Dosing & Uses
Dosage Forms & Strengths
tablet: Schedule III
- 25mg (Regimex)
- 50mg (Didrex)
Obesity
Indicated in the management of exogenous obesity as a short term (a few weeks) adjunct in a regimen of weight reduction based on caloric restriction in patients with an initial body mass index (BMI) of ≥30 kg/m² who have not responded to appropriate weight reducing regimen (diet and/or exercise) alone
25-50 mg PO qDay initially; may increase dose or frequency according to response up to TID
Dosage Forms & Strengths
tablet: Schedule III
- 25mg (Regimex)
- 50mg (Didrex)
Obesity
Indicated in the management of exogenous obesity as a short term (a few weeks) adjunct in a regimen of weight reduction based on caloric restriction in patients with an initial body mass index (BMI) of ≥30 kg/m² who have not responded to appropriate weight reducing regimen (diet and/or exercise) alone
<12 years: Safety and efficacy not established
≥12 years: 25-50 mg PO qDay initially; may increase dose or frequency according to response up to TID
Interactions
Interaction Checker
No Results
Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor
Contraindicated (6)
- isocarboxazid
isocarboxazid increases effects of benzphetamine by pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.
- linezolid
linezolid increases effects of benzphetamine by pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.
- methylphenidate
benzphetamine increases effects of methylphenidate by pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.
- phenelzine
phenelzine increases effects of benzphetamine by pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.
- selegiline transdermal
selegiline transdermal increases effects of benzphetamine by pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.
- tranylcypromine
tranylcypromine increases effects of benzphetamine by pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.
Serious - Use Alternative (33)
- abametapir
abametapir will increase the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. For 2 weeks after abametapir application, avoid taking drugs that are CYP3A4 substrates. If not feasible, avoid use of abametapir.
- amitriptyline
amitriptyline, benzphetamine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- amoxapine
amoxapine, benzphetamine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- apalutamide
apalutamide will decrease the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Coadministration of apalutamide, a strong CYP3A4 inducer, with drugs that are CYP3A4 substrates can result in lower exposure to these medications. Avoid or substitute another drug for these medications when possible. Evaluate for loss of therapeutic effect if medication must be coadministered. Adjust dose according to prescribing information if needed.
- bosentan
bosentan will decrease the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug.
- cabergoline
cabergoline, benzphetamine. Mechanism: pharmacodynamic synergism. Contraindicated. Additive vasospasm; risk of hypertension.
- clomipramine
clomipramine, benzphetamine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- desflurane
desflurane increases toxicity of benzphetamine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.
- desipramine
desipramine, benzphetamine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- dihydroergotamine
dihydroergotamine, benzphetamine. Mechanism: pharmacodynamic synergism. Contraindicated. Additive vasospasm; risk of hypertension.
- dihydroergotamine intranasal
dihydroergotamine intranasal, benzphetamine. Mechanism: pharmacodynamic synergism. Contraindicated. Additive vasospasm; risk of hypertension.
- doxapram
doxapram increases effects of benzphetamine by pharmacodynamic synergism. Avoid or Use Alternate Drug. Additive pressor effect.
- doxepin
doxepin, benzphetamine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- ergoloid mesylates
ergoloid mesylates, benzphetamine. Mechanism: pharmacodynamic synergism. Contraindicated. Additive vasospasm; risk of hypertension.
- ergotamine
ergotamine, benzphetamine. Mechanism: pharmacodynamic synergism. Contraindicated. Additive vasospasm; risk of hypertension.
- ether
ether increases toxicity of benzphetamine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.
- fexinidazole
fexinidazole will increase the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Fexinidazole inhibits CYP3A4. Coadministration may increase risk for adverse effects of CYP3A4 substrates.
- idelalisib
idelalisib will increase the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Idelalisib is a strong CYP3A inhibitor; avoid coadministration with sensitive CYP3A substrates
- imipramine
imipramine, benzphetamine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- iobenguane I 131
benzphetamine will decrease the level or effect of iobenguane I 131 by Other (see comment). Avoid or Use Alternate Drug. Based on the mechanism of action of iobenguane, drugs that reduce catecholamine uptake or that deplete catecholamine stores may interfere with iobenguane uptake into cells, and thus, reduce iobenguane efficacy. Discontinue interfering drugs for at least 5 half-lives before administration of either the dosimetry or an iobenguane dose. Do not administer these drugs until at least 7 days after each iobenguane dose.
