Randomized study of phentolamine mesylate for reversal of local anesthesia.

Local anesthetic solutions frequently contain vasoconstrictors to increase the depth and/or duration of anesthesia. Generally, the duration of soft-tissue anesthesia exceeds that of pulpal anesthesia. Negative consequences of soft-tissue anesthesia include accidental lip and tongue biting as well as difficulty in eating, drinking, speaking, and smiling. A double-blind, randomized, multicenter, Phase 2 study tested the hypothesis that local injection of the vasodilator phentolamine mesylate would shorten the duration of soft-tissue anesthesia following routine dental procedures. Participants (122) received one or two cartridges of local anesthetic/vasoconstrictor prior to dental treatment. Immediately after treatment, 1.8 mL of study drug (containing 0.4 mg phentolamine mesylate or placebo) was injected per cartridge of local anesthetic used. The phentolamine was well-tolerated and reduced the median duration of soft-tissue anesthesia in the lip from 155 to 70 min (p < 0.0001).

Comparing efficacy and safety of four intravenous sedation regimens in dental outpatients.

BACKGROUND: Management of patients' fear and anxiety during dental treatment is a primary concern of dental practitioners. Pharmacological strategies used in outpatient dental settings must be both safe and effective. Regimens of intravenously administered sedative drugs were evaluated in a collaborative, multicenter study of outpatients undergoing removal of impacted third molars. METHODS: A total of 997 patients randomly received one of five treatments: placebo; midazolam administered to a clinical endpoint of conscious sedation (mean dose, 8.6 milligrams); midazolam plus additional midazolam as needed during the procedure (mean total dose, 12.2 mg); fentanyl (1.4 micrograms/kilogram) plus midazolam to achieve the same endpoint of conscious sedation (mean dose, 5.7 mg); or fentanyl (1.4 (micrograms/kg), midazolam (mean dose, 5.8 mg) and methohexital as needed during the procedure (mean dose, 61.0 mg). RESULTS: Each drug regimen reduced anxiety during surgery in comparison with placebo, with the combination of midazolam, fentanyl and methohexital resulting in significantly less anxiety in comparison with the other treatment groups. Pain reports by patients during surgery also were reduced significantly by the combination of fentanyl, midazolam and methohexital. Patients' global evaluations of the efficacy of sedation ranked midazolam with supplemental midazolam and the combination of fentanyl, midazolam and methohexital as significantly more efficacious than the other two drug regiments. The authors noted transient respiratory depression in patients in the two opioid-treated groups, but no other physiological changes were detected. CONCLUSIONS: These data provide evidence that the drugs and doses evaluated resulted in therapeutic benefit to dental outpatients, with minimal incidence of potentially serious adverse effects. CLINICAL IMPLICATIONS: The results of this large-scale study provide assurance to both the public and the dental profession of the safety of parenteral sedation with these drugs and combinations of these drugs when titrated slowly in the recommended doses by appropriately trained dentists.

Making patients safe and comfortable for a lifetime of dentistry: frontiers in office-based sedation.

Conscious sedation administered in the office setting is one important method for helping people obtain necessary dental care. Patients who may benefit from sedation include the dentally fearful, young children, the behaviorally or medically challenged, and individuals who are undergoing invasive procedures or have problems with gagging or local anesthesia. In-office sedation is effective in reducing apprehension and can improve patient behavior without adversely affecting the patient's physiological status. Mortality and serious morbidity are exceedingly rare in modern practice. Although behavioral strategies are clearly more cost-effective for the patient receiving routine dental care, in-office sedation is usually the least expensive alternative for patients requiring pharmacologic management. Future advances in conscious sedation may include agents and techniques currently thought to be dangerous for nongeneral anesthesia-trained dentists because of their ability to produce rapid changes in anesthetic depth. However, delivery devices such as infusion pumps for drugs like propofol, when coupled with computers to help regulate the infusion rate and monitor the sedative effect, may provide the necessary control for safe administration of propofol and similar drugs by these individuals. A final approach to drug delivery may involve patient-controlled sedation in which the patient self-infuses small boluses incrementally until the desired effect is achieved.

Anesthesia and pain management.

