Nonsteroidal Anti-inflammatory Drugs

Effect of chirality on PVP/drug interaction within binary physical mixtures of ibuprofen, ketoprofen, and naproxen: a DSC study

We report on the thermal behavior of freshly prepared binary drug/polymer physical mixtures that contained ibuprofen, ketoprofen, or naproxen as a drug, and polyvinylpyrrolidone (PVP), hydroxyethylcellulose (HEC), or methylcellulose (MC) as excipient. At 6-10 degrees C/min heating rates the DSC detected a sharp, single endotherm that corresponds to the melting of drug. On heating physical mixtures of PVP and racemic ibuprofen or ketoprofen at lower heating rates, another endotherm was registered in front of the original one. To observe the additional endotherm, specific minimal values of the heating rate and of PVP weight fraction were needed; for ibuprofen and ketoprofen they were 1.5 and 2.0 degrees C/min, and 5 and 15% (w/w), respectively. At greater PVP weight fractions the top temperatures, T(mp), of both peaks were reduced almost linearly indicating strong solid-state interfacial reaction between the drug particles and PVP matrix. The additional endotherm was abolished at greater heating rates (2 degrees C/min for ibuprofen, 3 degrees C/min for ketoprofen), by replacing the racemate with respective S+-enantiomer and by replacing PVP with HEC and MC. Hence, the possible inclusion of enantioselective component within the PVP/drug interaction, responsible for the amorphization of physical mixture over storage, is assumed.

Solid molecular dispersions of poorly water-soluble drugs in poly(2-hydroxyethyl methacrylate) hydrogels

The applicability of cross-linked hydrogels in forming solid molecular dispersions to enhance the delivery of poorly soluble drugs has not been fully explored. The purpose of this study is to characterize physicochemical parameters affecting the formation of solid molecular dispersions of poorly water-soluble drugs in poly(2-hydroxyethyl methacrylate) (PHEMA) hydrogels and to investigate the effect of storage humidity levels on their physical stability. Samples were prepared by an equilibrium solvent loading process, using diclofenac sodium, piroxicam and naproxen as model drugs. These were characterized by X-ray diffraction (XRD), differential scanning calorimetry (DSC) and Fourier transform infrared spectroscopy (FTIR), as well as changes in the physical state during storage under different humidity conditions. The results show that a threshold drug loading level of about 30% exists in these solid molecular dispersions, above which amorphous to crystalline transition may occur. At any given drug loading, the onset of such change in physical state is accelerated at higher relative humidity levels during storage. The presence of hydrogen bonding between the polymer and the drug, as reflected in the observed FTIR band shifts, improves the compatibility between the drug and the polymer. This, together with a decreased mobility in the glassy polymer, helps to retard the crystallization event below the loading threshold. An increase in dissolution rate is also observed from the polymeric solid molecular dispersion as compared with that of the crystalline pure drug. These physicochemical results indicate that solid molecular dispersions based on PHEMA hydrogels can effectively enhance the dissolution and therefore should be potentially useful in improving the oral bioavailability of poorly water-soluble drugs.

Pharmacological treatments for persistent non-malignant pain in older persons

Persistent non-malignant pain is common, often neglected and under-treated among older persons. Some older adults do not complain because they consider chronic pain to be a characteristic of normal aging. Physicians have concerns regarding adverse effects of pharmacological treatment. The model of the World Health Organization for treatment of cancer pain is generally accepted and also recommended for persistent non-cancer pain. Furthermore, non-pharmacological treatment should complement drug treatment whenever possible. An initial assessment and possible treatment of underlying causes of pain are pertinent. Modern pharmacological pain management is based on non-opioid and opioid analgesics. NSAIDs are among the most widely prescribed class of drugs in the world. The new cyclo-oxygenase-2 inhibitors such as celecoxib and rofecoxib offer an alternative for the treatment of mild-to-moderate pain in patients with a history of gastric ulcers or bleeding. Paracetamol (acetaminophen) is being used widely for the management of mild pain across all age groups as it has moderate adverse effects at therapeutic dosages. For moderate pain, a combination of non-opioid analgesics and opioid analgesics with moderate pain relief properties (e.g. oxycodone, codeine, tramadol and tilidine/naloxone) is recommended. For severe pain, a combination of non-opioid analgesics and opioid analgesics with strong pain relief properties (e.g. morphine, codeine) is recommended. The least toxic means of achieving systemic pain relief should be used. For continuous pain, sustained-release analgesic preparations are recommended. Drugs should be given on a fixed time schedule, and possible adverse effects and interactions should be carefully monitored. Adjuvant drugs, such as antidepressants or anticonvulsants, can be very effective especially in the treatment of certain types of pain, such as in diabetic neuropathy. Effective pain management should result in decreased pain, increased function and improvement in mood and sleep.

