Clinical Pharmacy News summary

Questions raised over new advice following research into peanut oil Parents have been advised not to use arachis (peanut) oil containing topical preparations on their infants because of a possible link between such products and the development of peanut allergies. However, doubts have been raised over the suggestion...[more]

New drug for resistant malaria to be supplied to developing countries Developing countries are to be supplied with a new treatment for drug-resistant malaria at “affordable prices” by the World Health Organisation and Novartis...[more]

Risk of developing prostate cancer reduced in men who eat oily fish Men who eat oily fish, such as salmon, herring and mackerel, are less likely to develop prostate cancer than those who do not, according to researchers in Sweden...[more]

Dosage modification and new safety precautions for amfebutamone The dosage regimen for amfebutamone (Zyban, bupropion) has been modified to minimise the risk of adverse events, especially seizure...[more]

Benefits of beta-blockers in severe heart failure shown Two studies reporting the effects of beta-blockers in patients with severe heart failure have been published in The New England Journal of Medicine ...[more]

Combination asthma inhaler launched AstraZeneca has launched Symbicort Turbohaler, containing a combination of budesonide and formoterol, as a maintenance treatment for asthma...[more]

Questions raised over new advice following research into peanut oil

Parents have been advised not to use arachis (peanut) oil containing topical preparations on their infants because of a possible link between such products and the development of peanut allergies. Professor Jean Golding, University of Bristol, involved in the research, told The Journal on June 6 that she thinks that there is a serious possibility that the use of arachis-oil-containing creams on broken skin may be responsible for initiating peanut allergy in children.

However, doubts have been raised over the suggestion. A spokesman for the British National Formulary told The Journal this week that it was questionable as to whether arachis-oil-containing medicinal products used on the skin were responsible for peanut allergies as they contained refined arachis oil rather than crude arachis oil.

The BNF says that work conducted by a Committee on Toxicity of Chemicals in Food, Consumer Products and the Environment in 1998 showed that refined arachis oil did not contain allergenic peanut proteins. No convincing evidence has yet been published that refutes the Committee’s conclusions.

Nevertheless, lead researcher of the recent study Dr Gideon Lack, St Mary’s Hospital, London, says that peanut allergies now occur in one in 100 children, 90 per cent of whom previously suffered from eczema, which, he says, could be linked to the use of creams containing arachis oil. The researchers are investigating whether exposing the skin to products containing arachis oil could be responsible for causing peanut allergies. Dr Lack says that “in eczema, the skin barrier breaks down and there is an abundance of immune cells in the skin that could be exposed to substances that cause allergies.”

Christine Clarke, consultant pharmacist told The Journal on June 6: “It is essential that patients continue to use their emollients as they are the most important preventative treatment for eczema.”

A spokesperson for the Department of Health told The Journal: “We will consider in detail the results of a completed study [Avon Longitudinal Study of Parents and Children (see below)]. In the meantime the Department of Health endorses the advice given to parents by the Anaphylaxis Campaign, which is not to make any sudden changes to the treatment of children with skin conditions and to continue to apply the recommended dose of eczema cream as normal.”

The Department also currently recommends that pregnant or breast-feeding women who have diagnosed allergic reactions might wish to avoid eating foods containing peanuts. However, in a press release Dr Lack commented that his findings contradicted the Department’s recommendations and said that the quantity of peanuts consumed by mothers during pregnancy and while breast-feeding made no difference as to whether children developed a peanut allergy.

A number of national newspapers reported on June 5 that Ruth Carlyle, National Eczema Society, said: “None of the emollient or emollient bath additives listed in the British National Formulary — the products that your GP is likely to prescribe — contain peanut oil.”

However, several products in the BNF do contain arachis oil (see panel) and she said to The Journal: “Very few of the emollients prescribed for children with atopic eczema contain peanut oil. Although there does not seem to be conclusive evidence of a link between emollients used for eczema and the development of peanut allergy, any reputable company will ensure that details of ingredients are available.”

