Today's post from cochrane.org (see link below) looks at Milnacipran, an antidepressant and asks whether it's effective in reducing neuropathic pain. Due to antidepressants and especially SNRI (serotonin–norepinephrine reuptake inhibitor) antidepressants, being standard treatment for neuropathic pain, that doesn't mean to say that every antidepressant in the range is effective. Cochrane has looked at the drug and concludes that there is no evidence to suggest Milnacipran is of any help in taming nerve pain. Forewarned is forearmed as they say, so if your doctor suggests taking Milnacripan, it may be worth presenting this evidence to him or her.
Milnacipran for neuropathic pain in adults
Authors: Derry S, Phillips T, Moore R, Wiffen PJ Published: 6 July 2015
Neuropathic pain is pain coming from damaged nerves. It is different from pain messages that are carried along healthy nerves from damaged tissue (for example, a fall, or cut, or arthritic knee). Neuropathic pain is treated by different medicines to those used for pain from damaged tissue. Medicines such as paracetamol or ibuprofen are not usually effective in neuropathic pain, while medicines that are sometimes used to treat depression or epilepsy can be very effective in some people with neuropathic pain.
Milnacipran is an antidepressant, and antidepressants are widely recommended for treating neuropathic pain; milnacipran may also be useful in these painful conditions.
This is an update of a review of milnacipran for neuropathic pain and fibromyalgia, first published in 2012. That review has been split so that this one looked only at neuropathic pain, and a separate review looks at fibromyalgia.
In February 2015 we performed searches to look for clinical trials where milnacipran was used to treat neuropathic pain in adults.
We found only a single, small study of 40 participants who had chronic low back pain with a neuropathic component. Milnacipran was no different from placebo in terms of pain or adverse events (very low quality evidence).
There was no evidence to support use of milnacipran to treat neuropathic pain conditions.
Authors' conclusions:
There was no evidence to support the use of milnacipran to treat neuropathic pain conditions.
Background:
Milnacipran is a serotonin–norepinephrine reuptake inhibitor (SNRI) that is sometimes used to treat chronic neuropathic pain and fibromyalgia. This is an update of an earlier review of milnacipran for neuropathic pain and fibromyalgia in adults originally published in The Cochrane Library Issue 3, 2012. We split that review so that this one looked only at neuropathic pain, and a separate review looks at fibromyalgia.
Objectives:
To assess the analgesic efficacy and associated adverse events of milnacipran for chronic neuropathic pain in adults.
Search strategy:
We searched the Cochrane Central Register of Controlled Trials (CENTRAL), MEDLINE, and EMBASE to 23 February 2015, together with reference lists of retrieved papers and reviews.
Selection criteria:
We included randomised, double-blind studies of eight weeks' duration or longer, comparing milnacipran with placebo or another active treatment in chronic neuropathic pain.
Data collection and analysis:
Two review authors independently searched for studies, extracted efficacy and adverse event data, and examined issues of study quality. We did not carry out any analysis.
Main results:
We included a single study of 40 participants with chronic low back pain with a neuropathic component. It found no difference in pain scores between milnacipran 100 mg to 200 mg daily or placebo after six weeks (very low quality evidence). Adverse event rates were similar between treatments, with too few data to draw conclusions (very low quality evidence).
http://www.cochrane.org/CD011789/SYMPT_milnacipran-neuropathic-pain-adults
Today's post from psnc.org.uk (see link below) is a British view and advice to pharmacists on the changing status of Lyrica, as Pfizer's patent has now run out and generic versions will be coming onto the market. Pfizer in their wisdom, have decided to maintain a Lyrica patent for patients with neuropathy, at least until July 2017. This will effectively prevent other companies from bringing out a generic version until that date. Now in 2013, Pfizer were quite clear that pregabalin (Lyrica) was in their own eyes unsuitable for diabetes and HIV-related neuropathy patients. This was mainly due to adverse study outcomes and many court cases relating to side effect issues. The point is: what's changed? the answer: probably nothing: they still won't approve Lyrica for HIV and diabetes neuropathy patients and the FDA backs that up completely. So is this just a corporate move to prevent rivals from bringing generic Lyrica to the market too quickly? More importantly for neuropathy patients; will generic pregabalin (lyrica) be any more effective and any less dangerous for patients in the future. We'll have to wait and follow the recommendations for the US FDA and similar authorities across the world but until then, if your doctor is still prescribing Pregabalin (Lyrica) (generic or not) for your neuropathic problems, you need to have a serious discussion as to whether this is in fact, the best option.
January 29, 2015
Pregabalin (Lyrica) patent is changing and generic pregabalin is becoming available. The NPA have issued advice (shown below) regarding the licencing of the products.
The NPA have also informed us that are also in the process of discussing this issue with the MHRA and Pfizer.
Dear Pharmacist
You may find in the coming months that generic pregabalin is available to order. I would like to highlight to you that although the patent for pregabalin expired in July 2014, this patent expiry related to the use of pregabalin in epilepsy and generalised anxiety disorder; Pfizer will retain a patent for the use of pregabalin in the treatment of peripheral and central neuropathic pain in adults until July 2017.
This means that until July 2017, generic manufacturers of pregabalin will only be able to obtain a licence for pregabalin for use in epilepsy and/or generalised anxiety disorder and Lyrica, Pfizer’s branded product, will remain the only product licensed for use in pain as well as epilepsy and generalised anxiety disorder.