Use of inappropriate prescription drugs by older people

OBJECTIVES

To determine the prevalence and predictors of inappropriate drug prescribing defined by expert national consensus panel drug utilization review criteria for community-dwelling older people.

DESIGN

Survey.

SETTING

Five adjacent urban and rural counties in the Piedmont area of North Carolina.

PARTICIPANTS

A stratified random sample of participants from the fourth (n = 3,234) and seventh (n = 2,508) waves of the Duke Established Populations for Epidemiological Studies of the Elderly.

MEASUREMENTS

The prescribing appropriateness for digoxin, calcium channel blockers, angiotensin-converting enzyme inhibitors, histamine(2) receptor antagonists, nonsteroidal antiinflammatory drugs (NSAIDs), benzodiazepines, antipsychotics, and antidepressants as determined by explicit criteria (through Health Care Financing Administration expert consensus panel drug utilization review criteria for dosage, duplication, drug-drug interactions and duration, and U.S. and Canadian expert consensus panel criteria for drug-disease interactions). Multivariable analyses, using weighted data adjusted for sampling design, were conducted to assess the association between inappropriate prescribing and demographic, health-status, and access-to-healthcare factors cross-sectionally and longitudinally.

RESULTS

We found that 21.0 of the fourth wave and 19.2 of the seventh wave participants who used one or more agents from the eight drug classes had one or more elements identified as inappropriate. The therapeutic classes with the most problems were benzodiazepines and NSAIDs. The most common problems were with drug-disease interactions and duration of use. Longitudinal multivariable analyses found that participants who were white (adjusted odds ratio (AOR) = 1.67, 95 confidence interval (CI) = 1.28-2.17), were married (AOR = 1.40, 95% CI = 1.01-1.93), had arthritis (AOR = 1.74, 95% CI = 1.27-2.38), had one or more physical function disabilities (AOR = 1.42, 95% CI = 1.02-1.96), and had inappropriate drugs prescribed at wave 4 (AOR = 6.87, 95% CI = 5.11-9.22) were more likely to have inappropriate prescribing at wave 7.

CONCLUSION

These results indicate that inappropriate prescribing is common among community-dwelling older people and persists over time. Longitudinal studies in older people are needed to examine the impact of inappropriate drug prescribing on health-related outcomes.

Pain in nursing home residents: management strategies

Pain is prevalent and undertreated in nursing home residents, despite the existing wide array of effective pharmacological and nonpharmacological treatment modalities. In order to improve the quality of life of these vulnerable individuals, practitioners require education about the correct approach to assessment and management. Assessment should be comprehensive, taking into account the basic underlying pathology (e.g. osteoarthritis, osteoporosis, peripheral neuropathy, fibromyalgia, cancer) as well as other contributory pathology (e.g. muscle spasm, myofascial pain) and modifying comorbidities (e.g. depression, anxiety, fear, sleep disturbance). Pharmacological management should be guided by a stepped-care approach, modelled after that recommended by the World Health Organization for treatment of cancer pain. Nonopioid and opioid analgesics are the cornerstone of pharmacological pain management. Tricyclic antidepressants and anticonvulsants can be very effective for the treatment of certain types of neuropathic pain. In addition to treating the pain per se, attention should be given to prevention of disease progression and exacerbation, as maintaining function is of prime importance. Nursing home residents with severe dementia challenge the practitioner's pain assessment skills; an empirical approach to treatment may sometimes be warranted. The success of treatment should be measured by improvement in pain intensity as well as physical, psychosocial and cognitive function. Effective pain management may impact any or all of these functional domains and, therefore, substantially improve the nursing home resident's quality of life.

