methadone: dosage and conversion
Last reviewed 01/2018
- the conversion tables relating to heroin dosage to methadone dosage are of limited value because most illicit opiates are of unknown purity
- also patients may be untruthful about the amount of opiate abused
- therefore, for all patients it is safer to carry out a formal, stabilisation process (1)
Notes:
- for
patients who are using other opioids it is sometimes necessary to stabilise them
onto methadone or buprenorphine (2)
- it is not possible to accurately predict equivalent doses in most cases. This is especially true for street drugs where purity is notoriously variable. It is also problematic to convert from one drug to another when the half lives are not equivalent.
Reference:
- (1) Prescribers' Journal 2000; 40 (2): 67-76.
- (2) RCGP (2007). Drug misuse and dependence: UK guidelines on clinical management