Correspondence: Labelling; Breast cancer; Dyspepsia; Erratum

Avoid grapefruit and its juice
90 SIMVASTATIN 20 MG Tabs (ARRW)
Take ONE tablet ONCE daily (best taken in the evening). We recommend taking Co Enzyme Q10 with this medication. Ask your pharmacist.

Co-enzyme Q10 (also known as ubiquinone) assists in the production of energy within cells and helps protect cell membranes against oxidation. Approximately half of the body’s co-enzyme Q10 is obtained from the diet. Supplementation of co-enzyme Q10 is used as a treatment for serious mitochondrial disorders and other metabolic syndromes, when people are unable to produce enough co-enzyme Q10.

The suggestion that co-enzyme Q10 should be used concurrently with statins is most likely based on evidence that statin treatment can lower circulating levels of co-enzyme Q10, but the clinical significance of this is uncertain. Intramuscular levels of co-enzyme Q10 are not affected by low-dose statin treatment, therefore the role of co-enzyme Q10 for the treatment of statin-induced myopathy would be questionable. There have also been suggestions in the literature that co-enzyme Q10 may be used as a treatment for hypertension. However, to date, no clear evidence exists that co-enzyme Q10 should be used to treat, or supplement medication taken for any of these conditions.^1,2

For further information see “Upfront: The role of co-enzyme Q10 supplements in medical treatment”, BPJ 8 (Sept, 2007).

In regards to the appropriateness of additions being made to prescription labels, the Pharmaceutical Society has responded; It supports additional labelling to prevent adverse reactions, and to ensure that medicines are taken in the most effective manner. However, in the present case, the Society considers the labelling to be advertising and misleading, as it implies the recommendation has been endorsed by the patient’s doctor.

The Society also reminds Pharmacists that under their code of ethics: “Commercial interests shall not over ride their own professional judgement – obligation 4.4. And, that they may only promote a product as efficacious when there is creditable evidence of it being so – obligation 8.8.”

If a prescription is modified without the prescriber’s knowledge, they cannot be reasonably held accountable for any adverse consequences.

The statement made in the article “Increasing the uptake of breast screening”, Page 38, The breast cancer gene, does require clarification. Referrals for genetic risk assessment and genetic counselling are funded in all DHBs. BRCA mutation testing is also offered (and funded) where, following risk assessment, the probability of a mutation being present is calculated to be 20% or higher. Risk assessment requires a three generation family history and tumour histology analysis of affected family members. If a familial mutation has not been previously identified, testing begins with affected family member DNA (in order to reduce false negatives) and can take up to six months.

Private laboratories do offer BRCA testing for people who do not meet funding criteria, however, the cost is $2000-$3000.

In a further clarification of this section of the article – it was mentioned that women who test positive for a breast cancer gene mutation can reduce their risk of developing breast cancer, with options including more frequent screening, hormonal therapy (tamoxifen) or prophylactic mastectomy or oophorectomy (removal of the ovaries). It was stated that oophorectomy reduces the risk of breast and ovarian cancer for people with BRCA2 mutations. However, the correct procedure is a salpingo-oophorectomy (removal of an ovary together with the fallopian tube) since the majority of BRCA-related ovarian cancers start in the fallopian tubes. In addition, this reduces the risk of breast and ovarian cancer for both BRCA1 and BRCA2 mutations.

Thank you to Dr Caroline Lintott, Senior Genetic Associate, Genetic Services, Christchurch for expert guidance in developing this answer.

Proton Pump Inhibitors (PPI)

In the article “Managing dyspepsia and heartburn in general practice – an update” (BPJ 34, Feb 2011) proton pump inhibitors (PPI) are recommended as first-line treatment in undifferentiated and functional dyspepsia, i.e. dyspepsia which has either not been investigated in a low risk patient, or dyspepsia that has been investigated with no underlying pathology found.

Since the New Zealand Guidelines Group guideline for the Management of dyspepsia and heartburn was published in 2004,¹ there has been an evidence based shift in practice that favours the use of PPIs as first-line therapy. This is because there is increasing evidence that PPIs are more effective in their ability to resolve the symptoms of dyspepsia than H2 receptor antagonists.^2,3,4,5,6 Although not expressed as NNTs, this evidence shows consistent statistically significant benefits for the empiric use of PPIs. The Cochrane reviews (and NNTs) quoted in the 2007 article have been withdrawn from publication because the conclusions have changed and an updated Cochrane review is awaited.⁷ The availability of generic PPIs has also removed the previous cost benefit of H2 receptor antagonists.

The efficacy of prokinetic agents such as domperidone and metoclopromide has been debated in the recent literature.^5,8 Prokinetic agents are no longer recommended for first line therapy because of their potential for adverse effects and the evidence for their effectiveness is limited.^2,5,9,10

Empiric treatment with PPIs in undifferentiated and functional dyspepsia therefore is favoured in evidence based guidelines that have been produced since the 2004 New Zealand guideline.^9,11,12 In addition, the use of PPIs as first-line therapy is only one step in the suggested approach for the treatment of undifferentiated dyspepsia given in the article. The suggested approach includes:

• The need to rule out the possibility of serious disease
• Consideration of the need for H. pylori testing
• Monitoring the response to empiric treatment so that other medicines or further investigations can be initiated if there is no response to PPI treatment

Serology or faecal antigen test?

Each of the available tests for H. pylori has advantages and disadvantages, hence the recommendation that the choice should be determined by the clinical setting. Carbon-13 urea breath test is the most accurate test but is not consistently available to general practice. Serology is more convenient to obtain for both the GP and patient and can determine whether the patient has been exposed to the infection. If infection is present and treatment is given, the faecal antigen test, which is able to detect active infection, can be used to test cure.

Testing for H. pylori is also best determined by the likely prevalence of H. pylori in the community. It is recommended to consider testing for H.pylori when there is a local prevalence rate of greater than 30% (when serology tests are appropriate).

For further information about H. pylori testing, see “ Helicobactor pylori testing: Serology and stool antigen testing” Best Tests (March, 2010).

Safety concerns with domperidone

Domperidone has been associated with rare reports of serious ventricular arrhythmia, QT prolongation and sudden cardiac death. In most cases, these events have occurred in patients who have had other cardiac risk factors, or in patients who received domperidone intraveneously.⁷ The use of domperidone therefore should be avoided in patients who may be at increased risk of QT prolongation such as those with hypokalaemia, severe hypomagnesaemia or structural heart disease. It should also be used with caution in patients who are taking other drugs that may also cause QT prolongation, such as oral ketoconazole, fluconazole, erythromycin and amiodarone.¹⁰

The following text appeared in “Managing dyspepsia and heartburn in general practice” BPJ 34 (Feb, 2011):

“Barrett’s oesophagus is a complication of chronic GORD. It is a diagnosis made after endoscopy where normal cells lining the oesophagus (columnar epithelium) are found to be replaced by cells that usually line the gastric and intestinal mucosa (squamous epithelium).”

The correct text should read:

“…It is a diagnosis made after endoscopy where normal cells lining the oesophagus (squamous epithelium) are found to be replaced by cells that usually line the gastric and intestinal mucosa (columnar epithelium).”