THE LANCET, MAY 22, 1976

remIssIons were obtained, 10 of them after one cycle treat­ment, 4 after two cycles, and 1 after three cycles. The average interval between cycles was 20 days (range 15-27 days). 6 pa­tients were kept in germ-free rooms. All 20 cases had to be given blood-transfusions. In addition 16 had platelet trans­fusions and 12 had transfusions ofleucocytes.

The different types of toxicity caused by the treatment were as follows:

Complication No. NeurTophi/s/mm J:·

~IOO 19 WWOO I

Platelers/mm1;-

100~WOOO 18 10001-15 000 I IS 001-50000 I

Infections (where contracted): Nonnal hospital wards 14 Gcnn-free rooms 0

Infections (type): Pneumopathy 8 SepticEtmia, gram posith-c 3 Septiczmia, gram negative 3 Locai bacterial 5 Herpes I

Other complications: H",morrhagic 13 Cardiac 0 . Digesth"c intokrance 5 Alopecia . 19 Death (infection) I

"Average restoratIOn-time (to 1000 polymorphs!mm' and 80 DUO plate­lets!mm')=18 days (range 15-25 days).

1 patient died from septicremia caused by a gram-positive germ in a patient maintained in a conventional ward. Low neutrophil and platelet counts were almost universal. There were no infections in patients accommodated in germ-free rooms, while infections were common in those in traditional hospital wards. This observation confirms the importance of intensive care in the treatments of A.M.L.. II We therefore believe the drug combination used may be recommended for A.M.L.remission induction. Institute de Cancerologie et d'ImmunogtrJ<tique (INSERM), Hopilal Paul-Brousse, 14-16 avenue Paul Vaillant Couturier and Sen'ice d'llematologie de I'Institut Gustave-Roussy, 16 his, avenue Paul-Vaillant Couturier, 9480Q-Villejuif, Franc<

G. MATHE J, L. MISSEl

P. POUILLART M. HAYAT

F. DE VASSAL C. JASMIN

M. DELGADO D. BELPOMME

L. ScHWARZENBERG M. MUSSET

RADIATION EXPOSURE DURING CARDIAC CATHETERISATION

SIR,-Dr Uoyd and his colleagues (April 17, p. 854) report the chromosome aberration yields in cultured lymphocytes from babies X-rayed during cardiac catheterisation. Their yields seem high in comparison with those derived from experi­mentally produced adult calibration curves, and I should like to offer an explanation for this in addition to those suggested in their letter.

In children at the ages included in their study the field for fluoroscopy during cardiac catheterisation will certainly in­clude the thymus itself, lying as it does in the anterior and superior mediastina of the thorax. As the primary central organ of the lymphoid systein it would be surprising if it did not contain a substantial reservoir of the non-circulating T lymphocytes. These would consequently have sustained a com­paratively greater radiation dose, regardless of their degree of radiosensitivity.

Environmental and Medical Sciences Division, A.E.R.E. Harwell, Oxford,hire OXII ORA A. N. B. STOTT

18. E.O.R.T.C. Leuk"'mia and 1I2m.toSaream. Group. Nouv. Press< mid. 1975,4,1553.

1131

DRUG-WITHDRAWAL SYNDROMES SIR,-Articles on methyldopa,1 propranoloJl and c1onidine3

have drawn attention to the problems which can occur when these drugs are withdrawn. We have constructed a classifica­tion of drugs reported to be associated with withdrawal syn­dromes. We exclude drugs which affect the absorption, bind­ing, metabolism, or excretion of another drug and hormonal-replacement drugs since the problems of withdrawal of such drugs are well known.

Drugs Affecting the Central Nervous System (CN.sJ

Narcotics-including pentazocine, codeine, and dextropro­poxyphene.4

CN.S. general depressants-including alcohol, diphenyl­hydramine,' hypnotics, sedatives, and antiepileptics. CN.s. sympathomimetics-including amphetamine, fen­fluramine, and methylphenidate. Drugs of pleasure--including cannabis and nicoline. Psychotropic drugs-including phenothiazines and tricyclic antidepressants,6 butyrophenones,7 monoamine-oxidase in­hibitors,8 and neuroleptics.9

Anti-parkinsonian drugs-including anticholinergicss and levodopa. lo

Other Drugs

Analgesics (apart from narcotics}--acetanilide, paracetamol (acetaminophen), phenacetin. II Cathartics. Antihypertensives-donidine, propranolol. M iscellaneous-G:strogens I land anticoagulants.1l

The list may not be complete, but it does draw attention to a little-known therapeutic problem and reinforces the need for a full drug history from each patient and for wider use of devices which give a patient's current drug regimen (e.g., bra­celets). Only thus may potentially lethal withdrawal syn­dromes be avoided.

Royal Adelaide Hospital, Adelaide, 5000, South Australia

I P. J. PHILLIPS P. D. BASTIAN

D. D. BURROW

P. H. HENSCHKE

R. D. WALTHAM

EXCISION OF PILONIDAL SINUS

SIR,-Different types of conservative and surgical treatment have been tried for the cure of pilonidal sinus. Failure-rates are determined by the frequency of recurrence after adequate follow-up. The recurrence-rates have varied from 0 to 30%. In my own series14the recurrence-rate was nil at the time of publi­cation, but after a further two years, it was 10% (unpub­lished). Healing by primary intention after excision and sutur­ing has never been a problem, and wide excision is unnecessary. Dr Kohn (April 10, p. 815) claims that removal of the coccyx allows easy approximation of the skin margins but he does not state whether he practises wide excision. Skin flaps can easily be mobilised to obtain approximation without tension, so exci-

I. Burden, A. C., Alexander, C. P. T. Hr. mcd.J. 1976, i, 1056. 2. Shand, D. G.New Engl.]. Med. 1975,293,280. 3. Pettinger, W. A. ibid. 1975,293, 1179. 4. Wolfe, R. C., Reidenberg, M., Vispo, R.lI. Ann. intern. Med. 1969,70,773. 5.' Parkin, D. E.]. Pedial. 1974,85,580. 6. Gaffe, J. II. in The Pharmacological Basis of Therapeutics (edited by L. S.

Goodman and A. Gilman); p. 279.l\ew York, 1970. 7. Jacobson, G., Baldessarini, R. j., Manschreck; T. Am. J. Psychi.t. 1974,

131,910. . 8. Pill, B.Hr. med.J. 1974, ii, 332. 9. De Maio, D. Hr.]. Psych;"t. 1973,123,371.

'10. Argenta, G.Riv. Neurol. 1971,41,112. 11. Woodbury, D. M. in The Pharmacological Basis of Therapeutics (edited by

L. S. Goodman and A. Gilman); p. 330. "ow York, 1970. 12. Somerville,B. W.Neurology, 1972,22,355. 13. Br. med.]. 1966, ii, 1343. 14. Bose, B., Candy, J.Am.]. Surg. 1970, 120, 783.