Dosing & Uses
Dosage Forms & Strengths
doxylamine/dextromethorphan
oral liquid
- (6.25mg/15mg)/15mL
Cough, Rhinorrhea & Sneezing
30 mL PO q6hr; not to exceed 4 doses/day
Dosage Forms & Strengths
doxylamine/dextromethorphan
oral liquid
- (6.25mg/15mg)/15mL
Cough, Rhinorrhea & Sneezing
<4 years: Do not use
4-12 years: Ask a pediatrician
>12 years: 30 mL PO q6hr; not to exceed 4 doses/day
Interactions
Interaction Checker
No Results

Contraindicated
Serious - Use Alternative
Significant - Monitor Closely
Minor

Contraindicated (0)
Serious - Use Alternative (17)
- benzhydrocodone/acetaminophen
benzhydrocodone/acetaminophen, doxylamine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
- calcium/magnesium/potassium/sodium oxybates
doxylamine, calcium/magnesium/potassium/sodium oxybates. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
- fentanyl
fentanyl, doxylamine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.
- fentanyl intranasal
fentanyl intranasal, doxylamine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.
- fentanyl transdermal
fentanyl transdermal, doxylamine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.
- fentanyl transmucosal
fentanyl transmucosal, doxylamine. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration with other CNS depressants, such as skeletal muscle relaxants, may cause respiratory depression, hypotension, profound sedation, coma, and/or death. Consider dose reduction of either or both agents to avoid serious adverse effects. Monitor for hypotension, respiratory depression, and profound sedation.
- hydrocodone
hydrocodone, doxylamine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
- isocarboxazid
isocarboxazid increases effects of doxylamine by Other (see comment). Avoid or Use Alternate Drug. Comment: Isocarboxazid should not be administered in combination with antihistamines because of potential additive CNS depressant effects. MAO inhibitors also prolong and intensify anticholinergic effects of antihistamines. .
- lemborexant
lemborexant, doxylamine. Either increases effects of the other by sedation. Avoid or Use Alternate Drug. Use of lemborexant with other drugs to treat insomnia is not recommended.
- methylene blue
methylene blue and doxylamine both increase serotonin levels. Avoid or Use Alternate Drug. If drug combination must be administered, monitor for evidence of serotonergic or opioid-related toxicities
- metoclopramide intranasal
doxylamine, metoclopramide intranasal. Either increases effects of the other by Other (see comment). Avoid or Use Alternate Drug. Comment: Avoid use of metoclopramide intranasal or interacting drug, depending on importance of drug to patient.
- olopatadine intranasal
doxylamine and olopatadine intranasal both increase sedation. Avoid or Use Alternate Drug. Coadministration increases risk of CNS depression, which can lead to additive impairment of psychomotor performance and cause daytime impairment.
- selinexor
selinexor, doxylamine. unspecified interaction mechanism. Avoid or Use Alternate Drug. Patients treated with selinexor may experience neurological toxicities. Avoid taking selinexor with other medications that may cause dizziness or confusion.
- sodium oxybate
doxylamine, sodium oxybate. Either increases effects of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
- sufentanil SL
sufentanil SL, doxylamine. Either increases toxicity of the other by pharmacodynamic synergism. Avoid or Use Alternate Drug. Coadministration may result in hypotension, profound sedation, respiratory depression, coma, and death. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
- tranylcypromine
tranylcypromine increases effects of doxylamine by Other (see comment). Avoid or Use Alternate Drug. Comment: Tranylcypromine should not be administered in combination with antihistamines because of potential additive CNS depressant effects. MAO inhibitors also prolong and intensify anticholinergic effects of antihistamines. .
- valerian
valerian and doxylamine both increase sedation. Avoid or Use Alternate Drug.
Monitor Closely (178)
- acrivastine
acrivastine and doxylamine both increase sedation. Use Caution/Monitor.
- alfentanil
doxylamine and alfentanil both increase sedation. Use Caution/Monitor.
- alprazolam
alprazolam and doxylamine both increase sedation. Use Caution/Monitor.
