A variety of medications are now used to treat neuropathic pain and these are summarised below in alphabetical order.
Baclofen is used only for the muscle spasm seen with spinal conditions and for trigeminal neuralgia. It is difficult to use. Tolerance develops very quickly and sedation is a common problem. Note: There is no role for diazepam in the treatment of neuropathic pain.
Calcium channel blockers: pregabalin and gabapentin
Pregabalin is a calcium channel blocker and an analgesic, anticonvulsant, anxiolytic, and sleep-modulating agent that may be useful as a component of multimodal analgesia and may decrease opiate use. It does not work for all neuropathic pain; for example, it doesn’t work for HIV. It may also reduce post-surgical chronic pain.
Gabapentin, like pregabalin, is a calcium channel blocker but it has a slower onset.
Ketamine is an NMDA antagonist and phencyclidine derivative with multiple effects. It is given IV, SC, topically, and possibly orally and intrathecally (intrathecal use is not approved, so it is only used in palliative care with the necessary consent).
Lignocaine is a sodium channel blocker that acts especially on abnormal ion channels. It acute states it is given SC or IV. For chronic allodynia, it is given as a patch.
Methadone is a naturally long acting opioid that caused a statistically significant decrease in pain in a small randomised, double-blind, placebo-controlled study (N=18).
Oxycodone is up to twice as potent as morphine and may have some benefit in neuropathic pain but the effect is dose limited.
Tramadol has a low affinity for all opiate receptors and also inhibits noradrenaline and serotonin reuptake, making it helpful in neuropathic pain.
Tapentadol has fewer potential interactions than tramadol and less potential for abuse.
Tricyclic antidepressants improve all aspects of neuropathic pain but can cause side effects of sedation, cardiac arrhythmias, orthostatic hypotension, and urinary retention that limit dosing. Contraindications include conduction defects, and they should be used with care in the elderly.
Serotonin and norepinephrine reuptake inhibitors: venlafaxine and duloxetine
These have good safety, tolerability, and effectiveness in patients with painful diabetic neuropathy: their role in other neuropathic and nociceptive states is undetermined. Possibly, they have synergistic effects with other agents. There are minimal anticholinergic effects.
There is very little in literature about valproate and it is not TGA approved for neuropathic pain. However, it is sometimes used because it is a voltage-gated sodium channel blocker and it increases brain GABA levels. It should not be used in patients with impaired liver function or in pregnancy and it interacts with warfarin. Side effects include weight gain, hair loss/curliness, and drowsiness.
Source: Dr David Gronow, The General Practice Education Day, Sydney 2013Posted in News | Leave a comment
Women with estrogen-responsive breast cancer who consume soy protein supplements containing isoflavones to alleviate the side effects of menopause may be accelerating progression of their cancer, changing it from a treatable subtype to a more aggressive, less treatable form of the disease, new research suggests.
The study, published in the journal Molecular Nutrition and Food Research, raises troubling questions about the safety and the potential health consequences associated with long-term use of dietary supplements containing soy isoflavones, such as the phytoestrogen genistein.Uncategorized | Leave a comment
“There have been several trials now, including this one, where surgeons have examined whether meniscal tear surgery accomplishes anything, basically, and the answer through all those studies is no, it doesn’t,” said Dr. David Felson, a professor of medicine and public health at Boston University. He was not involved in the new research.
For the new study, doctors recruited patients between the ages of 35 and 65 who’d had a meniscal tear and knee pain for at least three months to have an arthroscopic procedure to examine the knee joint. If a patient didn’t also have arthritis, and the surgeon viewing the knee determined they were eligible for the study, he opened an envelope in the operating room with further instructions.
At that point, 70 patients had some of their damaged meniscus removed, while 76 other patients had nothing further done. But surgeons did everything they could to make the sham procedure seem like the real thing. They asked for the same instruments, they moved and pressed on the knee as they otherwise would, and they used mechanical instruments with the blades removed to simulate the sights and sounds of a meniscal repair. They even timed the procedures to make sure one wasn’t shorter than the other. Patients weren’t told if they’d had their knee repaired or not.
