EXPEDITED REVIEWS
Pharmacodynamic interaction of naproxen with low-dose aspirin in healthy subjects
Marta L. Capone, PhD*, ,
Maria G. Sciulli, PhD*,,
Stefania Tacconelli, PhD*,,
Marilena Grana, MD*,,
Emanuela Ricciotti, PharmD*,,
Giulia Renda, MD*,,
Patrizia Di Gregorio, MD ,
Gabriele Merciaro and
Paola Patrignani, PhD*,,*
* Department of Medicine and Center of Excellence on Aging, School of Medicine, "G. d’Annunzio" University, Chieti, Italy
"G. d’Annunzio" University Foundation, Ce.S.I., Chieti, Italy
SS Annunziata Hospital, Chieti, Italy.
Manuscript received October 22, 2004;
revised manuscript received December 17, 2004,
accepted January 4, 2005.
* Reprint requests and correspondence: Dr. Paola Patrignani, Dipartimento di Medicina e Scienze dell’Invecchiamento, Università "G. d’Annunzio," Via dei Vestini 31, 66013 Chieti, Italy. (Email: ppatrignani{at}unich.it).
 |
Abstract
|
|---|
OBJECTIVES: We investigated the occurrence of pharmacodynamic interaction between low-dose aspirin and naproxen.
BACKGROUND: The uncertainty of cardioprotection by naproxen has encouraged its combination with aspirin in patients with arthritis and cardiovascular disease.
METHODS: The incubation of washed platelets with naproxen for 5 min before the addition of aspirin reduced the irreversible inhibition of thromboxane (TX)B2 production by aspirin. The pharmacodynamic interaction between the two drugs was then investigated in four healthy volunteers who received aspirin (100 mg daily) for 6 days and then the combination of aspirin and naproxen for further 6 days: aspirin 2 h before naproxen (500 mg, twice-daily dosing). After 14 days of washout, naproxen was given 2 h before aspirin for further 6 days.
RESULTS: The inhibition of serum TXB2 production (index of platelet cyclooxygenase [COX]-1 activity) and platelet aggregation ex vivo and urinary 11-dehydro-TXB2 levels (index of TXB2 biosynthesis in vivo) by aspirin alone (99 ± 0.2%, 95 ± 0.6%, and 81 ± 4%, respectively) was not significantly altered by the co-administration of naproxen, given either 2 h after aspirin or in reverse order. In a second study, the concurrent administration of a single dose of aspirin and naproxen did not affect platelet TXB2 production and aggregation at 1 h after dosing, when aspirin alone causes maximal inhibitory effect. Moreover, the rapid recovery of platelet COX-1 activity and function supports the occurrence of a pharmacodynamic interaction between naproxen and aspirin.
CONCLUSIONS: Naproxen interfered with the inhibitory effect of aspirin on platelet COX-1 activity and function. This pharmacodynamic interaction might undermine the sustained inhibition of platelet COX-1 that is necessary for aspirin’s cardioprotective effects.
|
Abbreviations and Acronyms
| | AA = arachidonic acid | | BID = twice-daily dosing | | CI = confidence interval | | COX = cyclooxygenase | | IC50 = concentrations required to inhibit 50% of enzyme activity | | NANSAIDs = nonaspirin nonsteroidal anti-inflammatory drugs | | NSAIDs = nonsteroidal anti-inflammatory drugs | | PG = prostaglandin | | TX = thromboxane |
|
Aspirin and nonaspirin nonsteroidal anti-inflammatory drugs (NANSAIDs) inhibit the synthesis of platelet thromboxane (TX)A2 (the major product of arachidonic acid [AA] in platelets, serving as potent platelet agonists and vasoconstrictors) (1), but only the former has been shown to reduce the risk of myocardial infarction and stroke (2,3). It generally is accepted that the activity of platelet cyclooxygenase (COX)-1, the COX isoform expressed in platelets (4), has to be almost completely (>95%) and continuously inhibited ex vivo throughout the dosing intervals to translate into a detectable cardiovascular protection (1,3,5). This effect can be achieved by aspirin which causes an irreversible inactivation of platelet COX-1 activity, through a selective acetylation of Ser529 of human COX-1 (6,7), which lasts for all platelet lifespan (i.e., 8 to 10 days), because the lack of transcription and only scant translation in anucleated platelets (8). In contrast, NANSAIDs, which are reversible inhibitors of platelet COX-1, generally cause an incomplete and intermittent inhibition of platelet TXA2, which may be inadequate to prevent cardiovascular events, as shown by the results of epidemiologic studies (3,9–12).
Among NANSAIDs, naproxen recently has gained interest because the results of one randomized clinical trial (13) and several observational studies have suggested its possible cardioprotective effect (12,14–16). These results are consistent with the demonstration that the chronic administration of a therapeutic anti-inflammatory dose of naproxen (500 mg, twice-daily dosing [BID]) to healthy subjects causes a persistent and almost-complete suppression of platelet TXB2 production throughout the 12-h dosing interval (17). However, in other observational studies, naproxen does not affect the risk of cardiovascular events (11,12,18,19). The conflicting results of epidemiologic studies reconcile in consideration of the dependence of getting an almost complete inhibition of platelet COX-1 activity ex vivo (<95%) at the end of the dosing interval by a reversible inhibitor of COX-1 to translate into cardiovascular protection (3). Thus, the use of naproxen in real-life situations, photographed by observational studies which is neither regular nor continuous nor necessarily at high doses may explain the variable risk reductions detected.
