About

Nathan A. Painter, Pharm.D., CDCES, FADCES, FCCP, is a Health Sciences Clinical Professor at the Skaggs School of Pharmacy and Pharmaceutical Sciences at UCSD. He joined the faculty in September 2009, where he serves as a course coordinator and teaches in the Pharmacy Practice courses. Dr. Painter is a Certified Diabetes Care and Education Specialist and co-directs clinical pharmacy services at UCSD Family Medicine Clinics, providing remote care via telehealth. His research focuses on measuring the impact of pharmacist interventions in diabetes, hypertension, hyperlipidemia, prescription drug abuse, suicide prevention, and safe medication usage in patient populations. He has established the role of ambulatory care/family medicine pharmacists and contributed to the development and expansion of family medicine clerkships for pharmacy students.

Research topics

• Medicine
• Anesthesia
• Nursing
• Surgery
• Medical education

Selected publications

• Emerging and Off-Label Uses Of Glucagon-Like Peptide-1 Receptor Agonists (GLP1-RA) and Dual GIP/GLP1-RAs

  The Journal of the American Board of Family Medicine · 2026-01-01

  articleOpen accessSenior author

  BACKGROUND: Glucagon-like peptide-1 receptor agonists (GLP1-RAs) and the glucagon-dependent insulinotropic polypeptide (GIP)/GLP1-RA are approved for type 2 diabetes (T2D) and obesity given their profound impact on glycemic weight management. Additional indications include reducing cardiovascular disease risk and progression of chronic kidney disease (CKD) in T2D as well as obstructive sleep apnea in patients with obesity. These enhanced effects are likely due to their pleiotropic effects, leading to decreased inflammation and other benefits. This review explored emerging evidence for uses of GLP1-RAs and GIP/GLP1-RA that have been researched but not yet approved. Clinicians may use this information to guide treatment decisions. REVIEW PROCESS: PubMed and Embase literature searches were conducted using Medical Subject Heading terms. Studies referencing GLP1-RAs and GIP/GLP1-RA were included if they were published in approximately the last decade, included adults, and were either a randomized controlled trial, meta-analysis, or observational study. Of 319 articles reviewed, 27 met inclusion criteria. EMERGING AND COMPELLING USES: Initial positive impacts have been noted for the following conditions: liver disease/liver transplant, CKD/kidney transplant, Alzheimer's disease, Parkinson's disease, substance use disorders, osteoarthritis, rheumatoid arthritis, psoriasis, COVID-19 virus, asthma, chronic obstructive pulmonary disorder, polycystic ovarian syndrome, and short bowel syndrome. CONSIDERATIONS: Large randomized controlled trials may lead to approvals of these conditions and are encouraged. Safety and adverse effects of these medications must be assessed when initiating or modifying doses. CONCLUSION: GLP1-RAs and GIP/GLP1-RA have demonstrated early benefits to several conditions beyond their current approved indications. Clinicians can use this information to determine treatment options for patients, particularly in those with T2D, cardiovascular disease, and/or obesity.

  PublisherDOI

• Promotion and Beyond: A Comprehensive Faculty Mentorship Program

  American Journal of Pharmaceutical Education · 2025-11-01

  articleOpen access1st authorCorresponding
  PublisherDOI

• Mobilizing pharmacists to address the opioid crisis: A joint opinion of the ambulatory care and adult medicine practice and research networks of the American College of Clinical Pharmacy