- amifampridine
doxylamine increases toxicity of amifampridine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Amifampridine can cause seizures. Coadministration with drugs that lower seizure threshold may increase this risk.
- amisulpride
amisulpride and doxylamine both increase sedation. Use Caution/Monitor.
- amitriptyline
doxylamine and amitriptyline both increase sedation. Use Caution/Monitor.
- amobarbital
amobarbital and doxylamine both increase sedation. Use Caution/Monitor.
- amoxapine
doxylamine and amoxapine both increase sedation. Use Caution/Monitor.
- apomorphine
doxylamine and apomorphine both increase sedation. Use Caution/Monitor.
- aripiprazole
doxylamine and aripiprazole both increase sedation. Use Caution/Monitor.
- asenapine
asenapine and doxylamine both increase sedation. Use Caution/Monitor.
- asenapine transdermal
asenapine transdermal and doxylamine both increase sedation. Use Caution/Monitor.
- avapritinib
avapritinib and doxylamine both increase sedation. Use Caution/Monitor.
- azelastine
azelastine and doxylamine both increase sedation. Use Caution/Monitor.
- baclofen
doxylamine and baclofen both increase sedation. Use Caution/Monitor.
- belladonna and opium
doxylamine and belladonna and opium both increase sedation. Use Caution/Monitor.
- benperidol
doxylamine and benperidol both increase sedation. Use Caution/Monitor.
- benzhydrocodone/acetaminophen
benzhydrocodone/acetaminophen and doxylamine both increase sedation. Use Caution/Monitor.
- benzphetamine
doxylamine increases and benzphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- brexanolone
brexanolone, doxylamine. Either increases toxicity of the other by sedation. Use Caution/Monitor.
- brexpiprazole
brexpiprazole and doxylamine both increase sedation. Use Caution/Monitor.
- brimonidine
brimonidine and doxylamine both increase sedation. Use Caution/Monitor.
- brivaracetam
brivaracetam and doxylamine both increase sedation. Use Caution/Monitor.
- brompheniramine
brompheniramine and doxylamine both increase sedation. Use Caution/Monitor.
- buprenorphine
doxylamine and buprenorphine both increase sedation. Use Caution/Monitor.
- buprenorphine buccal
doxylamine and buprenorphine buccal both increase sedation. Use Caution/Monitor.
- buprenorphine subdermal implant
buprenorphine subdermal implant and doxylamine both increase sedation. Use Caution/Monitor.
- buprenorphine transdermal
buprenorphine transdermal and doxylamine both increase sedation. Use Caution/Monitor.
- buprenorphine, long-acting injection
doxylamine increases toxicity of buprenorphine, long-acting injection by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of buprenorphine and benzodiazepines or other CNS depressants increases risk of adverse reactions including overdose, respiratory depression, and death. Cessation of benzodiazepines or other CNS depressants is preferred in most cases. In some cases, monitoring at a higher level of care for tapering CNS depressants may be appropriate. In others, gradually tapering a patient off of a prescribed benzodiazepine or other CNS depressant or decreasing to the lowest effective dose may be appropriate.
buprenorphine, long-acting injection and doxylamine both increase sedation. Use Caution/Monitor. - butabarbital
butabarbital and doxylamine both increase sedation. Use Caution/Monitor.
- butalbital
butalbital and doxylamine both increase sedation. Use Caution/Monitor.
- butorphanol
doxylamine and butorphanol both increase sedation. Use Caution/Monitor.
- carbinoxamine
carbinoxamine and doxylamine both increase sedation. Use Caution/Monitor.
- carisoprodol
doxylamine and carisoprodol both increase sedation. Use Caution/Monitor.
- cenobamate
cenobamate, doxylamine. Either increases effects of the other by sedation. Use Caution/Monitor.
- chloral hydrate
chloral hydrate and doxylamine both increase sedation. Use Caution/Monitor.
- chlordiazepoxide
chlordiazepoxide and doxylamine both increase sedation. Use Caution/Monitor.
- chlorpheniramine
chlorpheniramine and doxylamine both increase sedation. Use Caution/Monitor.
- chlorpromazine
doxylamine and chlorpromazine both increase sedation. Use Caution/Monitor.