“It’s a wonderfully designed study, amazing,” said Felson.
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Children who suffer from frequent nightmares or bouts of night terrors may be at an increased risk of psychotic experiences in adolescence, according to new research from the University of Warwick.
Nightmares are considered to be commonplace in young children with incidence reducing as they grow older. They occur in the second half of sleep during REM (rapid eye movement) sleep. Those who have experienced them will be familiar with the sensation of waking suddenly with a sense of fear, worry and possible palpitations.
Night terrors, a sleep disorder, differ from nightmares and occur during deep sleep (non-REM) cycles in the first half of the night. A night terror bout is often signified by a loud scream and the individual sitting upright in a panicked state, though unaware of any of the involuntary action. The thrashing of limbs and rapid body movements are witnessed in more extreme cases. Children wake up in the morning unaware of their activity throughout the night.
Everyday chemicals are damaging the brains of unborn and young children, leading to conditions like autism, ADHD, dyslexia and lost IQ points, according to two prominent doctors.In an article published Friday in the journal Lancet Neurology, the two argue that chemicals should be better tested before being allowed on the market, and called for a global prevention strategy.”We need to do something to protect the next generation’s brains,” said Philippe Grandjean of the Harvard School of Public Health in Boston.Uncategorized | Leave a comment
Autism is a neurodevelopmental disorder the symptoms of which are evident in early childhood and infancy.
According to the Centres for Disease Control, one in 88 children has an autism spectrum disorder (ASD). Recent increases in the number of children being diagnosed with ASD are in part attributable to more younger children being diagnosed but are mostly explained by the inclusion of milder cases. However, about 5 to 10% of the increase remains unexplained.
There are ongoing diagnostic issues, for a range of reasons: there is no biological ‘test’ for autism, the clinical picture changes over time, the diagnostic manuals are constantly refining the diagnostic criteria, and ASD covers a heterogeneous group of children.
Several prenatal risk factors for ASD have been identified, including maternal age over 35, mothers born in SE and NE Asia, gestational bleeding, psychoactive medication use during pregnancy, prematurity, and multiple birth. The aetiology is thought to involve a mix of genetics (inherited and chromosomal abnormalities), in utero disruption to the development of the temporal and frontal lobes, autoimmune disorders, and infections of the brain in infancy.
There are three broad developmental trajectories:
- no period of typical development, with autism signs present from birth
- a developmental plateau, where a child achieves typical developmental milestones but then the rate of progress declines
- regression, where the child loses skills.
The following are clues to the possible presence of ASD:
- a child who does not seem to ‘bond’ with his or her mother
- a child who, when distressed, is not easily comforted by affection
- a lack of interest in social activities
- being child content to be alone
- suspected deafness
- no response when the child’s name is called.
- lack of vocalisations.
- unusual mannerisms used to express emotions, especially when the child is excited
- more frequent and intense distress reactions
- inexplicable crying
- a child who is less likely to look at a parent to seek reassurance and approval.
- sensitivity to noises (eg vacuum cleaners)
- delayed reflexes
- slowed motor development
- sleep disturbance
- feeding problems
- ear infections
- being longer or taller.
Regression typically starts between 10 and 30 months and peaks at 18 months. There is loss of previously acquired words or the child stops talking. There is significantly less eye contact and a loss of interest in social games and being with people and parents. Stereotyped behaviours (eg hand flapping) develop and the child becomes more irritable or anxious.
There should be no environmental, psychological or medical explanation for these changes.
The best screening test for children two years old and under is the Modified Checklist for Autism in Toddlers (MCHAT).
Questions a GP might ask parents of children aged 2–4 years include:
- How does your child communicate with you?
- Does your child point using an index finger?
- Does your child look you in the eyes when communicating?
- What does your child do if he or she sees something interesting, such as a plane or dog?
