Beneficial effects of ibuprofen in pacing-induced myocardial ischemia

Acute aspirin treatment abolishes, whereas acute ibuprofen treatment enhances morphine-induced cardioprotection: role of 12-lipoxygenase

Patients suffering an acute myocardial infarction routinely receive morphine and nonsteroidal anti-inflammatory drugs (NSAIDs) alone or in combination. However, the importance of the dose, timing, or the combined administration of both on infarct size reduction has not been assessed. Additionally, it is not known whether morphine or NSAIDs require 12-lipoxygenase (12-LO) to mediate infarct size reduction as found previously for ischemic preconditioning. Male Sprague-Dawley rats were subjected to 30 min of ischemia and 2 h of reperfusion, followed by infarct size assessment (mean +/- S.E.M.%, **P < 0.01). Morphine (0.3 mg/kg), ibuprofen (3 mg/kg), but not aspirin (3 mg/kg) reduced infarct size when administered 5 min before reperfusion compared with vehicle (42.3 +/- 1.5**, 40.8 +/- 2.8**, 60.7 +/- 2.3 versus 59.1 +/- 1.7%, respectively); however, none of these agents reduced infarct size when administered 10 s after reperfusion. Ibuprofen (3 mg/kg) administered with morphine (0.3 mg/kg) reduced infarct size (43.7 +/- 1.3%**), whereas aspirin (1 and 3 mg/kg) abolished morphine-induced infarct size reduction. Morphine (0.2 mg/kg) and ibuprofen (0.6 mg/kg) given at doses not effective individually reduced infarct size when given together (59.0 +/- 1.4, 57.6 +/- 2.8, and 43.9 +/- 1.6%**, respectively). Morphine- and ibuprofen-induced infarct size reduction was abolished by the 12-LO inhibitor baicalein (3 mg/kg) and mimicked by the 12-LO metabolite 12-(S)-hydroxyeicosa-5Z,8Z,10Z,14Z-tetraenoic acid (45.2 +/- 2.5%**). These data suggest that morphine and ibuprofen reduce infarct size individually or at subthreshold doses in combination by 12-LO when administered 5 min before reperfusion. Furthermore, acute aspirin administration has a detrimental interaction with morphine that abrogates morphine-induced infarct size reduction.

Ibuprofen in acute-care therapy

Ibuprofen is a potent cyclooxygenase inhibitor known to reduce the production of arachidonic acid metabolites. Prostacyclin and thromboxane are well-studied metabolites that play a prominent role in inflammation. Many of the effects of ibuprofen can be linked to its anti-inflammatory properties. Beneficial results from ibuprofen therapy have been documented, and more widespread use of the drug seems indicated. Conditions ranging from immunologic response to trauma and sepsis to postburn lung dysfunction to wound edema are improved by the use of ibuprofen. The fact that ibuprofen is effective in the various conditions detailed above, while other steroidal and nonsteroidal drugs are effective only in selective instances, increases the value of ibuprofen. Other properties of the drug, aside from its anti-inflammatory effects, are not as well studied and not as well known. Their importance, however, should not be overlooked. Superoxide radical tissue injury may be very important in acute injury and this phenomenon needs further study. In several studies ibuprofen has been shown to antagonize this type of injury. Similarly fibrinolysis inhibition is known to occur in burn wounds, but its role in other injuries is unknown. The antagonism of this inhibitor by ibuprofen maintains vascular patency. The clinical use of ibuprofen will increase as research further elucidates the mechanisms of tissue injury in acute situations and the many and varied mechanisms of action of ibuprofen.

Clinical differences among nonsteroidal antiinflammatory drugs: implications for therapeutic substitution in ambulatory patients

The practice of therapeutic substitution, i.e., replacing one drug with another chemically different drug from the same therapeutic class, represents an important therapeutic modification with potential clinical significance far beyond that of generic substitution. Adverse consequences following therapeutic substitution of nonsteroidal antiinflammatory drugs (NSAID) is of special concern because of substantial differences among these agents in pharmacokinetic, pharmacological, and clinical properties. Therapeutic substitution of NSAID for ambulatory patients may result in compromised clinical outcome because (1) patient response is unpredictable and selection of the optimal agent must be tailored for each patient; (2) substantial differences exist in adverse reaction profiles; (3) drug interaction studies are lacking; and (4) selection of an agent must be individualized to ensure compliance with the dosing regimen. Cost savings achieved through therapeutic substitution of NSAID may be lost by additional overall treatment costs due to adverse reactions or suboptimal therapy. The occurrence of adverse or suboptimal effects in ambulatory patients is more likely if NSAID are substituted without full knowledge of the patient's medical history and clinical status. Communication between the pharmacy and prescribing physician regarding a patient's specific needs is essential for rational substitution among NSAID.

Effect of complement depletion on O2 supply and consumption in ischemic dog myocardium

The purpose of this study was to determine whether depletion of serum complement can decrease the severity of an ischemic episode by improving regional O2 supply and consumption parameters in the ischemic region of the heart. Fourteen anesthetized dogs with serum complement intact or depleted (100 U/kg cobra venom factor given 8 hrs before) were subjected to left anterior descending coronary artery (LAD) occlusion for 6 hrs. Myocardial blood flows were determined before and 6 hrs after LAD occlusion using radioactive microspheres. Regional arterial and venous O2 saturations were determined using microspectrophotometry. In control animals, flow decreased from 122 +/- 42 to 13 +/- 14 ml/min/100 g (mean +/- SD) in the occluded LAD region. With complement depletion, LAD occlusion resulted in a flow reduction in the ischemic region (38 +/- 29 ml/min/100 g), but to a lesser degree than seen in the same region in control animals, especially in the subendocardium. O2 consumption was decreased in the ischemic region of both treatment groups, though O2 consumption was higher in this region in complement depleted animals compared to the values in control animals. The O2 supply/consumption ratio was decreased similarly in the ischemic region of control and complement depleted groups. Thus, with complement depletion, flow to the ischemic zone was improved but this region was still flow restricted. The flow increase during complement depletion was sufficient to allow an increased O2 utilization in the ischemic region.