A multicenter, randomized, controlled trial to evaluate the safety profile, tolerability, and efficacy of rofecoxib in advanced elderly patients with osteoarthritis

This 6-week study was conducted to test the efficacy, safety, and tolerability of rofecoxib (a selective COX-2 inhibitor) compared to nabumetone (a non-selective NSAID) and placebo in osteoarthritis (OA) patients aged 80 and older. Three hundred forty-one patients, mean age 83 years, were randomized. Allocations were made in an approximately 1:2:1:2 ratio (placebo: 12.5 mg rofecoxib: 25 mg rofecoxib: 1500 mg nabumetone). Least square mean changes from baseline in the primary efficacy endpoint, Patient Global Assessment of Disease Status, were as follows (with negative numbers indicating improvement): -14.85 mm for placebo; -25.34 mm for 12.5 mg rofecoxib; -25.40 mm for 25 mg of rofecoxib; and -25.95 mm for nabumetone (p<0.001 for all active treatments vs placebo.) Results from secondary endpoints, including the 3 WOMAC sub-scales (pain, stiffness, and disability) and the Investigator Global Assessment of Disease Status, were consistent with those for the primary endpoint. No significant between-group differences were observed in the proportions of patients who discontinued treatment due to either clinical or laboratory adverse experiences. Renal safety (edema and hypertension adverse experiences) was similar for rofecoxib and nabumetone. No gastroduodenal ulcers occurred; however, the demonstration of gastrointestinal risk with rofecoxib or nabumetone was beyond the scope of this trial. We conclude that in patients 80 years and older, rofecoxib, 12.5 mg and 25 mg once daily, demonstrated clinical efficacy for the treatment for OA as did 1500 mg of nabumetone. Rofecoxib and nabumetone were generally well tolerated in this elderly population.

Geropharmacology for the rheumatologist

Drug administration to older patients with rheumatic disease is a challenge because they are more likely to have adverse drug reactions compared with younger patients. Elderly patients are at risk for adverse drug effects because they often have multiple acute and chronic illnesses and are on several prescription and over-the-counter medications. This article will enhance the practitioner's understanding of how disease and age modulate the pharmacokinetics and pharmacodynamics of medications commonly prescribed for rheumatic disorders. Minimizing the number of drugs prescribed, starting medications at low doses and increasing slowly, and monitoring for toxicity are especially important in the elderly. With judicious use of medications, the quality of life of older patients with rheumatic disease can be enhanced.

Stereoselective pharmacokinetics of ketoprofen and ketoprofen glucuronide in end-stage renal disease: evidence for a 'futile cycle' of elimination

AIMS

To assess if futile cycling of ketoprofen occurs in patients with decreased renal function.

METHODS

Ketoprofen was administered to six haemodialysis-dependent patients with end-stage renal disease as single (50 mg) or multiple doses (50 mg three times daily, for 7 days). Plasma and dialysate concentrations of the unconjugated and glucuronidated R- and S-enantiomers of ketoprofen were determined using h.p.l.c. following the single and multiple dosing.

RESULTS

The oral clearance was decreased and terminal elimination half-lives of R- and S-ketoprofen and the corresponding acyl glucuronides were increased in functionally anephric patients compared with healthy subjects. In contrast with the R-isomers, S-ketoprofen and S-ketoprofen glucuronide exhibited an unexpected accumulation (2.7-3. 8 fold) after repeated dosing achieving S:R ratios of 3.3+/-1.7 and 11.2+/-5.3, respectively. The plasma dialysis clearances for R- and S-ketoprofen glucuronides were 49.4+/-19.8 and 39.0+/-15.9 ml min-1, respectively, and 10.8+/-17.6 and 13.3+/-23.5 ml min-1 for unconjugated R- and S-ketoprofen.

CONCLUSIONS

The selective accumulation of S-ketoprofen and its acyl glucuronide are consistent with amplification of chiral inversion subsequent to futile cycling between R-ketoprofen and R-ketoprofen glucuronide. Severe renal insufficiency, and possibly more modest decrements, results in a disproportionate increase in systemic exposure to the S-enantiomer which inhibits both pathologic and homeostatic prostaglandin synthesis.

