FIBRINOGEN AND CARBOXYHAEMOGLOBIN IN PERIPHERAL ARTERIAL DISEASE

121

change in smoking status from smoker to non-smoker accompanied by a similar change in plasma fibrinogen. COHb appears to be a superior index of smoking: plasma cotinine can be increased by passive smoking and thiocyanate by eating too much cabbage. As cigarettes are smoked to shorter butt lengths, tar and COHb concentrations increase logarithmically but those of nicotine only arithmetically. High-tar cigarettes are also associated with an increased level of COHb. The correlation between fibrinogen and COHb may seem perplexing but could provide clues for exploring the response of fibrinogen to smoking. The correlation also supports the hypothesis that some of the risk of cardiovascular disease associated with smoking is mediated by increased plasma fibrinogen. found that a was

Department of Surgery, Charing Cross and Westminster Medical School, Charing Cross Hospital,

fear

JANET T. POWELL MINDER SIAN SHEILA WISEMAN ROGER M. GREENHALGH

London W6 8RF

Benzodiazepine use 1980-86. Hypnotics (pale line) flunitrazepam,

flurazepam, loprazolam, lormetazepam, nitrazepam, temazepam, triazolam. Anxiolytlcs (dark line) alprazolam, bromazepam, chlordiazepoxide, clobazam, clorazepate, diazepam, ketazolam, lorazepam, medazepam, oxazepam, prazepam. In the Northern region in 1983 and again two years later we drew the attention of doctors and pharmacists to the risks of dependence associated with all benzodiazepines, but prescribing data for the region suggest that this has had a selective effect on their use. Analysis of the Prescription Pricing Authority data (a 1-in-200 sample of prescriptions dispensed in the Northern region) shows that the prescribing of benzodiazepines as anxiolytics fell by 40% since 1982 (figure). Prescriptions for benzodiazepines as hypnotics rose by 8%, although this is insufficient to account for a simple substitution of hypnotics for anxiolytics. These data suggest that doctors are aware of the risks of benzodiazepines but this has not influenced their prescribing of hypnotics. Further publicity should therefore emphasise that the problems of dependence are associated with the drugs rather than their indications. Northern Regional Drug Information Unit, Wolfson Unit, Royal Victoria Infirmary, Newcastle upon Tyne NE1 4LP

MINIMAL DOSE (1·25 µg) HEPATITIS B VACCINE FOR INFANTS AND NEWBORN BABIES, 4 YEARS LATER a symposium on perinatal medicine held in Florence 1983 we presented our experience, later published, with very small doses of hepatitis B vaccine (’Hevac B’; Pasteur)— namely, three doses of 0-25 ml (1-25 µg antigen) given intramuscularly with one month between doses. This regimen proved immunogenic in 8 infants and 4 newborn babies (first dose given within 5 days of delivery) and we suggested that the cost of immunising infants against hepatitis B might be much reduced. In 1984 Goudeau et aP noted the immunogenicity of 1-25 and 0-31 g doses in healthy adults.

SIR,-At

in

May,

-

ANTI-HBS IN BABIES RECEIVING THREE SMALL MONTHLY DOSES OF HEPATITIS B VACCINE AND BOOSTER AT

12

MONTHS -

S. CHAPLIN

FIBRINOGEN AND CARBOXYHAEMOGLOBIN IN PERIPHERAL ARTERIAL DISEASE

SiR,—Smoking is a risk factor for ischaemic heart disease and peripheral arterial disease. Dr Meade and colleagues (Oct 31, p 986) suggest that in ischaemic heart disease some of this effect is mediated via plasma fibrinogen, the observed rise in fibrinogen would increase the risk of ischaemic heart disease by about 20%. The mechanism whereby smoking increases plasma fibrinogen is not clear. For several years, we have been monitoring smoking markers and fibrinogen levels in patients with symptomatic peripheral arterial disease, many of whom are heavy smokers. We found increased fibrinogen levels in smokers (table), which were correlated with carboxyhaemoglobin (COHb), cotinine, and thiocyanate. Only COHb, after logarithmic transformation, showed an important correlation with fibrinogen level (r = 0-22, p < 0002). Our patients may smoke more heavily than the participants in Meade and colleagues’ study, but the correlation we found provides for a variation in fibrinogen of about 5 % with smoking. Meade et al SMOKING AND FIBRINOGEN LEVELS IN PATIENTS WITH PERIPHERAL ARTERIAL DISEASE I

I

I

I

I

I

*A-H infants, aged 2-12 months tBaselme (time zero) first dose.

I at time

I

I

of first dose; I-L newborn babies

I

aged 1-7 days.

Our small group of young vaccinees, four years after the first dose and three years after a booster, still have protective antibody titres (table). These results add to encouraging experiences with verylow-dose hepatitis B vaccines.I-5 CARLO SCARAVELLI ENZO BIANCHI VANNA BIRAGHI GIANCARLO CALLIGARI Departments of Paediatrics GAETANO MARIANI and Pathology, PATRIZIO LUCCHESI Fatebenefratelli Hospital, GIUSEPPE DELEO 22036 Erba (Como), Italy C, Calligari GC, Mariani G, et al. RIA evaluation of antibody levels in from HBsAg-positive mothers after active, passive, and combined immunoprophylaxis. Gynecol Obstet Invest 1984, 17: 208-12. Goudeau A, Dubois F, Dubois MC, et al. Immunogenicity of low dose (1·25 and 0 31 µg) hepatitis B vaccine Lancet 1984; ii. 1091-92. Yvonnet M, Coursaget F, Leboulleux D, et al Low-dose hepatitis B vaccine

1 Scaravelli

neonates

2

3.

*Mean

iSD) tsignificant difference IInmunonephelomen-y

between groups

(p <001)

Fibrinogen

was

determined by

immunisation in children. Lancet 1987; ii: 169. 4 Scaravelli C, Bianchi E, Biraghi V, et al. Efficacy of minimal doses of an American hepatitis B vaccine in neonates. Clin Ther 1985; 7: 680-83 5. Moyes CD, Milne A, Dimitrakakis K, et al Verv-low-doses hepatitis B vaccine in newborn infants an economic option for control in endemic areas Lancet 1987; i

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