- ivosidenib
ivosidenib will decrease the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration of sensitive CYP3A4 substrates with ivosidenib or replace with alternate therapies. If coadministration is unavoidable, monitor patients for loss of therapeutic effect of these drugs.
- lofepramine
lofepramine, benzphetamine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- lonafarnib
lonafarnib will increase the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid coadministration with sensitive CYP3A substrates. If coadministration unavoidable, monitor for adverse reactions and reduce CYP3A substrate dose in accordance with product labeling.
- maprotiline
maprotiline, benzphetamine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- methoxyflurane
methoxyflurane increases toxicity of benzphetamine by Mechanism: unknown. Avoid or Use Alternate Drug. Risk of V tach, HTN.
- methylergonovine
methylergonovine, benzphetamine. Mechanism: pharmacodynamic synergism. Contraindicated. Additive vasospasm; risk of hypertension.
- nortriptyline
nortriptyline, benzphetamine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- protriptyline
protriptyline, benzphetamine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- trazodone
trazodone, benzphetamine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- trimipramine
trimipramine, benzphetamine. Other (see comment). Avoid or Use Alternate Drug. Comment: Tricyclic antidepressants increase or decrease effects of sympathomimetics, by blocking reuptake of NE, or blocking uptake of indirect sympathomimetics into the adrenergic neuron.
- tucatinib
tucatinib will increase the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Avoid concomitant use of tucatinib with CYP3A substrates, where minimal concentration changes may lead to serious or life-threatening toxicities. If unavoidable, reduce CYP3A substrate dose according to product labeling.
- voxelotor
voxelotor will increase the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Avoid or Use Alternate Drug. Voxelotor increases systemic exposure of sensitive CYP3A4 substrates. Avoid coadministration with sensitive CYP3A4 substrates with a narrow therapeutic index. Consider dose reduction of the sensitive CYP3A4 substrate(s) if unable to avoid.
- yohimbe
yohimbe, benzphetamine. Mechanism: pharmacodynamic synergism. Contraindicated. Risk of acute hypertensive episode.
Monitor Closely (192)
- acetazolamide
acetazolamide will increase the level or effect of benzphetamine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- albuterol
albuterol and benzphetamine both decrease sedation. Use Caution/Monitor.
albuterol and benzphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - alfentanil
alfentanil increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- alprazolam
alprazolam increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- aluminum hydroxide
aluminum hydroxide will increase the level or effect of benzphetamine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- amitriptyline
amitriptyline increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- amobarbital
amobarbital increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- amoxapine
amoxapine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- arformoterol
arformoterol and benzphetamine both decrease sedation. Use Caution/Monitor.
arformoterol and benzphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - aripiprazole
aripiprazole increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- armodafinil
armodafinil and benzphetamine both decrease sedation. Use Caution/Monitor.
- azelastine
azelastine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- baclofen
baclofen increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- belladonna and opium
belladonna and opium increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- benperidol
benperidol increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- brompheniramine
brompheniramine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- buprenorphine
buprenorphine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- buprenorphine buccal
buprenorphine buccal increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- butabarbital
butabarbital increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- butalbital
butalbital increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- butorphanol
butorphanol increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- caffeine
caffeine and benzphetamine both decrease sedation. Use Caution/Monitor.
- calcium carbonate
calcium carbonate will increase the level or effect of benzphetamine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- carbamazepine
carbamazepine will decrease the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- carbinoxamine
carbinoxamine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- carisoprodol
carisoprodol increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- cenobamate
cenobamate will decrease the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Increase dose of CYP3A4 substrate, as needed, when coadministered with cenobamate.
