Saturday, September 28, 2013

Choosing Opiate Agonist Treatment

Choosing opioid agonist treatment
Dr. Meldon Kahan
Dr. Maya Nader
Dr. Anita Srivastava

Excellent presentation by three clinicians at the Canadian Society of Addiction Medicine annual meeting in Vancouver, 2013
These are my rough notes which hopefully give an idea of what was a very well presented, researched and clinically useful talk

Learning objections
initiation of opioid agonist treatment
 recent evidence regarding efficacy and side effects of buprenophine versus methadone

Opioid Agonist Treatment - OAT
-bruprenorphine USA 1980
-approved in Canada 2008

History of methadone
synthesized in germany in 1941
first methadone maitenance program in the world founded in Vancouver in 1967

Potential considerations
efficacy, safety, weight gain, mental clouding, sedation, sexual function, pain, withdrawal

Methadone more likely to retain patients than buprenorphine
With fixed medium dosing - buprenorphine less likely to suppress heroin desire

questions raised by cochrane review
-retention - was induction to buprenorphine too slow, etc

Stepped care approach
-Kakko 2007
Only 46% who started buprenorphine stayed and rest switched to MMT 
-treatment retention and urine screens and problems good with this group

Safety concerns
 buprenorphine considered safe
Bell 2009 , australia

QT intervals - evidence for prolonged QT - at higher dosages 200 to 300

Safety - Benzos
risk of overdose increased with any opiates
when benzo used with methadone or buprenorphine - methadone did poorer on benzo - Lintzeris et al 2007

Opioids are a risk factor for fractures in the elderly and it’s dose related

Diversion - patients who use methadone nonmedically have higher hospitalizations rates, greater icu, poorer outcomes

Patient preference
-Summit Trial , Pinto et al 2010
patients preferred methadone 2:1
-subset wouldn’t go on methadone
main reason for choosing buprenorphine
-ease of detoxification
  • more clear headed

Withdrawal severity may be less intense with buprenorphine - gowling et al, cochrane review 2009

At end of day similar relapse rates during withdrawal whether patient was on buprenorphine or methadone

-Neuman, 2013 - equally reduced in methadone and buprenorphine
-suggested alot of pain related to addiction

Adolescent Heroin Users
-better treatment retention with methadone than buprenorphine
-better treatment retention with long term buprenorphine treatemnt versus detox or abstinence (bell, 2006;woody208,)

Weight Gain
-perception of greater weight gain with MMT
-non dose related increase in first 2 years - but when compared to general populations methadone patients less
-no different in weight gain between methadone and buprenorphine

review of patient blogs - mixed response

Mental Alertness/sedation
-both methadone and buprenorphine appear to affect mental alertness and sedation 
-up to 100 mg no difference - but greater than 100 mg more with methadone-winstock 2009

Increased risk of traffic accidents in both patients on MMT and BMT
Bup pts performed somewhat better on psychomotor tasks than methadone
No on road testing done 

-double blind controlled trial (n=150)  - showed improvement in mood on beck in all with no improvement of one over the other drug

Quality of Life

Beneficial effects for both
Early onset of benefits with Methadone versus Buprenorphine but both good

Sexual Function

MMT patients have more erectile dysfunction and lower testosterone levels than buprenorphine

Side Effects
-Summit Trial
greater proportion of MMT complained of sweating, seadation and constipation than buprenorphine

Programmatic differences
-contigency management differences
-patient randomized to buprenorphine in one post jail study - more flexible environment for buprenorphine versus MMT - resulted in better retention and follow up

Soft Factors
-factors other than intrinsic pharmacological 
-family/work obligations -strict MMT requirements associated with treatment to protect against overdose 
-lack of mobility 
-comorbities - tying care to family doctor - a diabetic have buprenorphine in office versus going to clinic
-patient receiving high oral opioid doses from one doctor only
-socially unstable, doesn’t follow up with appointments - methadone might have better retention rate

In states and france - buprenorphine can be prescribed by a family doctor in office versus the clinic based methadone

Buprenorphine has been used in patients who were iatrogenically addicted to opiates for pain management and they are more willing to take buprenorphine

Methadone approved in pregnancy
buprenorphine/naloxone is not
-consider methadone for women at high-risk or planning a pregnancy

-cost - buprenorphine more expensive than methadone

Opiates can reduce testosterone and testosterone replacement and viagra can help
Paitents who are on heroin usually have poor sexual function and the majority have improvement with methadone maintenance

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