A double-blind, randomised trial of acyclovir versus placebo was conducted in 31 patients with initial and 85 patients with recurrent genital herpes. 17 patients with initial and 42 with recurrent disease were treated with 200 mg acyclovir by mouth five times a day for 5 days, and the remaining patients received matching placebo. In patients with initial genital herpes shedding virus acyclovir significantly reduced the duration of viral shedding, itching, and pain, the time to crusting and complete healing, and new lesion formation compared with controls. In patients with recurrence disease acyclovir significantly reduced the duration of viral shedding, time to complete healing, and new lesion formation. The reported incidence of adverse events was similar in both acyclovir and placebo groups. Oral acyclovir is effective and well tolerated in patients with initial and recurrent genital herpes and can be used in outpatient therapy.

23 unselected patients with mild to moderate essential hypertension, whose average supine blood pressure after two months' observation on no treatment was 154/99 mm Hg, were entered into an eight week double blind randomised crossover study of one month's treatment with slow release potassium tablets (60 mmol/day) versus placebo without alteration of dietary sodium or potassium intake. By the fourth week mean supine blood pressure had fallen by 4% on potassium supplementation compared with placebo. Urinary potassium excretion increased from 62 +/- 4.7 mmol/24 h on placebo to 118 +/- 7.4 mmol/24 h on potassium. The fall in blood pressure was not related to urinary sodium excretion before entry to the trial or while on placebo. Moderate potassium supplementation caused a small but significant fall in blood pressure in patients with mild to moderate essential hypertension and could be additive to the effects of moderate sodium restriction. This increase in potassium intake could be achieved with a potassium-based salt substitute and a moderate increase in vegetable and fruit consumption. Moderate dietary sodium restriction with dietary potassium supplementation may obviate or reduce the need for drug treatment in some patients with mild to moderate hypertension.

In a study designed to compare the Mantoux with the tine and 'Imotest' multiple-puncture tuberculin tests 200 subjects underwent a Mantoux test (10 IU PPD-Weybridge) and, simultaneously, either a tine test or an imotest. All tests were read after 72 h by two observers independently. The false-negative rate for the Mantoux was estimated by immediate repetition of the Mantoux in subjects with an initially negative Mantoux but positive multiple-puncture test. When the criterion for a positive reaction was at least 5 mm of induration for the Mantoux and at least 2 mm of induration for the multiple-puncture tests, the false-negative rate of 27% for the imotest was significantly higher than the 4% for the tine and 5% for the Mantoux (p less than 0.001 in each case). Positive multiple-puncture tests were always associated with a Mantoux test that was positive on either the first or second application. Observers agreed in their interpretation of 98% of all tests, and there were no significant differences between testers in frequency of false-negative results for any test. The tine test, when carefully applied and correctly interpreted, gives results which correlate well with those given by the standard Mantoux test. The imotest is less reliable and has no advantages over the tine test.

Multiresistant strains of Haemophilus ducreyi, the aetiological agent of chancroid, are prevalent in Nairobi, Kenya, where tetracyclines and sulphonamides are no longer very effective in the treatment of chancroid. The following regimens (given three times daily for seven days) were compared in a double-blind randomised trial--amoxycillin 500 mg, amoxycillin 500 mg and clavulanic acid 125 mg, and amoxycillin 500 mg and clavulanic acid 250 mg. 68 of 100 ulcers were culture-positive for H. ducreyi. All strains of H. ducreyi produced beta-lactamase. At day 7 none of the amoxycillin-treated patients had responded clinically or bacteriologically, whereas all but 2 of 56 patients treated with an amoxycillin/clavulanic-acid regimen had responded clinically and H. ducreyi had been eradicated from their ulcers. The combination of amoxycillin-clavulanic acid appears to be very effective for the treatment of chancroid. The results of this study accord with H. ducreyi as the primary pathogen of chancroid.

90 patients on medication for mild hypertension were randomly allocated to diet and control groups and kept under surveillance by their own doctors every 2 weeks for 12 weeks to test the short-term effectiveness of a diet free from sodium additives as an alternative to medication. Mean urinary sodium excretion was reduced 37.0 mmol/24 h in the diet group and 161.0 mmol/24 h in the control group, with average K/Na ratios of 3.9 and 0.50. Both groups had a fall in mean systolic and diastolic blood pressure, but the diet group finished on half of the initial amount of medication, with 1 patient in 3 off medication and 4 out of 5 having either stopped or reduced the dose. The control group remained on almost the full amount of medication, with 2 patients out of 3 having made no reduction. The diet group had a mean weight loss of 2.1 kg, a rise in serum potassium, and a fall in serum bicarbonate. There was no increase in overall frequency of muscle cramp, and the diet group reported feeling happier, less depressed, and less dependent on analgesics. Two-thirds of the diet group intend to continue to diet indefinitely. Reduction of sodium intake permitted drug treatment to be substantially reduced without side-effects or loss of blood-pressure control.