- chloral hydrate
chloral hydrate increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- chlordiazepoxide
chlordiazepoxide increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- chlorpheniramine
chlorpheniramine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- chlorpromazine
chlorpromazine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
chlorpromazine, benzphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only. - chlorzoxazone
chlorzoxazone increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- cinnarizine
cinnarizine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- clemastine
clemastine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- clomipramine
clomipramine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- clonazepam
clonazepam increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- clorazepate
clorazepate increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- clozapine
clozapine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- codeine
codeine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- crofelemer
crofelemer increases levels of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Crofelemer has the potential to inhibit CYP3A4 at concentrations expected in the gut; unlikely to inhibit systemically because minimally absorbed.
- cyclizine
cyclizine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- cyclobenzaprine
cyclobenzaprine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- cyproheptadine
cyproheptadine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dabrafenib
dabrafenib will decrease the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely.
- dantrolene
dantrolene increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- darunavir
darunavir will increase the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- desipramine
desipramine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dexchlorpheniramine
dexchlorpheniramine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dexfenfluramine
benzphetamine and dexfenfluramine both decrease sedation. Use Caution/Monitor.
benzphetamine and dexfenfluramine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - dexmedetomidine
dexmedetomidine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dexmethylphenidate
dexmethylphenidate and benzphetamine both decrease sedation. Use Caution/Monitor.
benzphetamine and dexmethylphenidate both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - dextroamphetamine
dextroamphetamine and benzphetamine both decrease sedation. Use Caution/Monitor.
benzphetamine and dextroamphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - dextromoramide
dextromoramide increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- diamorphine
diamorphine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- diazepam
diazepam increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- diethylpropion
benzphetamine and diethylpropion both decrease sedation. Use Caution/Monitor.
benzphetamine and diethylpropion both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - difenoxin hcl
difenoxin hcl increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- diltiazem
benzphetamine will decrease the level or effect of diltiazem by pharmacodynamic antagonism. Use Caution/Monitor. Amphetamines may diminish antihypertensive effects of diltiazem. Monitor BP.
- dimenhydrinate
dimenhydrinate increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- diphenhydramine
diphenhydramine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- diphenoxylate hcl
diphenoxylate hcl increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dipipanone
dipipanone increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dobutamine
dobutamine and benzphetamine both decrease sedation. Use Caution/Monitor.
dobutamine and benzphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - dopamine
benzphetamine and dopamine both decrease sedation. Use Caution/Monitor.
benzphetamine and dopamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - dopexamine
dopexamine and benzphetamine both decrease sedation. Use Caution/Monitor.
dopexamine and benzphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - doxepin
doxepin increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- doxylamine
doxylamine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- droperidol
droperidol increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- droxidopa
benzphetamine and droxidopa both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. May increase risk for supine hypertension
- elagolix
elagolix will decrease the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Elagolix is a weak-to-moderate CYP3A4 inducer. Monitor CYP3A substrates if coadministered. Consider increasing CYP3A substrate dose if needed.
- elvitegravir/cobicistat/emtricitabine/tenofovir DF
elvitegravir/cobicistat/emtricitabine/tenofovir DF increases levels of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Cobicistat is a CYP3A4 inhibitor; contraindicated with CYP3A4 substrates for which elevated plasma concentrations are associated with serious and/or life-threatening events.
- encorafenib
encorafenib, benzphetamine. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Encorafenib both inhibits and induces CYP3A4 at clinically relevant plasma concentrations. Coadministration of encorafenib with sensitive CYP3A4 substrates may result in increased toxicity or decreased efficacy of these agents.
- ephedrine
ephedrine and benzphetamine both decrease sedation. Use Caution/Monitor.
ephedrine and benzphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - epinephrine
epinephrine and benzphetamine both decrease sedation. Use Caution/Monitor.
epinephrine and benzphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - epinephrine inhaled
benzphetamine, epinephrine inhaled. Either increases effects of the other by sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
- epinephrine racemic
epinephrine racemic and benzphetamine both decrease sedation. Use Caution/Monitor.
epinephrine racemic and benzphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - estazolam
estazolam increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- ethanol
ethanol increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- etomidate
etomidate increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- fedratinib
fedratinib will increase the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Adjust dose of drugs that are CYP3A4 substrates as necessary.
