Opiates are useful pre-medicating agents as their respiratory depressing action can also potentiate. Pharmaceutical-grade opiates like morphine sulphate (as tablets or liquid), fentanyl (as a nasal or sublingual spray) or illegal products (like opium and heroin) can all perform useful pre-medicating roles.
Be aware that the oral ingestion of these drugs can cause vomiting so care is needed. Alternative administration, such as the use of sublingual spray, or administration by smoking the heroin ‘chasing the dragon’, or ‘snorting’ heroin powder is also possible.
The dose of opiates to be used is very dependent on previous exposure, as tolerance is a specific problem with these drugs. If sufficient quantities are available, one could experiment with these drugs to determine the exact amount that provides useful sedation.
Smoking pre-medicating opiates
Barbiturates are effective as stand-alone, end of life drugs. However, barbiturates are legally-restricted and difficult to obtain. For these reasons it is not unusual for an elderly person to have a quantity of a barbiturate that is either too small or too old to be reliably lethal. Barbiturates are also highly effective as pre-medication and potentiation facilitators.
Apart from sedation, barbiturates have a number of useful additional properties. They are effective anti-convulsants and their quick absorbtion,, even from the stomach, means that they can be taken at the same time as a lethal drug. An example of this is the slow-acting prescription drug, phenobarb. Phenobarb has recently been added to the oral drug mixture D-DMAPh to improve the speed of the drug mixture (see The Lethal Mixtures).