  JACCP JOURNAL OF THE AMERICAN COLLEGE OF CLINICAL PHARMACY · 2020-10-06 · 36 citations

  articleOpen access

  Abstract The opioid crisis represents one of the largest failures of our current health care system as it continues to claim lives at an unprecedented rate and has caused a devastating range of preventable morbidity. Although the availability of highly potent synthetic opioids has amplified the urgency of the crisis for patients and communities, this problem has evolved over several decades. Pharmacists are in a position to offer many potential solutions due to their widespread accessibility, extensive drug knowledge, and integration into various health care settings. This opinion paper challenges the status quo by calling on all pharmacists to embrace evidence‐based opioid stewardship and harm reduction practices, contribute to the medical management of opioid use disorder, and address the misconceptions and prejudices that serve as barriers to effective, compassionate patient care. Regardless of practice setting or available resources, pharmacists can take deliberate and impactful steps to address the opioid crisis. Some pharmacists may be positioned to implement innovative and far‐reaching pharmacist‐led clinical services, while others may simply begin with careful consideration of the language they use when speaking to and about patients with substance use disorders. To optimize patient outcomes, the ineffective laws, regulations, and policies that negatively impact pain and addiction care must be addressed so that evidence‐based solutions can be widely disseminated. Pharmacists must aggressively advocate for the removal of barriers preventing high‐level clinical practice or policies that perpetuate patient harm and abandonment. Finally, there must be support for continued research on pain and opioid use disorder treatments and services, as well as the impacts of harm reduction practices and pharmacist‐led clinical services, so that resources can be allocated effectively.

  PublisherOA PDFDOI

• Probable Interaction Between Warfarin and Inhaled and Oral Administration of Cannabis

  Journal of Pharmacy Practice · 2019-07-18 · 31 citations

  articleSenior authorCorresponding

  OBJECTIVE: A 35-year-old Middle Eastern male on warfarin long term with an INR goal of 2.5 (accepted range: 2.0-3.0). The patient has generally been stable on warfarin 10 mg daily from 2010 to 2018, until INR suddenly increased to 7.2 following 1 month of edible cannabis ingestion and cannabis smoking. Patient denied any signs and symptoms of bleeding. No other reasonable causes of the elevation in INR were apparent. The patient was advised to hold 2 doses of warfarin and discontinue cannabis use. The INR dropped below 4 upon discontinuation of cannabis with dose adjustments to warfarin. DISCUSSION: The elevation in INR can be explained by the inhibition of CYP2C9 by cannabis use causing decreased metabolism of warfarin. The interaction between warfarin and cannabis was determined to be probable using the Horn Drug Interaction Probability Scale. CONCLUSIONS: There are no previous reports of interactions between edible cannabis and warfarin, with very few case reports describing the interaction with other forms of cannabis. Close monitoring of INR in patients with concomitant cannabis is recommended for proper warfarin management.

  PublisherDOI

• Advancing Pharmacist Collaborative Care within Academic Health Systems

  Pharmacy · 2019-10-11 · 18 citations

  articleOpen access

  INTRODUCTION: The scope of pharmacy practice has evolved over the last few decades to focus on the optimization of medication therapy. Despite this positive impact, the lack of reimbursement remains a significant barrier to the implementation of innovative pharmacist practice models. SUMMARY: We describe the successful development, implementation and outcomes of three types of pharmacist collaborative care models: (1) a pharmacist with physician oversight, (2) pharmacist-interprofessional teams and (3) physician-pharmacist teams. The outcome measurement of these pharmacist care models varied from the design phase to patient volume measurement and to comprehensive quality dashboards. All of these practice models have been successfully funded by affiliated health systems or grants. CONCLUSIONS: The expansion of pharmacist services delivered by clinical faculty has several benefits to affiliated health systems: (1) significant improvements in patient care quality, (2) access to experts in specialty areas, and (3) the dissemination of outcomes with national and international recognition, increasing the visibility of the health system.

  PublisherOA PDFDOI

• Pharmacist training in suicide prevention

  Journal of the American Pharmacists Association · 2018-02-01 · 42 citations

  article1st authorCorresponding
  PublisherDOI

• Pharmacist Intention to Provide Medication Disposal Education

  Journal of Contemporary Pharmacy Practice · 2018-12-01 · 5 citations

  articleOpen access1st authorCorresponding
  PublisherOA PDFDOI

• The Impact of the U.S. Drug Enforcement Agency Schedule Changes for Hydrocodone and Tramadol on California Prescriptions Patterns

