MPS medicolegal consultant Dr Aine McCoy says that doctors who prescribe phentermine (duromine) for weight control should ensure that they comply with good prescribing practice, to avoid having to justify their practice to the Medical Council
Phentermine has been used for weight reduction for many years in New Zealand. It is chemically related to amphetamine, with major effects upon the dopaminergic and noradrenergic systems. These include appetite suppression, increased heart-rate and force of contraction, gastrointestinal side effects and general central nervous system stimulation – particularly mood changes. Rarely it can cause psychotic symptoms.1
As phentermine is similar to amphetamine, it is a controlled drug (class C5) and has the potential for abuse. Duromine is not funded by Pharmac, so patients pay $160-$200 per month when they present a standard prescription of 30mg daily – in addition to the GP consultation fee.
However, the medication does have a considerable street value. The Medicines Control section of the Ministry of Health (which is responsible for containment of drug abuse) carries out regular surveys of pharmacies nationwide to ascertain the number of phentermine prescriptions dispensed and to check on GP prescribing patterns. Where their investigations reveal cause for concern they may report the doctor to the Medical Council for further investigation.
Other ways of a doctor coming to the notice of the Medical Council include notifications by pharmacists and other medical or nursing colleagues. Patients rarely complain.