Non-Opioid Pharmacotherapeutic Options in Pain Management Charles E. Argoff, M.D. Professor of Neurology Albany Medical College Director, Comprehensive Pain Program Albany Medical Center “Discouraging data on the antidepressant.” Multidisciplinary Treatment of Chronic Pain Pharmacotherapy and other medical/surgical care with appropriate medicine reorganization Restorative care including active physical and occupational therapy Psychological counseling utilizing cognitive-behavioral pain management strategies Aim for Monotherapy Titrate only one drug at a time Pharmacotherapy Guidelines 1. Medication must result in: – – Significant pain relief Tolerable side effects function Pharmacotherapy Guidelines 2. Both physician & patient must realize significant individual variability Pharmacotherapy Guidelines 3. Slow titration until either: a) Significant pain relief b) Intolerable side effects c) “Toxic serum level” Pharmacotherapy Guidelines 4. Educate the patient Non-Opiate Pharmacotherapy NSAIDs/Cox-2 Acetaminophen Antidepressants Anticonvulsants Oral local anesthetics Alpha adrenergic agents Neuroleptics NMDA receptor antagonists Muscle relaxants Topical analgesics Emerging Agents Non-Opiate Pharmacotherapy NSAIDs/Cox-2 Acetaminophen Antidepressants Anticonvulsants Oral local anesthetics Alpha adrenergic agents Neuroleptics NMDA receptor antagonists Muscle relaxants Topical analgesics Emerging Agents Non-Opiate Pharmacotherapy NSAIDs/Cox-2 Acetaminophen Antidepressants Anticonvulsants Oral local anesthetics Alpha adrenergic agents Neuroleptics NMDA receptor antagonists Muscle relaxants Topical analgesics Emerging Agents Non-Opiate Pharmacotherapy NSAIDs/Cox-2 Acetaminophen Antidepressants Anticonvulsants Oral local anesthetics Alpha adrenergic agents Neuroleptics NMDA receptor antagonists Muscle relaxants Topical analgesics Emerging Agents Antidepressants* Tricyclic SSRI SNRI Amitriptyline (Elavil®) Fluoxetine (Prozac®) Duloxetine# (Cymbalta) Desipramine (Norpramin®) Paroxetine (Paxil®) Venlafaxine (Effexor®) Doxepin (Sinequan®) Sertraline (Zoloft®) Minalcipran# (Savella) Imipramine (Tofranil®) Fluvoxamine (Luvox®) Desvenlafaxine (Pristiq) Nortriptyline (Pamelor®) Citalopram (Celexa) * = Partial list # = FDA approved for at least one pain disorder SSRI = selective serotonin reuptake inhibitor SNRI = serotonin norepinephrine reuptake Review of Antidepressant Analgesia for Older Agents Meta-analysis by Onghena (1992) Diagnosis Synthesis by Magni (1991) No. of Studies Effect Size Diabetic neuropathy 1 1.71 Responsive Postherpetic neuralgia 2 1.44 Responsive Tension headache 6 1.11 Responsive Migraine 4 0.82 Responsive Atypical facial pain 3 0.81 Responsive Chronic back pain 5 0.64 Minimal clinical benefit Rheumatological pain 10 0.37 Fibrositis responsive; Osteo- and rheumatoid arthritis probably responsive Not specified or mixed 7 0.23 Probable effect Non-Opiate Pharmacotherapy NSAIDs/Cox-2 Acetaminophen Antidepressants Anticonvulsants Oral local anesthetics Alpha adrenergic agents Neuroleptics NMDA receptor antagonists Muscle relaxants Topical analgesics Emerging Agents Anticonvulsants Carbamazepine* Divalproex sodium* Gabapentin* Pregabalin* Clonazepam Phenytoin *Has FDA indication for pain/headache Lamotrigine Topiramate* Zonisamide Oxcarbazepine Levatriacetam Lacosamide Clinical Syndromes and Anticonvulsant Use Postherpetic neuralgia – lamotrigine – gabapentin – pregabalin – carbamazepine – gabapentin – Lamotrigine – pregabalin Trigeminal neuralgia – carbamazepine – lamotrigine – oxcarbazepine Diabetic neuropathy – phenytoin HIV-associated neuropathy Fibromyalgia - pregabalin Central poststroke pain – lamotrigine Mean pain score Gabapentin in the Treatment of Painful Diabetic 10 Placebo Neuropathy* Gabapentin 8 N=165 6 4 † † 2 ‡ † † ‡ ‡ ‡ 6 7 8 P<0.01; ‡P<0.05. 