Drug interactions in dentistry

Predictive Models for Human Cytochrome P450 3A7 Selective Inhibitors and Substrates

Inappropriate use of prescription drugs is potentially more harmful in fetuses/neonates than in adults. Cytochrome P450 (CYP) 3A subfamily undergoes developmental changes in expression, such as a transition from CYP3A7 to CYP3A4 shortly after birth, which provides a potential way to distinguish medication effects on fetuses/neonates and adults. The purpose of this study was to build first-in-class predictive models for both inhibitors and substrates of CYP3A7/CYP3A4 using chemical structure analysis. Three metrics were used to evaluate model performance: area under the receiver operating characteristic curve (AUC-ROC), balanced accuracy (BA), and Matthews correlation coefficient (MCC). The performance varied for each CYP3A7/CYP3A4 inhibitor/substrate model depending on the data set type, model type, rebalancing method, and specific feature set. For the active inhibitor/substrate data set, the optimal models achieved AUC-ROC values ranging from 0.77 ± 0.01 to 0.84 ± 0.01. For the selective inhibitor/substrate data set, the optimal models achieved AUC-ROC values ranging from 0.72 ± 0.02 to 0.79 ± 0.04. The predictive power of the optimal models was validated by compounds with known potencies as CYP3A7/CYP3A4 inhibitors or substrates. In addition, we identified structural features significant for CYP3A7/CYP3A4 selective or common inhibitors and substrates. In summary, the top performing models can be further applied as a tool to rapidly evaluate the safety and efficacy of new drugs separately for fetuses/neonates and adults. The significant structural features could guide the design of new therapeutic drugs as well as aid in the optimization of existing medicine for fetuses/neonates.

A Validated Method for Separation and Determination of Codeine Phosphate Hemihydrate Impurities in Bilayer Tablet Dosage Form of Naproxen Sodium and Codeine Phosphate by Using UHPLC

Background:

Apranax Plus® is a new bilayer tablet dosage form, which combines two active pharmaceutical ingredients: naproxen sodium and codeine phosphate.

Objective:

The purpose of this work was to develop an ultra-high-performance liquid chromatography (UHPLC) method for the separation and determination of codeine phosphate hemihydrate impurities in a bilayer tablet dosage form.

Methods:

The separation and determination of codeine phosphate hemihydrate and its impurities, methylcodeine, morphine, codeine dimer, 10-hydroxycodeine, 14-hydroxycodeine, thebaine and codeinone were achieved by using reversed-phase liquid chromatography with TUV (Tunable UV Detector) and PDA (Photodiode Array Detector) detection by UHPLC. The new proposed method utilized by the Waters Acquity UHPLC® TUV and PDA systems using a UHPLC column Waters Acquity, BEH, C18, 2.1x100 mm, 1.7 μm particle size with a mixture of component A and acetonitrile in a gradient mode at a flow rate of 0.3mL/min, at 25°C with a load of 5μL. The detection for all eluted compounds was carried out at 245nm.

Results:

The codeine phosphate hemihydrate and peaks of its impurities were adequately obtained, thus proving the stability-indicating power of the method. The developed method was validated as per the ICH guidelines with respect to parameters such as precision, accuracy, linearity, limit of detection (LOD), limit of quantification (LOQ) and robustness.

Conclusion:

It was verified as being adequate for all the mentioned impurities of codeine phosphate hemihydrate. The described method was found to be useful for routine purity testing and was also found suitable for the analysis of the stability samples of the drug product.

The Fe-N-C Nanozyme with Both Accelerated and Inhibited Biocatalytic Activities Capable of Accessing Drug-Drug Interactions

Emerging as a cost-effective and robust enzyme mimic, nanozymes have drawn increasing attention with broad applications ranging from cancer therapy to biosensing. Developing nanozymes with both accelerated and inhibited biocatalytic properties in a biological context is intriguing to peruse more advanced functions of natural enzymes, but remains challenging, because most nanozymes are lack of enzyme-like molecular structures. By re-visiting and engineering the well-known Fe-N-C electrocatalyst that has a heme-like Fe-N_x active sites, herein, it is reported that Fe-N-C could not only catalyze drug metabolization but also had inhibition behaviors similar to cytochrome P450 (CYP), endowing it a potential replacement of CYP for preliminary evaluation of massive potential chemicals, drug dosing guide, and outcome prediction. In addition, in contrast to electrocatalysts, the highly graphitic framework of Fe-N-C may not be obligatory for a competitive CYP-like activity.