- fenfluramine
benzphetamine and fenfluramine both decrease sedation. Use Caution/Monitor.
benzphetamine and fenfluramine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - fluphenazine
fluphenazine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
fluphenazine, benzphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only. - flurazepam
flurazepam increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- formoterol
formoterol and benzphetamine both decrease sedation. Use Caution/Monitor.
formoterol and benzphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - green tea
green tea, benzphetamine. Other (see comment). Use Caution/Monitor. Comment: Green tea may include caffeine. Caffeine is a CNS-stimulant and additive effects may be seen when coadministered with other CNS stimulants. Caffeine should be avoided or used cautiously.
- haloperidol
haloperidol increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- hydralazine
hydralazine, benzphetamine. Mechanism: pharmacodynamic synergism. Use Caution/Monitor. Risk of hypertension.
- hydromorphone
hydromorphone increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- hydroxyzine
hydroxyzine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- iloperidone
iloperidone increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
iloperidone increases levels of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Iloperidone is a time-dependent CYP3A inhibitor and may lead to increased plasma levels of drugs predominantly eliminated by CYP3A4. - imipramine
imipramine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- isoproterenol
isoproterenol and benzphetamine both decrease sedation. Use Caution/Monitor.
isoproterenol and benzphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - istradefylline
istradefylline will increase the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Istradefylline 40 mg/day increased peak levels and AUC of CYP3A4 substrates in clinical trials. This effect was not observed with istradefylline 20 mg/day. Consider dose reduction of sensitive CYP3A4 substrates.
- ketotifen, ophthalmic
ketotifen, ophthalmic increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- levalbuterol
levalbuterol and benzphetamine both decrease sedation. Use Caution/Monitor.
levalbuterol and benzphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - levorphanol
levorphanol increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- lisdexamfetamine
lisdexamfetamine and benzphetamine both decrease sedation. Use Caution/Monitor.
benzphetamine and lisdexamfetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - lofepramine
lofepramine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- lofexidine
lofexidine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- loprazolam
loprazolam increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- lorazepam
lorazepam increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- lormetazepam
lormetazepam increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- loxapine
loxapine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- loxapine inhaled
loxapine inhaled increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- maprotiline
maprotiline increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- marijuana
marijuana increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- melatonin
melatonin increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- meperidine
meperidine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- meprobamate
meprobamate increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- metaproterenol
metaproterenol and benzphetamine both decrease sedation. Use Caution/Monitor.
metaproterenol and benzphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - metaxalone
metaxalone increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- metformin
benzphetamine decreases effects of metformin by pharmacodynamic antagonism. Use Caution/Monitor. Patient should be closely observed for loss of blood glucose control; when drugs are withdrawn from a patient receiving metformin, patient should be observed closely for hypoglycemia.
- methadone
methadone increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- methamphetamine
methamphetamine and benzphetamine both decrease sedation. Use Caution/Monitor.
benzphetamine and methamphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - methocarbamol
methocarbamol increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- methyldopa
methyldopa increases effects of benzphetamine by unknown mechanism. Use Caution/Monitor.
- methylenedioxymethamphetamine
methylenedioxymethamphetamine and benzphetamine both decrease sedation. Use Caution/Monitor.
benzphetamine and methylenedioxymethamphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - midazolam
midazolam increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- midodrine
benzphetamine and midodrine both decrease sedation. Use Caution/Monitor.
benzphetamine and midodrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - mirtazapine
mirtazapine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- mitotane
mitotane decreases levels of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Mitotane is a strong inducer of cytochrome P-4503A4; monitor when coadministered with CYP3A4 substrates for possible dosage adjustments.
- modafinil
modafinil and benzphetamine both decrease sedation. Use Caution/Monitor.
- morphine
morphine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- motherwort
motherwort increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- moxonidine
moxonidine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- nabilone
nabilone increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- nalbuphine
nalbuphine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- norepinephrine
norepinephrine and benzphetamine both decrease sedation. Use Caution/Monitor.
norepinephrine and benzphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - nortriptyline
nortriptyline increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- olanzapine
olanzapine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- opium tincture
opium tincture increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- orphenadrine
orphenadrine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- oxazepam
oxazepam increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- oxycodone
oxycodone increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- oxymorphone
oxymorphone increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- oxytocin
oxytocin increases effects of benzphetamine by pharmacodynamic synergism. Use Caution/Monitor.
