Pain Management Part 2Use of Adjuvants

John Mulder, MD, FAAHPMVice President of Medical Services

Faith Hospice

Director, GR MEP Palliative Medicine Fellowship Program

Coanalgesic Drugs (Adjuvant Therapy)Definition: Drugs which enhance analgesic efficacy of opioids, treat concurrent symptoms that exacerbate pain, or produce independent analgesia for specific types of pain.

• Early use optimizes comfort and function by preventing or reducing side effects of higher doses of opioids

Coanalgesic Drugs (Adjuvant Therapy)Most amenable cancer pain syndromes• Bone metastases• Neuropathic pain • Visceral distention

Most commonly used coanalgesic drugs• NSAIDs• Corticosteroids• Antidepressants• Anticonvulsants

Bone Metastases - Adjuvants

• NSAIDs

• Steroids

• Decadron 4mg BID, titrate

• Bisphosphonates

• Zometa, Aredia

• Radioisotopes

Neuropatic Pain – Adjuvants

• Tricyclic antidepressants

• Anticonvulsants

• Steroids

• NSAIDs

• Antidepressants

• TCA - Elavil, gold standard; desipramine

• SSRI - Paxil only one shown effective thus far; Serzone, Effexor

promising

• Psychostimulants - dietary caffeine, Ritalin, amphetamines

Alternative/Adjuvant Medications

• Neuroleptics

• Benzodiazapines (watch for sedation)

• Anticonvulsants - especially for neurogenic pain (Neurontin)

• Baclofen

Alternative/Adjuvant Medications

• Steroids - high dose, short term/low-dose, long term

• Antihistamines (Benedryl, Vistaril)

• Alpha-2-adrenergic stimulants (Clonidine)

• Cannabanoids

Alternative/Adjuvant Medications

Alternative/Adjuvant Medications

• Capsaicin

• Colchicine

• Thalidomide

• Ketamine

• Lidocaine

• Dextromethorphan - (no guaifenesin or alcohol) - 30 mg BID - 1 g/d (400 - 600 mg/d usual )

Narcotic Resistant Pains• Headaches

• Muscle Spasm

• Tenesmoid (Bowel / Bladder)

• Incident to movement

• Decubitus

• Deafferentation

Deafferention Pain• Type I Complex Regional Pain Syndrome

A syndrome characterized by severe burning pain in an extremity accompanied by sudomotor, vasomotor, and trophic changes in bone without an associated specific nerve injury. ...

• Complex Regional Pain Syndromes

Conditions characterized by pain involving an extremity or other body region, HYPERESTHESIA, and localized autonomic dysfunction following injury to soft tissue or nerve. The pain ...

• Reflex Sympathetic Dystrophy Syndrome

A syndrome characterized by severe burning pain in an extremity accompanied by sudomotor, vasomotor, and trophic changes in bone without an associated specific nerve injury. ...

• OMM

• Acupuncture

• Acupressure

• Massage Therapy

• Music Therapy

• Hypnosis

• Relaxation

Non-pharmacologic Interventions

Unwarranted / Exaggerated Fears

• Respiratory Depression

• Addiction

• Rapid Tolerance

• Regulatory Reprisal

Opiate Side Effects: Constipation

– Most common side effect - expected– Mediated spinally and in GI tract– Decreased peristalsis & decreased intestinal

secretions– Tolerance does not readily occur– Treat with peristaltic agent and softeners -

prophylactically

Opiate Side Effects: Pruritis

– Caused by opioid induced histamine release– Tolerance generally develops quickly– Difficult cases may require a change in opioid– Usually treated with transient use of

antihistamines

Opiate Side Effects: Somnolence / Sedation

– Common, but tolerance typically develops within a few days

– Sedation varies with opioid and dosing schedule– Additive effects with other cerebral depressants– Decrease or discontinue other cerebral depressants– Concurrent use of Dextroamphetamine or

Methylphenidate is helpful, but tachyphylaxis is common

Opiate Side Effects: Hallucinations / Confusion

– Less common, but may occur especially in older patients

– Often an indication of excess dosing– Try dose reduction or different opioid

Opiate Side Effects: Nausea / Vomiting

– Occurs in 50 – 65% of patients on oral morphine

– Varies with drug and route– Usually easy to control, occasionally severe and

difficult to control

Opiate Side Effects: Urinary Retention

– Opioids increase smooth muscle tone (sphincter)

– May also cause bladder spasms– Try changing opioids or insertion of catheter

Opiate Side Effects: Myoclonus

– Can occur with all opioids– Typically due to high doses and/or dehydration– Long half-life metabolites are typically

implicated– Reduce dose, change opioids, change routes

and/or hydrate patient

Opiate Side Effects: Respiratory Depression

– Cause of death in opioid overdose– Tolerance develops rapidly– Rarely a concern with appropriate dose

escalations– If accidental overdose occurs in a patient

chronically receiving opioids, dilute Naloxone 1:10 and titrate very carefully to reverse respiratory depression without precipitating withdrawal or reversing analgesia