Prescriber 2010: 21(22) (19th November)

We’ve long been told to advise asthmatic patients with mild exacerbations to double the dose of their inhaled steroids, but this is, it seems, incorrect. It has been found not to be helpful in adults (even at doses of 1000 – 2000 mcg). In children, we don’t yet have enough evidence to know whether it helps or not.

There’s a new LABA on the market, that can be given as a once-daily dose – Indacaterol, selling under the brand name Onbrez. In one study, this improved breathlessness levels and trough FEV1 more than formoterol did, and was no more likely to produce side-effects. (It can often cause patients to cough just after taking it.) It comes in capsule form, similar to Tiotropium, so requires a certain level of manual dexterity.

New detail on how we should make the call on anticoagulation for our AF patients – via the CHA2DS2-VASc score.  (Those 2s should be in subscript, by the way, but I can’t figure out how to do that on this blog.) If this comes out as 2 or more then medical advice is for warfarin; for patients who score 1, warfarin is still first choice but aspirin is second choice; and if they score 0, don’t give them either.  The reason for this move away from aspirin as a therapy is, apparently, that it carries the same risk of major bleeding as warfarin does.  Another score to take into account is the HAS-BLED score, which estimates risk of bleeding when on anticoagulation; a score of 3 or more counts as high risk, and is not an absolute contraindication to continuing anticoagulation but does raise the flag to be cautious after initiation.

On to osteoporosis treatment.  Bear in mind the risk of oesophagitis, ulcers, erosions, and stricture with bisphosphonates, and, although osteonecrosis of the jaw is very rare, all patients should undergo dental examination and remedial work before starting a bisphosphonate and should be advised to brush their teeth well, continue going for regular dental checks during their treatment, and report any oral symptoms.  Blimey – how often do any of us follow that rule, I wonder?  Moderate or severe renal impairment is a contraindication to bisphosphonate use.  Finally, just so that I know what it is if the name comes up, Denosumab is a monoclonal antibody used to inhibit osteoclast activity.  Of course, since it’s administered as a subcut injection six-monthly, I probably won’t be seeing it on GP prescriptions any time soon.

The topic for the supplement was restless legs syndrome, an under-recognised condition with potentially major effects on quality of life, though more trivial forms may affect as many as 10% of the population.  Remember the four symptoms:  1. Urge to move the affected body part (most usually the legs), symptoms significantly worse 2. at night and 3 when resting, and 4. improved by movement.

It’s usually, but not invariably, associated with unpleasant sensations.  It’s also, in most cases, associated with something called periodic limb movements (PLMs), which consist of slow jerks every 20 seconds in one or both legs (or possibly arms).  These are often not as bothersome as the RLS, and can occur in elderly people without associated RLS.  Treatment of the RLS will usually treat the PLMs as well.

Iron deficiency is a known cause of RLS, probably because iron plays an essential role in the synthesis of dopamine (it’s a co-factor in the rate-limiting enzyme, if you want to know).  This could also account for the diurnal variation, as levels of iron in the periphery and in the brain are lower at night.  Other causes are end-stage renal disease and pregnancy.  Investigations should therefore include FBC, ferritin, U&Es, B12/folate, fasting glucose, and TFTs (the reason for the last few isn’t explained – presumably we’re looking at peripheral neuropathy causes as well).  Low normal levels of iron can also lead to the problem – it’s worth supplementing with iron if ferritin is below 75, and trying to get it to >50.

Oh, and RLS can also be familial.

Pramiprexole and ropinirole are the best treatments.  In each case, start with the lowest dose (taken in the evening before bedtime), review weekly, and double it until the patient responds well.  (The starting doses in question are 88 mcg base or 125 mcg salt for pramipexole and 0.25 mcg for ropinirole.)  Augmentation and rebound are potential problems but fairly unlikely and usually dealt with successfully by increasing the dose.  If those won’t work, a third option for moderate to severe RLS, though still on black triangle status, is the rotigotine patch, doses of 1 to 3 mg per 24 hours (start with 1 mg and titrate up weekly according to response).  Do not use co-careldopa or co-beneldopa, as the risks of rebound and augmentation are major.  (Rebound means that patients have the symptoms for longer; augmentation means that the symptoms become more severe and affect more of the body.)  The main side-effect of dopamine agonists is nausea, but another possible SE to watch for is impulse control disorder – excessive gambling or hypersexuality, for example.  This has been observed in Parkinson’s disease but seems rare in RLS – however, remember to ask about it.

Remember that some medications can exacerbate RLS.  Look out for CCBs, SSRIs, amitriptyline, metoclopramide, antihistamines, lithium, and tramadol on the patient’s medication list.

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About Dr Sarah

I'm a GP with a husband and two young children.
This entry was posted in Asthma, COPD, Osteoporosis, Respiratory. Bookmark the permalink.

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