The uncertainty of a cardioprotective effect by NANSAIDs has encouraged their combining with aspirin in patients with musculoskeletal disorders and vascular disease (20). However, it has been shown recently that the NANSAID ibuprofen interferes with the antiplatelet effect of low-dose aspirin when they are administered together (21,22). In fact, the stronger binding affinity of NANSAIDs to Arg120 of the COX-1 channel (a common docking site for all nonsteroidal anti-inflammatory drugs [NSAIDs], including aspirin) may prevent the acetylation of Ser529 by aspirin (3,23). In contrast, no interaction is detected in the co-administration of aspirin with the NANSAIDs acetaminophen and diclofenac or with the selective COX-2 inhibitor rofecoxib (21).
In the present study, we investigated the occurrence of a pharmacodynamic interaction between low-dose aspirin and naproxen. First, we assessed the effects of naproxen on the irreversible inhibition of platelet TXB2 production by aspirin in vitro. Then, we studied in healthy subjects the potential interference of naproxen with aspirin inhibitory effects on platelet TXB2 biosynthesis ex vivo and in vivo and on platelet aggregation ex vivo.
|
Methods
|
|---|
Study subjects.
The study protocol was approved by the ethical committee of "G. d’Annunzio" University of Chieti. Informed consent was obtained from the nine subjects enrolled. The subjects were between 23 and 30 years of age and within 30% of ideal body weight and had an unremarkable medical history, physical examination, and routine hematological and biochemical studies. Smokers and subjects with a bleeding disorder, an allergy to aspirin or any other NSAID, or a history of any gastrointestinal or cerebrovascular disease were excluded. Subjects abstained from the use of aspirin and other NSAIDs for at least two weeks before enrollment.
In vitro study.
First, we characterized the nature of the interaction (i.e., reversible or irreversible) between aspirin or naproxen and platelet COX-1 by assessing the capacity of increasing concentrations of exogenous AA to overwhelm the inhibitory effect of TXB2 production by aspirin or naproxen in washed human platelets. Fresh peripheral blood from healthy volunteers who had not taken NSAIDs for 14 days was collected in Vacutainer tubes without heparin and was mixed with 10% (vol/vol) anticoagulant solution (65 mmol/l citric acid/85 mmol/l sodium citrate/2% glucose, pH 7.4). Washed platelets (1.5 x 108 cells/ml), prepared as previously described (23), were incubated with increasing concentrations of aspirin (0.01 to 100 µmol/l), naproxen (0.01 to 100 µmol/l), or dimethyl sulfoxide vehicle (1 µl) for 25 min, and then 0.5 or 10 µmol/l of AA (Sigma Chemical Co., St. Louis, Missouri) was added for an additional 30 min at 37°C. To determine whether naproxen inhibited the acetylation of COX-1 by aspirin, we incubated an increasing concentration of naproxen (0.01 to 10 µmol/l) with washed platelets (1.5 x 108 cells/ml) for 5 min before the addition of aspirin (10 or 100 µmol/l), and the incubation continued for additional 20 min at 37°C. The cells were washed twice with Hanks’ balanced salt solution supplemented with 25 mmol/l HEPES/10% anticoagulant solution to remove the reversible inhibitor. The platelets were then resuspended in 500 µl of Hanks’ balanced salt solution supplemented with 25 mmol/l HEPES, challenged with AA 10 µmol/l for 30 min at 37°C, and TXB2 production was determined by radioimmunoassay (24). Under these experimental conditions, a detectable inhibition of platelet TXB2 production was dependent on the chance of aspirin to acetylate COX-1.
Clinical study: design, treatments, and assessment.
The potential interactions between low-dose aspirin and naproxen co-administered to four healthy subjects on platelet TX biosynthesis in vivo and ex vivo and platelet aggregation induced by AA (1 mmol/l) ex vivo (25) were evaluated in two different studies (Fig. 1). In the first study, uncoated aspirin (100 mg daily, at 8 AM) to be swallowed whole was given for 6 consecutive days, and then the combination of aspirin and naproxen was administered for further 6 days: aspirin was given 2 h before naproxen (500 mg BID, at 10 AM and 10 PM). After a washout period of 14 days, the treatments were administered in reverse order, i.e., low-dose aspirin (100 mg daily at 10 AM) was taken 2 h after naproxen (500 mg BID, at 8 AM and 8 PM) for further 6 days. Blood samples were collected before and at 2, 5, 14, and 26 h after the first study drug on the 6th, 12th, 27th, and 32nd study day to assess the inhibition of serum TXB2 (a capacity index of platelet COX-1 activity) (24) and lipopolysaccharide-induced prostaglandin (PG)E2 production (a capacity index of monocyte COX-2 activity) (26). Three consecutive urinary samples (time of collection: 0 to 6 h, 6 to 12 h, and 12 to 24 h were collected before treatment and on days 6, 12, 27, and 32 to evaluate the urinary excretion of 11-dehydro-TXB2 (a major enzymatic metabolite of TXB2 that is an index of TXA2 biosynthesis in vivo) (27). In the second study, a single dose of aspirin (100 mg) and naproxen (500 mg) was administered concurrently to 5 healthy subjects, and peripheral blood samples were collected before and up to 14 days after dosing to assess the time-dependent inhibition and recovery of serum TXB2 production and platelet aggregation ex vivo. Platelet aggregation induced by AA (1 mmol/l) was measured in platelet-rich plasma (25) using a Chrono-Log platelet aggregometer (Chrono-log Corp., Havertown, Pennsylvania), whereas immunoreactive TXB2, PGE2, and 11-dehydro-TXB2 were measured by previously validated radioimmunoassay techniques (24,26,27).