Use of Prescription Opioids and Initiation of Fatal 2-Vehicle Crashes

IMPORTANCE

The prevalence of prescription opioids detected in fatally injured drivers has increased markedly in the past 2 decades in the United States. It is unclear whether driver use of prescription opioids plays a role in fatal crash causation.

OBJECTIVE

To assess the association between driver use of prescription opioids and the risk of being culpable of crash initiation in fatal 2-vehicle crashes.

DESIGN, SETTING, AND PARTICIPANTS

This pair-matched study was based on data from the Fatality Analysis Reporting System for drivers involved in fatal 2-vehicle crashes on US public roads between January 1, 1993, and December 31, 2016. Data analysis was conducted from December 8, 2017, to December 7, 2018.

EXPOSURES

Testing positive for prescription opioids compared with testing negative, and blood alcohol concentrations (BACs) based on toxicological testing results.

MAIN OUTCOMES AND MEASURES

Culpability of crash initiation and adjusted odds ratios and 95% CIs.

RESULTS

A total of 36 642 drivers involved in 18 321 fatal 2-vehicle crashes were included. The most common driving error leading to fatal 2-vehicle crashes was failure to keep in lane (7535 [41%]). Drivers culpable of initiating the crashes were more likely than their nonculpable counterparts to test positive for prescription opioids (918 [5.0%] vs 549 [3.0%]; P < .001), alcohol (BAC ≥0.01 g/dL, 5258 [28.7%] vs 1815 [9.9%]; P < .001), and both substances (1.0% vs 0.3%, P < .001). The adjusted odds ratio of crash initiation was 2.18 (95% CI, 1.91-2.48) for drivers testing positive for prescription opioids compared with drivers testing negative, and increased with BACs (BAC 0.01-0.07 g/dL: adjusted odds ratio, 1.97; 95% CI, 1.75-2.22; BAC ≥0.08 g/dL: adjusted odds ratio, 8.20; 95% CI, 7.42-9.07; compared with BAC <0.01 g/dL). There was no significant interaction effect on crash initiation between prescription opioid use and alcohol use.

CONCLUSIONS AND RELEVANCE

Driver use of prescription opioids was associated with initiation of 2-vehicle crashes, independent of alcohol use. Clinicians should take into consideration the adverse effect of opioid analgesics on driving safety while prescribing these medications and counseling patients.

A Pharmacist's Role in a Dental Clinic: Establishing a Collaborative and Interprofessional Education Site

BACKGROUND

Dental patients often have comorbidities and take multiple medications, some of which could impact their dental health and treatment. A pharmacist in a dental clinic can assist with the gathering, documentation and evaluation of a dental patient's medication history as it pertains to their dental visit and overall health.

PURPOSE

To develop and implement a collaborative and interprofessional education program with a pharmacist providing services in a dental school clinic.

SUMMARY

Creighton University School of Dentistry, a student-operated dental clinic located in Omaha, Nebraska, provides dental care by student dentists, faculty and staff to the surrounding community in a learning-focused environment. A pharmacist was incorporated into the dental clinic to create and establish an interprofessional relationship with both dental students and faculty beginning August 2014. Pharmacy students on an ambulatory care advanced pharmacy practice experience rotation were eventually added to the team. The pharmacy team provided medication therapy management services including disease state and medication counseling, medication reconciliation, identifying drug-related problems and dental implications of medications, and recommendations for prescribed medications.