- chlorzoxazone
doxylamine and chlorzoxazone both increase sedation. Use Caution/Monitor.
- cinnarizine
cinnarizine and doxylamine both increase sedation. Use Caution/Monitor.
- clemastine
clemastine and doxylamine both increase sedation. Use Caution/Monitor.
- clobazam
doxylamine, clobazam. Other (see comment). Use Caution/Monitor. Comment: Concomitant administration can increase the potential for CNS effects (e.g., increased sedation or respiratory depression).
- clomipramine
doxylamine and clomipramine both increase sedation. Use Caution/Monitor.
- clonazepam
clonazepam and doxylamine both increase sedation. Use Caution/Monitor.
- clonidine
clonidine, doxylamine. Either increases toxicity of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration enhances CNS depressant effects.
- clorazepate
clorazepate and doxylamine both increase sedation. Use Caution/Monitor.
- clozapine
doxylamine and clozapine both increase sedation. Use Caution/Monitor.
- codeine
doxylamine and codeine both increase sedation. Use Caution/Monitor.
- cyclizine
cyclizine and doxylamine both increase sedation. Use Caution/Monitor.
- cyclobenzaprine
doxylamine and cyclobenzaprine both increase sedation. Use Caution/Monitor.
- cyproheptadine
cyproheptadine and doxylamine both increase sedation. Use Caution/Monitor.
- dantrolene
doxylamine and dantrolene both increase sedation. Use Caution/Monitor.
- daridorexant
doxylamine and daridorexant both increase sedation. Modify Therapy/Monitor Closely. Coadministration increases risk of CNS depression, which can lead to additive impairment of psychomotor performance and cause daytime impairment.
- desipramine
doxylamine and desipramine both increase sedation. Use Caution/Monitor.
- deutetrabenazine
doxylamine and deutetrabenazine both increase sedation. Use Caution/Monitor.
- dexchlorpheniramine
dexchlorpheniramine and doxylamine both increase sedation. Use Caution/Monitor.
- dexfenfluramine
doxylamine increases and dexfenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dexmedetomidine
dexmedetomidine and doxylamine both increase sedation. Use Caution/Monitor.
- dextromoramide
doxylamine and dextromoramide both increase sedation. Use Caution/Monitor.
- diamorphine
doxylamine and diamorphine both increase sedation. Use Caution/Monitor.
- diazepam
diazepam and doxylamine both increase sedation. Use Caution/Monitor.
- diazepam intranasal
diazepam intranasal, doxylamine. Either increases effects of the other by pharmacodynamic synergism. Use Caution/Monitor. Coadministration may potentiate the CNS-depressant effects of each drug.
- difelikefalin
difelikefalin and doxylamine both increase sedation. Use Caution/Monitor.
- difenoxin hcl
doxylamine and difenoxin hcl both increase sedation. Use Caution/Monitor.
- dimenhydrinate
dimenhydrinate and doxylamine both increase sedation. Use Caution/Monitor.
- diphenhydramine
diphenhydramine and doxylamine both increase sedation. Use Caution/Monitor.
- diphenoxylate hcl
doxylamine and diphenoxylate hcl both increase sedation. Use Caution/Monitor.
- dipipanone
doxylamine and dipipanone both increase sedation. Use Caution/Monitor.
- dopexamine
doxylamine increases and dopexamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- dosulepin
doxylamine and dosulepin both increase sedation. Use Caution/Monitor.
- doxepin
doxylamine and doxepin both increase sedation. Use Caution/Monitor.
- droperidol
doxylamine and droperidol both increase sedation. Use Caution/Monitor.
- esketamine intranasal
esketamine intranasal, doxylamine. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely.
- estazolam
estazolam and doxylamine both increase sedation. Use Caution/Monitor.
- ethanol
doxylamine and ethanol both increase sedation. Use Caution/Monitor.
- etomidate
etomidate and doxylamine both increase sedation. Use Caution/Monitor.
- fenfluramine
doxylamine increases and fenfluramine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- flibanserin
doxylamine and flibanserin both increase sedation. Modify Therapy/Monitor Closely. Risk for sedation increased if flibanserin is coadministration with other CNS depressants.