View larger version (35K):
[in this window]
[in a new window]
|
Figure 1 Flow chart of study protocols. In the study with multiple daily doses, aspirin (100 mg daily and once at 8 AM) was administered for 6 consecutive days and then naproxen (500 mg twice daily, once at 10 AM and 10 PM) was co-administered 2 h after aspirin for further 6 days to 4 healthy subjects. After a washout period of at least 14 days, the volunteers reversed the treatment, i.e., low-dose aspirin (100 mg daily at 10 AM) was administered 2 h after naproxen (500 mg twice daily, once at 8 AM and once at 8 PM) for further 6 days. Blood samples were collected before and up to 26 h after dosing with the first study drug on the 6th, 12th, 27th, and 32nd study day to assess the inhibition of serum thromboxane (TX)B2 (a capacity index of platelet cyclooxygenase [COX]-1 activity) and lipopolysaccharide-induced prostaglandin E2 production (a capacity index of monocyte COX-2 activity). Three consecutive urinary samples (time of collection: 0 to 6 h, 6 to 12 h, and 12 to 24 h) were collected before treatment and on days 6, 12, 27, and 32 to evaluate the urinary excretion of 11-dehydro-TXB2 (a major enzymatic metabolite of TXB2 that is an index of TXA2 biosynthesis in vivo). In the study with single dose, aspirin (100 mg) and naproxen (500 mg) were co-administered to 5 healthy subjects, and peripheral blood samples were collected before and up to 14 days after dosing to assess the time-dependent inhibition and recovery of serum TXB2 production and platelet aggregation ex vivo.
|
|
Statistical analysis.
The data are expressed as mean ± SEM. Statistical comparisons were made by analysis of variance followed by the Student-Newman-Keuls test. A probability value of p < 0.05 was considered to be statistically significant. The primary hypothesis was that naproxen (500 mg, BID), administered 2 h before aspirin, would interfere with the irreversible effects of aspirin, as assessed by the measurement of serum TXB2 (primary end point) and platelet aggregation (secondary end point) 26 h after a 6-day dosing of the combined therapy. Assuming an intersubject coefficient of variation of 20% for serum TXB2, four subjects would allow detection of a difference of 50% between the inhibitory effect by aspirin alone and its co-administration with naproxen, with a power of 90%, on the basis of two-tailed tests, with probability values less than the type I error rate of 0.05. Concentration-response curves were fitted, and IC50 (concentrations required to inhibit 50% of enzyme activity) values were analyzed with PRISM (GraphPad, San Diego, California). The IC50 values were reported as mean values, and 95% confidence intervals (CIs) were calculated.
|
Results
|
|---|
Pharmacodynamic interaction between aspirin and naproxen in vitro.
As shown in Figures 2A and 2B, aspirin and naproxen inhibited TXB2 production by washed platelets in a concentration-dependent fashion. However, in contrast to aspirin, the potency of naproxen to inhibit platelet COX-1 activity decreased in the presence of the higher concentration of AA, which supports the reversible interaction of naproxen, but not aspirin, with COX-1. At 0.5 and 10 µmol/l of AA, aspirin inhibited COX-1 activity, with IC50 values of 3.40 µmol/l (95% CI 2.70 to 4.30 µmol/l) and 4.50 µmol/l (95% CI 3.80 to 5.50 µmol/l), respectively, whereas the corresponding values for naproxen were 0.16 µmol/l (95% CI 0.10 to 0.20 µmol/l) and 0.75 µmol/l (95% CI 0.50 to 1.20 µmol/l), respectively. Experiments were then conducted to determine the ability of naproxen to affect platelet COX-1 acetylation by aspirin. Platelets were pretreated with naproxen for 5 min before the addition of 10 or 100 µmol/l of aspirin and incubated for an additional 20 min. The cells were then centrifuged and washed twice, as described previously, to remove any reversible clogging of COX-1 channel, and then challenged for TXB2 production with 10 µmol/l of AA.
View larger version (16K):
[in this window]
[in a new window]
|
Figure 2 Concentration-response curves for the inhibition of plate let cyclooxygenase (COX)-1 activity by aspirin (A) and naproxen (B). One-milliliter aliquots of washed platelets (1.5 x 108 cells) were preincubated with increasing concentrations of aspirin (0.01 to 100 µmol/l) or naproxen (0.01 to 100 µmol/l) for 25 min, and then 0.5 or 10 µmol/l of arachidonic acid (AA) was added for an additional 30 min at 37°C. In panel C, the antagonism of aspirin inhibition of platelet COX-1 by naproxen is shown. Increasing concentrations of naproxen (0.01 to 10 µmol/l) were incubated with washed platelets (1.5 x 108 cells/ml) for 5 min before the addition of aspirin (10 or 100 µmol/l) and the incubation continued for additional 20 min at 37°C. After washing twice, platelets were resuspended in 500 µl of Hanks’ balanced salt solution supplemented with 25 mmol/l HEPES, challenged with 10 µmol/l of AA for 30 min at 37°C, and thromboxane (TX)B2 levels were determined by radioimmunoassay. The data represent the average of inhibition of platelet TXB2 production from five different donors. IC50 = concentrations required to inhibit 50% of enzyme activity.
