What is Duloxetine?
Duloxetine is a type of antidepressant which falls under the class of serotonin–norepinephrine reuptake inhibitors (SNRIs). This class of antidepressant prevents the neurotransmitters, norepinephrine and serotonin, from reentering into the brain cells that release them. By doing so, the drug helps to maintain healthy levels of these two key mood regulating hormones:
- Norepinephrine – a stress hormone which is released when a person faces stress. It helps increase alertness and helps with memory.
- Serotonin – the happy hormone which helps to promote a sense of well-being and happiness. It also has a role in modulating sleep and pain perception.
Therefore, duloxetine is often used to treat anxiety, depression, neuropathic pain and fibromyalgia.
How Does Duloxetine Help Fibromyalgia?
Researchers believe that neurotransmitters like norepinephrine and serotonin play a role in analgesia in chronic pain. Hence, by increasing the levels of norepinephrine and serotonin, SNRIs like duloxetine can help to reduce pain.
However, it is still unclear exactly how duloxetine helps to reduce pain in fibromyalgia. This is partly because the cause behind fibromyalgia pain is still unknown. Many believe that fibromyalgia pain is due to abnormal changes in the nervous system causing nerve cells to fire signals along the pain pathways. Researchers suggest that duloxetine reduces fibromyalgia pain by calming down these pain signals.
As an antidepressant, duloxetine also helps to improve psychiatric symptoms such as depression and anxiety in fibromyalgia patients.
Various clinical trials found evidence that duloxetine provided pain relief and increased physical function in participants. In a 2015 study, duloxetine appeared to reduce two pain types in fibromyalgia: hyperalgesia and allodynia. However, like most fibromyalgia medications, there are some who did not respond to the drug.
Side Effects of Duloxetine
As with any medication, duloxetine comes with side effects. The more common side effects which may last 4-6 weeks include:
- Decreased appetite
- Dry mouth
Duloxetine can also cause more dangerous side effects which may be due to your medical condition or drug interactions with existing prescriptions. These side effects require your doctor’s attention. They include:
- Suicidal thoughts
- Allergy which can surface as rashes, swelling of face, eyes, lips or tongue
- Bleeding or bruising
Precautions of Duloxetine for Fibromyalgia
Duloxetine may not be suitable for everyone. Those who should take duloxetine with caution include:
- People with medical conditions like diabetes, heart disease, hypertension, liver disease, kidney disease, conditions that delay gastric emptying or have history of seizures or mania.
- People on medications that increase serotonin levels should avoid duloxetine due to drug interaction which can cause serotonin syndrome. These medications include pain medications like meperidine and tramadol, cough medications containing dexomethorphan, heartburn and nausea drugs like metoclopramine and ondansetron, Triptans for migraines
- People on blood thinning medications like warafin, aspirin, and nonsteroidal anti-inflammatory drugs (NSAIDs) should also take duloxetine with caution due to drug interactions.
- Women who are pregnant, breastfeeding or intending to get pregnant should take duloxetine with caution due to possible side effects on the child.
Those who should not take duloxetine include:
- People with uncontrolled narrow-angle glaucoma
- People on thioridazine medication
- People on Monoamine oxidase inhibitors (MAOIs)
Hence, it is crucial to speak to your doctor if you intend to try duloxetine for fibromyalga. Your doctor would be able to evaluate if you are suitable to administer the drug base on your current prescription and medical history.