15
Some Drug Interactions Contraindications
• Should not be administered with
opioids since naltrexone is an
opioid receptor antagonist
• All opioids should be
discontinued at least 7 days
prior to start of naltrexone HCl/
bupropion HCl
• Monoamine oxidase inhibitors
may increase risk of hypertensive
reactions when used
concomitantly.
• Bupropion is metabolized by
CYP2B6 into an active metabolite,
4-hydroxybupropion, which may
be the major active form.
• CYP2B6 inhibitors or inducers
may affect bupropion levels
with unclear consequences of
its eff icacy given simultaneous
changes in 4-hydroxybupropion
levels.
• Bupropion inhibits CYP2D6 which
may increase the concentration
of drugs metabolized by
CYP2D6: antidepressants, (e.g.,
selective serotonin reuptake
inhibitors and many tricyclics),
antipsychotics (e.g., haloperidol,
risperidone and thioridazine),
beta-blockers (e.g., metoprolol)
and type 1C antiarrhythmics (e.g.,
propafenone and flecainide)
• Digoxin levels may be decreased.
• Drugs that lower seizure
threshold should be used with
caution.
• Dopaminergic drugs (levodopa
and amantadine) can cause
central nervous system toxicity.
• Naltrexone HCl/bupropion HCl
extended release can cause false
positive urine test results for
amphetamines.
• Uncontrolled hypertension,
seizure disorders, anorexia
nervosa or bulimia, or
when undergoing abrupt
discontinuation of alcohol,
benzodiazepines, barbiturates,
or antiepileptic drugs
• Use of other products
containing bupropion
• Chronic opioid use
• During or within 14 days of
taking monoamine oxidase
inhibitors
• Known allergy to any of its
ingredients