|
|
Under these experimental conditions, a detectable inhibition of platelet TXB2 production was dependent on the chance of aspirin to acetylate COX-1. Aspirin alone at 10 and 100 µmol/l inhibited TXB2 production by 73 ± 7% and 89 ± 2%, respectively. The preincubation of platelets with increasing concentrations of naproxen reduced the irreversible inhibition of TXB2 production by aspirin (Fig. 2C). At aspirin concentrations of 100 µmol/l, the naproxen concentration-response curve was shifted to the right, suggesting that the pharmacodynamic interaction between the two drugs involved a competition at the enzyme active site (Fig. 2C). The irreversible inhibition of platelet COX-1 by aspirin was affected by naproxen concentrations lower than those blocking platelet COX-1 activity. In fact, it was detectable at 0.1 µmol/l of naproxen (Fig. 2C), which did not affect TXB2 production by platelets challenged with 10 µmol/l of AA (Fig. 2B).
Study with multiple daily doses.
As shown in Figures 3A and 3B, the administration of low-dose aspirin for six consecutive days caused an almost complete inhibition of platelet COX-1 activity and platelet aggregation (99 ± 0.2% and 95 ± 0.6%, respectively, mean ± SEM, n = 4) that persisted up to 26 h after the last dose and was not altered by the co-administration of naproxen (2 h after aspirin) or in reverse order (naproxen 2 h before aspirin) for further 6 days. The reduction of urinary levels of 11-dehydro-TXB2 (81 ± 4%, 74 ± 6%, and 83 ± 6%, respectively) assessed in three consecutive urine collections (0 to 6 h, 6 to 12 h, and 12 to 24 h respectively) obtained after chronic dosing with aspirin alone was not affected by the concomitant administration of naproxen given 2 h after aspirin (Fig. 3C). A comparable inhibition of the urinary enzymatic metabolite was found when naproxen was given 2 h before aspirin (Fig. 3C).
View larger version (52K):
[in this window]
[in a new window]
|
Figure 3 Mean inhibition of platelet cyclooxygenase-1 activity ex vivo, as assessed by the measurement of serum thromboxane (TX)B2 levels (A), arachidonic acid-induced platelet aggregation ex vivo (B), and TX biosynthesis in vivo, as assessed by the measurement of urinary 11-dehydro-TXB2 levels (C), in subjects taking low-dose aspirin alone (100 mg daily) for six days (hatched bars) and then readministered with naproxen (500 mg twice daily, with the first dose administered 2 h after aspirin) for further six days (open bars). The solid bars show the effects of the same medications administered in reversed order for further six days after a washout period of 14 days. Values are reported as mean ± SEM, n = 4. All times are hours after the administration of the first study drug. Open bars = aspirin before naproxen (twice daily); solid bars = naproxen (twice daily) before aspirin; hatched bars = aspirin.
|
|
As shown in Figure 4, lipopolysaccharide-induced PGE2 production was not significantly affected by the chronic administration of low-dose aspirin, whereas it was profoundly inhibited by the concomitant chronic administration of naproxen given 2 h after aspirin or in reverse order.
View larger version (27K):
[in this window]
[in a new window]
|
Figure 4 Mean inhibition of monocyte cyclooxygenase-2 activity ex vivo, as assessed by measurement of whole-blood lipopolysaccharide (LPS)-induced prostaglandin (PG)E2 levels in subjects taking low-dose aspirin alone (100 mg daily) for 6 days (hatched bars) and then readministered with naproxen (500 mg twice daily, with the first dose administered 2 h after aspirin) for a further 6 days (open bars). The solid bars show the effect of the same medications, administered in reversed order for further six days after a washout period of 14 days, on monocyte cyclooxygenase-2 activity. The values are reported as mean ± SEM of inhibition (%) of LPS-induced PGE2 levels caused by the different treatments, n = 4. *p < 0.05, **p < 0.01 versus pre-drug values. All times are hours after the administration of the first study drug. Open bars = aspirin before naproxen (twice daily); solid bars = naproxen (twice daily) before aspirin; hatched bars = aspirin.
|
|
Study with single dose.
Because the profound and long-lasting inhibition of platelet COX-1 activity caused by naproxen (17) might have shaded its possible antagonism on the irreversible antiplatelet effect of aspirin, we studied the time-dependent inhibition and recovery of platelet COX-1 activity and AA-induced platelet aggregation up to 14 days after the concurrent administration of single doses of aspirin (100 mg) and naproxen (500 mg). The co-administration of the two drugs caused a time-dependent inhibition of platelet COX-1 activity and function (Fig. 5). Interestingly, at 1 h after dosing, serum TXB2 and platelet aggregation were not significantly affected (92 ± 5% and 99 ± 0.1% of pre-drug values, respectively), which suggests that naproxen concentrations lower than those inhibiting platelet COX-1 activity interfered with the irreversible inhibition of aspirin. The inhibition of serum TXB2 production and platelet aggregation recovered in a time-dependent fashion. At 72 h after dosing, serum TXB2 and platelet aggregation values (65 ± 12% and 80 ± 19% of pre-drug values, respectively) did not differ, in a statistically significant fashion, from those assessed before (100 ± 11% and 100 ± 0.6% of pre-drug values, respectively) or 14 days after treatment (86 ± 7% and 99 ± 0.7% of pre-drug values, respectively). The rapid recovery of COX-1 activity and function confirmed the occurrence of the pharmacodynamic interaction between naproxen and aspirin.
