top of page
  • robinapark

Acute pain management in illicit drug users

Updated: Feb 22, 2021

General considerations

On admission to hospital the patient may experience:

- Fear of withdrawal

- Fear of pain not being taken seriously

- Fear of discrimination

- (In those currently abstinent) - Fear of relapse


The clinician may experience:

- Mistrust of patients with addiction

- Overtreatment of pain - leading to OIVI

- Possibility of being told fabricated stories

- Diversion of their prescribed opioids

- Fear that patients may leave the hospital against medical advice and associated harms


Factors that need assessment at admission

Appropriate use and dosage of opioid substitution therapies

Enquiring about other prescribed, not-prescribed, OTC and illicit drugs

Routes of administration of drugs

Medical comorbidities (e.g. HIV, hepatitis etc)

Psychiatric comorbidities (e.g. anxiety etc)

Social disadvantage

Support systems for after discharge

Acute management of patients with opioid dependence

3 Key interlinked issues:

  1. Opioid-induced hyperalgesia - increased pain sensitivity

  2. Opioid tolerance - reduced effectiveness of prescribed opioids

  3. Opioid withdrawal if usual opioids not given

Opioid-induced hyperalgesia

Common in those abusing heroin and on methadone and buprenorphine substitution

Likely these effects can remain even when abstinent for a period of time

  1. Optimise multimodal analgesia (Paracetamol, NSAIDs, COS2, local anaesthetics, opioid rotation)

  2. Utilise adjuvants - Ketamine, Gabapentin and pregabalin, clonidine... might attenuate


Opioid Tolerance

Higher doses of opioids are needed in patients who are tolerant

Adjuvants that reduce OIH also reduce tolerance

Ketamine is useful in postoperative pain in opioid-tolerant patients

Gabapentin, pregabalin, paracetamol, NSAIDs, COX2, Alpha2 - all help


Opioid withdrawal

Symptoms are sympathetically driven - tachycardia, anxiety, restlessness, insomnia, sweating, diarrhoea, rhinorrhea, muscle aches, yawning and 'gooseflesh'.

Opioid maintainence treatment (OST) is giving a long-acting opioid to maintain blood levels in a narrow range so they experience minimal withdrawal and minimal intoxication long term


Has been shown to reduce drug use, overdose risk, reduce risk of blood-borne viruses, and gives social stability


An acute pain episode is a high risk event for these patients to return to haphazard drug taking


Methadone

Clinicians should continue methadone

Withdrawal suppression lasts around 24 hrs - can give once a day or BD/TDS in hospital

THEY WILL NOT GET ANALGESIA FROM THIS DOSE - so analgesia should be provided SEPARATELY!


NB: Can cause QT prolongation


Buprenorphine

Partial agonst at mu-opioid receptor with HIGH-binding affinity

At high doses (those in OST - 16-32mg) the receptors are blocked by buprenorphine so pure agonists like heroin, would impart no benefit

So in the past, the buprenorphine would be stopped during admission to allow receptors for analgesia

But, it seems now that when given in divided doses, patients on bup OST do better if it is continued - so doses should be split into 2 or 3, and then restarted on discharge


Other opioids

If not on OST, but dependent on opioids, in hospital patients can be given low doses (10-20 mg) of methadone to help prevent withdrawal and reduce cravings


Nil by mouth

IV controlled analgesia can be added to patient-controlled analgesia for opioid withdrawal prevention. However, need very close monitoring of withdrawal, sedation, respiratory rate. Tamper-proof housing must be used.


Abstinent patients - risk of relapse

IV opioids given for analgesia are at higher risk than SR oral opioids

Severity of acute pain varies with activity so this is usually best treated with short-acting

Have to find a balance

 

Other drugs


Stimulants

Amphetamine withdrawal leads to a 'crash' of dysphoria, irritability, melancholia, anxiety, hypersomnia (but poor sleep), and marked cravings with paranoia


Hyperarousal - Drug craving, agitation, vivid dreams

Reversed vegetative factor - Decreased energy, increased appetite, increased sleep craving

Anxiety factor - Loss of interest or pleasure, anxiety, slowing of movement


 

Discharge

Referral to social worker

Community housing etc.

Communication with primary care givers and pharmacists

Consideration of discharge opioids - high risk obviously of shorter acting versions




59 views0 comments

Recent Posts

See All

Commentaires


bottom of page