Oilatum cream was among the preparations mentioned in the national press as containing arachis oil. However, the product was reformulated earlier this year and now contains light liquid paraffin 6 per cent and white soft paraffin 15 per cent instead of arachis oil, which was the active ingredient (see PJ, February 10, p199).

Dr Lack’s study was part of a larger ongoing study, known as the Avon Longitudinal Study of Parents and Children (ALSPAC), which is being carried out to find both the genetic and environmental factors that, over time, lead to diseases including eczema, asthma and allergies. The findings, to date, of the ALSPAC were presented at the Royal Society, London, this week.

Skin preparations containing arachis oil:

• Polytar Emollient bath additive
• Polytar liquid
• Polytar AF shampoo
• Polytar Plus liquid
• Hewletts Cream
• Zinc Cream, BP
• Zinc and Caster Oil Ointment, BP
• Siopel barrier cream
• Calamine oily lotion

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New drug for resistant malaria to be supplied to developing countries

Developing countries are to be supplied with a new treatment for drug-resistant malaria at “affordable prices” by the World Health Organisation and Novartis.

The drug, Coartem, is a combination of artemether, a derivative of a Chinese herb, and lumefantrine. It has demonstrated a cure rate of over 95 per cent even in areas of multi-drug resistance, the WHO says. “These kinds of private-public partnerships are key to the fight against diseases of poverty,” said the director general of the WHO, Dr Gro Harlem Brundtland. Novartis is supplying the WHO with the drug at cost price, which will be less than $2.50 per full treatment for adults and “considerably less” for children.

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Risk of developing prostate cancer reduced in men who eat oily fish

Men who eat oily fish, such as salmon, herring and mackerel, are less likely to develop prostate cancer than those who do not, according to researchers in Sweden.

Dr Paul Terry and colleagues from the Karolinska Institute in Stockholm studied the association between oily fish consumption and prostate cancer in a prospective study of 6,272 Swedish men. They say that high concentrations of eicosapentaenoic acid, an essential fatty acid present in fish, can lead to changes in relative concentrations of tumour-enhancing prostaglandins.

During the 30-year follow-up period, there were 466 diagnoses of prostate cancer. The researchers found that men who ate no fish had a two- to three-fold higher frequency of prostate cancer than men who ate moderate or high amounts. The study is published in The Lancet (2001;357:1764).

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Dosage modification and new safety precautions for amfebutamone

The dosage regimen for amfebutamone (Zyban, bupropion) has been modified to minimise the risk of adverse events, especially seizure. New safety precautions have also been added to the product’s summary of product characteristics (see p795).

The Committee on Safety of Medicines (CSM) has advised GlaxoSmithKline, manufacturer of Zyban, that to minimise the risk of adverse events, more time should be given in the dosage regimen to allow drug levels to stabilise. In response, the initial dosage regimen for amfebutamone has been changed to 150mg once daily for six days (previously three days), increasing to 150mg twice daily from day seven (previously day four) for the remainder of the course of treatment. Amfebutamone is also contraindicated in patients with any history of seizure, in those with a known central nervous system tumour and in those undergoing abrupt withdrawal from alcohol or from benzodiazepines.

All patients should be assessed for predisposing risk factors that lower seizure threshold. Those found to have other risk factors for seizures must not be prescribed amfebutamone unless the clinical benefit of stopping smoking outweighs the risk of seizure. GlaxoSmithKline has also added antimalarials, tramadol, quinolones and sedating antihistamines to the list of medicinal products that lower seizure threshold.

A letter regarding changes to prescribing information has been sent to all pharmacists, general practitioners and smoking cessation clinics. It refers health care professionals to a letter published in The Journal that lists the drugs that might interact with amfebutamone (see PJ, May 26, p721). The CSM further advises that any patient currently taking amfebutamone at the original dosage and who continues to feel well should continue taking the drug. In a recent press release, Professor Alasdair Breckenridge, chairman of the CSM, said: “The changes to the prescribing regimen and the strengthened warnings will help to further reduce the number of people who experience adverse reactions while taking Zyban.”