  Journal of Contemporary Pharmacy Practice · 2018-03-01 · 1 citations

  articleOpen accessSenior author

  The Centers of Disease Control and Prevention (CDC) have declared prescription drug abuse an epidemic, with 14,000 deaths in 2014 involving prescription opioids.(1) Prescription related mortality is the number one cause of accidental deaths, more than motor vehicle collisions.(2) In California, over 4,000 people a year die from overdoses of prescription medication.(3) Opioids are involved in the majority of the accidental overdose deaths, accounting for 61% of these deaths.(2) There is a direct relationship in the number of prescriptions and number of deaths.(4)Hydrocodone containing products (HCP) are the number one prescribed medication in the United States, more than cholesterol and blood pressure medications.(5) Congress passed the Controlled Substances Act in 1970, and placed hydrocodone in schedule II, and HCP in schedule III.(6) In 2014, the U.S. Drug Enforcement Administration (DEA) published in the Federal Register the Final Rule, moving HCP from schedule III to the more restrictive schedule II, which was supported by the U.S. Department of Health and Human Services.(7) The reasoning given for the schedule change was the high potential for abuse with psychological or physical dependence, as well as the science that adding non-narcotic substances like acetaminophen to hydrocodone does not diminish abuse potential.(6) The impact of changing HCP to schedule II has several effects for both providers and dispensers: (1) HCP had to be written on hard copy prescription forms, (2) HCP could not be called into the pharmacy and (3) HCP could not be refilled.(6)Tramadol is a centrally acting synthetic opioid analgesic first approved in the U.S. in 1995 under the name “Ultram.”(8) Many providers prescribe tramadol not realizing that the daily dose of tramadol has higher morphine equivalents than hydrocodone. Tramadol comes in a 50 mg tablet, has a morphine milligram equivalent (MME) of 0.1 MME per milligram, and therefore has 5 MME per tablet.(9) Hydrocodone comes in 5 mg (per tablet) as its lowest dose, containing 1 MME per milligram, and therefore has 5 MME per tablet.(10) Thus tramadol is equally potent to hydrocodone given the average daily dosing recommendations. Tramadol is advertised as safer than other opioids. However, in addition to the same side effects as other opioids, tramadol can precipitate seizures, especially when combined with alcohol, and when experiencing withdrawal.(11) Tramadol is addicting and has been implicated in cases of doctor shopping.(12) Tramadol was rescheduled by the DEA from schedule V to schedule IV, stating an eight-factor analysis concluding that tramadol has a potential for abuse that is lower compared to drugs classified as schedule III and similar to abuse potential of propoxyphene, which is schedule IV.(6) For Californians, this change had minimal procedural impacts, except that now tramadol could be viewed as part of the CURES system as a schedule IV medication. Clinicians, who can no longer call in prescriptions for HCP, can still call in tramadol prescriptions.The Drug Enforcement Administration rescheduling for tramadol became effective on August 18, 2014, and for HCP on October 6. Most providers were not aware of the alternate dates for the two medications, as there was much advertisement about a single August date.California's Prescription Drug Monitoring System (PDMP), commonly known as CURES (Controlled Substance Utilization Review and Evaluation System), has been in effect since 1996 for schedule II drugs.(13) In 2007 CURES was expanded to include schedule II through IV prescriptions from pharmacies in California with the exception of military hospitals, methadone clinics, and out of state prescriptions. The Veterans Administration started uploading data into CURES on August 2016. Senate Bill 809 allowed for the funding to upgrade the system to CURES 2.0, which became available in January 2016. The legal requirement that all prescribers must be registered was enforced in July 2016.(13)The tip of the iceberg in the opioid epidemic is the number of deaths, with a majority (80%) involving combination of medications. Studies using CURES and the San Diego medical examiner's data on 254 people who had unintentional prescription related deaths showed that opioids, including hydrocodone and tramadol, accounted for 75% of deaths.(14) Most deaths, 80%, involved a combination of medications.(15) Of the 254 deaths, 186 had data in the CURES system reflecting 273 pharmacies, 4,366 prescriptions, 42 formulations and 713 providers.(16)Intercontinental Marketing Services (IMS) Health, a national healthcare services and technology company, published a study that was used to compare national and California data. The IMS published data in a letter in the Journal of the American Medical Association comparing prescriptions before and after the DEA rescheduling of hydrocodone and reported that the number of hydrocodone prescriptions decreased by 22% and the number of tablets dispensed decreased by 16%, while the non-hydrocodone controlled substance prescriptions increased by 4.9% and tablets dispensed by 1.2%.(17)The purpose of this study was to determine the impact of the DEA rescheduling of hydrocodone and tramadol on California prescriptions patterns as documented in the CURES system.This is a retrospective descriptive analysis comparing three groups of prescriptions: (1) hydrocodone containing products (HCP), (2) tramadol, and (3) total opioids in the state of California documented through the CURES system for 12 months before and 12 months after the DEA rescheduling of hydrocodone and tramadol. The data were obtained from the California Department of Justice, which manages the CURES system that provided de-identified data of the number of prescriptions and the number of tablets for HCP, tramadol, and total opioids on a monthly basis from August 2013 until August 2015. The number of tablets as well as number of prescriptions were reviewed in order to account for potential changes in length of prescription. Analyses were made for the three groups of medication for 12 months before the schedule change, August 1, 2013, through July 31, 2014, and 12 months after, September 1, 2014, through August 31, 2015. The transition month of August was not included. California data were compared to national IMS data.The monthly pattern of CURES prescriptions from August 2013 through October 2015 showed a decline in the number of tablets of HCP