A preliminary study on plasma concentration achieved following intrapterygomandibular space injection of dexamethasone as a route of drug delivery with lignocaine inferior alveolar nerve block-correlation of clinical effects.

PURPOSE: To determine the quantity of dexamethasone plasma concentration achieved following intrapterygomandibular space injection of dexamethasone when co-administered with inferior alveolar nerve block correlating with the clinical effects in the postoperative phase. OBJECTIVE: A preliminary prospective study to evaluate the dexamethasone plasma concentration achieved following intrapterygomandibular space injection of dexamethasone with 2% lignocaine inferior alveolar nerve block to achieve hemi-mandibular anesthesia for minor oral surgical procedures and derive clinical correlations. BACKGROUND: Dexamethasone is a glucocorticoid, chiefly used for the management of postsurgical sequelae like trismus and swelling in maxillofacial surgical practice. Conventionally, parenteral dexamethasone is administered via intravenous or intramuscular route. Intrapterygomandibular space injection is a novel route of steroid delivery described in literature. For minor oral surgical procedures in maxillofacial surgical practice requiring inferior alveolar nerve block, dexamethasone can be administered along with local anesthetic through a single injection as a mixture (twin mix). METHODS: Prospective double-blind randomized clinical trial was designed to evaluative plasma concentration of dexamethasone achieved following injection of a freshly prepared mixture of 1.8 ml of 2% lignocaine with adrenaline (1:200000) and 1 ml (4 mg) dexamethasone [2.8 ml solution of twin mix] in the pterygomandibular space. The 30 candidates included for the trial were randomly split into three study groups (ten each)-(1) control group (C); (2) intramuscular group (IM); (3) intraspace group (IS). RESULTS: The mean plasma dexamethasone concentration at 30 min postinjection in group IM was 226.41 ± 48.67 ng/ml and for IS group it was 209.67 ± 88.13 ng/ml. Post hoc (Bonferroni-Holm test) intergroup comparison for plasma dexamethasone concentration (IM and IS) was found statistically insignificant (P = 0.605). CONCLUSION: Intraspace route of drug administration can be utilized to deliver dexamethasonized local anesthetics safely with predictable clinical effects in the patients requiring mandibular minor oral surgery under local anesthesia.