Clonazepam for example is easy to give by the oral, sublingual or subcutaneous route. It is usually given 12 hourly in doses from 0.5mgm to 2mgm.

Midazolam given subcutaneously is useful for emergencies such as fitting and severe restlessness and agitation - the usual dose is 2.5mgm to 5mgm. Its effects usually only last for about three hours.

Occasionally a major tranquillizer is needed particularly for delerium. It is not advisable to use morphine primarily for its sedative effect.

The other caution with the use of morphine in terminal therapy is the problem of morphine toxicity where morphine given in doses that are too high can cause drowsiness, restlessness, confusion, agitation and myoclonic jerks etc. This is a particular risk with the build up of morphine seen as renal function diminishes during a terminal illness. Morphine dose and administration intervals need to be adjusted in these situations.

Morphine is of some but limited use for severe ischaemic pain. Peripheral vasodilators are also of some use. An old drug well known to anaesthetists is ketamine. Ketamine activates the limbic system and depresses the cerebral cortex producing profound analgesia, slight respiratory depression, cardiovascular stimulation and amnesia. The protective reflexes are maintained. When simple touch leads to intense and prolonged pain resistant to other analgesics, ketamine may be considered. Use of ketamine will be discussed in a later article.