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:
Opioid-induced hyperalgesia - increased pain sensitivity
Opioid tolerance - reduced effectiveness of prescribed opioids
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
Optimise multimodal analgesia (Paracetamol, NSAIDs, COS2, local anaesthetics, opioid rotation)
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
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