dispensed, but an increase in the total number of dispensed opioids. Tramadol is shown to enter the database in August 2014, (Figure 1. Number of Prescriptions August 2013 – October 2015 and Figure 2. Number of Tablets August 2013 – October 2015).For Hydrocodone containing products, the number of prescriptions decreased by 3%, from 15,667,302 to 15,204,104. In evaluating tramadol, the number of prescriptions was available only after the schedule change as 4,151,099 prescriptions. Total opioid prescriptions increased from 23,562,191 to 29,292,835. In order to account for the entry of tramadol into the CURES database, the total opioid measurement, the total opioid data were re-calculated excluding tramadol. Excluding tramadol, total opioid prescriptions went from 23,562,191 to 25,141,736 reflecting an increase of 6.7%, (Figure 3. Prescriptions before and after DEA Rescheduling).The number of tablets for HCP increased from 1,079,183,143 to 1,060,648,828, reflecting a decrease of 1.72%. A total of 298,343,473 tramadol tablets were dispensed during this period. Total opioid tablets dispensed went from 1,730,654,629 to 2,119,935,743. Excluding tramadol in order to account for the new data entry, total opioid tablets increased from 1,730,654,629 to 1,821,592,270, reflecting an increase of 5.3%, (Figure 4. Tablets before and after DEA Rescheduling).The DEA reschedule of hydrocodone had the expected effect of reducing the number of prescriptions and tablets by 3% and 1.7% respectively. The decrease represent a decline of over 400,000 prescriptions and 19 million tablets; however, the statistical significance is not determined. The California numbers showed less of an impact compared to the national data of 22% and 16% for prescriptions and tablets. The IMS national study reported that 73.7% of the reduction was attributed to the elimination of automatic refills. It is unclear if California had fewer automatic refills of hydrocodone prior to rescheduling and therefore less of a decline in hydrocodone prescriptions.The expected effect of the schedule change was to decrease the overall number of prescriptions, especially since hydrocodone is the leading opioid prescription. However, both national and California data showed that total opioid prescriptions and tablets increased despite the DEA rescheduling of HCP. IMS data showed an increase of 4.9% in prescriptions and 1.2% in tablets, while California data showed an increase of 6.7% in prescriptions and 5.3% in tablets. California and IMS data were not identical. The California numbers reflect total opioids excluding tramadol. The IMS data reflect non-hydrocodone products. Despite the difference in data, it appears that Californians have increased use of total opioid prescriptions to a greater degree than the rest of the country after the DEA rescheduling of HCP.In reviewing the monthly prescription numbers, it is not evident that the data represent a trend rather than continued monthly fluctuations. Future longer-term study of prescription patterns is necessary.The Controlled Substance Utilization Review and Evaluation System includes data from the majority of pharmacies in California, but at the time of the study did not include Veterans Affairs hospitals, military hospitals, medication assisted treatment programs (also known as methadone clinics), and medications brought across the border from Mexico. The data uploaded to CURES are not perfectly accurate as clinical anecdotal experience has shown. The error rate is unknown, but is expected to be small. Pharmacies report to CURES both the date a prescription is filled and the date a prescription is dispensed. The Controlled Substance Utilization Review and Evaluation System uses the date filled as the surrogate marker for prescription use. Therefore we do not know if the prescription was picked up, filled too soon, or used as directed. This introduced a bias in interpreting the effect of the DEA schedule change. Future studies can determine if there is a significant difference between date filled and date dispensed.Prescription patterns are a single marker in the opioid epidemic, although it is an important one as it follows the more significant problem of death rate.(18) According to the January 2016 CDC guidelines, higher morphine milligram equivalents are a greater risk for death.(19) The San Diego Medical Examiner data points out that both prescribers and dispensers may not be aware that patients are receiving multiple prescriptions from multiple providers and pharmacies.(16) Another risk factor is chronic users. Of the patients who died, 78% were taking the same medication for three consecutive months or more.(14) Safe prescribing and pain education are evolving and must reflect risks and benefits of the total patient's medication regimen. Underprescribing to patients who have legitimate requirements should be avoided. Despite the media attention, educational programs and policy changes, there are too many people who die every day from unintentional overdose of prescriptions.This study is limited by the accuracy and completeness of the data provided by CURES and IMS. Ideally, the National Data by IMS Health and the California data presented in this study for hydrocodone prescriptions and tablets should use identical metrics. However, IMS data reviewed non-hydrocodone prescriptions and tablets while this California study reviewed total opioids.The DEA reschedule of hydrocodone containing products in California had the expected effect of reducing the number of prescriptions and tablets by 3% for prescriptions and 1.72% for tablets, but not to the degree reported by national data of 22% and 16%. The total opioid prescriptions across the country increased despite the schedule change. California noted an increase of total opioid excluding tramadol of 6.7% for prescriptions and 5.3% for tablets. IMS National statistics reflected an increase of non-HCP of 22% for prescriptions and 16% for tablets. In reviewing the monthly prescription numbers, it is not evident that the data represents a trend rather than continued monthly fluctuations. Future longer term study of prescription patterns is necessary.Mike Small, Program Manager, Department of Justice, California Prescription Drug Monitoring Program (Controlled Substance Utilization Review and Evaluation System) provided data for the study and has been an advocate for patient safety. For more information on the San Diego Prescription Drug Abuse Medical Task Force and safe prescribing resources, please visit SanDiegoSafePrescribing.org.