- paliperidone
paliperidone increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- papaveretum
papaveretum increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- papaverine
papaverine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- pentazocine
pentazocine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- pentobarbital
pentobarbital increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- perphenazine
perphenazine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
perphenazine, benzphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only. - phendimetrazine
benzphetamine and phendimetrazine both decrease sedation. Use Caution/Monitor.
benzphetamine and phendimetrazine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - phenobarbital
phenobarbital increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- phentermine
phentermine and benzphetamine both decrease sedation. Use Caution/Monitor.
benzphetamine and phentermine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - phenylephrine
benzphetamine and phenylephrine both decrease sedation. Use Caution/Monitor.
benzphetamine and phenylephrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - phenylephrine PO
benzphetamine and phenylephrine PO both decrease sedation. Use Caution/Monitor.
benzphetamine and phenylephrine PO both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - pholcodine
pholcodine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- pimozide
pimozide increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- pirbuterol
pirbuterol and benzphetamine both decrease sedation. Use Caution/Monitor.
pirbuterol and benzphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - primidone
primidone increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- prochlorperazine
prochlorperazine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
prochlorperazine, benzphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only. - promazine
promazine, benzphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only.
- promethazine
promethazine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
promethazine, benzphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only. - propylhexedrine
benzphetamine and propylhexedrine both decrease sedation. Use Caution/Monitor.
benzphetamine and propylhexedrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - protriptyline
protriptyline increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- pseudoephedrine
benzphetamine and pseudoephedrine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
- quazepam
quazepam increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- quetiapine
quetiapine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- ramelteon
ramelteon increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- risperidone
risperidone increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- rucaparib
rucaparib will increase the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Adjust dosage of CYP3A4 substrates, if clinically indicated.
- salmeterol
salmeterol and benzphetamine both decrease sedation. Use Caution/Monitor.
salmeterol and benzphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - scullcap
scullcap increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- secobarbital
secobarbital increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- serdexmethylphenidate/dexmethylphenidate
serdexmethylphenidate/dexmethylphenidate and benzphetamine both decrease sedation. Use Caution/Monitor.
benzphetamine and serdexmethylphenidate/dexmethylphenidate both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - shepherd's purse
shepherd's purse increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- sodium bicarbonate
sodium bicarbonate will increase the level or effect of benzphetamine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- sodium citrate/citric acid
sodium citrate/citric acid will increase the level or effect of benzphetamine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- sodium lactate
sodium lactate will increase the level or effect of benzphetamine by passive renal tubular reabsorption - basic urine. Use Caution/Monitor.
- solriamfetol
benzphetamine and solriamfetol both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor.
- stiripentol
stiripentol, benzphetamine. affecting hepatic/intestinal enzyme CYP3A4 metabolism. Modify Therapy/Monitor Closely. Stiripentol is a CYP3A4 inhibitor and inducer. Monitor CYP3A4 substrates coadministered with stiripentol for increased or decreased effects. CYP3A4 substrates may require dosage adjustment.
- sufentanil
sufentanil increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- tapentadol
tapentadol increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- tazemetostat
tazemetostat will decrease the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor.
- tecovirimat
tecovirimat will decrease the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Use Caution/Monitor. Tecovirimat is a weak CYP3A4 inducer. Monitor sensitive CYP3A4 substrates for effectiveness if coadministered.
- temazepam
temazepam increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- terbutaline
terbutaline and benzphetamine both decrease sedation. Use Caution/Monitor.
terbutaline and benzphetamine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - thioridazine
thioridazine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
thioridazine, benzphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only. - thiothixene
thiothixene increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- topiramate
topiramate increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Modify Therapy/Monitor Closely.