CONCLUSION

The pharmacy team's presence was largely accepted by dental faculty, staff, dental students, and patients. Pharmacists can play an important role in a dental clinic by performing thorough health and medication histories and communicating with dental and medical providers involved in a patient's care.

Prime Drug Interplay in Dental Practice

Drug interaction is a negative representation of pharmacotherapy. In order to provide the best patient care possible, a thorough knowledge of how the drug interactions occur is needed for proper application in practice. Possible interactions among current medication and drugs being prescribed should be considered always. A thorough understanding of the mechanism of interactions among drugs is a must for the health care practitioner. Considering the astounding number of drugs patients may be taking, this task seems discouraging. The count of possible interactions in dental practice are less due to few number of drugs utilized and brief period of therapy, but still notable number are to be considered. The aim of present preview is to consider the manifold and multiplex nature of pharmacological drug-drug interaction in the general dental practice setting.

Effects of pharmaceuticals present in aquatic environment on Phase I metabolism in fish

The fate of pharmaceuticals in aquatic environments is an issue of concern. Current evidence indicates that the risks to fish greatly depend on the nature and concentrations of the pharmaceuticals and might be species-specific. Assessment of risks associated with the presence of pharmaceuticals in water is hindered by an incomplete understanding of the metabolism of these pharmaceuticals in aquatic species. In mammals and fish, pharmaceuticals are primarily metabolized by cytochrome P450 enzymes (CYP450). Thus, CYP450 activity is a crucial factor determining the detoxification abilities of organisms. Massive numbers of toxicological studies have investigated the interactions of human pharmaceuticals with detoxification systems in various fish species. In this paper, we review the effects of pharmaceuticals found in aquatic environments on fish hepatic CYP450. Moreover, we discuss the roles of nuclear receptors in cellular regulation and the effects of various groups of chemicals on fish, presented in the recent literature.

Antidepressants relevant to oral and maxillofacial surgical practice

Background:

Depression is commonly associated with a high-carbohydrate diet, lack of interest in proper oral hygiene and xerostomia connected to the use of antidepressants. Patients often consult their dentists as a result of changes affecting the hard dental substance and the soft-tissues.

Aim:

The aim of this study was to identify adverse drug interactions between the antidepressants and medications commonly administered in dentistry in order to give practicing dentists an overview of the scientific literature.

Objective:

The objective is to identify the adverse drug interactions between antidepressants and medication commonly administered in dentistry.

Study Design:

The literature search was performed using PubMed, Cochrane and the specific search items. The review (1984-2009) focused on medicines used in dental practice (vasoconstrictors, non-opioid analgesics, non-steroidal anti-inflammatory drugs, antibiotics, antifungals and benzodiazepines).

Results:

There are various drug interactions between antidepressants and medicines used in dentistry. When two or more drugs are co-administered, a drug interaction must always be anticipated though many of the interactions are potential problems, but do not seem to be real clinical issues.

Conclusion:

The probability of a drug interaction can be minimized by careful history-taking, skillful dose adjustment and safe administration of the therapeutic agent.

A proposal for a problem-oriented pharmacobiochemistry course in dental education

Problem-oriented learning is an effective method of learning that increases students' learning motivation, improves the relationship amongst students and results in open-minded discussions. In this study, a new problem-oriented pharmacobiochemistry course related to 'oxidative metabolism of drugs by cytochrome P450 (CYP450) systems' was designed. Students were divided into seven groups. Three keywords related to drug interaction through CYP450 were provided to each group in order for them to conduct research on the information given. After 1 month, the groups attended a session under the supervision of a tutor to solve a simulated problem case that was designed using the keywords. At the end of the integrated course, a multiple-choice examination was given. The success rate of 76 students who attended the course was found to be significantly higher than the success rate of the students who received the lecture-based course only (P < 0.0001). A questionnaire containing 20 items (Cronbach's alpha: 0.92) was administered to the students to learn about their perception regarding this educational model. The questionnaire was evaluated using the Likert scale. Student feedback was very positive, with fourteen answers rated as 'agree' and the remaining six rated as 'strongly agree'. Students thought that the problem-oriented model was very enjoyable and useful in regard to dental education. Based on these results, we conclude that this course model may help achieve an integrated curriculum for dental school programmes.

