Heroin overdose: the case for take-home naloxone

Home based supplies of naloxone would save lives

Non-fatal overdose is an occupational risk of heroin misuse1 and fatal overdose is a common cause of premature death in heroin users.2 3 4 One of the major contributors to a fatal outcome is the inadequacy of heroin users' responses to the overdoses of their peers. They may delay calling an ambulance for fear of the police arriving, and their efforts to revive comatose users are often ineffective. The distribution of naloxone to opiate users was first mooted in 19925 as an intervention that would be life saving in such situations.6 With a rising toll of deaths from heroin overdose it is time to take the suggestion seriously.

Interviews with 320 heroin users in Sydney found that two thirds had had a drug overdose, a third within the past year, and that 80% had been present at the overdose of another user.7 In Australia the incidence of deaths from heroin overdose has increased over the past decade while deaths from other drug related causes have fallen. In the United Kingdom a sharp increase in the numbers of deaths among opiate users has recently been reported from Glasgow.8

Naloxone has a long established use in emergency resuscitation of patients with opiate overdose.9 Such a tried and tested product might be suitable for distribution to opiate misusers so that they could give themselves the drug after inadvertent overdose or have others give it to them.

An obvious target group for naloxone would be opiate misusers at high risk of overdose, such as those leaving the emergency department against medical advice after resuscitation with naloxone. The short duration of action of naloxone puts such people at high risk of re-entering overdose. Patients could be given a dose of naloxone for self administration in the event of re-emergence of overdose in the next few hours. Another group at high risk is those re-entering the community after loss of opiate tolerance, either on release from prison or after discharge from a treatment programme.

More controversial would be the distribution of naloxone to all opiate users receiving treatment, as a precaution against unexpected overdose. Even more controversial would be distribution to all opiate users through needle and syringe exchanges. All opiate users are at risk of overdose—not only those who are dependent or undergoing treatment. Indeed, a heroin user who is not undergoing treatment seems to be at even greater risk of fatal and non-fatal overdose.

What concerns are raised by these proposals? Martindale concludes that adverse effects tend not to be a problem with naloxone at therapeutic doses.10 Nausea and vomiting have occurred, with seizures reported infrequently. Individual reports of hypertension, pulmonary oedema, and cardiac arrhythmias have generally been in patients with pre-existing heart disease undergoing cardiac surgery,10 and the role of naloxone in two reported cases of pulmonary oedema in healthy young men11 12 has since been questioned.13 The National Poisons Information Service in London reported that it had never been informed of a suspected adverse reaction to naloxone despite being contacted by about 800 cases of opioid poisoning each year.14

The potential for abuse of naloxone is negligible: it has virtually no agonist effects and is strongly antagonist to heroin and methadone. Removal of the deterrent effect of overdose might perhaps increase the frequency and intensity of opiate intoxication, although this seems unlikely given heroin users' dislike of the withdrawal symptoms produced by naloxone. Education about such dangers would need to accompany the introduction of naloxone and is already necessary to prevent post-resuscitation overdose as the short acting effect of naloxone wears off (thus leaving the heroin user at potentially even greater risk if further opiates have been used in the interim).15 A black market in naloxone might develop if opiate misusers wanted to protect themselves from overdoses: in such a case, however, the drug would be used for its intended purpose, and the black market would simply circumvent inequalities in access to the drug.

If naloxone were to be provided to opiate misusers for emergency resuscitation it would need some modification. The onset of many overdoses is too sudden to allow time for the victim to open an ampoule, draw up the contents, and inject himself or herself. The drug might be better provided in a disposable preloaded syringe, though such a form of delivery would increase its cost. Attention would also need to be paid to the shelf life of a product which would be kept for emergencies—though even reduced potency naloxone may still be life saving.

Further issues are raised by the possibility of naloxone being administered by third parties, such as friends or family members, or its use to resuscitate a person who had not been prescribed the drug. Lifesaving applications may include administration of home based emergency naloxone to a child who has inadvertently taken the parent's prescribed supply of opiate, as has been reported.16 Is such behaviour to be discouraged, or should drug users be educated in the use of naloxone as part of training in cardiopulmonary resuscitation? We may even wish to reconsider its legal status so that it could be sold over the counter by community pharmacists to a wider population of drug misusers—in the same way as needles and syringes to drug injectors or insulin to people with diabetes.

The distribution of naloxone to opiate misusers should be seriously considered for trial and evaluation. While the problem of heroin misuse grows worldwide, the problem of deaths from accidental overdose17 is a problem we can address today. We have the opportunity to gather great potential health gains from tools already in our hands.