- fluphenazine
doxylamine and fluphenazine both increase sedation. Use Caution/Monitor.
- flurazepam
flurazepam and doxylamine both increase sedation. Use Caution/Monitor.
- gabapentin
gabapentin, doxylamine. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of CNS depressants can result in serious, life-threatening, and fatal respiratory depression. Use lowest dose possible and monitor for respiratory depression and sedation.
- gabapentin enacarbil
gabapentin enacarbil, doxylamine. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of CNS depressants can result in serious, life-threatening, and fatal respiratory depression. Use lowest dose possible and monitor for respiratory depression and sedation.
- ganaxolone
doxylamine and ganaxolone both increase sedation. Use Caution/Monitor.
- gotu kola
gotu kola increases effects of doxylamine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- haloperidol
doxylamine and haloperidol both increase sedation. Use Caution/Monitor.
- hawthorn
hawthorn increases effects of doxylamine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- hops
hops increases effects of doxylamine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- hyaluronidase
doxylamine decreases effects of hyaluronidase by Other (see comment). Use Caution/Monitor. Comment: Antihistamines, when given in large systemic doses, may render tissues partially resistant to the action of hyaluronidase. Patients may require larger amounts of hyaluronidase for equivalent dispersing effect. .
- hydromorphone
doxylamine and hydromorphone both increase sedation. Use Caution/Monitor.
- hydroxyzine
hydroxyzine and doxylamine both increase sedation. Use Caution/Monitor.
- iloperidone
doxylamine and iloperidone both increase sedation. Use Caution/Monitor.
- imipramine
doxylamine and imipramine both increase sedation. Use Caution/Monitor.
- kava
kava increases effects of doxylamine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- ketamine
ketamine and doxylamine both increase sedation. Use Caution/Monitor.
- ketotifen, ophthalmic
doxylamine and ketotifen, ophthalmic both increase sedation. Use Caution/Monitor.
- lasmiditan
lasmiditan, doxylamine. Either increases effects of the other by sedation. Use Caution/Monitor. Coadministration of lasmiditan and other CNS depressant drugs, including alcohol have not been evaluated in clinical studies. Lasmiditan may cause sedation, as well as other cognitive and/or neuropsychiatric adverse reactions.
- levorphanol
doxylamine and levorphanol both increase sedation. Use Caution/Monitor.
- lofepramine
doxylamine and lofepramine both increase sedation. Use Caution/Monitor.
- lofexidine
doxylamine and lofexidine both increase sedation. Use Caution/Monitor.
- loprazolam
loprazolam and doxylamine both increase sedation. Use Caution/Monitor.
- lorazepam
lorazepam and doxylamine both increase sedation. Use Caution/Monitor.
- lormetazepam
lormetazepam and doxylamine both increase sedation. Use Caution/Monitor.
- loxapine
doxylamine and loxapine both increase sedation. Use Caution/Monitor.
- loxapine inhaled
doxylamine and loxapine inhaled both increase sedation. Use Caution/Monitor.
- lurasidone
lurasidone, doxylamine. Either increases toxicity of the other by Other (see comment). Use Caution/Monitor. Comment: Potential for increased CNS depressant effects when used concurrently; monitor for increased adverse effects and toxicity.
- maprotiline
doxylamine and maprotiline both increase sedation. Use Caution/Monitor.
- marijuana
doxylamine and marijuana both increase sedation. Use Caution/Monitor.
- melatonin
doxylamine and melatonin both increase sedation. Use Caution/Monitor.
- meperidine
doxylamine and meperidine both increase sedation. Use Caution/Monitor.
- meprobamate
doxylamine and meprobamate both increase sedation. Use Caution/Monitor.
- metaxalone
doxylamine and metaxalone both increase sedation. Use Caution/Monitor.
- methadone
doxylamine and methadone both increase sedation. Use Caution/Monitor.
- methocarbamol
doxylamine and methocarbamol both increase sedation. Use Caution/Monitor.
- methylenedioxymethamphetamine
doxylamine increases and methylenedioxymethamphetamine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- midazolam
midazolam and doxylamine both increase sedation. Use Caution/Monitor.