Acute orofacial pain is usually managed by the administration of local anesthetics, systemic analgesics, or a combination of the two methods. In an emergency, intraoral maxillary nerve blockade is helpful for controlling pain in the midface, although infiltrations may be more suitable for discomfort originating from individual teeth or portions of the alveolar process. Mandibular anesthesia can be achieved by open or closed-mouth techniques for inferioral alveolar-lingual nerve blockade. Systemic pain relief is optimized by using full analgesic doses of NSAIDs, with opioids serving to increase the degree of analgesia if required, or to be used, often with acetaminophen, in patients intolerant to NSAIDs.

Office-based anesthesia in dentistry. Past, present, and future trends.

The history of office-based anesthesia dates back to the discovery of nitrous oxide and ether in the 1840s. In recent years, advances in intravenous anesthetic techniques and the rising costs of hospital-based services have combined to promote the practice of ambulatory anesthesia. Dental patients who may benefit from office-based anesthesia include patients undergoing stressful procedures, fearful patients, medically or behaviorally challenged patients, young children, and patients with a history of gagging or local anesthesia problems. The future of office-based anesthesia in dentistry appears bright. Its development, however, will be influenced by organized dentistry, medical anesthesia, and other groups interested in pain and anxiety control, and state legislatures reacting to public demands for both safe and cost-effective anesthesia care.

Adverse drug interactions in dental practice: interactions associated with vasoconstrictors. Part V of a series.

BACKGROUND: Adrenergic vasoconstrictors are commonly used by dentists to enhance the pain-relieving action of local anesthetics and to control local bleeding. Although normally considered safe for these applications, vasoconstrictors can participate in drug interactions that potentially are harmful to patients. METHODS: The faculty of a March 1998 symposium entitled "Adverse Drug Interactions in Dentistry: Separating the Myths From the Facts" extensively reviewed the literature on drug interactions. They then established a significance rating of alleged adverse drug interactions pertaining to dentistry, based on the quality of documentation and severity of effect. The author of this article focused on the adrenergic vasoconstrictors epinephrine and levonordefrin. RESULTS: Vasoconstrictor drug interactions involving tricyclic antidepressants, nonselective beta-adrenergic blocking drugs, certain general anesthetics and cocaine are well-documented in both humans and animals as having the potential for causing serious morbidity or death. Evidence for adverse interactions involving adrenergic neuronal blocking drugs, drugs with alpha-adrenergic blocking activity, local anesthetics and thyroid hormones is much less compelling, suggesting for the most part that clinically significant reactions may occur only when both the vasoconstrictor and the interacting drug are used in excessive doses. In the case of monoamine oxidase inhibitors, there is no credible evidence of a significant interaction with epinephrine or levonordefrin. CONCLUSIONS: Potentially serious adverse drug interactions involving adrenergic vasoconstrictors can occur in dental practice. In most circumstances, careful administration of small doses of vasoconstrictors and avoidance of gingival retraction cord containing epinephrine, coupled with monitoring of vita signs, will permit these drugs to be used with no risk or only minimally increased risk. Only in the case of cocaine intoxication must adrenergic vasoconstrictors be avoided completely. CLINICAL IMPLICATIONS: For optimal patient safety, dentists must recognize potential drug interactions involving adrenergic vasoconstrictors and modify their use of these agents accordingly.

Adverse drug interactions in dental practice. Professional and educational implications.

