Drug Interactions between evening primrose and Yosprala

Coadministration with proton pump inhibitors may decrease the oral bioavailability of aspirin and other salicylates. The interaction has been studied with omeprazole and aspirin, although data are conflicting. In one study, pretreatment with omeprazole (20 mg/day for 2 days) in 11 healthy volunteers led to a significant and progressively greater reduction in the mean serum salicylate level at 30, 60, and 90 minutes after administration of aspirin (650 mg single dose). The investigators suggest that acid suppression may reduce the lipophilic nature of aspirin, thereby adversely affecting its absorption from the gastrointestinal tract. Another study found no effect of omeprazole pretreatment (20 mg/day for 4 days) on plasma salicylate and aspirin levels, skin bleeding times, or antiplatelet effect of low-dose aspirin (125 mg single dose) in 14 healthy volunteers. However, these results do not exclude the possibility that omeprazole might interfere with the analgesic, antipyretic, or anti-inflammatory effects of aspirin, which has been demonstrated in rats.

Proton pump inhibitors may enhance the release rate of salicylates from enteric-coated formulations due to premature disruption of the coating and intragastric release of the drug secondary to an increase in gastric pH. In eight healthy volunteers, omeprazole pretreatment (20 mg/day for 4 days) did not affect the bioavailability of salicylate from uncoated aspirin tablets but significantly increased the absorption rate of salicylate from enteric-coated sodium salicylate tablets. The clinical significance of this interaction is unknown. Theoretically, it may increase the risk of gastric adverse effects associated with salicylates.

Theoretically, use of borage or evening primrose oil with anticoagulants or antiplatelet aggregation drugs may increase the risk of bleeding in some patients. In one study, 12 hyperlipidemic males took gamma linolenic acid 240 mg and linolenic acid 2200 mg (both main components of borage and evening primrose oil) daily for 4 months. After 4 months on this supplementation and compared to baseline, platelet aggregation decreased by 50% when platelets were aggregated with adenosine diphosphate (ADP), and by 60% with adrenaline. Also, in the same study platelet thromboxane B2 levels were reduced by 54% as compared to placebo. However, another study suggests platelet aggregation in healthy patients may not be affected by borage oil supplementation. Until further information is available, clinical and laboratory observation for hematologic complications is recommended. Patients should be advised to promptly report any signs of bleeding to their physician, including prolonged bleeding from cuts, increased menstrual flow, vaginal bleeding, nosebleeds, bleeding of gums from brushing, unusual bruising, red or brown urine, or red or black stools.