View larger version (18K):
[in this window]
[in a new window]
|
Figure 5 Mean inhibition of platelet cyclooxygenase-1 activity ex vivo (solid circles) (as assessed by measurement of serum TXB2) and arachidonic acid-induced platelet aggregation ex vivo (open circles) in subjects taking a single dose of aspirin (100 mg) and naproxen (500 mg). Values are reported as mean ± SEM, n = 5. Serum TXB2 and platelet aggregation were significantly inhibited versus pre-drug values at 3 h (p < 0.01 and 0.05, respectively), 12 h (p < 0.01), 24 h (p < 0.01), and 48 h (p < 0.01 and 0.05, respectively) after dosing. No significant differences were found at 1, 72, 144, 192, and 336 h after dosing versus pre-drug values. Open circles = platelet aggregation; solid circles = serum TXB2.
|
|
|
Discussion
|
|---|
Several epidemiologic studies have been performed to establish the possible antithrombotic effect of naproxen, but the results did not present a clear picture (9–12,14–16,18,19). Probably, the administration of the drug not at high doses, not continuously and regularly, as occurs in real life photographed by the observational studies, may have contributed to the unsettled cardioprotective effect of naproxen. The final say on the risk reduction of myocardial infarction by naproxen will be made when prospective controlled trials of adequate size are performed. In the meantime, patients with musculoskeletal disorders treated with naproxen should receive low-dose aspirin as well if they require an antithrombotic treatment. However, a pharmacologic study has shown that the NANSAID ibuprofen, but not diclofenac, acetaminophen, or rofecoxib, can antagonize the irreversible inhibition of platelet TXA2 by aspirin when they are administered together (21).
In the present study, we have addressed whether naproxen might competitively inhibit the ability of aspirin to cause an irreversible inhibition of platelet COX-1 in vitro, ex vivo, and in vivo in healthy subjects. First, we characterized the interaction between aspirin or naproxen and platelet COX-1 in washed platelets in vitro. Aspirin caused an irreversible inhibition of platelet COX-1. In fact, the inhibition of TXB2 production by aspirin was not influenced by the concentrations of exogenous AA (the substrate of COX-1) (Fig 2A). Differently, naproxen caused a reversible inhibition of COX-1 (Fig. 2B). Next, we studied whether the preincubation of naproxen had the ability to affect the irreversible inhibition of platelet COX-1 by aspirin. We pretreated platelets with naproxen for 5 min before the addition of aspirin, and we evaluated the production of TXB2 in response to AA after having washed the cells to remove reversible blockage of COX-1. Under these experimental conditions, a detectable inhibition of platelet TXB2 production was dependent on the chance of aspirin to acetylate COX-1. Naproxen, indeed, reduced the inhibition of platelet TXB2 production by aspirin in a concentration-dependent fashion (Fig. 2C). This effect occurred even at lower drug concentrations than those inhibiting platelet COX-1 activity. The explanation is that in the first case naproxen competes with aspirin, which is a weak inhibitor of platelet COX-1, whereas in the second case the drug competes with AA, which binds the enzyme strongly. Similar results have been reported for ibuprofen and COX-2 inhibitors in vitro (23).
After having highlighted a pharmacodynamic interaction between aspirin and naproxen in vitro, we verified its occurrence ex vivo. The concurrent administration of a single dose of the two drugs to healthy subjects was associated with undetectable inhibition of serum TXB2 production at 1 h after dosing. This finding is consistent with the interference of naproxen on the irreversible inhibition of platelet COX-1 by aspirin. In fact, it has been reported previously that the administration of aspirin inhibits platelet COX-1 activity (as assessed by the measurement of serum TXB2 production) before the drug reaches the systemic circulation; this effect is maximal at 20 min after dosing, coinciding with the peak plasma concentrations of the active drug (28). Despite the short half-life of aspirin (approximately 20 min), the inhibition of platelet COX-1 activity persists up to 24 h as the result of irreversible enzyme inactivation (Fig. 2A) (18).
Similar to that found in vitro, naproxen interfered with aspirin acetylation at concentrations lower than those inhibiting platelet COX-1 activity. In fact, circulating plasma levels of the drug suited to inhibit the platelet enzyme are reached more than 1 h after dosing since time to reach peak concentration in the systemic circulation (Tmax) of naproxen is 3 to 4 h. The finding of a rapid recovery of platelet TXB2 production and platelet aggregation detected after the co-administration of a single dose of aspirin and naproxen corroborates the occurrence of the interaction between naproxen and aspirin (29). However, the chronic administration of naproxen 2 h after aspirin or in reverse sequence for 6 consecutive days did not affect the inhibition of TXB2 biosynthesis ex vivo and in vivo and platelet aggregation ex vivo caused by aspirin alone. The most likely explanation of these results is that the pharmacodynamic interaction between the two drugs was shaded because of the capacity of high-dose naproxen to mimic the antiplatelet COX-1 effect of low-dose aspirin (17).
