Interaction between Naproxen and Danaparoid
Major Synergy

ID DDInter1266 and DDInter471
Interaction In patients receiving neuraxial anesthesia or spinal puncture, the risk of developing an epidural or spinal hematoma during low molecular weight heparin (LMWH) or heparinoid 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. Theoretically, NSAIDs may potentiate the risk of bleeding complications associated with LMWH or heparinoid therapy. 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 LMWHs or heparinoids on the clotting cascade.
Management Products containing NSAIDs, especially if given chronically and in high dosages, should preferably be avoided in patients receiving LMWHs or heparinoids. 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.
References
Alternative for Naproxen G02C
Ritodrine
Cabergoline
Flibanserin
Bromocriptine

M02A
Phenylbutazone
Rabeprazole
Dimethyl sulfoxide
Tolazoline
Capsaicin (topical)

M01A
Misoprostol
Chondroitin sulfate
More
Alternative for Danaparoid B01A
Heparin (flush)
Selexipag
Acenocoumarol
Protein C

Potential Metabolism Interactions

Substrate-Substrate Interaction：If more than one drug is metabolized by the same CYP, it is possible that its metabolism is inhibited because of the competition between the drugs. That means, it can be useful to lower the dosage of the drugs in the drug-cocktail because they remain longer in the organism than in monotherapy.
Inhibitor-Inhibitor Interaction：Combining two or more inhibitors of one CYP, should be compensated by lowering the dosage of these drugs because the metabolism is reduced and the drugs remain longer in the organism than in monotherapy. Not adapting the dosage bears the risk of even more side effects.
Inhibitor-Substrate Interaction：Combining drugs that have inhibitory effect and are substrates of one particular CYP, should be compensated by lowering the dosage. They rest longer in the organism than in monotherapy. Not adapting the dosage bears the risk of even more side effects.