Nephrotoxicity of nonsteroidal anti-inflammatory drugs: physiologic foundations and clinical implications

Although the prevalence of nephrotoxicity in patients treated with nonsteroidal anti-inflammatory drugs (NSAIDs) is relatively low, the extensive use profile of these agents implies that many persons are at risk. At basal states of normal renal function, the role of renal prostaglandin production for maintenance of stable renal hemodynamic function is relatively limited. Nonetheless, in the clinical setting of reduced renal perfusion as seen in various forms of cardio-renal disease, dehydration, and the aging kidney, the adequacy of renal prostaglandin production mediated predominantly by cyclooxygenase-1 (COX-1) and, potentially, by COX-2 enzyme activity becomes of major significance in the activation of compensatory renal hemodynamics. Inhibition of renal prostaglandin production by the use of NSAIDs in these circumstances can potentially lead to the emergence of several distinct syndromes of disturbed renal function. These include fluid and electrolyte disorders, acute renal dysfunction, nephrotic syndrome/ interstitial nephritis, and renal papillary necrosis. In addition, by blunting the homeostatic renal effects of prostaglandins, NSAIDs can adversely influence blood pressure control, particularly during the use of angiotensin-converting enzyme (ACE) inhibitors, diuretics, and beta blockers. This is a matter of considerable public health concern, in that some 12 million US citizens are concurrently treated with NSAIDs and antihypertensive drugs. Finally, the risk of congestive heart failure is significantly increased when NSAIDs are given to patients receiving diuretic therapy who have cardiovascular risk factors. Physiologic factors, clinical presentations, diagnostic modalities, and clinical management strategies appropriate to these NSAID-induced renal syndromes are described.

Nonsteroidal anti-inflammatory drugs, traditional opioids, and tramadol: contrasting therapies for the treatment of chronic pain

The treatment of chronic pain is an important function of physicians. In the United States, available drug treatments for chronic pain currently include simple analgesics such as acetaminophen, salicylates and other nonsteroidal anti-inflammatory drugs, traditional opioid drugs, and adjuvant agents (eg, antidepressants, anticonvulsants). Typically, the choice of a drug is made by balancing the indications for treatment, the clinical efficacy of the drug, and its toxicity. An understanding of the mechanism of action of these drugs helps to establish their role in therapy. Tramadol is an effective analgesic that works through a combined mechanism of weak mu receptor binding and the inhibition of serotonin and norepinephrine reuptake. Tramadol has a favorable adverse-effect profile and therefore is likely to have an important role in the management of chronic pain syndromes.

Relation of prescription nonsteroidal antiinflammatory drug use to cognitive function among community-dwelling elderly

PURPOSE

To evaluate the relationship of nonsteroidal antiinflammatory drug (NSAID) use to level of cognitive function in community-dwelling elderly persons.

METHODS

The prospective cohort study included 2765 nonproxy subjects from the Duke University Established Populations for Epidemiologic Studies of the Elderly who were cognitively intact at baseline (1986-1987) and alive at follow-up three year later. Cognitive function was assessed by the Short Portable Mental Status Questionnaire (i.e., intact vs. impaired and change in score) and by the individual domains of the Orientation-Memory-Concentration Test (i.e., number of errors). NSAID use, determined from in-home interviews, was coded for chronicity, dose, frequency of use, and prescription status.

RESULTS

After controlling for demographic factors as well as health status and behavior, continuous, regularly-scheduled, prescription use of NSAID was associated with preservation of one aspect of cognitive functioning: concentration (beta coefficient, 0.29; 95% confidence interval [CI] -0.54 to -0.04, indicating fewer errors). However, no consistent dose-response relationship was found. Current and prior NSAID use was unrelated to level of cognitive functioning across all five measures; among current users, those taking moderate or high doses (beta coefficient, 0.41; 95% CI, 0.08 to 0.74) made more errors on the memory test compared with those taking low doses (beta coefficient 0.03; 95% CI, -.85 to 0.91).

CONCLUSIONS

These results suggest no substantial or consistent protective effect of prescription NSAID use on cognitive function in community-dwelling elderly. However, recent use at higher doses may be associated with memory deterioration in this population.

Factors associated with suboptimal analgesic use in community-dwelling elderly

OBJECTIVE

To examine patterns and factors associated with overall and suboptimal analgesic use among community-dwelling elderly.

DESIGN

Cross-sectional survey.

SETTING

Five-county urban and rural region in Piedmont, NC.

PARTICIPANTS

A stratified random sample from the Duke Established Populations for Epidemiologic Studies of the Elderly of 3973 participants aged 65 years or older.

MAIN OUTCOME MEASURES

Use of any analgesic medication, suboptimal analgesic use (taking 2 or more analgesics from the same class, using 3 or more analgesics concurrently, or use of an analgesic that has a major interaction with another drug).

