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Exogenous cannabinoids are structurally and pharmacologically diverse compounds that are widely used. The purpose of this systematic review is to summarize the data characterizing the potential for these compounds to act as substrates, inhibitors, or inducers of human drug metabolizing enzymes, with the aim of clarifying the significance of these properties in clinical care and drug interactions. In vitro data were identified that characterize cytochrome P-450 (CYP-450) enzymes as potential significant contributors to the primary metabolism of several exogenous cannabinoids: tetrahydrocannabinol (THC; CYPs 2C9, 3A4); cannabidiol (CBD; CYPs 2C19, 3A4); cannabinol (CBN; CYPs 2C9, 3A4); JWH-018 (CYPs 1A2, 2C9); and AM2201 (CYPs 1A2, 2C9). CYP-450 enzymes may also contribute to the secondary metabolism of THC, and UDP-glucuronosyltransferases have been identified as capable of catalyzing both primary (CBD, CBN) and secondary (THC, JWH-018, JWH-073) cannabinoid metabolism. Clinical pharmacogenetic data further support CYP2C9 as a significant contributor to THC metabolism, and a pharmacokinetic interaction study using ketoconazole with oromucosal cannabis extract further supports CYP3A4 as a significant metabolic pathway for THC and CBD. However, the absence of interaction between CBD from oromucosal cannabis extract with omeprazole suggests a less significant role of CYP2C19 in CBD metabolism. Studies of THC, CBD, and CBN inhibition and induction of major human CYP-450 isoforms generally reflect a low risk of clinically significant drug interactions with most use, but specific human data are lacking. Smoked cannabis herb (marijuana) likely induces CYP1A2 mediated theophylline metabolism, although the role of cannabinoids specifically in eliciting this effect is questionable.

Equianalgesic conversion methods are commonly used to switch patients from one opioid to another due to suboptimal pain relief or adverse events. There is no universally accepted opioid conversion method, however, and there is often significant variability between conversion resources. As a result, patients are at risk for undertreated pain and serious adverse events. The purpose of this survey was to compare the equianalgesic conversion estimates between nurse practitioners, pharmacists, and physicians for commonly prescribed opioids.A survey form was developed using Survey Monkey. Participation was solicited by providing a link to the survey via social media (e.g., Facebook, Twitter, LinkedIn, etc.) and emailing professional organizations for sharing with their members and followers. Data collected included demographics and estimated morphine equivalents (MEQs) of hydrocodone 80 mg, fentanyl transdermal patches 1,800 mcg (as 75 mcg/hour), methadone 40 mg, oxycodone 120 mg, and hydromorphone 48 mg. Participants were also asked to provide their choice of reference utilized to complete the conversions, including personal knowledge. Descriptive analyses were performed using measures of central tendency. Hypothesis testing was performed using Pearson's chi-squared and Fisher's Exact Test for categorical data and the Kruskal-Wallis equality of populations rank test for continuous data to assess differences between median opioid doses by professional groups.The total number of respondents included in the analysis was 319. Physicians, pharmacists, and nurse practitioners/physician assistants comprised 25.4%, 56.7%, and 16.3%, respectively, of respondents. The overall mean (± standard deviation) MEQ doses for fentanyl, hydrocodone, hydromorphone, methadone, and oxycodone were: 176 (±117) mg, 88 (±42) mg, 192 (±55) mg, 193 (±201) mg, and 173 (±39) mg, respectively. For fentanyl, the mean (±standard deviation) MEQ doses were 180 (±122) mg, 178 (±128) mg, and 157 (±68) mg, for physicians, pharmacists, and nurse practitioners/physician assistants, respectively. For all three groups of clinicians, the median MEQ dose for fentanyl was 150 mg. The mean (±standard deviation) MEQ doses of methadone for physicians, pharmacists, and nurse practitioners/physician assistants were: 214 (±142) mg, 171 (±107) mg, and 185 (±129) mg, respectively. The median MEQ dose for methadone was 160 mg for each of the clinician groups.As evidenced by large standard deviations, there was significant variation in mean opioid conversions to MEQ doses within each profession type, particularly for fentanyl and methadone. The median MEQ doses provided for opioid conversions were the same among each profession. No universal method exists that allows each of the five studied opioids to be accurately and consistently converted to another opioid (i.e., morphine).