BACKGROUND: Rapid progress in dental pharmacotherapeutics requires that clinicians constantly update their knowledge of new drugs, drug interactions and useful therapeutic trends. This article is the first in a five-part series based on a 1998 International Association for Dental Research symposium entitled "Adverse Drug Interactions in Dentistry: Separating the Myths From the Facts." The goal of the series is to identify specific adverse drug interactions that are relevant to the therapeutic agents commonly used in general dental practice: analgesics, antibiotics, sedatives, local anesthetics and vasoconstrictors. METHODS: A group of dentist/clinical pharmacologists, with documented expertise in specific areas of dental therapeutics, reviewed the current literature regarding adverse drug interactions in dentistry. This expert panel evaluated the quality of information used to document these drug interactions and assess the severity of these drug reactions with respect to the drugs' use in dental practice. RESULTS: On the basis of the quality and severity of each reported interaction, the authors summarized the clinical importance of these drug interactions using a Significance Rating for Dental Drug Interactions. The participants presented their recommendations at the above-mentioned IADR symposium. CONCLUSIONS: Although thousands of drug interactions are described in the literature, the authors found many to be poorly documented or of minor importance to dental practitioners. For interactions that they determined to be relevant, the participants provided recommendations and precautions for preventing these potential complications. This article discusses the professional impact of drug interactions on dental practice; the classification and documentation of drug interactions; the determination of causality between drug interactions and adverse effects; risk factors; and unique characteristics of dental therapeutics. Subsequent articles will present specific summary recommendations for drug interactions associated with the use of antibiotics, analgesics, sedatives, and local anesthetics and vasoconstrictors. CLINICAL IMPLICATIONS: Although thousands of drug interactions have been reported in the literature, only a few are significantly associated with dental therapeutic agents. Avoiding these drug interactions will prevent potentially severe reactions in dental practice.

Prophylactic antibiotics: cardiac and prosthetic considerations.

The administration of antibiotics in dentistry to prevent systemic disease should be based on a rational consideration of both the anticipated benefits of such practice and the potential risks. In the case of patients susceptible to infective endocarditis, the routine use of prophylactic antibiotics is justified for high-risk patients and for procedures likely to cause significant bacteremia; in the case of patients with prosthetic joints, it is not.

Dental management of the adolescent with panic disorder.

Panic disorder is a psychiatric disease without obvious cause. It is accompanied by signs of terror, such as chest pain, palpitation, and shortness of breath. One of every 75 Americans is afflicted. Onset occurs most commonly during adolescence. Some infants and children exhibit anxiety-like responses, such as retreat and avoidance, and behavioral restraint when faced with unfamiliar people, objects, and events. Panel disorder has a special relevance for dentistry, because it is frequently associated with mitral valve prolapse. Furthermore, medications used to treat the disorder are associated with detrimental changes in the oral cavity and adverse interactions with dental therapeutic agents. The authors discuss the podromal characteristics of children at risk for panic disorder and the characteristics of the malady recognized by the American Psychiatric Association. Associated medical problems are also presented and discussed. A survey of ninth graders found as many as 12 percent had spontaneous panic attacks. Approximately 20 percent of all adults with the disorder report its onset before age ten. Etiology, medical and dental management are discussed.

Dental management of the child and adolescent with major depression.

Major depression is a psychiatric disorder in which mood, thought content, and behavioral patterns are impaired, often for an extended period of time. This condition appears to have an increasing prevalence among young children and adolescents. It may be associated with a disinterest in performing appropriate preventive oral hygiene techniques, a cariogenic diet, rampant dental decay, and advanced periodontal disease. Appropriate dental management necessitates a vigorous preventive dental education program and special precautions when administering local anesthetics and prescribing sedative and analgesic medications.

Health hazards and nitrous oxide: a time for reappraisal.

Recent adoption by the American Conference of Governmental Industrial Hygienists of a Threshold Limit Value of 50 ppm for an 8-hour average exposure to nitrous oxide (N2O) increases the likelihood for its regulation by state and federal occupational health agencies. This review outlines current information on the health risks of N2O inhalation to provide a basis from which safe and reasonably attainable exposure limits can be proposed. Although N2O was for many years believed to have no toxicity other than that associated with its anesthetic action, bone marrow depression in patients administered N2O for extended periods of time and neurological abnormalities in health care workers who inhaled N2O recreationally have disproved this notion. Retrospective surveys of dental and medical personnel have also linked occupational exposure to N2O with a number of health problems and reproductive derangements. Nitrous oxide reacts with the reduced form of vitamin B12, thereby inhibiting the action of methionine synthase, an enzyme that indirectly supports methylation reactions and nucleic acid synthesis. Many, if not all, of the nonanesthetic-related adverse effects of N2O may be ascribed to this action. Animal and human studies indicate that the toxic effects of N2O are concentration- and time-dependent. It is suggested that a time-weighted average of 100 ppm for an 8-hour workday and/or a time-weighted average of 400 ppm per anesthetic administration would provide adequate protection of dental personnel and be achievable with existing pollution control methods.