RESULTS

Analgesics were used by 60.4% of the participants. Use was more likely for those who had physical functional impairment, a history of cardiovascular disease, one or more health visits in the previous year, or were female. Use was less likely for older participants and for African-Americans with adequate financial status. Suboptimal use occurred in 9.2% of analgesic users. Therapeutic duplication was more likely in those who were depressed, needed help with basic activities of daily living, or used alcohol, and was less likely in those with adequate financial status. Multiple analgesic use was more likely in those who were depressed, had impaired physical functional status, had one or more health visits in the previous year, were African-American (of either sex), or were white women. Only two persons had a potential major analgesic-drug interaction.

CONCLUSIONS

Suboptimal analgesic use is common in community-dwelling elderly, and its risk in consistently increased in those who are depressed or have impaired physical functional status.

Acute and chronic effects of nonsteroidal antiinflammatory drugs on glomerular filtration rate in elderly patients

To assess the effects of nonsteroidal antiinflammatory drugs (NSAIDs) on glomerular filtration rate (GFR) in elderly patients with and without renal insufficiency, we conducted an open-label, randomized, prospective three-period cross-over study. Twenty-nine patients at least 65 years old were assigned to groups with preserved GFR (> 1.16 mL/s [70 mL/min]) or with renal insufficiency (GFR 0.50-1.16 mL/s [30-70 mL/min]). Patients received 800 mg ibuprofen three times daily, 20 mg piroxicam daily, or 200 mg sulindac twice daily for 1 month. Three-hour inulin and two-day creatinine clearances were measured before and after the first and last doses of NSAIDs. Ibuprofen, piroxicam, and sulindac decreased inulin clearance after single-doses in both groups of patients. In patients with renal insufficiency, creatinine clearance did not change after administration of ibuprofen for 1 month (0 +/- 0.06 mL/s, mean +/- standard error), but was decreased similarly with administration of either piroxicam or sulindac (-0.12 +/- 0.06 mL/s [-7.2 +/- 3.6 mL/min], P < 0.02). One patient with preserved GFR, but with other risk factors for NSAID-associated renal impairment, met our criteria for withdrawal by experiencing at least a 40 mumol/L (0.5 mg/dL) increase in serum creatinine above their baseline value. Our data indicate that NSAIDs do not adversely affect GFR in patients with preserved renal function unless they have another risk factor for NSAID-associated renal impairment. In contrast, patients with renal insufficiency may have significant chronic decrements in GFR with long-acting NSAIDs such as piroxicam and sulindac, but not with short-acting ibuprofen. Such patients should have renal function monitored while being treated with long-acting NSAIDs.

Potential for adverse drug-alcohol interactions among retirement community residents

OBJECTIVES

Medications and alcohol are both used commonly by older people. Thus, the potential for adverse drug-alcohol interactions is very high in this population, but data on actual concurrent use of alcohol and medicines likely to interact with alcohol are lacking. The objectives of this study were to determine the frequency of alcohol and medication use and the potential for specific adverse drug-alcohol interactions in residents of retirement communities.

DESIGN

Cross-sectional study using a mailed survey.

SETTING

Three retirement communities in suburban Milwaukee, Wisconsin.

PARTICIPANTS

All 454 independently living residents of the communities were surveyed. Of these, 311 residents (68%) returned completed questionnaires. Mean age of respondents was 83 +/- 6 years, 100% were white, 77% were female.

MEASUREMENTS

The questionnaire included alcohol use questions adapted from the Khavari questionnaire and the CAGE questionnaire to screen for alcohol abuse. Respondents were asked to list all prescription and nonprescription medications.

RESULTS

Thirty-eight percent of the population reported using both alcohol and a high risk medication. Six percent had seven or more drinks per week and took a high risk medication. High risk drugs commonly used by drinkers were antihypertensives in 50%, aspirin in 27%, nonsteroidal anti-inflammatory drugs in 20%, medication for congestive heart failure in 18%, antacids or H2 blockers in 16%, sedatives in 11%, narcotics in 5%, and warfarin in 5%.

CONCLUSIONS

Concurrent use of alcohol and medications is common in residents of these retirement communities. Many of the drugs taken by regular drinkers have potential for adverse drug-alcohol interactions even at moderate levels of alcohol use. This represents a strong possibility of adverse outcomes and a need for increased awareness on the part of both the public and physicians of the potential for interactions between drugs and alcohol.

