Effect of inflammation on the delivery of drugs to dental pulp.

Although numerous studies have evaluated the effects of drugs on inflammation, comparatively few studies have evaluated the effects of inflammation on drugs. In this study, we have evaluated whether pulpal inflammation alters the delivery of flurbiprofen or Evan's blue, two agents that bind with high affinity to plasma proteins. The results indicate that pulpal inflammation alters the delivery of these agents to inflamed molars, that activation of capsaicin-sensitive nerves increases pulpal content of protein-bound agents, and that reduced pH increases free drug concentrations of flurbiprofen. Thus, alterations in both plasma extravasation and tissue pH seem to be relevant factors regulating the delivery and bioavailability of this nonsteroidal anti-inflammatory drug to dental pulp. Because many drugs used in endodontics (e.g. nonsteroidal anti-inflammatory drugs, clindamycin, bupivacaine, etc.) are heavily bound to plasma proteins, it is likely that the status of pulpal inflammation is a contributing factor in modifying the pharmacological efficacy of these agents.