- Does your child turn to look at you when you call his or her name?
- What does your child like to play with?
- Describe what he or she does while playing.
- Has your child stopped doing something he or she could previously do (such as talking, using eye contact)?
Once the diagnosis is made, continuing medical support for the patient and family is essential:
- Family stress, and especially mother’s stress, must be monitored and addressed.
- The child is at increased risk for epilepsy, an anxiety disorder, depression, anger management problems, and allergic and autoimmune diseases including asthma, allergic rhinitis, atopic dermatitis, urticaria (hives), type 1 diabetes, and Crohn’s disease.
- Medication reviews are important.
- GPs can help with sleep, diet and constipation, adolescence and sexuality.
Many parents will naturally want to know whether subsequent pregnancies are likely to be affected.
One study found that the overall recurrence risk was 19%. Specifically, this was 26% for a boy and 9% for a girl.
If more than one sibling had a diagnosis of ASD, the recurrence rate was 32%.
Source: Professor Tony Attwood, The Annual Women’s and Children’s Health Update, Brisbane 2013Posted in News | Leave a comment
Rapid technological advances mean it’s faster and cheaper than ever to read a person’s entire genetic code, known as the genome.
Genomic sequencing has two potential applications in health: the care of patients with a condition and the prevention of disease in healthy people. But how far away are we from making this a reality?News | Leave a comment
Synthetic cannabis, known commercially as Kronic, K2, Kaos or Spice, was designed to circumvent drug laws and give users a “legal high”. But Western Australia banned the product earlier this month and South Australia, Victoria and Tasmania are poised to take similar steps.
What is synthetic cannabis?
While pharmaceutical cannabis has been used to treat conditions including nausea and pain with varying effectiveness, synthetic cannabis has been marketed under its commercial names predominantly for its euphoric effects.
Researchers looking at the composition of synthetic cannabis have found laboratory-synthesised chemical copies of the active ingredients of marijuana: delta-9-tetrahydrocannibinol or THC.
These lab-made chemicals, which have fairly lacklustre names like JWH-018 or CP-47,497-C8, act on the same brain receptors as those found in “conventional” plant cannabis.
Synthetic cannabis is smoked so it produces a quick and intense psychoactive drug effect.News | Leave a comment
In a Review published in The Lancet Neurology, two of the world’s leading experts on the link between environment and children’s health are sounding the alarm on the dangers of industrial chemicals.
They are calling on countries to transform their chemical risk-assessment procedures in order to protect children from everyday toxins that may be causing a global “silent epidemic” of brain development disorders.
Findings from the Review indicate that in the past 7 years, the number of recognised chemical causes of neurodevelopmental disorders has doubled from six to 12, while the list of chemicals that are known to damage the human brain, but are not regulated to protect children’s health, has also expanded from 202 to 214. These hazardous chemicals are found in everyday items such as clothing, furniture, and toys.
“Current chemical regulations are woefully inadequate to safeguard children whose developing brains are uniquely vulnerable to toxic chemicals in the environment”, explains Dr Philippe Grandjean from Harvard School of Public Health in Boston. “Until a legal requirement is introduced for manufacturers to prove that all existing industrial chemicals and all new chemicals are non-toxic before they enter the marketplace, along the lines of the European Union’s reformed chemicals law REACH, we are facing a pandemic of neurodevelopmental toxicity.”News | Leave a comment
Researchers from the University at Buffalo in New York say two bacteria that cause many common infections in children and the elderly, such as strep throat and ear infections, can live outside the human body for long periods of time on various objects, including books, cribs and toys.
The investigators found that Streptococcus pneumoniae and Streptococcus pyogenes linger on many surfaces significantly longer than previously thought, opposing previous studies that suggest the bacteria quickly die once they have left the human body.
The researchers say their findings suggest that better strategies are needed to prevent infections, particularly in hospitals, schools and daycare centers.News | Leave a comment ← Older posts