Table 1: Pain Classification

Pain can be classified based on pain physiology, intensity, temporal characteristics, type of tissue affected, and syndrome:

  • Pain physiology (nociceptive, neuropathic, inflammatory)
  • Intensity (mild-moderate-severe; 0-10 numeric pain rating scale)
  • Time course (acute, chronic)
  • Type of tissue involved (skin, muscles, viscera, joints, tendons, bones)
  • Syndromes (cancer, fibromyalgia, migraine, others)
  • Special considerations (psychological state, age, gender, culture)

Table 2: Pain Assessment Mnemonic (QISS TAPED)

Q Quality What were your first symptoms? What words would you use to describe the pain? (achy, sharp, burning, squeezing, dull, icy, etc...)
Besides sensations you consider to be "pain," are there other unusual sensations, such as numbness?
I Impact How does the pain affect you?
How does the pain impact your sleep, activity, mood, appetite (other - work, relationships, exercise, etc.)
What does the pain prevent you from doing?(Depression screen) Do you feel sad or blue? Do you cry often? Is there loss of interest in life? Decreased or increased appetite?
(Anxiety screen) Do you feel stressed or nervous? Have you been particularly anxious about anything? Do you startle easily?
S Site Show me where you feel the pain. Can you put your finger/hand on it?
Or show me on a body map?
Does the pain move/radiate anywhere? Has the location changed over time?
S Severity On a 0-10 scale with 0 = no pain and 10 = the worst pain imaginable, how much pain are you in right now?
What is the least pain you have had in the past (24 hours, one week, month)?
What is the worst pain you have had in the past (24 hours, one week, month)?
How often are you in severe pain? (hours in a day, days a week you have pain)?
T Temporal Characteristics When did the pain start? Was it sudden? Gradual? Was there a clear triggering event?
Is the pain constant or intermittent? Does it come spontaneously or is it provoked?
Is there a predictable pattern? (e.g., always worst in the morning or in the evening? Does it suddenly flare up?)
A Aggravating and Alleviating Factors What makes the pain better?
What makes the pain worse? When do you get the best relief? How much relief do you get? How long does it last?
P Past Response, Preferences How have you managed your pain in the past? (Ask about both drug and non-drug methods)
What helped? What did not help? (Be specific about drug trials - how much and how long?)
What medications have you tried? Was the dose increased until you had pain relief or side effects? How long did you take the drug?
Are there any pain medicines that have caused you an allergic or other bad reaction?
How do you feel about taking medications?
Have you tried physical or occupational therapy? What was done? Was it helpful?
Have you tried spinal or other injections for pain treatment? What was done? Was it helpful?
E Expectations, Goals, Meaning What do you think is causing the pain?
How may we help you? What do you think we should do to treat your pain?
What do you hope the treatment will accomplish?
What do you want to do that the pain keeps you from doing?
What are you most afraid of? (Uncovers specific fears, such as fear of cancer, which should be acknowledged and addressed.)
D Diagnostics & Physical Exam Examine and inspect site (see below)
Perform a systems assessment and examination as indicated
Review imaging, laboratory and/or other test results as indicated

Table 3: Components of a Sensory Examination

Nerve fiber type/receptor Testing tool Technique of testing Abnormal Findings Indicates
↓(decrease) ↑(increase)
Light touch (LT) Aβ fibers/
Hair follicleMerkel
Brush, cotton wisp/swab/von Frey hairs

Touch or gentle rub
Perpendicular contact with skin surface until fiber bends

Hypoaesthesia or anesthesia 1. Hyperesthesia: increased LT- pain
2. Allodynia increased LT+ pain;
Dynamic mechanical (rub); Static mechanical (pressure;vonFrey)
Sensitization: central & or peripheral
Sharp (punctuate) Aδ fibers/ unencapsulated free nerve endings Pin (safety pin, Medipin, Neuropen) Perpendicularly contact skin surface without breaching skin integrity Pinprick hypoalgesia
(sharp sensation perceived as dull sensation)
Pinprick hyperalgesia: sharp and excessively painful Sensitization: central & or peripheral
Vibration Aβ fibers/
Tuning fork at 128 Hz Vibrate the tuning fork and place stem on a bony prominence e.g., malleolus Hypoesthesia 1. Hyperesthesia: increased without pain
2. Allodynia:
increased & painful
Cold Aδ fibers and C fibers/ unencapsulated free nerve endings Tuning fork dipped in cold water/ice chips Apply flat surface to skin for 2-3 seconds Cold hypoalgesia Cold hyperalgesia /Cold allodynia Sensitization:

Table 4: Differences between Treatment of Acute and Chronic Pain

Acute Chronic

Medical model of care
Reduced pain intensity is primary goal in order to facilitate recovery and prevent chronic pain
Generally time limited and successful
Treatment ends when pain resolves

Rehabilitation-disease management model of care
Improved function (physical, psychological and social) is often primary goal
Patients must actively participate in care
Treatment and pain may never end

Table 5: Analgesics - Medications for pain and symptom relief

Examples of representative drug classes with evidence from randomized trials

Mechanism of Action
Side effects
Comments and Cautions

Non-opioid analgesics

acetaminophen Uncertain; may enhance descending inhibitory pathways Mild to moderate pain Few side effects at therapeutic dose Hepatotoxic at high dose. No more than 4 g/24 h or 2 g/ 24 h if consume more than 2-3 alcoholic drinks per day. Caution: many opioid combination products contain acetaminophen
aspirin Irreversible inhibition of both cyclooxygenase (COX) isozymes, COX-1 and COX-2 Mild to moderate pain GI bleed, ↓kidney function, ↓platelet aggregation, hypersensitivity reactions Risk of Reye's syndrome in children
Ibuprofen, naproxyn, diclofenac, others Reversibly inhibit both COX-1 and COX-2 Mild to moderate pain Same as aspirin except reversible effect on platelets Use lowest dose for shortest period of time. High dose may increase the risk of MI and stroke. Formulations of topical diclofenac are available
celecoxib   Primarily inhibits COX-2 Mild to moderate pain No effect on platelets;
50% less risk of GI effects unless taken in combination with aspirin; ↓kidney function
Only "selective" COX-2 inhibitor marketed. High dose increases the risk of myocardial infarction and stroke


Pure μ-receptor agonists
morphine, oxycodone, hydrocodone, codeine, fentanyl, hydromorphone, oxymorphone, methadone*, meperidine, levorphanol
Inhibition of ascending transmission of nociceptive impulses; activation of descending pain inhibitory pathways; reduction of emotional response to pain Moderate to severe pain, any age; also neuropathic pain. Long-term efficacy in chronic noncancer pain not established Constipation - most persistent; sedation; nausea, pruritus; myoclonus and hallucinations at higher doses;
Respiratory depression (during acute administration in opioid naive persons and with coadministration of other central nervous system depressants);
endocrine dysfunction, hyperalgesia and immune suppression reported with chronic use and dose escalation
Side effects are frequently bothersome; many patients become tolerant to side effects.
Avoid meperidine.
Be aware of potential for misuse, abuse, and diversion
*Caution! With regular dosing, risk of accumulation in the elderly or persons with impaired renal function,; monitor for patient variability in duration of action. In patients on chronic opioids, there are large interindividual variations in the equianalgesic dose of methadone compared to other opioids. PO morphine : PO methadone ratio may range from 4:1 to 14:1. For more detail see: Methadone is also used for the treatment of opioid dependence.
Dual action tramadol,
Dual mode of action: μ-opioid receptor agonists, and inhibit reuptake of norepinephrine and serotonin in CNS. Moderate pain, including neuropathic pain Tramadol is a weak μ- opioid agonist and not a controlled substance
Tapentadol is a Schedule II controlled substance
Increased risk of seizures. Serotonin syndrome with concomitant use of other serotonergic drugs such as SSRIs, SNRIs, triptans, etc.
Partial agonist buprenorphine
(Buprenex injectable,
Subutex and Suboxone sublingual tablets)
Partial agonist (mixed agonist-antagonist) Mild to moderate pain; used in the treatment of opioid dependence Typical opioid agonist side effects but with ceiling. Side effects not readily reversed by naloxone Has an analgesic ceiling; in high doses acts as an antagonist; naloxone in Suboxone is intended to discourage IV abuse; Subutex and Suboxone approved for the treatment of opioid dependence by specially certified physicians. Do not combine with pure opioid agonists. Will precipitate withdrawal symptoms if administered to patients being treated with opioid analgesics

Adjuvants - Diverse mechanisms of action, originally designed for other purposes
List not inclusive of local anesthetics, capsaicin, α2 agonists, others


