Pain Management

in Cancer Patients

ByDr.Ayush Garg

Types

Nociceptive : pain signals from nerve endings

Neuropathic : damage to nerve fibres.

•What Pain Rating Scales Do

We Know??

Descripatientive pain rating scales

Numeric pain rating scale

Wong-Baker faces pain rating scale

Verbal Pain Scale

Cancer PainNociceptiveSomatic:

intermittent to constantsharp, knife-like, localizede.g. soft tissue infiltration

Cancer PainNociceptiveVisceral: constant/intermittent

crampy/squeezingpoorly localized, referrede.g. intra-abdominal mets

Cancer PainNociceptiveBony: constant, dull ache

localized, may haveneuropathic featurese.g. vertebral metastasis pathologic fractures

Cancer PainNeuropathic

Destruction/infiltration of nervesa) dysesthetic:

burning/tinglingconstant, radiatese.g. post-herpetic neuralgia

Cancer PainNeuropathic

Destruction/infiltration of nervesb) neuralgic:

shooting/stabbingshock-like/lancinating

paroxysmale.g. trigeminal neuralgia

Neuropathc pain Chemotherapy induced Neuropathies• Cisplatin,Oxaliplatin• Paclitaxel,Thalidomide• Vincristine,Vinblastine

Surgical Neuropathies• Phantom Limb pain• Post mastectomy syndrome• Post thoracotomy syndrome

Cancer PainBreakthrough “Incidental” painSevere transitory increase in pain on

baseline of moderate intensity or lessCaused by movement, positioning, cough,

wound dressing, etcOften associated with bony metastasis

Adapted WHO pain ladder.

Opioid receptorsClassically, opioids active on CNS receptors mu () kappa () delta () receptorsNow found on:

Peripheral NeuronsImmune CellsInflammed TissueRespiratory TissueGI Tract

Opioid Side Effects Common UncommonConstipation Bad Dreams /

HallucinationsDry Mouth Dysphoria / Delirium

Nausea / Vomiting Myoclonus / SeizuresSedation Pruritus / UrticariaSweats Respiratory Depression

Urinary Retention

Opioid-Induced Neurotoxicity (OIN)

Neuropsychiatric syndrome• Cognitive dysfunction• Delirium• Hallucinations• Myoclonus/seizures• Hyperalgesia/allodynia

Pain ManagementNociceptive Soft Tissue Visceral

Agent Opioids Opioids Steroids Surgery Radiation Treatment

Bone PainPharmacologic treatment• Opioids• NSAIDs/steroids/Cox-2 inhibitors• Bisphosphonates

Pamidronate Clodronate Zoledronate

Bone PainRadiation treatment1. Single treatment (800 cGy)2. Multiple fraction (200 cGy x 3-5)3. Effective immediately4. Maximal effect 4 - 6 weeks5. 60-80% patients get relief

Bone PainSurgical opatientions1. Pathologic # (splint, cast, ORIF)2. Intramedullary support3. Spinal cord decompression4. Vertebral reconstruction

AdjuvantsNSAIDs

Anti-inflammatory, anti-PEGS/E: gastritis/ulcer, renal failure K+ , platelet dysfunctionIbuprofen, naproxen

Don’t use both steroids & NSAIDs!

AdjuvantsCox-2 InhibitorsCelecoxib Rofecoxib MeloxicamValdecoxib

Anti-inflammatoryAnti-prostaglandinS/E: less gastritisno platelet dysf’nrenal failure still a problemOD dosingexpensive

AdjuvantsSteroids

inflammation edema spontaneous nerve depolarizationMultipurpose

AdjuvantsAnticonvulsants

Gabapentin Lamotrigine Carbamazepine Valproic acid

AdjuvantsAntidepressants

Amitriptyline Nortriptyline DesipramineSSRIs: results disappointing

AdjuvantsNMDA Receptor Antagonists(N-methyl-D-aspartate)

KetamineDextromethorphanMethadone

Neuropathic PainNon-pharmacologic Radiation treatment Anaesthetic treatment

• Nerve Block• Epidural Block

Neuropathic PainPharmacologic treatment• Opioids• Steroids• Anticonvulsants• TCAs (dysesthetic)• NMDA receptor antagonists• Anaesthetics

Step 4

Interventions

Alternative TherapiesAcupuncture Cognitive/behavioral therapyMeditation/relaxationGuided imageryHerbal preparationsMagnetsTherapeutic massage

Key Points• Current, accurate information• Use available resources• Involve family & caregivers• Know patient knowledge base• Address patient priorities first• Small doses of useful info (e.g., S/E)• Individualize to patient (social, education

level)

Conclusion Cancer pain can be from the cancer

itself, or from cancer-related treatments Can be somatic, visceral, or neuropathic Negative effects of cancer-related pain

can effect QOL, mortality Ask the patient about pain and

REASSESS!

Choose non-opioid / adjuvants carefully paying close attention to side effect profile

Use WHO ladder guidelines when titrating pain medications

Use long-acting opioids for chronic cancer pain

Recognize “4th step” in WHO ladder and utilize your multidisciplinary resources

Can we offer this ?