However, in our earlier work, we found that even within the context of a controlled and well-monitored study, the chronic administration of naproxen 500 mg BID gets into the functionally relevant range, i.e., >95% inhibition of platelet COX-1 activity ex vivo at the end of the dosing interval, in some but not all subjects (17). Such heterogeneity, as well as departure from the rigor of monitored drug intake, might explain the weak and irregular signal of cardioprotection from naproxen in epidemiologic analyses (19,22,30). We cannot assess whether naproxen heterogeneity occurred in the present study because of the background of aspirin; perhaps in those subjects in whom functional inhibition of COX-1 was not attained by naproxen, a partial contribution was afforded by aspirin. Another limitation is the small sample size, which allowed us to discern only large differences and did not enable us to assess the impact of other covariates such as gender and age.
Conclusions.
Naproxen interfered with the irreversible inhibitory effect of aspirin on platelet COX-1 activity in vitro and ex vivo. This effect was undetectable during the continuous and regular administration of an anti-inflammatory dose of naproxen (500 mg BID) and low-dose aspirin because naproxen can mimic the inhibitory effect of aspirin on platelet TXA2 generation. However, in the real world, naproxen combination with aspirin might undermine the sustained inhibition of platelet COX-1 necessary for cardioprotection from aspirin.
|
Acknowledgments
|
|---|
We thank the medical students of "G. d’Annunzio" University for their generous cooperation in the undertaking of this study.
|
Footnotes
|
|---|
Supported by grants from the Italian Ministry of University and Research (MIUR) to the Center of Excellence on Aging, "G. d’Annunzio" University of Chieti, and to Dr. Patrignani (FIRB).
|
References
|
|---|
1. FitzGerald GA. Mechanisms of platelet activationthromboxane A2 as an amplifying signal for other agonists. Am J Cardiol 1991;68:11B-15B.[CrossRef][Medline]
2. Antithrombotic Trialists’ Collaboration Collaborative meta-analysis of randomized trials of antiplatelet therapy for prevention of death, myocardial infarction, and stroke in high risk patients BMJ 2002;324:71-86.[Abstract/Free Full Text]
3. Patrono C, Coller B, FitzGerald GA, Hirsh J, Roth G. Platelet active drugthe relationships among dose, effectiveness, and side effects. Chest 2004;126:234S-264S.[Abstract/Free Full Text]
4. Patrignani P, Sciulli MG, Manarini S, Santini G, Cerletti C, Evangelista V. COX-2 is not involved in thromboxane biosynthesis by activated human platelets J Physiol Pharmacol 1999;50:661-667.[Web of Science][Medline]
5. Reilly IA, FitzGerald GA. Inhibition of thromboxane formation in vivo and ex vivoimplications for therapy with platelet inhibitory drugs. Blood 1987;69:180-186.[Abstract/Free Full Text]
6. Roth GJ, Majerus PW. The mechanism of the effect of aspirin on human platelets. Acetylation of a particulate fraction protein J Clin Invest 1975;56:624-632.[Web of Science][Medline]
7. Loll PJ, Picot D, Garavito RM. The structural basis of aspirin activity inferred from the crystal structure of inactivated prostaglandin H2 synthase Nat Struct Biol 1995;2:637-643.[CrossRef][Web of Science][Medline]
8. Weyrich AS, Dixon DA, Pabla R, et al. Signal-dependent translation of a regulatory protein, Bcl-3, in activated human platelets Proc Natl Acad Sci USA 1998;95:5556-5561.[Abstract/Free Full Text]
9. Garcia Rodriguez LA, Varas C, Patrono C. Differential effects of aspirin and non-aspirin nonsteroidal anti-inflammatory drugs in the primary prevention of myocardial infarction in postmenopausal women Epidemiology 2000;11:382-387.[CrossRef][Web of Science][Medline]
10. Ray WA, Stein CM, Daugherty JR, Hall K, Arbogast PG, Griffin MR. Non-steroidal anti-inflammatory drugs and risk of coronary heart diseasean observational cohort study. Lancet 2002;359:118-123.[CrossRef][Web of Science][Medline]
11. Garcia Rodriguez LA, Varas-Lorenzo C, Maguire A, Gonzalez-Perez A. Nonsteroidal antiinflammatory drugs and the risk of myocardial infarction in the general population Circulation 2004;109:3000-3006.[Abstract/Free Full Text]
12. Howard PA, Delafontaine P. Nonsteroidal anti-inflammatory drugs and cardiovascular risk J Am Coll Cardiol 2004;43:519-525.[Abstract/Free Full Text]
13. Bombardier C, Laine L, Reicin A, et al. VIGOR Study Group Comparison of upper gastrointestinal toxicity of rofecoxib and naproxen in patients with rheumatoid arthritis N Engl J Med 2000;343:1520-1528.[Abstract/Free Full Text]
