Drugs and Medications

Analgesics (Pain Relievers)

Analgesics are medications specifically used to relieve pain. They are broadly categorized based on their mechanism and strength (1, 2).

Non-Opioid Analgesics & NSAIDs

• Acetaminophen (Paracetamol): Relieves pain and reduces fever but has little anti-inflammatory effect. Generally well-tolerated at recommended doses but overdose can cause severe liver damage (1).
• Non-Steroidal Anti-Inflammatory Drugs (NSAIDs): Examples include ibuprofen, naproxen, diclofenac (e.g., Voltaren), ketoprofen, meloxicam, celecoxib (COX-2 specific). They reduce pain, fever, and inflammation by inhibiting cyclooxygenase (COX) enzymes (1, 2). Commonly used for musculoskeletal pain, arthritis, headaches, and injuries. Potential side effects include gastrointestinal upset/ulcers/bleeding, kidney problems, and increased cardiovascular risk (especially with long-term use or higher doses) (1).

Opioid Analgesics

• Examples range from weaker opioids often combined with acetaminophen (e.g., codeine, hydrocodone combinations) to stronger agents (e.g., tramadol, oxycodone, morphine, fentanyl) (1, 2). They act on opioid receptors in the central nervous system to reduce the perception of pain.
• Used for moderate to severe acute pain (e.g., post-operative, trauma) and sometimes for severe chronic pain under careful supervision.
• Significant risks include sedation, constipation, nausea, respiratory depression, tolerance, physical dependence, and potential for addiction/misuse. Their use, especially long-term, requires careful patient selection, monitoring, and management strategies (1, 2).

Other Analgesics (Calcitonin)

• Specific agents like Calcitonin (e.g., Miacalcic nasal spray) are sometimes used for the acute pain associated with osteoporotic vertebral compression fractures. Its mechanism involves effects on bone turnover and potentially direct analgesic actions (3).

 

Medications for Neuropathic Pain

Certain medications originally developed as antidepressants or anticonvulsants are effective in treating neuropathic pain (pain arising from nerve damage or dysfunction), often seen in conditions like diabetic neuropathy, post-herpetic neuralgia, fibromyalgia, or chronic radiculopathy (1, 4). They work by modulating neurotransmitters or nerve excitability involved in pain pathways.

• Antidepressants:
  • Tricyclic Antidepressants (TCAs): Examples include amitriptyline, nortriptyline, desipramine. Effective for various neuropathic pain types but can have significant side effects (dry mouth, sedation, constipation, cardiac effects) (1, 4).
  • Serotonin-Norepinephrine Reuptake Inhibitors (SNRIs): Examples include duloxetine, venlafaxine. Often better tolerated than TCAs and indicated for neuropathic pain and fibromyalgia (1, 4).
• Anticonvulsants (Gabapentinoids): Examples include gabapentin and pregabalin. Commonly used first-line agents for various neuropathic pain conditions (1, 4). Side effects can include dizziness and sedation.

These medications can sometimes help reduce reliance on opioid analgesics for chronic pain conditions and may improve sleep and mood, which are often affected by chronic pain (4).

 

Muscle Relaxants

Skeletal muscle relaxants are used to treat muscle spasms and associated pain, often related to acute musculoskeletal injuries or conditions like fibromyalgia (1, 5). Examples include:

• Cyclobenzaprine
• Methocarbamol
• Carisoprodol (use often limited due to potential for dependence)
• Metaxalone
• Tizanidine (e.g., Sirdalud) - Also has alpha-2 agonist activity.
• Baclofen - Primarily used for spasticity related to CNS conditions (e.g., MS, spinal cord injury) but sometimes used off-label for musculoskeletal spasm (1, 5).
• Diazepam (Valium) - A benzodiazepine with muscle relaxant properties, but also significant sedation and dependence potential (1).
• Tolperisone (e.g., Mydocalm) - Used in some regions.

They generally work centrally to reduce muscle tone. Common side effects include drowsiness and dizziness. Often recommended for short-term use for acute conditions (1, 5). They can complement physical therapy or manual techniques by reducing muscle guarding.

