Pathophysiology of Fibromyalgia
Fibromyalgia is a chronic condition that causes muscle pain and stiffness. The pathophysiology of fibromyalgia includes a combination of several different factors. Environmental stressors and genetic factors are included in the pathophysiology of fibromyalgia.
Fibromyalgia is sourced from changes and regulations of the neuroendocrine system. The pain processing in fibromyalgia amplifies sensory signals, which causes constant pain.
Fibromyalgia is commonly associated with anxiety and depression. Fibromyalgia’s association with mood disorders suggests its connection with stress responses.
Peripheral pain generators such as intestinal irritability can also cause fibromyalgia (Siracusa et al., 2021).
Patients with fibromyalgia experience fatigue and often have sleep disorders. Patients with fibromyalgia can have cognitive difficulties and memory issues.
Antidepressant Medication for Fibromyalgia Treatment
Antidepressant medications can ease fibromyalgia symptoms and pain. Fibromyalgia involves decreased levels of serotonin. Antidepressant medications target raising the levels of serotonin production. Increased levels of serotonin can help with controlling the feeling of pain. Antidepressants can also improve sleep and mood issues for patients with fibromyalgia.
- Duloxetine (Cymbalta) is a serotonin and norepinephrine reuptake inhibitor (SNRI). Duloxetine is used to treat depression, anxiety disorder, and neuropathic pain. Cymbalta prevents serotonin from re-entering cells, increasing its levels in the organism.
- Milnacipran (Savella) is also an SNRI used to treat psychiatric disorders. Savella increases the number of neurotransmitters, which reduces pain.
Anti-Seizure Medication for Fibromyalgia Treatment
Anti-Seizure medications, also known as anticonvulsants, can be used to treat fibromyalgia. Anticonvulsants help to slow the neurons’ communications. Thus, anticonvulsants reduce the number of amplified pain sensory signals in the brain. Anticonvulsants can reduce pain and other fibromyalgia symptoms. Anti-seizure medications can help to reduce patients’ feelings of fatigue and improve sleep quality.
- Pregabalin (Lyrica) is an anti-seizure drug recommended by FDA for fibromyalgia treatment. Lyrica reduces the number of pain signals from overly sensitive nerve cells. Lyrica improves sleep quality for people with fibromyalgia.
- Gabapentin (Neurontin) is used to treat seizures and relieve nerve pain. Gabapentin has slower absorption capacities than pregabalin.
Pharmacokinetics, Pharmacodynamics, Safety/Monitoring, & Pregnancy/Lactation
Duloxetine (Cymbalta)
In fibromyalgia, the recommended daily dosage for Cymbalta is 60mg. A higher dosage can cause adverse reactions. Suddenly stopping the medicine can cause side effects.
Cymbalta requires monitoring as it can increase suicidal throughs. Cymbalta can also cause hyponatremia. There is no information about the drug’s relationship with pregnancy and lactation.
Milnacipran (Savella)
The recommended dosage is 50mg two times each day. Patients should gradually increase the dosage from 12.5mg to monitor the response.
Cymbalta requires monitoring as it can cause behavior changes. A combination of Savella with blood-thinning medications can cause abnormal bleeding. Pregnant women should consult with doctors before starting Savella.
Pregabalin (Lyrica)
The recommended daily dosage is 300 to 600mg, split into several (2-3) doses. A combination of Lyrica with ACE inhibitors and diabetes medications can cause swelling. Combining Lyrica with other drugs can cause increased drowsiness. Alcohol intake can increase Lyrica’s side effects. Pregnant and breastfeeding should consult with doctors before starting Lyrica.
Gabapentin (Neurontin)
The recommended daily dosage is 900-1800mg, split into three doses. Overdose of Neurontin can cause breathing difficulty, which is a life-threatening condition. Gabapentin can cause an allergic reaction. Alcohol intake can worsen the side effects of the drug. Neurontin is not recommended for pregnant or breastfeeding women.
Contraindications of Antidepressant Medications for Fibromyalgia Treatment
Duloxetine (Cymbalta) can increase the risk of cardiovascular events for people with high blood pressure. Duloxetine can cause hyponatremia in elderly adults (Oliver et al., 2020).
Savella should not be used in patients with glaucoma. The combination of Savella with monoamine oxidase inhibitors (MAOIs) increases the risk of serotonin syndrome (Gupta et al., 2021). SNRIs can worsen depression symptoms and cause suicidal throughs.
Contraindications of Anti-Seizure Medications for Fibromyalgia Treatment
A combination of Lyrica with other medications can increase their sleepiness side effects. Lyrica can negatively affect an individual’s ability to drive due to dizziness. Lyrica can cause fluid retention or swelling. Individuals with breathing problems should avoid gabapentin. Gabapentin also causes drowsiness as a side effect.
Summary
Medications approved for fibromyalgia treatment by the FDA reduce pain and improve sleep quality. Painkillers can cause drug dependence. The effect of painkillers may gradually decrease with time. Thus, antidepressants and anti-seizure medications can be more effective for fibromyalgia treatment. It is vital to know about the side effects of medications to ensure patients’ safety.
References
Gupta, H., Girma, B., Jenkins, J. S., Kaufman, S. E, Lee, C. A., & Kaye, A. D. (2021). Milnacipran for the treatment of fibromyalgia. Health Psychology Research, 9(1) 1-13.
Oliver, W. D., D’Angelo, R., Gonzales, J., Wilson, T., & Millstein, L. S. (2020). Acute severe hyponatremia induced by a duloxetine overdose in an elderly woman. Cureus, 12(9), 1-4.
Siracusa, R., Paola, R. D., Cuzzocrea, S., & Impellizzeri, D. (2021). Fibromyalgia: Pathogenesis, mechanisms, diagnosis and treatment options update. International Journal of Molecular Sciences, 22(8), 1-31.