Table 2.
Comparison of methadone versus buprenorphine use in pregnancy.
| Methadone | Buprenorphine | |
|---|---|---|
| Type of opioid | Synthetic long-acting agonist | Semi-synthetic long-acting partial agonist |
| Route of administration | Oral (liquid), tablet | Sublingual, transdermal |
| Typical dose range | 20–120 mg | 4–24 mg |
| Dose increase interval | 3 days | 1 day |
| Costa approximate (USD/week) including medical care | $126 | $115 |
| Dispensed | Daily by pharmacy (with options for small numbers of carries with proof of adherence and depending on urine drug testing results). | Maximum 100-day prescription in Canada (and other jurisdictions). Can be taken by patients unsupervised. |
| Dose modification in pregnancy | May be necessary to increase the dose towards end of pregnancy due to CYP3A4 and CYP2B6 induction and increased metabolism (particularly in 3rd trimester). | Generally not required, although some studies have suggested the need for small dose increases towards the end of pregnancy. |
| Breastfeeding | Safe | Safe |
| Advantages | • Difficult to divert:• supervised consumption• liquid dissolved in orange juice• No requirement for patients to demonstrate signs and symptoms of opioid withdrawal prior to starting treatment. Careful supervised dose titration is required once initiated. | • Fewer drug–drug interactions• No QTc prolongation• Higher ceiling for respiratory depression• Can be prescribed in the office setting and patients can take buprenorphine unsupervised. |
| Disadvantages | • In most jurisdictions prescribers need authorization to prescribe. • Higher risk of adverse events: overdose, respiratory depression. • Dose-dependent QTc prolongation. • Important drug–drug interactions, including but not limited to antiretroviral drugs, anticonvulsants, rifampin. • Care must be taken when combining with other drugs that can cause CNS depression or lower the respiratory rate (e.g. benzodiazepines). | • Risk of abuse and diversion, particularly with the buprenorphine monoproduct. • Initiation typically requires the patient to be in mild opioid withdrawal.b This can be problematic in pregnancy as opioid withdrawal can lead to premature labor and other adverse pregnancy outcomes. • In patients taking full opioid agonists, starting buprenorphine in the absence of withdrawal symptoms can precipitate opioid withdrawal. |
aFrom: How much does opioid treatment cost. NIH National Institute on Drug Abuse. www.drugabuse.gov/publications/research-reports/medications-to-treat-opioid-addiction/how-much-does-opioid-treatment-cost.
bNewer buprenorphine microdosing protocols may avoid the need to have patients go into withdrawal.
QTc, electrocardiogram corrected QT interval