Urinary incontinence and diarrhoea associated with the switch from oral to injectable risperidone

OBJECTIVE

Urgency, urinary incontinence and bowel disturbances are distressing side effects that have been observed during treatment with risperidone and other antipsychotics probably due to the receptor affinity profile. This occurrence can lead to poor compliance and therefore impair clinical outcome.

METHOD

We report the case of a 50 year-old lady, who experienced urinary incontinence and diarrhoea, when switching from oral to injectable risperidone, which ceased when discontinuing the drug. Results and conclusions It should be taken into account that some side effects can be revealed when switching from oral to depot formulations due to non-compliance to orals; nevertheless dose-dependent mechanisms and individual metabolic variability must be considered when observing idiosyncratic reactions to drugs.

Potentially serious drug-drug interactions among community-dwelling older adult dental patients

OBJECTIVES

Reducing adverse drug events, including those resulting from drug-drug interactions, will be a health safety issue of increasing importance for dental practitioners in the coming decades as greater numbers of older adults seek oral health care. The purpose of this study was to identify prescription drugs with the potential for serious interactions and estimate prevalent use among older adults visiting the dentist.

STUDY DESIGN

The Medicare Current Beneficiary Survey is an ongoing series of nationally representative surveys of Medicare beneficiaries. Potentially serious drug interactions were selected with the use of published work by Partnership to Prevent Drug-Drug Interactions. Drug interactions were identified and prevalence estimates made for community-dwelling older adults visiting the dentist. Analyses were completed to test associations between sociodemographic and health-related variables and the use of prescription drugs with the potential for serious interactions.

RESULTS

Overall, 3.4% of those visiting the dentist were estimated to have been prescribed drugs with the potential for a serious drug interaction. Drugs commonly prescribed in dentistry with the potential for serious interactions include the benzodiazepines, macrolide antibiotics, and nonsteroidal antiinflammatory analgesics.

CONCLUSIONS

Understanding potentially harmful drug combinations, their clinical consequences, and the frequency with which implicated drugs are being prescribed will assist practitioners in clinically managing patients and avoiding inappropriate prescribing.

Evaluation of CYP450 inhibitory effects and steady-state pharmacokinetics of genistein in combination with cholecalciferol and citrated zinc bisglycinate in postmenopausal women

Background

The combination of genistein 27 mg, cholecalciferol 200 IU, citrated zinc bisglycinate (4 mg elemental zinc) 20 mg per capsule in Fosteum^®, a prescription medical food regulated by the FDA and indicated for the dietary management of osteopenia and osteoporosis, was tested for drug interactions and to determine the pharmacokinetic profile for genistein, the principal bone-modulating ingredient in the product.

Methods

In vitro human liver microsome cytochrome P450 (CYP450) assays were used to test the product for potential drug interactions with the isoforms 1A2, 2C8, 2C9, 2C19, 2D6, and 3A4. Due to specific 2C8 and 2C9 inhibition, a steady-state pharmacokinetic study was performed to assess serum genistein concentrations by high-pressure liquid chromatography-coupled mass spectroscopy in healthy fasting (n = 10) and fed (n = 10) postmenopausal women.

Results

The product showed minimal inhibition of 1A2, 2C19, 2D6, and 3A4, exhibiting IC₅₀ > 10 μM, but 2C8 and 2C9 yielded IC₅₀ of 2.5 μM and 2.8 μM, respectively, concentrations which are theroretically achievable when dosing the product twice daily. After seven days of administration in a steady-state pharmacokinetic study, significant differences were found for unconjugated genistein (including free and protein-bound), regarding time to peak concentration (1.88 ± 1.36 hours), maximum concentration reached (0.052 ± 0.055 μM), elimination half-life (2.3 ± 1.6 hours), and area under the concentration-time curve (53.75 ± 17.59 ng · hour/mL) compared with results for total genistein (including glucuronidated and sulfonated conjugates) time to peak concentration (2.22 ± 1.09 hours), maximum concentration reached (2.95 ± 1.64 μM), elimination half-life (10.4 ± 4.1 hours), and area under the concentration-time curve (10424 ± 6290 ng · hour/mL) in fasting subjects. Coadministration of food tended to extend the time and extent of absorption as well as slow elimination of genistein, but not in a statistically significant manner.

