Sedatives warfarin interactions

Udall JA. Clinical implications of warfarin interactions with five sedatives. Am J Cardiol (1975) 35, 67-71. 

Propoxyphene interacts with several drugs. The use of sedatives in combination with propoxyphene can be fatal. In addition, the metabolism of the drug is increased in smokers due to induction of liver enzymes. Thus, smokers may require a higher dose of the drug for pain relief. Propoxyphene enhances the effects of both warfarin and carbamazepine and may increase the toxicity associated with both drugs, such as bleeding and sedation, respectively. 

Tea Tree (Melaleuca alternifolia) Uses Rx of superficial wounds (bacterial, viral, fungal, insect bites, minor burns, cold sores, acne Action Broad-spectrum antibiotic activity against E. coli, S. aureus, C. albicans Available forms Topical creams, lotions, oint, oil apply topically PRN Notes/SE Ataxia, contact dermatitis, D, drowsiness, GI mucosal irritation Interactions Effects OF drugs that affect histamine release EMS effects of Benadryl Valerian (Valeriana officinalis) Uses Anxiolytic, antispasmodic, dys-menorrheal, restlessness, sedative Action Inhibits uptake stimulates release of GABA, which T GABA concentration extracellularly causes sedation Available forms Ext 400-900 mg PO 30 min < hs, tea 2-3 g (1 tsp of crude herb) qid, PRN, tine 3-5 mL (1/2-1 tsp) (1 5 ratio) PO qid, PRN Efficacy Probably effective sedative (reduces sleep latency) Notes/SE GI upset, HA, insomnia, N/V, palpitations, restlessness, vision changes Interactions T Effects OF barbiturates, benzodiazepines, opiates, EtOH, catnip, hops, kavakava, passion flower, skullcap effects OF MAOIs, phenytoin, warfarin EMS T Effects of benzodiazepines and opiates abruptly D/C may cause withdrawal symptoms... 

Phenylbutazone displaces warfarin from binding sites on serum albumin, temporarily increasing its effects before the clearance of warfarin increases because of an increase in the unbound fraction (37). If that were the only mechanism, this interaction would not be important. However, phenylbutazone also inhibits the metabolism of 5-warfarin and induces the metabolism of -warfarin (38) the half-life of racemic warfarin is unchanged, but because the S isomer is more potent than the R isomer, the action of warfarin is potentiated (SED-9,144) (36,39). 

Waifann An interaction of gemfibrozil with warfarin [SED-15, 1361] has again been described and the interaction reviewed [20" ]. 

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