666 BRITISH MEDICAL JOURNAL 22 JUNE 1974 and transient swelling of face, body, and mothers were confirmed as having Interaction of Nalidixic Acid and Warfarin limbs (1); hypopyon of left eye (1); acute gonorrhoea. One disturbing feature is that SIR,-It has been demonstrated in vitro that monarticular arthritis (1); and sulphonamide the conjunctivitis developed between the Br Med J: first published as 10.1136/bmj.2.5920.666-c on 22 June 1974. Downloaded from crystalluria (1). sixth and ninth days after delivery. With the nalidixic acid can disolace warfarin from Of the 12 meningococcal isolates obtained now common practice of early discharge binding sites on plasma proteins.' This does so far only one has shown sulphonamide after delivery in most obstetric units it is not appear to be significant clinically.2 Dr. resistance employing standard disc diffusion easy to miss the diagnosis unless the district J. C. Petrie and his colleagues (4 May, p. methods. Three of the four most recent midwife and general practitioner are alert to 262) in their interesting study of the aware- strains have been found to be groupo I the possibility of a gonococcal cause. ness of selected drug interactions go so far meningococci, the fourth belonging to group In a recent circular the Royal College of as to call the nalidixic acid-warfarin inter- C. The minimum inhibitory concentration Obstetricians and Gynaecologists recomn- action "theoretical." The following case of the group B strains to sodium sulpha- mends trainees in obstetrics and gynae- suggests that nalidixic acid given to patients diazine was 16 Mg/ml, and in two of them cology to consider a post in venereology as stabilized on warfarin can produce poten- it was 0 4 ,ug/ml to benzylpenicillin. Follow- part of the elective year. This would bi tially dangerous excess anticoagulation and up studies on six patients (including four beneficial in developing an insight into the should be avoided. infants less than 1 year of age) 4-10 weeks problems of gonorrhoea detection and A 55-year-old woman was knocked down by a after discharge showed no evidence of car in March 1972 fracturing her pelvis and left control.-I am, etc., femur. This was followed by a left ileofemoral residual damage.-We are, etc., R. A. SPARKS venous thrombosis, venous gangrene of the toes, St. David's and Llandough Hospitals, and acute renal failure requiring peritoneal dialysis L. M. DE SILVA Cardiff over a period of several weeks. Her anticoagulation Public Health Laboratory, with warfarin was maintained after discharge and Middlesbrough 1 Chief Medical Officer, Department of Health and was well controlled with a prothrombin ratio Social Security, British 7ournal of Venereal around 2-0 on 11 mg/day. The ratio was satisfactory B. M. MUHAMMAD Diseases, 1974, 50, 73. on 20 December. She then developed Escherichia 2 Rees, D. A., and Hamlett, J. D., fournal of coli urinary infection and was given nalidixic acid K. DEVADAS Obstetrics and Gynaecology of the British 500 mg four times daily by her family doctor on Middlesbrough General Hospital, Commonwealth, 1972, 79, 344. 8 January 1973. She was readmitted to hospital on Middlesbrough 3 Hughes, W. M., and Davies, J. M., British Medical Y7ornal, 1971, 4, 424. 14 January with a purpuric rash on her abdomen 4 Silverston, P I., Snodgrass, C. A., and Wigfield, and bruises on her left leg and back, which came A. S., British fournal of Venereal Diseases, on a few days after starting nalidixic acid. Her 1974, 50, 53. prothrombin time was 45 seconds (control 13). The Gonorrhoea in Obstetrics and Gynaecology 5 Thayer, J. D., and Martin, J. E., jun., Public platelet count was normal. Both drugs were Health Reports, 1966, 81, 559. discontinued. She was later discharged well with a SIR,-Gonorrhoea is still on the increase, prothrombin time of 22 seconds on 10 mg of with 18,341 postpubertal female cases in warfarin daily. -I 1972.1 From the low incidence reported influenzae in am, etc., from antenatal screening (the highest figure Haemophilus Meningitis B. I. HOFFBRAND only Adults Whittington Hospital, obtained by British investigators being London N.19 0-6%2) and the screening of gynaecological SIR,-So far as I know, the interesting re- patients3 it is easy to conclude that port by Dr. Susannah J. Eykyn and others 1 Sellers, E. M., and Koch-Weser, J., Clinical Pharmacology and Therapeutics, 1970, 11, 524. gonorrhoea is not a problem in obstetrics (1 June, p. 463) is unprecedented in that half 2 Smith, S. E., and Rawlins, M. D., Variability in and gynaecology in Britain, but caution is of their cases of haemophilus meningitis Human Drug Response. London, Butterworths, required, especially in gynaecological occurred in adults. Could this distribution 1973. patients. Many units still erroneously rely be related to the location of St. Thomas's on a high vaginal swab for diagnosis, which Hospital? The population of that area, parti- may or may not be placed in Stuart's trans- cularly during