Bind to α2δ subunit of the calcium channel in the dorsal horn. Neuropathic pain; pregabalin also approved for fibromyalgia Somnolence; mental clouding
dizziness; ataxia; weight gain
Many side effects but all reversible after discontinuation. Also have antianxiety effects. No drug-drug interactions
Na+ channel blockers Neuropathic pain; CBZ drug of choice for trigeminal neuralgia CBZ: sedation, dizziness, nausea, unsteadiness, 2% leukopenia, thrombocytopenia.
lamotrigine, Stevens Johnson syndrome (necrotizing rash)
Considered third-line agents for neuropathic pain
topiramate Multiple effects Migraine prophylaxis Somnolence, fatique, nervousness The rare medication used in pain management that causes weight loss


inhibition of norepinephrine and serotonin reuptake; also block Na+ channel
Neuropathic pain Sedative, anticholinergic effects; impaired balance ; cognitive impairment; postural hypotension; weight gain; cardiac toxicity (arrhythmia, tachycardia, stroke, acute myocardial infarction) Avoid amitriptyline in elderly. Use small doses and titrate slowly. Check EKG for conduction abnormalities prior to prescribing
Antidepressant effect manifests at higher doses, analgesic effect seen at lower doses
SNRIs- dual reuptake inhibitors
Inhibit norepinephrine and serotonin reuptake in CNS Neuropathic pain, FDA approved for fibromyalgia GI upset, ataxia, sedation, Relieve insomnia, depression and anxiety

Table 6

Evaluation of the Patient
Obtain a medical history and conduct a physical examination; document these steps in the medical record.
The medical record should document:
  • Nature and intensity of pain
  • Current and past treatments for pain
  • Underlying or coexisting diseases or conditions
  • Effect of the pain on physical and psychological function
  • History of substance abuse
  • Presence of one or more recognized medical indications for the use of a controlled substance

Refer as necessary for additional evaluation and treatment in order to achieve treatment objectives
Pay special attention to patients at risk for medication misuse, abuse, or diversion.

Provide extra care, monitoring, documenting, and consulting with, or referring to a pain specialist when treating patients with a history of substance abuse or with a comorbid psychiatric disorder

Treatment Plan
The written treatment plan should:
  • State objectives that will be used to determine success, such as pain relief and improved physical and psychosocial function
  • Indicate if any further diagnostic evaluations or other treatments are planned

Adjust plan as needed to the individual medical needs of each patient.
Include other treatment modalities or a rehabilitation program in treatment plan, depending on the etiology of the pain and the extent to which the pain is associated with physical and psychosocial impairment.

Medical Records
Keep accurate and complete records that include:
  • Medical history and physical examination
  • Diagnostic, therapeutic, and laboratory results
  • Evaluations and consultations
  • Treatment objectives
  • Discussion of risks and benefits
  • Informed consent
  • Treatments
  • Medications (including date, type, dosage, and quantity prescribed)
  • Instructions and agreements
  • Periodic reviews

Keep records current and maintain them in an accessible manner so that they are readily available for review.

Informed Consent and Agreement for Treatment
Discuss the risks and benefits of the use of controlled substances with the patient/designee/surrogate/guardian.
Obtain the patient's agreement to receive prescriptions from one physician and one pharmacy whenever possible.
Develop a written agreement with a patient at high risk for medication abuse or with a history of substance abuse, that includes:
  • Urine/serum medication level screening
  • Number and frequency of all prescription refills
  • Reasons for which drug therapy may be discontinued (e.g., violation of agreement)
Compliance With Controlled Substances Laws and Regulations
Note that to prescribe, dispense, or administer controlled substances, the physician must be registered with the Drug Enforcement Administration (DEA), be licensed in the state and comply with all applicable federal and state laws and regulations.
A Practitioner's Manual has been prepared by the DEA to assist practitioners "in their understanding of the Federal Controlled Substances Act and its implementing regulations." State laws and regulations are available on the web site for the Pain & Policy Studies Group.
Periodic Review
Follow up regarding the course of pain treatment and any new information about the etiology of the pain or the patient's state of health.
Determine whether to continue or modify use of controlled substances for pain management therapy. Base the decision on progress toward treatment objectives according to the following factors:
  • Satisfactory response, indicated by the patient's decreased pain, increased level of function, or improved quality of life
  • Objective evidence of improved or diminished function, based on information from the family members or other caregivers who are monitoring treatment

Assess the appropriateness of continuing the current treatment plan if the patient's progress is unsatisfactory and consider the use of other therapeutic modalities.


Table reproduced from Stanos D. J Fam Pract 2007 Feb;56(2 Suppl Pain):23-32.
Federation of State Medical Boards of the United States, Inc. Available at Accessed December 20, 2008