Conclusion

Because the serum genistein concentrations achieved during pharmacokinetic testing at therapeutic doses were well below those required for enzyme inhibition in the in vitro liver microsome assays, these results indicate a low potential for drug interactions.

Novel inhibitors of Plasmodium falciparum dihydroorotate dehydrogenase with anti-malarial activity in the mouse model

Plasmodium falciparum, the causative agent of the most deadly form of human malaria, is unable to salvage pyrimidines and must rely on de novo biosynthesis for survival. Dihydroorotate dehydrogenase (DHODH) catalyzes the rate-limiting step in the pyrimidine biosynthetic pathway and represents a potential target for anti-malarial therapy. A high throughput screen and subsequent medicinal chemistry program identified a series of N-alkyl-5-(1H-benzimidazol-1-yl)thiophene-2-carboxamides with low nanomolar in vitro potency against DHODH from P. falciparum, P. vivax, and P. berghei. The compounds were selective for the parasite enzymes over human DHODH, and x-ray structural data on the analog Genz-667348, demonstrated that species selectivity could be attributed to amino acid differences in the inhibitor-binding site. Compounds from this series demonstrated in vitro potency against the 3D7 and Dd2 strains of P. falciparum, good tolerability and oral exposure in the mouse, and ED(50) values in the 4-day murine P. berghei efficacy model of 13-21 mg/kg/day with oral twice-daily dosing. In particular, treatment with Genz-667348 at 100 mg/kg/day resulted in sterile cure. Two recent analogs of Genz-667348 are currently undergoing pilot toxicity testing to determine suitability as clinical development candidates.

Mechanism-based inhibition of CYP1A2 by antofloxacin, an 8-NH2 derivative of levofloxacin in rats

A recent focus was to investigate whether antofloxacin, an 8-NH(2) derivative of levofloxacin, inhibited cytochrome P450 (CYP) 1A2 activity in rats. Phenacetin, the representative substrate of CYP1A2, was used as the model drug to evaluate the activity of CYP1A2. In an in vivo study, an oral single dose of antofloxacin (20 mg kg(-1)) did not affect the pharmacokinetic behaviour of phenacetin, but a multidose (20 mg kg(-1) twice daily for 7.5 days) significantly increased phenacetin's area under the curve (AUC). In an in vitro study, only when pre-incubated with beta-nicotinamide adenine dinucleotide phosphate, a reduced form (NADPH) system in rat liver microsomes, did antofloxacin inhibit phenacetin O-deethylation. The inhibition was NADPH-, pre-incubation time-, and antofloxacin concentration-dependent. A physiologically based pharmacokinetic model with mechanism-based inhibition was successfully developed for predicting the interaction between antofloxacin and phenacetin in vivo from the in vitro data. The simulated AUC was 1.4-fold of the control, which was near the observed value of 1.6-fold. From the results, it can be concluded that the inhibition of CYP1A2 by antofloxacin is mechanism-based.

Mini-series: I. Basic science. Uncertainty and inaccuracy of predicting CYP-mediated in vivo drug interactions in the ICU from in vitro models: focus on CYP3A4

