Anticonvulsants are used to treat seizures however the also help with neuropathic pain.
This drug is helpful for neuropathic pain such as shingles. Some have used it for other forms of chronic pain such as back pain or sciatica however it is rarely helpful for this. There is some evidence for use in restless leg syndrome. The most common side effect is fatigue, sleepiness, dizziness and unsteady gait. Some patients can experience weight gain.
Gabapentin may interact with NSAIDs.
Lyrica has been used for fibromyalgia, diabetic neuropathy, herpes zoster or spinal cord injury.
Common side effects include dizziness, and somnolence, headache, unsteadiness, insomnia, urinary issues, nausea, aches and pains.
Compared to gabapentin, Lyrica is more likely to cause dry mouth, constipation, swelling, and weight gain. Gabapentin may be associated with a higher risk of fevers or viral infections.
While gabapentin is only technically indicated for postherpetic neuralgia and restless leg syndrome, Lyrica has additional evidence in fibromyalgia, diabetic peripheral neuropathy, and spinal cord injury.
Approximately 1 in 11 patients started on Lyrica experienced moderate to substantial symptom benefit after taking the medication for fibromyalgia.
Other studies suggest that the NNT to achieve a 50% reduction in pain for fibromyalgia is 9.7 and a 30% reduction in pain is 5.3.
Approximately 1 in 10 people will notice a 50% reduction of pain in their fibromyalgia symptoms at a dose of 450 mg per day. It can take 12 to 26 weeks to notice full effect. Approximately 1 in 19 people had weight gain or swelling.
This drug is mainly used for migraines.
Side effects include: Tiredness, drowsiness, dizziness, nervousness, numbness or tingly feeling in the hands or feet, coordination problems, diarrhea and weight loss.
While some antidepressants are used in pain management to manage mood, there are others that have an effect on chronic pain.
Amitriptyline: This medication is mainly used for headaches but can help in other forms of neuropathic pain. Side effects include constipation. Dizziness, dry mouth, feeling sleepy, difficulty peeing, headache.
Nortriptyline: This drug is similar to Amitriptyline but it has less side effects. It is not as well studied as Amitriptyline.
Duloxetine: This drug has been shown in a double blind placebo controlled study to help patients with back pain as well as other types of skeletal pain. Although it generally improves mood, some people can notice a worsening. I also recommend that some people wean off the drug slowly to avoid any withdrawal symptoms. Side effects include difficulty sleeping, headaches, dizziness, blurry vision, constipation, diarrhoea, nausea, dry mouth, sweats.
Cyclobenzaprine (Flexeril): This works at the level of the brain to reduce spasms. It tends to be less effective over time. It can cause serotonin syndrome if taken with antidepressants. Common side effects include dry mouth, headache, blurry vision, drowsiness, dizziness, fatigue, loss of appetite, stomach pain.
Baclofen: This medication works on a brain receptor called GABA. It reduces spasticity especially in spinal cord disorders. Common side effects include drowsiness, dizziness, weakness, tiredness, headache, trouble sleeping, nausea, increased urination, or constipation.
Tizanidine (Zanaflex): This works on a brain receptor called alpha-2. This drug only lasts for 6-8 hours so it should be used when you are engaged in an activity that generally causes spasms. Side effects include dizziness, drowsiness, weakness, nervousness, depression, vomiting. tingling sensation in the arms, legs, hands, and feet and dry mouth.
Botox: When used to treat migraines, about half the treated patients can expect a 50% reduction in headaches. Common side effects include post injection headache, neck pain, eyelid drooping and rarely flu like symptoms.
Opioids such as morphine, hydromorphone, oxycodone and fentanyl carry risks when used in chronic pain. These risks include tolerance, addiction, impaired mentation, worsening of mood and possible worsening of pain.
In the last few years, there are some drugs that have come out which I like to call ‘New Generation Opioids”. While these new drugs may carry some of the risks associated with traditional opioids, they are far less frequent.
Tapentadol (Nucynta) This comes in IR (immediate release) and ER (extended release). Common side effects include Constipation, Dizziness, Drowsiness, Headache, Nausea, Vomiting.
Tramadol: Comes in extended release forms such as Tridural and immediate release forms such as Ultram. When combined with Acetaminophen (Tylenol) it is called Tramacet. Side effects include Nausea, vomiting, constipation, lightheadedness, dizziness, drowsiness, or headache.
Bruprenorphine: This comes in 2 formulations:
Suboxone: This is usually taken as a wafer that is dissolved under the tongue or in the cheek. Side effects include mouth irritation, headache, dizziness, numbness or tingling, drowsiness, insomnia.
Butrans Patch: This patch is applied every 7 days. It is great for providing 24 hour pain relief. The most common side effect is a rash at the site of application. Sometimes steroid creams and other strategies may help reduce the rash but in some patients, we have to discontinue it. Other side effects include constipation, dizziness, drowsiness, dry mouth, headache, nausea/vomiting.
Low Dose Naltrexone (LDN): This medication was initially used to manage opioid and alcohol addiction at doses of 50 to 200mg however at lower doses of 4-6 mg, it works completely differently. It has a left handed molecule which works on our internal endorphin system and helps the body better manage pain. It also has a right handed molecule which works on the inflammatory system and helps to reduce inflammation. Studies have shown that it can reduce fibromyalgia symptoms by up to 30% in 60% of patients who take the drug. It has also been used in Multiple Sclerosis (MS), Crohn's Disease, ME/CFS (Chronic Fatigue Syndrome), Mental Health, Autism etc. It should be noted that this is considered an off label use of the drug. Since it cannot be patented there no large scale pharmaceutical dollars to support research. As such, most of the studies are quite small. Here is a great website which discusses the medication in detail. Side effects include nausea, vomiting, abdominal pain, decreased appetite, constipation, headache, fatigue, insomnia, dizziness, depression and anxiety. Most side effects are dose related. They can be managed with reducing the dose for a few days and titrating much more slower.
Marijuana can broadly be categorized as predominantly CBD or THC. In general, CBD is helpful for pain relief and possibly inflammation while THC may help for sleep or relaxation. Research is showing that it is the terpenes that may be playing a larger role in determining which strain is best for which conditions. I generally refer patients to a Cannabis clinic if we are considering this option.
This is a useful concept when choosing a drug. Most pain drugs work on less than half the people that we treat. Lyrica, for example, only benefits 1 in 13 people when used for fibromyalgia. This is the number of people you have to treat to find someone who says their pain is cut in half. If we are looking to improve pain by 20-30% then we probably need to treat 1 in 5 patients. Number needed to harm represents the number of people that we prescribe the medication who have to stop it due to side effects. Opioids, for example, harm more people than they benefit. Here is a list of commonly used drugs.