the working day, must con- Antibacterial Preparations in the B.N.F. port medium before plating is possible. The tain an exceptionally large preponderance of http://www.bmj.com/ most effective means of diagnosis is to take adults. SIR,-The section of the new edition of the samples from the cervix and urethra and Dr. Eykyn and her colleagues comment British National Formulary' dealing with plate them at the bedside on to prewarmed several times on the difficulty of identifying "Drugs Acting on Infections: Antilbacterial selective gonococcal medium,5 the cultures H. influenzae in the Gram-stained deposit of Preparations" contains a number of state- being immediately placed in an incubator cerebrospinal fluid. I should like once again ments whtich might be challenged. Some of with a carbon dioxide-enriched atmosphere. to draw attention to the value of a good these are listed below. At the same time Gram-stained smears are typing serum for H. influenzae type b in this (1) Carbenicillin. It is advised that for made from further samples. situation. Typing is not mentioned in Dr. systemic infections this be given by con- In the 6! months between November Eykyn's paper, but as your leading artidle tinuous intravenous infusion. The data sheet on 29 September 2021 by guest. Protected copyright. 1973 and mid-May 1974 10 cases of (p. 462) pointed out capsulated strains of issued by the makers advises that carbeni- gonococcal salpingitis and one of gonococcail type b are responsible for the great majority cillin be given intravenously either by bolus cervicitis have been found by this active of cases of haemophilus meningitis. The injection or rapid infusion on the grounds approach in gynaecological patients. In six practical relevance of this is that a capsule- that infusion over longer periods may result of these the Gram film gave immnediate swelling test with a good type b antiserum in sutbtherapeutic concentrations. Whatever warning of the positive culture to come. I,t (such as that made by Hyland Laboratories) the relative therapeutic merits of inter- can be argued that it is immaterial to makes possible the firm identification of mittent versus continuous administration, indentify the causative organism as anti- type b H. influenzae in C.S.F., even if they one is left with the other potential draw- biotics would ibe given anyway once a are few in numribers, within minutes of the back of continuous infusion of the penicillins diagnosis of salpingitis has been reached. arrival of the specimen in the laboratory.' -that is, their possible inactivation by other T,his is fallacious as it fails to identify the Your leading article was a joy to read and components of the intravenous solution or cases in which sexual contacts should be I am sorry to have to point out any fault incompatibility with other additives, notably investigated by the venereology department. in it; indeed, the fault lies not in the article gentamicin in the case of carbenicillin. This No cases of Bartholin's abscess due to but in its title. It dealt not with "Haemo- is not mentioned by the B.N.F. gonococcal infection were found during the philus influenzae infections" but with one (2) Ampicillin. Amoxycillin and its better same period. Most patients had already re- group of such infections, making no refer- absorption by the oral route should have ceived antibiotics from their general practi- ence, for example, to the activities of non- been mentioned in a volume published in tioner so this is not surprising. It should be capsulated strains in the bronchi, which 1973. stressed that patients with a Bartholin's account for the great majority of IH. (3) Gentamicin. This is said usually to abscess should -be admitted for surgical influenzae infections in Britain.-I am, etc., have "a slightly wider margin of safety" than drainage and not treated first with anti- kanamycin. In fact the margin between biotics as they are ineffective and also con- D. C. TURK therapeutically active and toxic serum levels Department of Bacteriology, is greater with kanamycin.2 For some reason fuse the bacteriological diagnosis. Radcliffe Infirmary, Despite the screening of "at risk" ante- Oxford the intravenous use of gentamicin is vetoed, natal patients, three cases of gonococcal though this mode of administration must be 1 Turk, D. C., and May, J. R., Haemophilus widespread for serious systemic infections, ophthalmia neonatorum were found between influenzae. Its Clinical Importance, pp. 35 and September 1972 and September 1973. The 120. London, English Universities Press, 1967. notably with Pseudomonas aeruginosa. BRITISH MEDICAL JOURNAL 22 JUNE 1974 667 (4) Tetracyclines. It is recommended The bacterial contamination of the hos- the infection; after the acute stage parasitized that, given parenterally, "the total dose pital environment by patients with infectee red cells may be extremely few and very exceed 1 g in 24 hours (less dermatological lesions can be truly pro- difficult to find.