- tramadol
tramadol increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- trazodone
trazodone increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- triazolam
triazolam increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- triclofos
triclofos increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- trifluoperazine
trifluoperazine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
trifluoperazine, benzphetamine. Mechanism: unknown. Use Caution/Monitor. Risk of cardiac arrhythmia or sudden death, more likely w/thioridazine than other phenothiazines. Interaction more likely in certain predisposed pts. only. - trimipramine
trimipramine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- triprolidine
triprolidine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- xylometazoline
benzphetamine and xylometazoline both decrease sedation. Use Caution/Monitor.
benzphetamine and xylometazoline both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - yohimbine
yohimbine and benzphetamine both decrease sedation. Use Caution/Monitor.
benzphetamine and yohimbine both increase sympathetic (adrenergic) effects, including increased blood pressure and heart rate. Use Caution/Monitor. - ziconotide
ziconotide increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- ziprasidone
ziprasidone increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
Minor (9)
- acetazolamide
acetazolamide will increase the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- anastrozole
anastrozole will increase the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- cyclophosphamide
cyclophosphamide will increase the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- desmopressin
desmopressin increases effects of benzphetamine by pharmacodynamic synergism. Minor/Significance Unknown.
- eucalyptus
eucalyptus increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Minor/Significance Unknown.
- larotrectinib
larotrectinib will increase the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- levoketoconazole
levoketoconazole will increase the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- ribociclib
ribociclib will increase the level or effect of benzphetamine by affecting hepatic/intestinal enzyme CYP3A4 metabolism. Minor/Significance Unknown.
- sage
sage increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Minor/Significance Unknown.
Adverse Effects
Frequency Not Defined
Abdominal pain
Blood pressure incr
Constipation
Diarrhea
Dizziness
Dry mouth
Headache
Insomnia
Ischemic cardiac events associated with chronic amphetamine use
Libido changes
Nausea
Palpitations
Psychotic episodes (rare)
Restlessness
Tachycardia
Tremor
Warnings
Contraindications
Advanced arteriosclerosis
Symptomatic cardiovascular disease including arrhythmias
Hyperthyroidism
Moderate to severe hypertension
Hypersensitivity to sympathomimetic amines
Glaucoma
Agitated state
History of drug abuse
Pregnancy/lactation; women planning to get pregnant
Use within 14 days of MAOIs
Do not use in combination with other anorectic agents including prescription, OTC, or herbal
Use of anorectic agents associated with increased risk of developing pulmonary hypertension (PH) (rare, but often fatal disorder); use >3 months associated with 23-fold increased risk of developing PH (benzphetamine not specifically studied)
Immediately discontinue if onset or aggravation of exertional dyspnea, or unexplained symptoms of angina pectoris, syncope, or lower extremity edema emerge suggesting possible PH
Valvular heart disease associated with use of some anorectics (no cases reported with benzphetamine monotherapy)
Not recommended for patients who used any anorectic agents within prior year
Cautions
Discontinue when tolerance develops - DO NOT EXCEED recommended dose
Diabetics: insulin requirements may be altered
Mild hypertension
May impair ability to drive &/or operate heavy machinery
Alkaline urine will increase half-life
Pregnancy & Lactation
Pregnancy
Contraindicated
Lactation
Excreted in human milk; mothers taking amphetamines should be advised to refrain from nursing
Pregnancy Categories
A: Generally acceptable. Controlled studies in pregnant women show no evidence of fetal risk.
B: May be acceptable. Either animal studies show no risk but human studies not available or animal studies showed minor risks and human studies done and showed no risk. C: Use with caution if benefits outweigh risks. Animal studies show risk and human studies not available or neither animal nor human studies done. D: Use in LIFE-THREATENING emergencies when no safer drug available. Positive evidence of human fetal risk. X: Do not use in pregnancy. Risks involved outweigh potential benefits. Safer alternatives exist. NA: Information not available.Pharmacology
Mechanism of Action
Amphetamine anorexigenic agent
Pharmacokinetics
Metabolism: by cytochrome P450 enzymes
Excretion: 5-30% unchanged in urine, highly dependent on pH
Images
| BRAND | FORM. | UNIT PRICE | PILL IMAGE |
|---|---|---|---|
| benzphetamine oral - | 50 mg tablet |  | |
| benzphetamine oral - | 50 mg tablet |  |
Copyright © 2010 First DataBank, Inc.
Formulary
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Adding plans allows you to:
- View the formulary and any restrictions for each plan.
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