14. Solomon DH, Glynn RJ, Levin R, Avorn J. Nonsteroidal anti-inflammatory drug use and acute myocardial infarction Arch Intern Med 2002;162:1099-1104.[Abstract/Free Full Text]
15. Watson DJ, Rhodes T, Cai B, Guess HA. Lower risk of thromboembolic cardiovascular events with naproxen among patients with rheumatoid arthritis Arch Intern Med 2002;162:1105-1110.[Abstract/Free Full Text]
16. Rahme E, Pilote L, LeLorier J. Association between naproxen use and protection against acute myocardial infarction Arch Intern Med 2002;162:1111-1115.[Abstract/Free Full Text]
17. Capone ML, Tacconelli S, Sciulli MG, et al. Clinical pharmacology of platelet, monocyte, and vascular cyclooxygenase inhibition by naproxen and low-dose aspirin in healthy subjects Circulation 2004;109:1468-1471.[Abstract/Free Full Text]
18. Mamdani M, Rochon P, Juurlink DN, et al. Effect of selective cyclooxygenase 2 inhibitors and naproxen on short-term risk of acute myocardial infarction in the elderly Arch Intern Med 2003;163:481-486.[Abstract/Free Full Text]
19. Kimmel SE, Berlin JA, Reilly M, et al. The effects of nonselective non-aspirin non-steroidal anti-inflammatory medications on the risk of nonfatal myocardial infarction and their interaction with aspirin J Am Coll Cardiol 2004;43:985-990.[Abstract/Free Full Text]
20. Baigent C, Patrono C. Selective cyclooxygenase 2 inhibitors, aspirin, and cardiovascular diseasea reappraisal. Arthritis Rheum 2003;48:12-20.[CrossRef][Web of Science][Medline]
21. Catella-Lawson F, Reilly MP, Kapoor SC, et al. Cyclooxygenase inhibitors and the antiplatelet effects of aspirin N Engl J Med 2001;345:1809-1817.[Abstract/Free Full Text]
22. MacDonald TM, Wei L. Effect of ibuprofen on cardioprotective effect of aspirin Lancet 2003;361:573-574.[CrossRef][Web of Science][Medline]
23. Ouellet M, Riendeau D, Percival MD. A high level of cyclooxygenase-2 inhibitor selectivity is associated with a reduced interference of platelet cyclooxygenase-1 inactivation by aspirin Proc Natl Acad Sci USA 2001;98:14583-14588.[Abstract/Free Full Text]
24. Patrono C, Ciabattoni G, Pinca E, et al. Low dose aspirin and inhibition of thromboxane B2 production in healthy subjects Thromb Res 1980;17:317-327.[CrossRef][Web of Science][Medline]
25. Pedersen AK, FitzGerald GA. Cyclooxygenase inhibition, platelet function, and metabolite formation during chronic sulfinpyrazone dosing Clin Pharmacol Ther 1985;37:36-42.[Web of Science][Medline]
26. Patrignani P, Panara MR, Greco A, et al. Biochemical and pharmacological characterization of the cyclooxygenase activity of human blood prostaglandin endoperoxide synthases J Pharmacol Exp Ther 1994;271:1705-1712.[Abstract/Free Full Text]
27. Ciabattoni G, Maclouf J, Catella F, FitzGerald GA, Patrono C. Radioimmunoassay of 11-dehydrothromboxane B2 in human plasma and urine Biochim Biophys Acta 1987;918:293-297.[Medline]
28. Pedersen AK, FitzGerald GA. Dose-related kinetics of aspirin. Presystemic acetylation of platelet cyclooxygenase N Engl J Med 1984;311:1206-1211.[Abstract]
29. Patrignani P, Filabozzi P, Patrono C. Selective cumulative inhibition of platelet thromboxane production by low-dose aspirin in healthy subjects J Clin Invest 1982;69:1366-1372.[Web of Science][Medline]
30. Kurth T, Glynn RJ, Walker AM, et al. Inhibition of clinical benefits of aspirin on first myocardial infarction by nonsteroidal antiinflammatory drugs Circulation 2003;108:1191-1195.[Abstract/Free Full Text]
Related Article
-
The use of anti-inflammatory analgesics in the patient with cardiovascular disease: What a pain
- Steven R. Steinhubl
J. Am. Coll. Cardiol. 2005 45: 1302-1303.
[Full Text]
[PDF]
This article has been cited by other articles:
|
|
|
|
 
L. Di Francesco, L. Totani, M. Dovizio, A. Piccoli, A. Di Francesco, T. Salvatore, A. Pandolfi, V. Evangelista, R. A. Dercho, F. Seta, et al.
Induction of Prostacyclin by Steady Laminar Shear Stress Suppresses Tumor Necrosis Factor-{alpha} Biosynthesis via Heme Oxygenase-1 in Human Endothelial Cells
Circ. Res.,
February 27, 2009;
104(4):
506 - 513.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
F. Santilli, B. Rocca, R. De Cristofaro, S. Lattanzio, L. Pietrangelo, A. Habib, C. Pettinella, A. Recchiuti, E. Ferrante, G. Ciabattoni, et al.
Platelet cyclooxygenase inhibition by low-dose aspirin is not reflected consistently by platelet function assays implications for aspirin "resistance".
