Orudis or Oruvail contain ketoprofen. Like other drugs of its class, ketoprofen is not free of side effects. The side effects of these drugs can cause discomfort and rarely, there are more serious side effects, such as gastrointestinal bleeding, which may result in hospitalization and even fatal outcomes. NSAIDs are often essential agents in the management of arthritis and have a major role in the treatment of pain, but they also may be commonly employed for conditions which are less serious. Physicians may wish to discuss with their patients the potential risks and likely benefits of NSAID treatment, particularly when the drugs are used for less serious conditions where treatment without NSAIDs might represent an acceptable altemative to both the patient and physicisn.
Because aspirin causes an increase in the level of unbound ketoprofen, patients should be advised not to take aspirin while taking ketoprofen. It is possible that minor adverse symptoms of gastric intolerance may be prevented by administering Orudis with antacids, food or milk. Oruvail has not been studied with antacids. Because food and milk do affect the rate but not the extent of absorption (see CLINICAL PHARMACOLOGY), physicians may want to make specific recommendations to patients about when they should take ketoprofen in relation to food and/ or what patients should do if they experience minor Gi symptoms associated with ketoprofen therapy.
The following drug interactions were studied with ketoprofen doses of 200 mg/day. The possibility of increased interaction should be kept in mind when Orudis doses greater than 50 mg as a single dose or 200 mg of ketoprofen per day are used concomitantly with highly bound drugs.
1. Antacids: Concomitant administration of magnesium hydroxide and aluminum hydroxide does not interfere with the rate or extent of the absorption of ketoprofen administered as Orudis.
2. Aspirin: Ketoprofen does not alter aspirin absorption; however, in a study of 12 normal subjects, concurrent administration of aspirin decreased ketoprofen protein binding and increased ketoprofen plasma clearance from 0.07 L/kg/h without aspirin to 0.11 L/kg/h with aspirin. The clinical significance of these changes has not been adequately studied. Therefore, concurrent use of aspirin and ketoprofen is not recommended.
3. Diuretic: Hydrochlorothiazide, given concomitantly with ketoprofen, produces a reduction in urinary potassium and chloride excretion compared to hydrochlorothiazide alone. Patients taking diuretics are at a greater risk of developing renal failure secondary to a decrease in renal blood flow caused by prostaglandin inhibition.
4. Digoxin: In a study in 12 patients with congestive heart failure where ketoprofen and digoxin were concomitantly administered, ketoprofen did not alter the serum levels of digoxin.
5. Warfarin: In a short-term controlled study in 14 normal volunteers, ketoprofen did not significantly interfere with the effect of warfarin on prothrombin time. Bleeding from a number of sites may be a complication of warfarin treatment and GI bleeding a complication of ketoprofen treatment. Because prostaglandina play an important role in hemostasis and ketoprofen has an effect on platelet function as well, concurent therapy with ketoprofen and warfarin requires close monitoring of patients on both drugs.
6. Probenecid: Probenecid increases both free and bound ketoprofen by reducing the plasma clearance of ketoprofen to about one-third, as well as decreasing its protein binding. Therefore, the combination of ketoprofen and probenecid is not recommended.
7. Methotrexate: Ketoprofen, like other NSAIDs, may cause changes in the elimination of methotrexate leading to elevated serum levels of the drug and increased toxicity.
8. Lithium: Nonsteroidal anti-inflammatory agents have been reported to increase steadystate plasma lithium levels. It is recommended that plasma lithium levels be monitored when ketoprofen is coadministered with lithium.
DRUG/LABORATORY TEST INTERACTIONS: EFFECT ON BLOOD COAGULATION
Ketoprofen decreases platelet adhesion and aggregation. Therefore, it can prolong bleeding time by approximately 3 to 4 minutes from baseline values. There is no significant change in platelet count, prothrombin time, partial thromboplastin time, or thrombin time.
Ketoprofen is contraindicated in patients who have shown hypersensitivity to it. Ketoprofen should not be given to patients in whom aspirin or other nonsteroidal anti-inflammatory drugs induce asthma, urticaria, or other allergic-type reactions, because severe, rarely fatal, anaphylactic reactions to ketoprofen have been reported in such patients.