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Opioid Overdose Recognition and Naloxone Use in Pharmacy

How to recognise an opioid overdose in or near the pharmacy, when and how to use naloxone, and the pharmacist's role in take-home naloxone supply and harm reduction.

Why this matters

Drug poisoning deaths in England and Wales have risen significantly over recent years, with opioids involved in the majority of cases. Community pharmacies are on the front line: they supply methadone and buprenorphine for supervised consumption, dispense prescribed opioids, and are often located in areas where people who use drugs may be present. A patient or bystander presenting at the counter with a collapsed or unresponsive individual nearby is a scenario that any pharmacist may face.

Respiratory depression is the mechanism by which opioid overdose kills. Opioids suppress the brain's drive to breathe, causing breathing to become progressively slower, shallower, and eventually absent. It is the rate and depth of breathing, not the overdose triad as a whole, that determines the urgency of the response. A patient who is drowsy with pinpoint pupils but breathing normally at an adequate rate requires close monitoring. A patient with slow or absent breathing requires immediate action regardless of other features.

Risk is significantly increased when opioids are combined with other sedating substances. Alcohol, benzodiazepines, pregabalin, gabapentin, z-drugs, and other central nervous system depressants potentiate opioid-induced respiratory depression and are frequently implicated in fatal overdoses. Tolerance also plays a critical role: people recently released from prison, those who have completed detoxification, or those who have experienced any period of reduced opioid use have substantially lower tolerance and are at greatly increased risk at doses that previously caused them no harm.

Naloxone is a fast-acting opioid antagonist that can reverse opioid-induced respiratory depression within minutes. Commissioning arrangements for naloxone supply vary across England, Wales, Scotland, and Northern Ireland, but many community pharmacies can supply it without a prescription through local services. Knowing how to recognise an overdose, when to act, and how to use whatever naloxone product is available can save a life.

Red flags vs more likely benign

FeatureMore likely benignRed flag ⚠
BreathingNormal rate and effortSlow, shallow, irregular, or absent breathing: this is the most important sign of life-threatening opioid overdose
ConsciousnessAlert and responsive to voiceDrowsy, difficult to rouse, unconscious, or unresponsive
Airway soundsQuiet, normal breathingGurgling, snoring, or other signs of airway obstruction
Skin and lipsNormal colour and temperaturePale, cold, clammy, or blue-tinged lips and fingertips: suggests cyanosis from inadequate breathing
PupilsNormal size and reactive to lightPinpoint pupils poorly reactive to light. Note: absence of pinpoint pupils does not exclude overdose, particularly with synthetic opioids or mixed presentations
Muscle toneNormalLimp or floppy
Response to stimuliResponds to voice or gentle touchNo response to voice or gentle physical stimulation

Breathing Is the Priority

In opioid overdose, it is the breathing that kills. The following two points should guide every pharmacist's assessment.

  • Slow, shallow, or absent breathing is the most important sign of life-threatening opioid overdose. A patient who is drowsy but breathing adequately requires close monitoring. A patient who is not breathing normally requires CPR and immediate naloxone.
  • Absence of pinpoint pupils does not exclude opioid overdose. Synthetic opioids, mixed overdoses, and severe hypoxia can all alter the classic presentation. Act on the clinical picture, not the pupils alone.

If in doubt about the cause of collapse, follow basic life-support procedures, call 999, use an AED if indicated and available, and administer naloxone if opioid overdose is suspected.

🛑 OVERDOSE: Pharmacy Response Framework

Use this sequence when opioid overdose is suspected.

O
Observe breathing

Is breathing slow, shallow, or absent? This is the most critical assessment. Breathing rate and depth determine urgency.

V
Voice and rouse

Call their name and try to rouse. No response to voice or touch requires immediate action.

E
Emergency: call 999

Call 999 immediately. Do not delay calling for help to attempt naloxone first.

R
Recovery position or CPR

If breathing normally: recovery position. If not breathing normally: commence CPR and follow 999 call-handler instructions. Naloxone does not replace CPR.

D
Do not leave them

Stay with the patient at all times. Do not allow a drowsy patient to leave the premises unaccompanied.

O
Open airway

Maintain the airway throughout. Airway obstruction from loss of muscle tone is a common cause of deterioration.

S
Supply naloxone

Administer naloxone according to training, the product instructions, and local protocols. Multiple doses may be needed.

E
Effects may return

Naloxone wears off before the opioid. All patients need ambulance assessment even after apparent recovery. Patients may become agitated or experience withdrawal symptoms after naloxone administration.

What to do in pharmacy

Call 999 immediately if the patient is unresponsive, breathing very slowly, breathing irregularly, or not breathing at all. Also call 999 if there are signs of cyanosis, airway obstruction, or suspected overdose with reduced consciousness.

Open and maintain the airway. If the patient is not breathing normally, commence CPR and follow 999 call-handler instructions. Naloxone does not replace basic life support: CPR takes priority if the patient is not breathing. If the patient is breathing normally and the airway can be maintained, place them in the recovery position.

If naloxone is available, administer it according to training, the product instructions, and local protocols. Different products are available in different settings: use whichever product is to hand. If there is no response or symptoms return, repeat doses may be needed according to the product instructions. The aim of naloxone is to restore adequate breathing and airway protection, not necessarily to make the person fully alert.

Even if the patient appears to recover after naloxone, they must be assessed by emergency medical services. The effects of naloxone may wear off before the effects of the opioid, and recurrent respiratory depression can occur. Patients may also become agitated or experience withdrawal symptoms after naloxone administration.
Call 999 and monitor closely if the patient is drowsy but rousable and opioid overdose is suspected. Do not leave them alone. Consider what opioid has been taken, when it was taken, and whether alcohol, benzodiazepines, pregabalin, gabapentin, or other sedating substances have also been used, as combinations significantly increase risk.

Patients taking prescribed opioids who become unexpectedly sedated, particularly following a dose increase or the addition of another sedating medicine, require urgent assessment. Patients receiving supervised methadone who appear unusually sedated require urgent clinical assessment before leaving. Ask whether naloxone has already been given by a bystander.
Many community pharmacies may be able to supply take-home naloxone where this is available under local service arrangements or applicable legal supply routes. Check local protocols, training, stock arrangements, and record-keeping requirements before supplying. When supplying naloxone, provide clear verbal and written advice on recognising overdose, calling 999, administering naloxone, placing the person in the recovery position, staying with them until help arrives, and giving further doses if required.

Proactively consider naloxone for patients prescribed high-dose opioids, those prescribed opioids alongside benzodiazepines or gabapentinoids, those receiving opioid substitution therapy, those recently released from prison, those who have recently completed detoxification or experienced a period of abstinence, and those with a history of overdose.

Naloxone supply is one of the most effective harm-reduction interventions available in community pharmacy.

Key takeaways

  • Call 999 first. If the patient is not breathing normally, commence CPR and follow 999 call-handler instructions. Naloxone buys critical time but does not replace basic life support.
  • Slow, shallow, or absent breathing is the most important sign of life-threatening opioid overdose. Absence of pinpoint pupils does not exclude overdose. Administer naloxone according to the product available, training, and local protocols.
  • Many community pharmacies can supply take-home naloxone. Proactively offer it to people prescribed high-dose opioids, those on opioids with benzodiazepines or gabapentinoids, and anyone at risk of witnessing an overdose.

Download the checklist

Download the one-page pharmacy opioid overdose checklist