Pfizer has indicated that it will contest any challenges to the patent for pain.
To avoid any possible patent infringement by pharmacists, steps will need to be taken to ensure that where generic pregablin is requested on a prescription the correctly licensed product is supplied. This may mean contacting the prescriber and establishing the indication and requesting that the prescription is amended and ordered by brand as Lyrica if necessary.
Although generic pregabalin is unlikely to differ clinically from the branded Lyrica, supplying the generic version of pregabalin for neuropathic pain may have the following implications for pharmacists:
Generic pregabalin preparations will not include information relating to neuropathic pain in the patient information leaflet and pharmacists will be supplying a product off-licence
Supplying generic pregabalin for neuropathic pain would not be in line with Medicines and Healthcare products Regulatory Agency’s risk hierarchy guidance for the supply of unlicensed medicinal products, which states that a UK-licensed product should always be supplied for the correct licensed indication
Using generic pregabalin for neuropathic pain may be deemed by Pfizer to be a patent infringement by all parties concerned, including the prescriber and the supplying pharmacist
Currently, reimbursement for NHS prescriptions for pregabalin is based on Lyrica. This may change when generic versions become available meaning that pharmacists may not be correctly reimbursed where Lyrica is supplied against a generically written prescription for pregabalin. I advise that where generic prescriptions for pregabalin are received, the prescriber is contacted to ascertain the indication. Where the indication is for neuropathic pain, the prescription should be returned to the prescriber for amendment to Lyrica. Prescriptions for pregabilin for epilepsy or generalised anxiety disorder can be dispensed with either Lyrica or appropriately licensed generic versions.
When supplying pregabalin for the treatment of epilepsy, pharmacists should also consider MHRA guidance issued in 2013 regarding the generic prescribing of antiepileptics. The guidance states that pregabalin does not generally need to be prescribed by brand for the treatment of epilepsy unless there are specific concerns such as patient anxiety and a risk of confusion or dosing errors.
For further information on this or any other query please contact the NPA Pharmacy Services Team on 01727 891 800 / 08447 364 201
or email pharmacyservices@npa.co.uk .
http://psnc.org.uk/sunderland-lpc/our-news/pregabalin-lyrica-licensing-differences-bewteen-lyrica-and-generic/
Today's post from diabetic2.tophealthychoices.com (see link below) reflects the varying opinions about the benefits of electrical nerve stimulation machines such as Tens, for people with nerve damage. As a result, this article can only be seen as one person's opinion and the best advice would be to consult as many people as possible (including your doctor) and do your own research before starting using such appliances. That said, if numbers are to be believed, thousands of people across the world do get some benefit from using Tens and others but that can be said from almost all given neuropathy treatments. Do all the research you can but remember, as with all neuropathy treatments, what works for some doesn't work for others - it remains a minefield.
Using Electrical Nerve Stimulation Machine for Diabetic Neuropathy Should Be Considered
No visible author 18 Jun, 2015 The most common forms of electro-analgesia is the Tens machine. There has been several clinical reports and ongoing research with regards to the use of Tens machines for certain medical conditions such as arthritic pain, myofacial, lower back pain, bladder incontinence, visceral pain, post operative pain and neurogenic pain. Due to these studies being inconclusive, the question as to whether the Tens are more effective than a placebo in combating pain is still unresolved. The mechanisms currently proposed with regards to the Neuro modulation that Tens produces include pain control, restoration of input afferent, and presynaptic inhibition in the dorsal horn of the spinal cord and direct inhibition of an abnormal excited nerve.
Studies revealed that the electrical stimulation reduces pain via nociceptive inhibition in the horn of the spines dorsum horn at a presynaptic level and in turn limits its central transmission and that the electrical nerve stimulation machine on the skin myelinated nerve fibres and the electrical stimuli activates a low threshold. With low frequency Tens a marked increase in met-enkephalin and beta endorphins were noted and also demonstrated antinociceptive reversal effects by naloxone. Through micro opioid receptors the effects were postulated. However, naloxone was not reversed with high frequency Tens analgesia, implicating a dynorphin binding receptor that is naloxone resistant. Increased levels of dynorphin A were revealed in cerebral spinal fluid samples. Pain in interpreted when painful peripheral stimulation occurs as the C fibres carry the information which causes the T cells to open the gate which in turn the cortex and thalamus receive the pain transmission centrally. This theory explains the gate control theory, as the gate is usually closed. A range of both positive and negative outcomes have been noted in a wide range of medical conditions when using the Tens machine. Due to several trials and studies conducted there has been an overall consensus in favour of the use of Tens. Around 70 to 80% of patients experience initial pain relief provided by Tens, and around 20 to 30% success rate decreased after a few months of using Tens. In order to establish the full benefits, the Tens should be applied for at least an hour.
The stimulus preferences differ, and studies revealed that 57% of patients that used the Tens machine daily most definitely benefited as well as displayed different stimuli to particular pulse patterns and frequencies and were found to be adjusting their stimulators in subsequent treatment sessions. Tens has also proved positive for mild levels of pain post operative and post traumatic and proved ineffective for acute pain and tension headaches. However, Tens proved positive for painful diabetic neuropathy and treatment using Tens should be considered for this disorder.
http://diabetic2.tophealthychoices.com/using-electrical-nerve-stimulation-machine-for-diabetic-neuropathy-should-be-considered-31/
