Pinacidil, a new cyanoguanidine derivative, is an antihypertensive agent with arteriolar vasodilating properties, which acts on precapillary resistance vessels. A trial was carried out in 30 patients with essential hypertension WHO I-II. The treatment period was divided into three phases. Hydrochlorothiazide (HCTZ) and amiloride were administered for 4 weeks in Phase 1 and supine and standing blood pressure decreased significantly. During Phase 2 pinacidil was added to HCTZ/amiloride for the following 3 months. A further significant reduction in blood pressure was obtained. In the next period of treatment (Phase 3) patients were divided into two groups. For 1 month Group A (15 patients) received pinacidil alone and Group B (15 patients) received HCTZ/amiloride. Conventional laboratory blood tests in all patients remained unchanged during treatment. Reported side effects during Phase 2 were headache (2 patients), dizziness (3 patients), palpitations (2 patients) and ankle oedema (2 patients). Plasma renin activity was slightly increased at the end both of Phases 1 and 2. Plasma catecholamines were increased but not significantly at the end of Phase 2 as compared to Phase 1. The results indicate that pinacidil is effective in lowering blood pressure in mild to moderate essential hypertension.

The clinical analgesic effect of 5 mg morphine given intraarticularly is equal to 5 mg morphine given intramuscularly. The occurrence of villous synovitis seems to be of no clinical importance concerning the local effect of morphine.

The comparative efficacy of antibacterial therapy with pivmecillinam or cotrimoxazole and general supportive care only was studied in patients with severe bacterial gastroenteritis. Overall, treatment with antibiotics proved significantly superior to rehydration alone in 42 children. Active therapy also had a statistically beneficial effect in children infected with Vibrio cholerae and V. parahaemolyticus. Pivmecillinam and co-trimoxazole were equally effective. Pivmecillinam and oral mecillinam appeared to be of equal value in a further 22 adults infected by Vibrio spp. No side-effects were recorded in any of the subjects treated. Further investigations with pivmecillinam and oral mecillinam are advocated.

The efficacy of mecillinam when given orally in preventing travellers' diarrhoea has been studied. Preliminary investigations in volunteers showed that single daily doses of up to 200 mg for 3 weeks were well tolerated. A randomised double-blind study was carried out in a group of tourists visiting Egypt and the Far East. The subjects took either mecillinam (200 mg daily) or placebo for 25 days. 19/36 tourists (53%) taking placebo and 5/38 tourists (13%) taking mecillinam developed travellers' diarrhoea during the treatment period (p less than 0.001). In the placebo group enterotoxigenic Escherichia coli (LT/ST) were found in 2 cases of diarrhoea and Salmonella in another 2 cases. In the remaining cases of diarrhoea the etiological agent was not found in either of the 2 groups.