Welcome to Dr. Fudin’s “Quick reference” page where you will find commonly requested PDF documents.  These documents consist of tables, algorithms, and figures (chemistry) for various analgesic classes that are commonly prescribed.  They are arranged below by therapeutic or pharmacological category with a short explanation of content for each file. 

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Opioid Serum Predictabilities – This comprehensive table provides expected serum predictabilities in patients receiving commonly prescribed opioids.
Opioid Chemistry – Lists various opioids in columns by their chemical class beneath the chemical structure of the prototypical agent.  For example, morphine is the prototypical phenanthrene of which all others are measured against.  This also indicates which opioids are more or less likely to have cross-sensitivity to others based on similarity between and among chemical structures.
Fentanyl (Licit and Illicit): This document includes three tables of Characteristics of Pharmaceutical Fentanyl and its Derivatives; Pharmacokinetic and Pharmacodynamic Properties of Pharmaceutical Fentanyl and its Derivatives; Characteristics of Nonpharmaceutical Fentanyls Listed by DEA as Schedule 1 as of April, 2018; and one figure, Metabolic Pathways of Pharmaceutical Fentanyl and its Derivatives.
PAMORAs – This is a table of currently available peripherally acting mu opioid receptor antagonists that are used for opioid induced constipation.  Included is dosing, FDA approved indications, and pharmacokinetics.
Urine Drug Screening: Practical Guide for Clinicians – Provides a table of chemicals and drugs that may cause false negative or false positive results for common substances of abuse.
Urine Drug Testing in Clinical Practice. The Art and Science of Patient Care. Ed6. “Before ordering UDT, clinicians should understand methods of testing, the potential benefits and limitations of UDT, and how to interpret results, so that they can rationally employ patient-centered UDT in clinical practice. This monograph will assist clinicians to appropriately use UDT to improve patient care.”
Comparison of Abuse Deterrent Formulations Table – This is a comprehensive table includes Brand and Generic Names, Formulation Approval Year, Manufacturer, Abuse Deterrent Technology Type, FDA Approved Abuse Deterrent Labeling,  and Pipeline ADFs.
Opioid Risk Stratification Tools Summarized – This includes two tables that summarize the various risk stratification tools by opioid abuse and opioid misuse and delineates which have been validated and the advantages/disadvantages of each. You may access these tools directly from Painedu.or by clicking this LINK.
Methadone Information and Safety Page – A click here will bring you to our Methadone page which has many links, references, and explanations about appropriate methadone dosing, EKG monitoring, and much more.
General Agreement and Consent for Chronic Opioid Maintenance Therapy and/or Other Controlled Substances – This tool is a generic template for which a general practice or pain specialty practice can customize.  It was adapted from Howard A. Heit MD, FACP, FASAM as it appears on painedu.org.
Buprenorphine– This partial agonist is often misunderstood; it is a partial mu-opioid agonist, full ORL1 and sigma-opioid agonist and a competitive agonist at the kappa-opioid receptor.  A nice buprenorphine summary may be found at this provided link.  Also, questions often arise regarding pain management in the perioperative setting. Consider reading Marcucci C, Fudin J, Thomas P, et al.  A new pattern of buprenorphine misuse may complicate perioperative pain control.
Buprenorphine Thresholds (euphoria, respiratory depression, and analgesia) and Activities Location (Brain v Spinal) – A bar graph comparing full agonists to buprenorphine.
Opioid Receptor Delineation and Activities – A figure outlining various opioid receptors and their activities.
Fentanyl Transmucosal Administered Products (aka ROOS, or “Rapid Onset Opioids”) – This table includes trade and generic names, dosage form to be administered, available strengths, bioavailability, Cmax, and Tmax.
Pharmacodynamic and Pharmacokinetic Properties of Commonly Prescribed Opioids – This offers comprehensive pharmacokinetic and pharmacodynamic data, including the receptor types that are most commonly bound by each opioid listed.
Tramadol Metabolism – This is a schematic of the five metabolites from the parent compound tramadol.
Changes in Annual Opioid Prescriptions Compared to Overdose Death Rates From Different Types of Opioids: This is provided in figures as 2006 thru 2012 and 2011 thru 2017.