- midazolam intranasal
midazolam intranasal, doxylamine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Concomitant use of barbiturates, alcohol, or other CNS depressants may increase risk of hypoventilation, airway obstruction, desaturation, or apnea and may contribute to profound and/or prolonged drug effect.
- mirtazapine
doxylamine and mirtazapine both increase sedation. Use Caution/Monitor.
- morphine
doxylamine and morphine both increase sedation. Use Caution/Monitor.
- motherwort
doxylamine and motherwort both increase sedation. Use Caution/Monitor.
- moxonidine
doxylamine and moxonidine both increase sedation. Use Caution/Monitor.
- nabilone
doxylamine and nabilone both increase sedation. Use Caution/Monitor.
- nalbuphine
doxylamine and nalbuphine both increase sedation. Use Caution/Monitor.
- nortriptyline
doxylamine and nortriptyline both increase sedation. Use Caution/Monitor.
- olanzapine
doxylamine and olanzapine both increase sedation. Use Caution/Monitor.
- oliceridine
oliceridine, doxylamine. Either increases toxicity of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Profound sedation, respiratory depression, coma, and death may result if coadministered. Reserve concomitant prescribing of these drugs in patients for whom other treatment options are inadequate. Limit dosages and durations to the minimum required. Monitor closely for signs of respiratory depression and sedation.
- opium tincture
doxylamine and opium tincture both increase sedation. Use Caution/Monitor.
- orphenadrine
doxylamine and orphenadrine both increase sedation. Use Caution/Monitor.
- oxazepam
oxazepam and doxylamine both increase sedation. Use Caution/Monitor.
- oxycodone
doxylamine and oxycodone both increase sedation. Use Caution/Monitor.
- oxymorphone
doxylamine and oxymorphone both increase sedation. Use Caution/Monitor.
- paliperidone
doxylamine and paliperidone both increase sedation. Use Caution/Monitor.
- papaveretum
doxylamine and papaveretum both increase sedation. Use Caution/Monitor.
- papaverine
doxylamine and papaverine both increase sedation. Use Caution/Monitor.
- passion flower
passion flower increases effects of doxylamine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- pentazocine
doxylamine and pentazocine both increase sedation. Use Caution/Monitor.
- pentobarbital
pentobarbital and doxylamine both increase sedation. Use Caution/Monitor.
- perphenazine
doxylamine and perphenazine both increase sedation. Use Caution/Monitor.
- phenelzine
phenelzine increases effects of doxylamine by Other (see comment). Modify Therapy/Monitor Closely. Comment: Coadministration of phenelzine and antihistamines may result in additive CNS depressant effects. MAO inhibitors also prolong and intensify anticholinergic effects of antihistamines. .
- phenobarbital
phenobarbital and doxylamine both increase sedation. Use Caution/Monitor.
- phenylephrine PO
doxylamine increases and phenylephrine PO decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor. .
- pholcodine
doxylamine and pholcodine both increase sedation. Use Caution/Monitor.
- pimozide
doxylamine and pimozide both increase sedation. Use Caution/Monitor.
- pregabalin
pregabalin, doxylamine. Either increases effects of the other by pharmacodynamic synergism. Modify Therapy/Monitor Closely. Coadministration of CNS depressants can result in serious, life-threatening, and fatal respiratory depression. Use lowest dose possible and monitor for respiratory depression and sedation.
- primidone
primidone and doxylamine both increase sedation. Use Caution/Monitor.
- prochlorperazine
doxylamine and prochlorperazine both increase sedation. Use Caution/Monitor.
- promethazine
promethazine and doxylamine both increase sedation. Use Caution/Monitor.
- propofol
propofol and doxylamine both increase sedation. Use Caution/Monitor.
- propylhexedrine
doxylamine increases and propylhexedrine decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- protriptyline
doxylamine and protriptyline both increase sedation. Use Caution/Monitor.
- quazepam
quazepam and doxylamine both increase sedation. Use Caution/Monitor.
- quetiapine
doxylamine and quetiapine both increase sedation. Use Caution/Monitor.