0 Screening 1 2 3 4 5 Week *Not approved by FDA for this use. 46 Adapted from Backonja M et al. JAMA. 1998;280:1831-1836. Non-Opiate Pharmacotherapy NSAIDs/Cox-2 Acetaminophen Antidepressants Anticonvulsants Oral local anesthetics Alpha adrenergic agents Neuroleptics NMDA receptor antagonists Muscle relaxants Topical analgesics Emerging Agents Non-Opiate Pharmacotherapy NSAIDs/Cox-2 Acetaminophen Antidepressants Anticonvulsants Oral local anesthetics Alpha adrenergic agents Neuroleptics NMDA receptor antagonists Muscle relaxants Topical analgesics Emerging Agents Currently Available AlphaAdrenergic Agonists Clonidine Tizanidine Possible Effective Uses of Tizanidine Trigeminal neuralgia (Fromm 1993) Chronic low back pain(Berry 1988) Cluster headache (D’alessandro 1996) Chronic tension-type headache (Nakashima 1994) Spasmodic torticollis (Houten 1984) Neuropathic pain Chronic headache(2002) Non-Opiate Pharmacotherapy NSAIDs/Cox-2 Acetaminophen Antidepressants Anticonvulsants Oral local anesthetics Alpha adrenergic agents Neuroleptics NMDA receptor antagonists Muscle relaxants Topical analgesics Emerging Agents Non-Opiate Pharmacotherapy NSAIDs/Cox-2 Acetaminophen Antidepressants Anticonvulsants Oral local anesthetics Alpha adrenergic agents Neuroleptics NMDA receptor antagonists Muscle relaxants Topical analgesics Emerging Agents NMDA receptor antagonists Preclinical Data Mu-Opioid-R Activation Nerve Injury NMDA-R Inhibitors PKC Excitability Neurotoxicity Hyperalgesia Mu-Efficacy Mu-Opioid Tolerance Drugs with Potential NMDA-R Antagonist Properties Dextromethorphan Ketamine d-Methadone Amantadine Memantine Amitriptyline DEXTROMETHORPHAN Postherpetic Neuralgia & Painful diabetic neuropathy 2 RCTs Crossover: 6 weeks – Dextromethorphan alone vs placebo DN: – mean daily dose = 381 mg/day – Pain decreased ( p=0.01) PHN: – mean daily dose = 439 mg/day – Did not significantly reduce pain (Nelson 1997) Non-Opiate Pharmacotherapy NSAIDs/Cox-2 Acetaminophen Antidepressants Anticonvulsants Oral local anesthetics Alpha adrenergic agents Neuroleptics NMDA receptor antagonists Muscle relaxants Topical analgesics Emerging Agents Muscle Relaxants Cyclobenzaprine (Flexeril®) Carisoprodol (Soma®) Methocarbamol (Robaxin®) Metaxalone (Skelaxin®) Orphenadrine citrate (Norflex®) Cyclobenzaprine Structurally similar to tricyclics Centrally acting Nocturnal muscle spasm effects Side effects: – Drowsiness – Anticholinergic - Cardiac dysrhythmias Dry mouth Blurred vision Urine retention Constipation Increased intraocular pressure Carisoprodol Precursor of meprobamate Centrally active Reduction of muscle spasm Side effects: – Sedation, drowsiness, dependence – Withdrawal symptoms Agitation Anorexia N/V Hallucination Seizures Methocarbamol Investigative usage: MS Daily dosage: 1000 mg qid Side effect: drowsiness Mechanism of action: – Centrally active – Inhibits polysynaptic reflexes Clinical effects: – Reduction of muscle spasms Metaxalone Daily dosage: 400-800 mg tid Clinical effects: – Reduction in muscle spasm Side effects: – Nausea – Drowsiness – Dizziness Orphenadrine Citrate Investigative usage: SCI Daily dosage: 100 mg bid Analog of diphenhydramine Given IV for antispasticity trials Side effects: – Anticholinergic – Rare aplastic anemia Non-Opiate Pharmacotherapy NSAIDs/Cox-2 Acetaminophen Antidepressants Anticonvulsants Oral local anesthetics Alpha adrenergic agents Neuroleptics NMDA receptor antagonists Muscle relaxants Topical analgesics Emerging Agents Topical Analgesics: Key Facts Topical agents are active within the skin, soft tissues and peripheral nerves. In contrast to transdermal, oral or parenteral medications, use of a topical agent does not result in clinically significant serum drug levels. Other benefits include lack of systemic side effects and drug-drug interactions. The mechanism of action of a topical analgesic is unique to the specific agent considered. Topical Treatments for Chronic Pain Diclofenac (patch/gel/lotion) Aspirin Capsaicin Local anesthetics - lidocaine patch 5%/eutectic mixture of local anesthetics Tricyclic antidepressants Opiates Investigational agents Non-Opiate Pharmacotherapy NSAIDs/Cox-2 Acetaminophen Antidepressants Anticonvulsants Oral local anesthetics Alpha adrenergic agents Neuroleptics NMDA receptor antagonists Muscle relaxants Topical analgesics Emerging Agents Emerging Analgesics Botulinum Toxin (Type A, Type B) New intraspinal agents New topical agents Cannabinoids Bisphosphonates Summary Numerous pharmacotherapeutic options are available for the management of chronic pain. Proper evaluation including pain assessment is key to providing the best analgesic approach. Optimizing analgesia in the long term care setting requires achieving a proper balance among efficacy, adverse effects, cost and other factors.