Cannabinoid Categories and Pipeline Products – These include two tables and lots of references that include potency toward CB Receptors, metabolism, medicinal chemistry, and delineation by product name, pharmacological mechanism, pipeline products, stage of research, and ongoing trials.


COX-2 Specificity – A figure listing various non-steroidal anti-inflammatory agents and their relative COX-2 specificity compared to one another. A special thanks to Richard Wheeler Pharm D., BCPS for contributing.
NSAIDS Chemical Classes – A compilation of chemical structures and the category for each NSAID. For example, ibuprofen and naproxen are both propionic acid derivatives.
Discontinuing NSAID Therapy Prior to a Procedure – This provides two tables that outline when to expect individual NSAIDs will be out of the body based on half-life and provides recommendations on which NSAID should be discontinued based both on half-life COX-2 specificity.  The tables are from Younan M, Atkinson TJ, Fudin J. A Practical Approach to Discontinuing NSAID Therapy Prior to a Procedure. Practical Pain Management. 2013 Nov/Dec; 13(10):45-51.
Schematics for New Biologics for Psoriatic Arthiritis – Interpreting the Nomeclature – This summary includes Monoclonal Antibody Nomenclature Structure, Infix (Substem A and Substem B) and Stem definitions. Also included are the two major classes of monoclonal antibodies used in the management of psoriatic arthritis, tumor necrosis factor inhibitors (TNF-I) and interleukin pathway inhibitors (IL-12/23/17i), plus a list of newly developed interleukin (IL) agents as of January 2020.

Neurotherapy Treatments

National and International Neuropathic Pain Guidelines – Comparison of Drug Therapy including Canadian, IASP, NICE, and EFNS guidelines in table format.

Comparison of CGRP medication products currently available in the United States – This table includes Approval Date; Dosing; Storage/Administration; Adverse Reactions; Anti-Drug Antibodies; Geriatric and Renal Impairment (CrCl<30 ml/min); PK data.


Tricyclic Antidepressant Summary – This table as compiled by Kelsie W. Flynn PharmD, PGY-1 Pharmacy Practice Resident and Dr. Timothy J Atkinson includes an excellent summary of chemical structure, category (tertiary/secondary), form & strength available, FDA Indications, starting dose, therapeutic dose for pain, antidepressant target dose, receptor antagonism (Ki), ADRs, protein binding, metabolism, half-life, and unique warnings.Antidepressant Pharmacology – A table listing various antidepressants by catagory (TCA, SSRI, SARI, SNRI, atypicals, and MAOI)
Select Medications for the Treatment of Neuropathic Pain

Skeletal Muscle Relaxants

Skeletal Muscle Relaxant compilation of chemical structures, mechanism of action, and the category for each skeletal muscle relaxant. Here we include recommended dosage, common adverse effects, therapeutic issues to consider, pharmacokinetics, and drug interactions
Benzodiazepines compilation of chemical structures, metabolic pathways, and common drug interactions.

Chronic Kidney Disease

Pharmacokinetic Considerations is CKD is a table that categorizes changes in pharmacokinetic parameters (including Absorption, Vd, elimination) in patients with chronic kidney disease and how drugs are impacted by these physiological changes.

Drug Interactions

Cytochrome P450 and p-glycoprotein drug interactions are often responsible for reducing or elevating various analgesic blood levels.  Drugs most often affected are antidepressants, anticonvulsants (other than gabapentin or pregabalin), and probably most concerning, the opioids.  Significant drug interactions can lead to poorly controlled pain, or in the case of opioids, overdose and death. A schematic concept of these interactions is provided at the above link as it appears in RXPrep2014.