OPRM1 and CYP3A4 association with methadone dose in Iranian patients undergoing methadone maintenance therapy

BACKGROUND

Investigations proposed that genetic polymorphisms within proteins in methadone pharmacokinetic and pharmacodynamics are critical factors in determination of methadone dose in methadone maintenance therapy (MMT).

OBJECTIVE

This study aimed to assess the associations between two polymorphisms, CYP3A4 (rs2740574) and OPRM1 (rs1799971), with dose of methadone in Iranian patients undergoing MMT.

METHODS

A total of 124 Iranian male subjects aged 18-65 years old who were confirmed to be addicted by the addiction diagnostic tests and underwent MMT were assessed. Patients were divided into three groups of low (less than 40 mg/day), moderate (more than 40 mg/day and less than 110 mg/day) and high (more than 110 mg/day) methadone dose consumption. DNAs of included patients were extracted from their blood samples and were assessed for CYP3A4 and OPRM1 polymorphisms.

RESULTS

Results showed that there was no significant association between the studied polymorphisms and methadone dose in Iranian addicted patients underwent MMT (P > 0.05).

CONCLUSIONS

CYP3A4 and OPRM1 single variations cannot explain variability in methadone dosage in MMT. Studying the interactions of more genetic factors in larger samples may elucidate factors influencing the required dose of methadone and better individualized therapy.

Methadone and buprenorphine prescribing and referral practices in US prison systems: results from a nationwide survey

BACKGROUND

More than 50% of incarcerated individuals have a history of substance use, and over 200,000 individuals with heroin addiction pass through American correctional facilities annually. Opiate replacement therapy (ORT) with methadone or buprenorphine is an effective treatment for opiate dependence and can reduce drug-related disease and recidivism for inmates. Provision of ORT is nevertheless a frequently neglected intervention in the correctional setting.

OBJECTIVE AND METHODS

We surveyed the 50 state; Washington, District of Columbia (DC); and Federal Department of Corrections' medical directors or their equivalents about their facilities' ORT prescribing policies and referral programs for inmates leaving prison.

RESULTS

We received responses from 51 of 52 prison systems nationwide. Twenty-eight prison systems (55%) offer methadone to inmates in some situations. Methadone use varies widely across states: over 50% of correctional facilities that offer methadone do so exclusively for pregnant women or for chronic pain management. Seven states' prison systems (14%) offer buprenorphine to some inmates. The most common reason cited for not offering ORT was that facilities "prefer drug-free detoxification over providing methadone or buprenorphine." Twenty-three states' prison systems (45%) provide referrals for some inmates to methadone maintenance programs after release, which increased from 8% in 2003; 15 states' prison systems (29%) provide some referrals to community buprenorphine providers.

CONCLUSION

Despite demonstrated social, medical, and economic benefits of providing ORT to inmates during incarceration and linkage to ORT upon release, many prison systems nationwide still do not offer pharmacological treatment for opiate addiction or referrals for ORT upon release.