  PublisherOA PDFDOI

• An Overview of Concentrated Insulin Products

  Diabetes Spectrum · 2016-08-01 · 17 citations

  articleOpen access1st authorCorresponding

  IN BRIEF This article provides a summary of the use of available concentrated insulins in the outpatient treatment of patients with diabetes. Concentrated insulins work through the same mechanisms as other insulin products. They vary from each other in concentrations and pharmacokinetic/pharmacodynamics profiles but are each similar to their U-100 concentration counterparts. Patient education is important to minimize errors and the risk of hypoglycemia when using these insulin formulations.

  PublisherOA PDFDOI

• Understanding and Applying the AADE Competencies for Diabetes Educators and Paraprofessionals

  AADE in Practice · 2016-12-28 · 1 citations

  articleSenior author
  PublisherDOI

Frequent coauthors

• Tiffany Tedore

  Presbyterian Hospital

  41 shared

• Geza Kiss

  Robert Wood Johnson University Hospital

  33 shared

• Mark Poler

  University of Pennsylvania

  26 shared

• Mark Giska

  Henry Ford Hospital

  26 shared

• Matthew Giuca

  Winthrop-University Hospital

  25 shared

• Eric Brumberger

  New York Hospital Queens

  25 shared

• Robert D. Sanders

  University of Sydney

  25 shared

• Richard L. Applegate

  Loma Linda University

  25 shared

Awards & honors

• Phi Lambda Sigma 2007
• UC San Diego Pharmacy Week Certificate of Recognition 2010
• NCLAM 2011
• UCSD WOW Factor 2011
• Cardinal Health Generation RX Champion (CPhA) 2013