 

Medications Affecting Bone & Nerve Health

Various medications and supplements target specific aspects of bone and nerve health:

• Bone Health (Osteoporosis):
  • Calcium and Vitamin D: Essential baseline supplements for bone density (6).
  • Bisphosphonates: (e.g., alendronate, risedronate, zoledronic acid - e.g., Aclasta) Reduce bone resorption by inhibiting osteoclasts. First-line therapy for osteoporosis (6).
  • Other Osteoporosis Agents: Denosumab, teriparatide, raloxifene, etc., target different pathways in bone metabolism (6).
• Nerve Health Support:
  • B Vitamins: Often used empirically for neuropathies, particularly B1, B6, and B12. Evidence is strongest for deficiency states (e.g., B12 deficiency neuropathy). Some combination products (e.g., Milgamma - common in some regions) are available (1).
  • Alpha-Lipoic Acid: An antioxidant sometimes used for diabetic neuropathy pain (evidence is mixed) (1).
• Microcirculation Improvement: Medications like pentoxifylline (e.g., Trental) or cilostazol are sometimes used for peripheral artery disease to improve blood flow. Their specific role in directly improving nerve microcirculation in neuropathies is less established or condition-specific (1).
• Cartilage/Joint Supplements: Products containing glucosamine, chondroitin (e.g., Gelenk Nahrung - brand name example) are marketed for osteoarthritis. Scientific evidence for significant clinical benefit is generally weak or inconsistent (1).

 

Topical Medications (Ointments, Creams, Gels)

Topical agents are applied directly to the skin over painful areas, offering localized effects with potentially fewer systemic side effects than oral medications (1):

• Topical NSAIDs: (e.g., Diclofenac gel - Voltaren Gel, Ketoprofen gel - e.g., Fastum Gel). Deliver anti-inflammatory medication directly to the area. Effective for localized musculoskeletal pain like osteoarthritis or soft tissue injuries (1).
• Counterirritants: (e.g., Menthol - Bengay, Methyl Salicylate, Camphor). Create a cooling or warming sensation that distracts from underlying pain (1).
• Capsaicin Cream: (Derived from chili peppers, e.g., Kapsikam - brand name example). Depletes substance P (a pain neurotransmitter) in nerve endings. Used for neuropathic pain and arthritis pain, but can cause initial burning sensation (1).
• Topical Lidocaine: Patches or creams provide local anesthesia (1).
• Other Combination Products: Some products combine multiple ingredients like counterirritants and analgesics (e.g., Apizartron - contains bee venom, methyl salicylate).

Important Considerations

The selection, dosing, and combination of medications must be individualized by a qualified healthcare professional after a thorough evaluation (1). Factors considered include:

• The specific diagnosis and underlying cause of symptoms.
• The severity and type of symptoms (e.g., nociceptive vs. neuropathic pain).
• Patient's age, weight, and overall health status.
• Presence of comorbidities (other health conditions, e.g., kidney or liver disease, cardiovascular disease).
• Potential drug interactions with other medications the patient is taking.
• Previous responses to medications and history of allergies or side effects.

Treatment plans may involve combining different medication classes and are often used alongside non-pharmacological therapies like physical therapy, exercise, or injections. Treatment settings can range from outpatient management to inpatient care depending on the condition's severity and the required interventions.

References

1. Katzung BG, Masters SB, Trevor AJ. Basic & Clinical Pharmacology. 14th ed. McGraw-Hill Education; 2018. (Standard Pharmacology Textbook)
2. Chou R, Qaseem A, Snow V, et al. Diagnosis and treatment of low back pain: a joint clinical practice guideline from the American College of Physicians and the American Pain Society. Ann Intern Med. 2007;147(7):478-491. doi:10.7326/0003-4819-147-7-200710020-00006 (Guideline example covering analgesics)
3. Knopp-Sihota JA, Newburn-Cook CV, Homik J, Cummings GG, Voaklander D. Calcitonin for treating acute and chronic pain of recent and remote osteoporotic vertebral compression fractures: a systematic review and meta-analysis. Osteoporos Int. 2012;23(11):2683-2699. doi:10.1007/s00198-012-1908-y
4. Finnerup NB, Attal N, Haroutounian S, et al. Pharmacotherapy for neuropathic pain in adults: a systematic review and meta-analysis. Lancet Neurol. 2015;14(2):162-173. doi:10.1016/S1474-4422(14)70251-0
5. See S, Ginzburg R. Choosing a skeletal muscle relaxant. Am Fam Physician. 2008;78(3):365-370. Available from: https://www.aafp.org/pubs/afp/issues/2008/0801/p365.html
6. Cosman F, de Beur SJ, LeBoff MS, et al; National Osteoporosis Foundation. Clinician's Guide to Prevention and Treatment of Osteoporosis. Osteoporos Int. 2014;25(10):2359-2381. doi:10.1007/s00198-014-2794-2