GlaxoSmithKline says that, although seizure is the most significant adverse event associated with Zyban, when the drug is used in accordance with the prescribing information in the SPC, the risk of seizure, which is dose-related, is rare (approximately 1 in 1,000 people).

A website to help health care professionals provide patients with practical advice on smoking cessation has been launched by Pharmacia. The website (smokingcessation.co.uk), which provides information on smoking, tobacco dependence and smoking cessation therapies, aims to help achieve government-set smoking cessation targets.

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Benefits of beta-blockers in severe heart failure shown

Two studies reporting the effects of beta-blockers in patients with severe heart failure have been published in The New England Journal of Medicine (2001;344: 1651 and 1659).

The first shows that adding carvedilol to conventional therapy decreases both the rate of premature death and the rate of hospital admissions in patients with severe heart failure. The researchers, from the Carvedilol Prospective Randomised Cumulative Survival Study Group, randomly assigned 2,289 patients with severe heart failure to receive either carvedilol (titrated up to a maximum of 25mg twice daily) or placebo for a mean period of 10.4 months.

There were 190 deaths in the placebo group compared with 130 deaths in the carvedilol group, which the researchers say reflects a 35 per cent decrease in the rate of death with carvedilol (95 per cent confidence interval, 19 to 48 per cent; P=0.0014, adjusted for interim analysis). The combined risk observed for patients who either died or who were admitted to hospital was 24 per cent lower in those treated with carvedilol (13 to 33 per cent; P<0.001).

The researchers comment: “If physicians treated 1,000 patients with severe heart failure similar to that found in patients in our trial with carvedilol for one year, approximately 70 premature deaths would be prevented.”

In the second study, researchers for the Beta-Blocker Evaluation of Survival Trial (BEST) concluded that treatment with bucindolol, a non-selective beta-adrenergic blocker not currently licensed in the United Kingdom, does not result in a significant overall survival benefit in patients with advanced heart failure.

They randomly assigned 2,708 patients to receive either bucindolol (titrated up to a maximum of 100mg twice daily) or placebo for a planned average follow-up of three years. There were 449 deaths in the placebo group compared with 411 deaths in the bucindolol group, which the researchers say represents a non-significant trend. However, the researchers found that bucindolol lowered both the rate of death from cardiovascular causes, and the proportion of patients who had to be admitted to hospital for heart failure-related illnesses. A sub-group analysis showed a significant survival benefit with bucindolol in non-black patients and also a trend towards improved survival with bucindolol among patients with less advanced heart failure.

They comment that their findings raise questions about the efficacy of beta-blockers in black patients and in patients with more advanced heart failure, as well as about the equivalency of beta-blockers.

In an accompanying editorial (ibid, p1711), Dr Eugene Braunwald comments that to determine whether the differences among the beta-blockers studied in trials are clinically meaningful, head-to-head comparisons need to be made. She adds that the two trials, when considered alongside previous studies, show that beta-blockers are an important addition to the treatment options available for heart failure.

She concludes: “These drugs should be administered cautiously, and the dose escalated slowly in all patients with heart failure, especially those in whom the condition is severe.”

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Combination asthma inhaler launched

AstraZeneca has launched Symbicort Turbohaler, containing a combination of budesonide and formoterol, as a maintenance treatment for asthma (see p795). Symbicort is the first combination inhaler that allows patients, under licence, to adjust the dose of their maintenance treatment (within a range of one to four inhalations per day, and in line with their doctor’s advice).

Two strengths are available, 200/6 and 100/6. The 200/6 inhaler, which the company says is expected to be the appropriate choice for most patients, delivers 160µg budesonide and 4.5µg formoterol per inhalation. The 100/6 inhaler, for those requiring a lower dose of steroid delivers 80µg budesonide and 4.5µg formoterol per inhalation.

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