Renal effects of over-the-counter analgesics

Recent case reports have shown that over-the-counter (OTC) analgesics, which are generally considered to be a safe treatment for minor aches and pains and fever, may cause adverse renal effects. Many renal syndromes induced by nonsteroidal antiinflammatory drugs (NSAIDs) can be attributed to prostaglandin inhibition. Fluid and electrolyte disturbances, acute renal failure, and acute interstitial nephritis also occur predominantly with NSAIDs. Acetaminophen lacks significant peripheral prostaglandin inhibition and may be a preferred first-line agent, particularly in patients susceptible to the induction of renal impairment. Apart from obvious clinical overdosage situations, limited reports of adverse renal effects exist with acetaminophen. Some studies have reported an association between analgesic nephropathy, one of the most severe analgesic-related adverse renal effects, and long-term abuse of phenacetin, acetaminophen, aspirin, ibuprofen, analgesic combinations, or other NSAIDs, although for some of these agents, this relationship is controversial. The overall risk for serious renal effects with OTC analgesics appears to be low, but given the accessibility and vast number of persons taking these agents, the absolute number of patients affected may be substantial. Therefore, it is important that healthcare providers recognize the risk factors for adverse analgesic-related renal effects.

The effect of competitive and non-linear plasma protein binding on the stereoselective disposition and metabolic inversion of ibuprofen in healthy subjects

The stereoselective disposition and metabolic inversion of ibuprofen were studied in 12 healthy subjects under conditions of competitive and non-linear plasma protein binding. Each subject received each of four oral treatments according to a Latin-square design: 300 mg R(-)-ibuprofen, 300 mg S(+)-ibuprofen, 300 mg R(-)(-)+300 mg S(+)-ibuprofen, and 300 mg R(-)(-)+600 mg S(+)-ibuprofen. For a given treatment, the partial clearance of S(+)-ibuprofen was greater than that of R(-)-ibuprofen for all stereoisomeric drug species. Likewise, the unbound partial clearances of S(+)-ibuprofen were greater for most stereoisomeric drug species. There was also less difference among treatment groups when partial clearances were referenced to unbound as opposed to total plasma concentrations of enantiomer. The unbound intrinsic clearance and fractional inversion of R(-)-ibuprofen were unchanged across the four treatments, and chiral inversion was systemic, averaging 69%. In conclusion, stereoselective differences exist for the partial and composite clearances of R(-)- and S(+)-ibuprofen even when corrected for differences in plasma protein binding. However, differences among treatment groups for a particular elimination pathway are largely due to ibuprofen's non-linear binding.

Pain in older persons

Chronic pain is more prevalent in older persons than in young adults. In this review the physiological, pathological, and psychological reasons for altered pain sensibility in older persons are explored and strategies for the management of pain in older persons described. The evidence suggests that altered physiology of peripheral and central pain mechanisms combine with psychological attitudes, such as stoicism and reluctance to confirm the presence of pain, to raise pain threshold. However, once pain is experienced, older persons describe the same severity, quality, and psychological disturbance as younger persons. There is some evidence to suggest that the complaint of pain in the presence of pathology is reported less often in older persons. On the other hand, the presence of persistent or recurrent clinical pain may have a greater impact on the psychological, social, and physical function of older adults. It is also clear, however, that further empirical studies are required in order to delineate the age-related differences and similarities in the chronic pain experience. Management of chronic pain in the elderly requires meticulous diagnosis of the causal pain mechanisms as well as a holistic approach which gives due regard to psychological and social consequences of pain.

Assessing physician choice of nonsteroidal antiinflammatory drugs in a health maintenance organization

OBJECTIVE

To develop a categorization scheme for grouping various nonsteroidal antiinflammatory drugs (NSAIDs) by relative safety; to develop a method to quantify the appropriateness of the initial and subsequent choices of NSAID therapy; to assess whether NSAID prescribing was consistent with the developed criteria; to examine the cost of inappropriate, acute NSAID use as defined by the established criteria.

DESIGN

Retrospective drug utilization review focusing on NSAIDs.

SETTING/PARTICIPANTS

Members aged > or = 18 years of a 40,000-person southeastern Michigan health maintenance organization.

MAIN OUTCOME MEASURES

(1) Appropriateness of therapy using a four-level safety classification system for the NSAIDs developed by a consensus process; criteria based on safety under the assumption that any particular NSAID is equally likely to be effective when dosed appropriately; (2) evaluation of progression of NSAID therapy using the NSAID Therapy Progression Formula.