Drug-drug interactions (DDIs) contribute significantly to the incidence of adverse drug reactions. Important advances in the knowledge of human drug-metabolizing enzymes have fueled the integration of in vitro drug metabolism and clinical DDIs studies for use in drug development programs and in the clinical setting. The activity of cytochrome P450 (CYP) 3A4 and P-glycoprotein are critical determinant of drug clearance, interindividual variability in drug disposition and clinical efficacy, and appears to be involved in the mechanism of numerous clinically relevant DDIs. Cell-based in vitro models are being increasingly applied in elucidating the pharmacokinetic profile of drug candidates during the preclinical steps of drug development. Human liver, intestinal samples and recombinant human CYP3A4 are now readily available as in vitro screening tools to predict the potential for in vivo DDIs. Although it is easy to determine in vitro metabolic DDIs, the interpretation and extrapolation of in vitro interaction data to in vivo situations requires a good understanding of pharmacokinetic principles. Clinicians and pharmacokineticists should recognize that in vitro models may not be clinically relevant in all situations. In the current article, research will be presented on drug metabolism and DDIs along with examples illustrating the utility of specific in vitro or in vivo approaches. In addition, the impact and clinical relevance of complexities such as dosing-route dependent effects, multi-site kinetics of drug-metabolizing enzymes and non-CYP determinants of metabolic clearance will be addressed.

Drug therapy in Alzheimer disease: an update for the oral health care provider

Alzheimer disease (AD) is a progressive neurologic disorder that manifests as memory loss, personality changes, global cognitive dysfunction, and functional impairment. As the United States population continues to age, the prevalence of AD will rise. Accordingly, oral health care providers will be more likely to treat patients affected by this disease; therefore, it is necessary to understand the pharmacologic agents used for the management of AD. This article provides an update of the available drug therapies for AD and discusses their implications on the oral and dental health of patients.

Variability in the pharmacokinetics of intravenous busulphan given as a single daily dose to paediatric blood or marrow transplant recipients

AIM

To examine inter- and intrapatient variability in the pharmacokinetics of intravenous (i.v.) busulphan given as a single daily dose to children with malignant (n = 19) and nonmalignant (n = 21) disease.

METHODS

Busulphan (120 mg m(-2), 130 mg m(-2) or 3.2 mg kg(-1)) was administered over median 2.1 h. Blood samples (4-10) were collected after the first dose, busulphan concentrations were measured and pharmacokinetic parameters, including clearance (CL) and area under the concentration-time curve (AUC), were determined using the Kinetica software (Innaphase). Interpatient variability was assessed as percent coefficient of variation (% CV). Intrapatient variability was assessed by calculating percent differences between observed full dose AUC and AUC predicted from an initial 65 mg m(-2) dose in 13 children who had busulphan pharmacokinetic monitoring.

RESULTS

Clearance of i.v. busulphan in 40 children was 4.78 +/- 2.93 l h(-1) (% CV 61%), 0.23 +/- 0.08 l h(-1) kg(-1) (% CV 35%) and 5.79 +/- 1.59 l h(-1) m(-2) (% CV 27%). Age correlated significantly (p < 0.001) with CL (l h(-1)) and CL (l h(-1) kg(-1)), but not with CL (l h(-1) m(-2)). AUC normalized to the 130 mg m(-2) dose ranged from 14.1 to 56.3 mg l(-1) x h (% CV 37%) and also did not correlate with age. Interpatient variability in CL (l h(-1) m(-2)) was highest in six children with immune deficiencies (60%) and lowest in seven children with solid tumours (14%). Intrapatient variability was <13% for nine (of 13) children, but between 20 and 44% for four children.

CONCLUSIONS

There is considerable inter- and intrapatient variability in i.v. busulphan CL (l h(-1) m(-2)) and exposure that is unrelated to age, especially in children with immune deficiencies. These results suggest that monitoring of i.v. busulphan pharmacokinetics is required.

Adverse drug interactions involving common prescription and over-the-counter analgesic agents

BACKGROUND

Eight analgesic preparations with approved indications for acute pain were among the top 200 drugs prescribed in the United States in 2006. In addition, an estimated 36 million Americans use over-the-counter (OTC) analgesics daily. Given this volume of use, it is not surprising that a number of drug interactions involving analgesic drugs have been reported.

OBJECTIVES

This article examines the pharmacologic factors that enhance the clinical relevance of potential drug interactions and reviews the literature on drug interactions involving the most commonly used analgesic preparations in the United States.

