... and 1 in 1000.Therefore, either:1 ml of 1:10 000 epinephrine diluted to atotal volume of 20 ml = 1 :20 0 000solution or0·1 ml of 1:1000 epinephrine diluted to atotal volume of 20 ml = 1 :20 0 ... considered. The main reasons for givingpremedication are shown in Box 19.5.A variety of drugs including opiates, benzodiazepines,anticholinergics, phenothiazines, and H 2 receptor blocking drugs areused. ... the principles ofregional anaesthesia at an early stage of your training.The drugs in common use are lignocaine, bupivacaine, and prilocaineand their characteristics are shown in Table 20 .1....