RESULTS

For acute patients, almost half of the prescriptions were for ibuprofen and 33 percent were for naproxen. Ibuprofen usage accounted for 16 percent of total NSAID cost and naproxen agents accounted for over 50 percent of that cost. Potential cost savings of approximately $82,000 probably would have occurred had a 50 percent interchange rate for ibuprofen been acceptable. For chronic patients, 85 percent were treated with one or two NSAIDs; treatments were of reasonable high quality when compared by safety profiles. There was low use of ibuprofen in patients who only received one NSAID.

CONCLUSIONS

NSAID usage assessment in a large population was achieved by developing a classification and scoring system based on NSAID safety; in this population, prescribing patterns were generally consistent with established criteria; however, when considering cost, improvement in initial NSAID selection for acute patients was possible.

Stereoselective, competitive, and nonlinear plasma protein binding of ibuprofen enantiomers as determined in vivo in healthy subjects

The plasma protein binding and competitive inhibition parameters of R(-)- and S(+)-ibuprofen were determined in vivo in 12 healthy subjects. Subjects participated in a 4 x 4 Latin square design in which oral solutions of drug were administered as 300 mg R(-)-ibuprofen, 300 mg S(+)-ibuprofen, 300 mg R(-)- + 300 mg S(+)-ibuprofen, and 300 mg R(-)- + 600 mg S(+)-ibuprofen. Unlabeled ibuprofen enantiomers were quantitated using a stereospecific reversed-phase HPLC assay, and plasma protein binding experiments were performed using radiolabeled 14C-enantiomers and an ultrafiltration method at 37C. At therapeutic drug concentrations, the protein binding of each enantiomer was greater than 99%. Furthermore, the binding of ibuprofen enantiomers was stereoselective and mutually competitive, as well as nonlinear. The bound-free data were fitted to a model in which the non-linearity of plasma protein binding and competition between enantiomers for binding sites could be accommodated. There were substantial differences in the affinity of ibuprofen enantiomers for protein binding sites (RP2 = 0.358 +/- 0.185 vs. SP2 = 0.979 +/- 0.501 micrograms/ml; mean +/- SD) but no differences in their binding capacity (RP1 = 160 +/- 86 vs. SP1 = 161 +/- 63 micrograms/ml). Although statistically significant, the differences in competitive inhibition parameters were more modest (SKI = 0.661 +/- 0.363 vs. RKI = 0.436 +/- 0.210 micrograms/ml). As a result, the intrinsic binding (i.e., P1/P2) of R(-)-ibuprofen was greater than S(+)-ibuprofen, and the unbound fraction was significantly greater for S-enantiomer vs. R-enantiomer after a given dose of R-ibuprofen or racemate.

Improvement of pain and disability in elderly patients with degenerative osteoarthritis of the knee treated with narrow-band light therapy

OBJECTIVE

To evaluate the effects of low-power light therapy on pain and disability in elderly patients with degenerative osteoarthritis of the knee.

DESIGN

Partially double-blinded, fully randomized trial comparing red, infrared, and placebo light emitters.

PATIENTS

Fifty patients with degenerative osteoarthritis of both knees were randomly assigned to three treatment groups: red (15 patients), infrared (18 patients), and placebo (17 patients). Infrared and placebo emitters were double-blinded.

INTERVENTIONS

Self-applied treatment to both sides of the knee for 15 minutes twice a day for 10 days.

MAIN OUTCOME MEASURES

Short-Form McGill Pain Questionnaire, Present Pain Intensity, and Visual Analogue Scale for pain and Disability Index Questionnaire for disability were used. We evaluated pain and disability before and on the tenth day of therapy. The period from the end of the treatment until the patient's request to be retreated was summed up 1 year after the trial.

RESULTS

Pain and disability before treatment did not show statistically significant differences between the three groups. Pain reduction in the red and infrared groups after the treatment was more than 50% in all scoring methods (P less than 0.05). There was no significant pain improvement in the placebo group. We observed significant functional improvement in red- and infrared-treated groups (p less than 0.05), but not in the placebo group. The period from the end of treatment until the patients required treatment was longer for red and infrared groups than for the placebo group (4.2 +/- 3.0, 6.1 +/- 3.2, and 0.53 +/- 0.62 months, for red, infrared, and placebo, respectively).

CONCLUSIONS

Low-power light therapy is effective in relieving pain and disability in degenerative osteoarthritis of the knee.