METHODS

A PubMed search was conducted for English-language articles published between January 1967 and July 2007. Among the search terms were drug interactions, acetaminophen, aspirin, ibuprofen, naproxen, celecoxib, NSAIDs, hydrocodone, oxycodone, codeine, tramadol, OTC analgesics, alcohol, ethanol, antihypertensive drugs, methotrexate, warfarin, SSRIs, paroxetine, fluoxetine, sertraline, citalopram, serotonin syndrome, MAOIs, and overdose. Controlled clinical trials, case-control studies, and case reports were included in the review.

RESULTS

A number of case reports and well-controlled clinical trials were identified that provided evidence of the relatively well known drug-drug interactions between prescription/OTC NSAIDs and alcohol, antihypertensive drugs, high-dose methotrexate, and lithium, as well as between frequently prescribed narcotics and other central nervous system depressants. In contrast, the ability of recent alcohol ingestion to exacerbate the hepatotoxic potential of therapeutic doses of acetaminophen is not supported by either case reports or clinical research. Use of ibuprofen according to OTC guidelines in patients taking cardioprotective doses of aspirin does not appear to interfere with aspirin's antiplatelet activity, whereas chronic prescription use of ibuprofen and other NSAIDs may interfere. Low-dose aspirin intake appears to abolish the gastroprotective effects of cyclooxygenase-2-selective inhibitors, including celecoxib. There is evidence of other less well known and potentially clinically significant drug-drug interactions, including the ability of selective serotonin reuptake inhibitors to inhibit the analgesic activity of tramadol and codeine through inhibition of their metabolic activation, to induce serotonin syndrome when used chronically in the presence of high doses of tramadol through synergistic serotonergic action, and to increase the potential for gastrointestinal bleeding associated with NSAID therapy through additive or supra-additive antiplatelet activity.

CONCLUSIONS

Considering the widespread use of analgesic agents, the overall incidence of serious drug-drug interactions involving these agents has been relatively low. The most serious interactions usually involved other interacting drugs with low therapeutic indices or chronic and/or high-dose use of an analgesic and the interacting drug.

Assessing postoperative discomfort after third molar surgery: a prospective study

PURPOSE

The purpose of this study was to identify the risk factors for severe discomfort after mandibular third molar surgery and to assess the validity of the Postoperative Symptom Severity (PoSSe) scale.

PATIENTS AND METHODS

In a 2-year prospective study, a total of 255 unilateral impacted mandibular third molar teeth were surgically removed under local anesthesia by 3 surgeons. Standardized surgical and analgesic protocols were followed. At the review appointment, 1 week after surgery, all patients returned a completed follow-up questionnaire (PoSSe scale) and were evaluated clinically for postoperative pain (number of painkillers taken) and trismus (differences in mouth opening). Sixteen predictive variables were evaluated using stepwise logistic regression analysis to identify the risk factors associated with severe discomfort.

RESULTS

Severe postoperative discomfort was predicted by these independent variables: gender, tobacco use, ramus relationship/space available, and antibiotic prophylaxis. Oral contraceptive use and operation time were not identified as risk factors. The patients' perceptions of the severity of symptoms (PoSSe scale score) was strongly correlated with clinical assessment of trismus (r = 0.54) and pain (r = 0.42).

CONCLUSION

The PoSSe scale resulted in a valid and responsive measure of the severity of symptoms after surgical extraction of lower third molars and reflected the clinical severity of the postoperative discomfort. From a patient's perspective, operative factors had little bearing on the quality of life after removal of mandibular third molars.

