. Doxycycline in serum and bronchial secretions. The concentration of doxycycline hydrochloride was measured in serum and bronchial secretions in five patients with chronic bronchitis receiving doxycycline orally in normal therapeutic dosage for seven days (200 mg day 1, 100 mg days 2 to 7). After the loading dose of 200 mg, serum concentrations ranged between 540 and 345 ,ug/ml (mean 433 p.g/ml) at 3 hours, declining to between 228 and 121 ,ug/ml (mean 1-71 tg/ml) at 23 hours. The mean serum levels for days 2 to 7 were 215, 179, and 138 at 3, 8, and 23 hours respectively. There was considerable individual variability and a wide range of concentrations of doxycycline in the sputum (0 07 to 2 10 tg/ml, mean 0 34 jug/ml). During the course of treatment there was a progressive increase in sputum levels and sputum/serum concentration ratios. There was no correlation between sputum concentration and degree of purulence. The clinical efficacy of doxycycline does not appear to be related to sputum concentration, although the progressive increase in sputum doxycycline levels may be relevant in preventing recurrence of acute infection when the drug is administered as long-term prophylactic therapy.

1. The bronchodilator effects of 500 microgram rimiterol by pressurized aerosol, 375 mg oral theophylline and both drugs in combination were compared in a randomized, placebo‐controlled, double‐blind trial in eight patients with chronic, partially reversible airways obstruction. 2. The four treatments were (i) oral theophylline, placebo aerosol (TP); (ii) oral placebo, rimiterol aerosol (PR); (iii) oral theophylline, rimiterol aerosol (TR) and; (iv) oral placebo, placebo aerosol (PP). The aerosol was administered 2 h after the oral treatment. 3. Significant bronchodilatation (% FEV1 change from control) compared to PP occurred with TP from 60 to 480 min and with TR from 60 to 300 min, whereas with PR only for 45 min (P less than 0.05). 4. The mean, peak % FEV1 increases from control were 51.8% at 125 min, 31.7% at 125 min, 26.1% at 210 min and 0.9% at 30 min for TR, PR, TP and PP respectively. 5. At 125 min (5 min after aerosol inhalation) the mean % FEV1 change from control with TR (51.8%) Was significantly greater than with PR (31.7%), TP (22.2%) (P less than 0.05) and PP (− 2.4%) (P less than 0.01). 6. The mean, peak plasma theophylline levels were 10.19 microgram/ml at 120 min and 9.98 microgram/ml at 180 min with TR and TP respectively. Theophylline half‐life ranged between 4.3 and 12.5 h (mean +/‐ s.e. mean, 8.0 +/− 0.8 h). 7. Additive bronchodilatation was produced when rimiterol was administered with theophylline at a time when therapeutic plasma theophylline levels were achieved.

The use of multidetector CT scanners for CT angiography requires rapid injection of radiographic contrast media. Central venous catheters are now widely used for this purpose. Several complications may occur while using central venous access for rapid, large volume contrast injection such as catheter rupture and contrast extravasation. We describe a case in which inadvertent malposition of a central venous catheter led to a high volume extravasation of contrast in the mediastinum in a trauma patient.

The bronchodilator effects of 375 mg theophylline orally and 200 μg salbutamol by pressurized aerosol were compared in a randomized, cross‐over, double‐blind trial in fourteen asthmatic patients. The mean peak percentage FEV1 increase from control was 43.7% at 60 min after salbutamol and 30.3% at 180 min after theophylline. Salbutamol produced significantly greater bronchodilatation than theophylline for the initial 30 min (P<0.01). Theophylline demonstrated a longer duration of action than salbutamol, with a significantly greater FEV1 response at 360 min (P < 0.02). There was no significant difference between the total effect of each drug for the 360 min period, as calculated by the areas under the respective FEV1 response curves.

. Acute pulmonary reaction to nitrofurantoin. Acute pulmonary reaction to nitrofurantoin is a rare complication of a commonly used drug. This report of such a reaction presents studies of pulmonary function more detailed than are so far available. Studies made nine days after the drug had been withdrawn showed arterial hypoxaemia and abnormalities in ventilation-perfusion relationships. Challenge with 200 mg nitrofurantoin produced increased minute ventilation, hypoxaemia, hypocapnia, deterioration in ventilationperfusion relationships, marked veno-arterial shunting, and a fall in steady-state transfer factor for carbon monoxide and fractional carbon monoxide uptake. Spirometry and lung volume measurements indicated a restrictive lung abnormality without effect on large airways which persisted for at least nine weeks. Three years later there had been complete resolution of the process, apart from some persistent reduction in transfer factor, possibly related to the patient's smoking habits.