 mL/h, P < 0.001). Median pain scores at rest and on coughing were lower in the R + F group (P < 0.0001). The incidence of hypotension was more in the R + F group (P = 0.01). Time to readiness for discharge was delayed in the R + F group (median 6.6 vs 5.5 days, P = 0.012). The addition of fentanyl to ropivacaine resulted in decreased infusion rates and enhanced pain control; however, adverse effects were increased and readiness to discharge was delayed.

IMPLICATIONS

Epidural infusions of ropivacaine with and without fentanyl were administered to patients to control pain after colonic surgery. Patients who received ropivacaine with fentanyl had better pain control, increased side effects, and delayed readiness to discharge. This study questions the value of adding opioids to epidural infusions of local anesthetics.

Comparison of 0.5% intrathecal bupivacaine with 0.5% intrathecal ropivacaine in the treatment of refractory cancer and noncancer pain conditions: results from a prospective, crossover, double-blind, randomized study

BACKGROUND AND OBJECTIVES

Intrathecal (IT) administration of bupivacaine (BUP) for treatment of "refractory" pain has sometimes been associated with unacceptable side effects. This study was undertaken to determine if IT-ropivacaine (ROP) can reduce the rate and intensity of these side effects e.g., urinary retention, paresthesia, and particularly, paresis with gait impairment. A prospective, crossover, double-blind, randomized study.

METHODS

Twenty-one patients were enrolled, 9 dropped out of the study, and data were analyzed from 12 patients. Patients were treated by insertion of IT tunneled nylon catheters, continuous infusion of 0.5% ROP followed by 0.5% BUP or 0.5% BUP followed by 0.5% ROP solutions from an external electronic pump. Each local anesthetic was infused for 7 days, and their order of infusion randomized. The comparative efficacy of the ROP and BUP IT infusions was assessed from the daily doses of IT ROP and IT BUP, oral and parenteral opioids, and daily scores of nonopioid analgetic and sedative drug consumption. Self-reported pain intensity (visual analogue scale [VAS] mean scores) and scores of Bromage relaxation, ambulation, nocturnal sleep pattern, rates of side-effects attributable to the IT drugs, the patients' assessment of the IT ROP v the IT BUP periods of the trial, and the comparative daily cost of IT ROP v IT BUP were recorded.

RESULTS

The daily doses of the local anesthetics used were 23% higher for ROP than for BUP. Further, the daily cost was approximately equals 3 times higher for ROP than for BUP. No other significant differences between IT ROP and IT BUP were found.

CONCLUSION

The results of this study do not support the hypothesis that IT infusion of 0.5% ROP has advantages over IT infusion of 0.5% BUP when administered for relief of "refractory" pain.

Ropivacaine

Ropivacaine (Naropin, AstraZeneca) is a long-acting amide local anaesthetic released for clinical use in 1996. Similar to bupivacaine, ropivacaine is equally effective for s.c. infiltration, epidural and peripheral nerve block for surgery, obstetric and post-operative analgesia. Ropivacaine differs from most other amide-type local anaesthetics in that it is marketed as a pure S-enantiomer, instead of as a racemate. This feature improves the safety of ropivacaine, and, indeed, studies have shown ropivacaine to have less cardiovascular and CNS toxicity than bupivacaine. Ropivacaine is nearly identical to bupivacaine in onset, quality and duration of sensory block, but it produces less motor block. Whether or not the motor sparing effect of ropivacaine is due to a lower relative potency compared to bupivacaine is a matter of intense debate. Despite a better safety profile, the increased cost of ropivacaine may limit its clinical utility.