Use of prophylactic antifungals in the immunocompromised host

Oral candidiasis is a significant infection in patients being treated with chemotherapy and radiotherapy for cancer, and in patients who are immunocompromised because of HIV infection and AIDS. Candida albicans is the most common fungal pathogen and has developed an extensive array of putative virulent mechanisms that allows successful colonization and infection of the host under suitable predisposing conditions. The purpose of this review of the literature was to assess the effectiveness of interventions for the prevention of oral candidiasis in immunocompromised patients and in patients treated for cancer with radiotherapy and/or chemotherapy. These patient categories were selected because they have been the topic of published randomized controlled clinical trials. The studies reviewed provide strong evidence that oral candidiasis is associated with greater morbidity and mortality in these populations, which substantiates the aggressive treatment and prophylaxis of this infection. The literature supports the recommendation that systemically applied antifungal drugs have the greatest efficacy for the treatment of oral candidiasis in cancer and immunocompromised patients; however, these therapies must be prescribed with a thorough assessment for the risk for developing drug-induced toxicities. Guidelines on the prevention of drug-resistant oral candidiasis in these patients are not available and require elucidation. Further studies are required to expand the knowledge base of evidence-based antifungal therapies in a wider variety of immunocompromised patients and conditions, such as Sjögren's syndrome, diabetes, and denture wearers. Additional exploration is needed to determine which antifungal drug formulation, dose, and method of delivery is preferable for the type of fungal infection and the underlying etiology.

Drug-induced changes in P450 enzyme expression at the gene expression level: a new dimension to the analysis of drug-drug interactions

Drug-drug interactions (DDIs) caused by direct chemical inhibition of key drug-metabolizing cytochrome P450 enzymes by a co-administered drug have been well documented and well understood. However, many other well-documented DDIs cannot be so readily explained. Recent investigations into drug and other xenobiotic-mediated expression changes of P450 genes have broadened our understanding of drug metabolism and DDI. In order to gain additional information on DDI, we have integrated existing information on drugs that are substrates, inhibitors, or inducers of important drug-metabolizing P450s with new data on drug-mediated expression changes of the same set of cytochrome P450s from a large-scale microarray gene expression database of drug-treated rat tissues. Existing information on substrates and inhibitors has been updated and reorganized into drug-cytochrome P450 matrices in order to facilitate comparative analysis of new information on inducers and suppressors. When examined at the gene expression level, a total of 119 currently marketed drugs from 265 examined were found to be cytochrome P450 inducers, and 83 were found to be suppressors. The value of this new information is illustrated with a more detailed examination of the DDI between PPARalpha agonists and HMG-CoA reductase inhibitors. This paper proposes that the well-documented, but poorly understood, increase in incidence of rhabdomyolysis when a PPARalpha agonist is co-administered with a HMG-CoA reductase inhibitor is at least in part the result of PPARalpha-induced general suppression of drug metabolism enzymes in liver. The authors believe this type of information will provide insights to other poorly understood DDI questions and stimulate further laboratory and clinical investigations on xenobiotic-mediated induction and suppression of drug metabolism.

The pharmacological importance of cytochrome CYP3A4 in the palliation of symptoms: review and recommendations for avoiding adverse drug interactions

BACKGROUND

Adverse drug interactions are major causes of morbidity, hospitalizations, and mortality. The greatest risk of drug interactions occurs through in the cytochrome system. CYP3A4, the most prevalent cytochrome, accounts for 30-50% of drugs metabolized through type I enzymes.

MATERIALS AND METHODS

Palliative patients received medications for symptoms and co-morbidities, many of which are substrate, inhibitors, or promoters of CYP3A4 activity and expression. A literature review on CYP3A4 was performed pertinent to palliative medicine.

DISCUSSION

In this state of the art review, we discuss the CYP3A4 genetics, and kinetics and common medications, which are substrates or inhibitor/promoters of CYP3A4.

CONCLUSION

We made some recommendations for drug choices to avoid clinically important drug interaction.

Common medications prescribed for adolescent dental patients

Common prescription medications taken by adolescent patients include various psychopharmacologic agents (to manage depression,obsessive-compulsive disorders, and attention deficit/hyperactivity disorders), pulmonary drugs (to prevent and treat asthma), and dermatologic agents (to treat acne). Other agents encountered when treating adolescent patients are antidiabetes agents, antibiotics, and birth control medications. This overview identifies prescription medications commonly used by adolescent patients and discusses their possible impact on dental care.