J. Am. Coll. Cardiol.,
February 24, 2009;
53(8):
667 - 677.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
L. A. Garcia Rodriguez, S. Tacconelli, and P. Patrignani
Role of Dose Potency in the Prediction of Risk of Myocardial Infarction Associated With Nonsteroidal Anti-Inflammatory Drugs in the General Population
J. Am. Coll. Cardiol.,
November 11, 2008;
52(20):
1628 - 1636.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
V. F. Panoulas, G. S. Metsios, A. V. Pace, H. John, G. J. Treharne, M. J. Banks, and G. D. Kitas
Hypertension in rheumatoid arthritis
Rheumatology,
September 1, 2008;
47(9):
1286 - 1298.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
N. Zimmermann, E. Gams, and T. Hohlfeld
Aspirin in coronary artery bypass surgery: new aspects of and alternatives for an old antithrombotic agent.
Eur. J. Cardiothorac. Surg.,
July 1, 2008;
34(1):
93 - 108.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
C. Patrono, C. Baigent, J. Hirsh, and G. Roth
Antiplatelet Drugs: American College of Chest Physicians Evidence-Based Clinical Practice Guidelines (8th Edition)
Chest,
June 1, 2008;
133(6_suppl):
199S - 233S.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. I. Schwartz, A. L. Dallob, P. J. Larson, O. F. Laterza, J. Miller, J. Royalty, K. M. Snyder, D. L. Chappell, D. A. Hilliard, M. E. Flynn, et al.
Comparative Inhibitory Activity of Etoricoxib, Celecoxib, and Diclofenac on COX-2 Versus COX-1 in Healthy Subjects
J. Clin. Pharmacol.,
June 1, 2008;
48(6):
745 - 754.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
P. Patrignani, M. L Capone, and S. Tacconelli
NSAIDs and cardiovascular disease
Heart,
April 1, 2008;
94(4):
395 - 397.
[Full Text]
[PDF]
|
|
|
|
|
|
|
G. A. FitzGerald
Summary
Arterioscler Thromb Vasc Biol,
March 1, 2008;
28(3):
s51 - s52.
[Full Text]
[PDF]
|
|
|
|
|
|
|
C. Patrono and B. Rocca
Aspirin: Promise and Resistance in the New Millennium
Arterioscler Thromb Vasc Biol,
March 1, 2008;
28(3):
s25 - s32.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
F. M. Gengo, L. Rubin, M. Robson, M. Rainka, M. F. Gengo, D. E. Mager, and V. Bates
Effects of Ibuprofen on the Magnitude and Duration of Aspirin's Inhibition of Platelet Aggregation: Clinical Consequences in Stroke Prophylaxis
J. Clin. Pharmacol.,
January 1, 2008;
48(1):
117 - 122.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
J. D. Snoep, M. M. C. Hovens, J. C. J. Eikenboom, J. G. van der Bom, and M. V. Huisman
Association of Laboratory-Defined Aspirin Resistance With a Higher Risk of Recurrent Cardiovascular Events: A Systematic Review and Meta-analysis
Arch Intern Med,
August 13, 2007;
167(15):
1593 - 1599.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. L. Capone, S. Tacconelli, M. G. Sciulli, P. Anzellotti, L. Di Francesco, G. Merciaro, P. Di Gregorio, and P. Patrignani
Human Pharmacology of Naproxen Sodium
J. Pharmacol. Exp. Ther.,
August 1, 2007;
322(2):
453 - 460.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
M E Farkouh, J D Greenberg, R V Jeger, K Ramanathan, F W A Verheugt, J H Chesebro, H Kirshner, J S Hochman, C L Lay, S Ruland, et al.
Cardiovascular outcomes in high risk patients with osteoarthritis treated with ibuprofen, naproxen or lumiracoxib
Ann Rheum Dis,
June 1, 2007;
66(6):
764 - 770.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
W. B. White
Cardiovascular Effects of the Cyclooxygenase Inhibitors
Hypertension,
March 1, 2007;
49(3):
408 - 418.
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Chaiamnuay, J. J. Allison, and J. R. Curtis
Risks versus benefits of cyclooxygenase-2-selective nonsteroidal antiinflammatory drugs.
Am. J. Health Syst. Pharm.,
October 1, 2006;
63(19):
1837 - 1851.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
|
|
|
D. L. Bhatt
NSAIDS and the risk of myocardial infarction: do they help or harm?
Eur. Heart J.,
July 2, 2006;
27(14):
1635 - 1636.
[Full Text]
[PDF]
|
|
|
|
|
|
|
C. Patrono, L. A. Garcia Rodriguez, R. Landolfi, and C. Baigent
Low-dose aspirin for the prevention of atherothrombosis.
N. Engl. J. Med.,
December 1, 2005;
353(22):
2373 - 2383.
[Full Text]
[PDF]
|
|
|
|
|
|
|
M. Hermann, H. Krum, and F. Ruschitzka
To the Heart of the Matter: Coxibs, Smoking, and Cardiovascular Risk
Circulation,
August 16, 2005;
112(7):
941 - 945.
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. R. Steinhubl
The use of anti-inflammatory analgesics in the patient with cardiovascular disease: What a pain
J. Am. Coll. Cardiol.,
April 19, 2005;
45(8):
1302 - 1303.
[Full Text]
[PDF]
|
|
|
|
|
|
|
S. Fries and T. Grosser
The Cardiovascular Pharmacology of COX-2 Inhibition
Hematology,
January 1, 2005;
2005(1):
445 - 451.
[Abstract]
[Full Text]
[PDF]
|
|
|
|
Top
Abstract
Methods