Effect of midazolam pretreatment on the intravenous toxicity of lidocaine with and without epinephrine in rats.

The effect of the benzodiazepine midazolam on the intravenous toxicity of lidocaine with and without epinephrine was studied in male Sprague-Dawley rats. Test rats with and control rats without midazolam premedication (2.5 mg/kg intraperitoneally, 10% of the median dose that caused loss of the righting reflex in a third group of rats) were given 2% lidocaine with and without 10 micrograms/ml epinephrine intravenously in doses sufficient to construct log-dose response curves for both convulsant and lethal responses. In control rats the median convulsant dose (CD50) of lidocaine was 15.2 mg/kg given alone and 10.9 mg/kg with epinephrine (a statistically significant difference); respective values for the median lethal dose (LD50) were 26.4 and 18.5 mg/kg (also statistically significant). While epinephrine enhanced lidocaine seizure activity and lethality by approximately 50%, midazolam almost completely prevented lidocaine-induced convulsions but had no significant effect on mortality.

The use of amide local anesthetics in patients susceptible to malignant hyperthermia.

The use of amide local anesthetics in dental patients presumed to be susceptible to malignant hyperthermia (MH) is controversial. A literature review of 17 recent dental publications and their reference citations revealed that the recommendation to avoid local anesthetics of the amide type in dental treatment of MH-susceptible (MHS) patients is based on in vitro muscle investigations, unpublished communications, and a single case report suggestive of MH. Therefore, a survey of members of the Malignant Hyperthermia Association of the United States designed to determine what, if any, MH-like reactions have occurred in patients with MHS receiving dental treatment was conducted. Of a total of 307 MHS respondents, 36 (12%) reported adverse reactions to dental care. Only one respondent, however, reported symptoms suspicious of MH (fever, muscle pain) in which the administration of amide local anesthetics appeared to be closely linked. Fifty-six (18%) of the respondents have had difficulty obtaining routine dental care since being identified as MHS; this includes 27 who have been refused dental treatment or have had to undergo operative procedures without the benefit of local anesthesia. These results support the conclusions that amide local anesthetics may be administered to MHS patients without significant risk and that currently the diagnosis of MH susceptibility can adversely affect the quality of dental care.

Hypertensive response to levonordefrin in a patient receiving propranolol: report of case.

Propranolol is a commonly used drug; of new and refilled prescriptions, it ranked no. 1 in 1984 and no. 2 in 1985. Medical conditions for its use include angina pectoris, myocardial infarction, hypertension, cardiac dysrhythmias, hypertrophic subaortic stenosis, migraine headache, hyperthyroidism, and pheochromocytoma. Almost all dental practitioners will treat a patient receiving propranolol for one of these conditions. The following recommendations seem appropriate at this time: The patient should continue to receive propranolol during dental treatment. Sudden withdrawal of the beta-blocker will cost the patient the benefit of propranolol therapy and may lead to acute myocardial ischemia. Acute stress should be minimized, as hypertensive responses may also be caused by endogenously released epinephrine. Short appointments scheduled in the morning, possibly with conscious sedation, should be considered. The dosage of adrenergic vasoconstrictors should be limited and gingival retraction cord containing epinephrine avoided entirely. The blood pressure should be taken approximately 5 minutes after local anesthesia is administered to determine if a systemic response has occurred. In the unlikely event of a hypertensive emergency, a rapidly acting, short-duration antihypertensive drug, such as the alpha-blocker phentolamine (Regitine, 5 mg intravenously) should be administered. Sublingual nitroglycerin (Nitrostat, 0.4 mg) may be useful as a nonparenteral alternative. These recommendations apply to other nonselective beta-blockers, including nadolol (Corgard) and timolol (Blocadren). They may also apply to labetalol (Normodyne, Trandate), a nonselective beta-antagonist with some alpha-blocking activity and to pindolol (Visken), a beta-blocker with some intrinsic beta 2-agonistic activity.(ABSTRACT TRUNCATED AT 250 WORDS)