Objective. Equianalgesic conversion methods are commonly used to switch patients from one opioid to another due to suboptimal pain relief or adverse events. There is no universally accepted opioid conversion method, however, and there is often significant variability between conversion resources. As a result, patients are at risk for undertreated pain and serious adverse events. The purpose of this survey was to compare the equianalgesic conversion estimates between nurse practitioners, pharmacists, and physicians for commonly prescribed opioids. Methods. A survey form was developed using Survey Monkey. Participation was solicited by providing a link to the survey via social media (e.g., Facebook, Twitter, LinkedIn, etc.) and emailing professional organizations for sharing with their members and followers. Data collected included demographics and estimated morphine equivalents (MEQs) of hydrocodone 80 mg, fentanyl transdermal patches 1,800 mcg (as 75 mcg/hour), methadone 40 mg, oxycodone 120 mg, and hydromorphone 48 mg. Participants were also asked to provide their choice of reference utilized to complete the conversions, including personal knowledge. Descriptive analyses were performed using measures of central tendency. Hypothesis testing was performed using Pearson's chi-squared and Fisher's Exact Test for categorical data and the Kruskal–Wallis equality of populations rank test for continuous data to assess differences between median opioid doses by professional groups. Results. The total number of respondents included in the analysis was 319. Physicians, pharmacists, and nurse practitioners/physician assistants comprised 25.4%, 56.7%, and 16.3%, respectively, of respondents. The overall mean (± standard deviation) MEQ doses for fentanyl, hydrocodone, hydromorphone, methadone, and oxycodone were: 176 (±117) mg, 88 (±42) mg, 192 (±55) mg, 193 (±201) mg, and 173 (±39) mg, respectively. For fentanyl, the mean (±standard deviation) MEQ doses were 180 (±122) mg, 178 (±128) mg, and 157 (±68) mg, for physicians, pharmacists, and nurse practitioners/physician assistants, respectively. For all three groups of clinicians, the median MEQ dose for fentanyl was 150 mg. The mean (±standard deviation) MEQ doses of methadone for physicians, pharmacists, and nurse practitioners/physician assistants were: 214 (±142) mg, 171 (±107) mg, and 185 (±129) mg, respectively. The median MEQ dose for methadone was 160 mg for each of the clinician groups. Conclusions. As evidenced by large standard deviations, there was significant variation in mean opioid conversions to MEQ doses within each profession type, particularly for fentanyl and methadone. The median MEQ doses provided for opioid conversions were the same among each profession. No universal method exists that allows each of the five studied opioids to be accurately and consistently converted to another opioid (i.e., morphine).

Objective This article reviews topical nonsteroidal anti-inflammatory drug (NSAID) formulations available in the United States, including advantages and disadvantages, therapeutic usefulness, adverse effects, and formulation considerations. Results In the United States, several topical NSAID products are approved to treat painful conditions including diclofenac sodium 1% gel (Voltaren Gel®; Endo Pharmaceuticals), diclofenac sodium topical solution 1.5% w/w in 45.5% dimethyl sulfoxide (PENNSAID®; Mallinckrodt, Inc.), and diclofenac epolamine 1.3% (Flector Patch®; Alpharma Pharmaceuticals LLC, a subsidiary of Pfizer, Inc.). Recent studies suggest topical diclofenac preparations are effective for osteoarthritis pain and suggest the efficacy of topical formulations is similar to that achieved with oral NSAID formulations. All NSAID formulations contain the same boxed warnings regarding cardiovascular and renal toxicity; however, topical NSAIDs are proposed to have a more favorable safety profile than oral NSAIDs due to the low serum concentrations achieved with topical NSAID formulations. Conclusions Topical NSAIDs have been shown to be beneficial from both a therapeutics and adverse effect perspective, and are increasingly recommended in treatment guidelines.