Drug Interactions between famotidine / ibuprofen and fondaparinux

GENERALLY AVOID: In patients receiving neuraxial anesthesia or spinal puncture, the risk of developing an epidural or spinal hematoma during LMWH, heparinoid, or fondaparinux therapy may be increased by the concomitant use of other drugs that affect coagulation, including nonsteroidal anti-inflammatory drugs (NSAIDs). The development of epidural and spinal hematoma can lead to long-term or permanent paralysis.

GENERALLY AVOID: Theoretically, NSAIDs may potentiate the risk of bleeding complications associated with the use of fondaparinux. NSAIDs interfere with platelet adhesion and aggregation and may prolong bleeding time in healthy individuals. While these effects are generally slight and of relatively short duration with most NSAIDs (except aspirin) at recommended dosages, they may be of pronounced clinical significance when combined with the inhibitory effects of fondaparinux on the clotting cascade. In addition, NSAIDs are known to cause dose-related gastrointestinal bleeding, which may be complicated by anticoagulant therapy.

MANAGEMENT: Products containing NSAIDs, especially if given chronically or in high dosages, should preferably be discontinued prior to initiation of fondaparinux therapy. Close clinical and laboratory observation for bleeding complications is recommended if concurrent therapy is necessary. In patients undergoing neuraxial intervention, coadministration of these agents should be approached with caution and only after thorough assessment of risks and benefits. Besides bleeding complications, patients should also be monitored frequently for signs and symptoms of neurologic impairment such as midline back pain, sensory and motor deficits (numbness or weakness in lower limbs), and bowel or bladder dysfunction.

H2 antagonists may alter the pharmacokinetic disposition of some nonsteroidal anti-inflammatory drugs (NSAIDs), resulting in increased or decreased plasma concentrations. Data have been varied, even for the same NSAID. The mechanism may involve inhibition of metabolism, changes in gastric pH resulting in altered absorption, and/or reduced urinary elimination of the affected NSAIDs. Statistically significant changes have been small and of limited clinical significance when interactions have been observed.