- ramelteon
doxylamine and ramelteon both increase sedation. Use Caution/Monitor.
- remimazolam
remimazolam, doxylamine. Either increases toxicity of the other by sedation. Modify Therapy/Monitor Closely. Coadministration may result in profound sedation, respiratory depression, coma, and/or death. Continuously monitor vital signs during sedation and recovery period if coadministered. Carefully titrate remimazolam dose if administered with opioid analgesics and/or sedative/hypnotics.
- risperidone
doxylamine and risperidone both increase sedation. Use Caution/Monitor.
- scullcap
doxylamine and scullcap both increase sedation. Use Caution/Monitor.
- secobarbital
secobarbital and doxylamine both increase sedation. Use Caution/Monitor.
- sevoflurane
sevoflurane and doxylamine both increase sedation. Use Caution/Monitor.
- shepherd's purse
doxylamine and shepherd's purse both increase sedation. Use Caution/Monitor.
- stiripentol
stiripentol, doxylamine. Either increases effects of the other by sedation. Use Caution/Monitor. Concomitant use stiripentol with other CNS depressants, including alcohol, may increase the risk of sedation and somnolence.
- sufentanil
doxylamine and sufentanil both increase sedation. Use Caution/Monitor.
- tapentadol
doxylamine and tapentadol both increase sedation. Use Caution/Monitor.
- temazepam
temazepam and doxylamine both increase sedation. Use Caution/Monitor.
- thioridazine
doxylamine and thioridazine both increase sedation. Use Caution/Monitor.
- thiothixene
doxylamine and thiothixene both increase sedation. Use Caution/Monitor.
- topiramate
doxylamine and topiramate both increase sedation. Modify Therapy/Monitor Closely.
- tramadol
doxylamine and tramadol both increase sedation. Use Caution/Monitor.
- trazodone
doxylamine and trazodone both increase sedation. Use Caution/Monitor.
- triazolam
triazolam and doxylamine both increase sedation. Use Caution/Monitor.
- triclofos
doxylamine and triclofos both increase sedation. Use Caution/Monitor.
- trifluoperazine
doxylamine and trifluoperazine both increase sedation. Use Caution/Monitor.
- trimipramine
doxylamine and trimipramine both increase sedation. Use Caution/Monitor.
- triprolidine
triprolidine and doxylamine both increase sedation. Use Caution/Monitor.
- valerian
valerian increases effects of doxylamine by pharmacodynamic synergism. Use Caution/Monitor. May enhance CNS depression.
- xylometazoline
doxylamine increases and xylometazoline decreases sedation. Effect of interaction is not clear, use caution. Use Caution/Monitor.
- ziconotide
doxylamine and ziconotide both increase sedation. Use Caution/Monitor.
- ziprasidone
doxylamine and ziprasidone both increase sedation. Use Caution/Monitor.
- zotepine
doxylamine and zotepine both increase sedation. Use Caution/Monitor.
Minor (6)
- ashwagandha
ashwagandha increases effects of doxylamine by pharmacodynamic synergism. Minor/Significance Unknown. May enhance CNS depression.
- brimonidine
brimonidine increases effects of doxylamine by pharmacodynamic synergism. Minor/Significance Unknown. Increased CNS depression.
- eucalyptus
doxylamine and eucalyptus both increase sedation. Minor/Significance Unknown.
- nettle
nettle increases effects of doxylamine by pharmacodynamic synergism. Minor/Significance Unknown. (High dose nettle; theoretical interaction) May enhance CNS depression.
- sage
doxylamine and sage both increase sedation. Minor/Significance Unknown.
- Siberian ginseng
Siberian ginseng increases effects of doxylamine by pharmacodynamic synergism. Minor/Significance Unknown. May enhance CNS depression.
Adverse Effects
Common Adverse Effects
Agranulocytosis
Potential for abuse
Leukopenia
Serotonin syndrome
Dizziness
Drowsiness
Thrombocytopenia
Toxic psychosis
GI disturbances
Dry mouth, throat, and nose
Thickening of mucus in nose or throat
Constipation
Blurred vision
Headache
Urinary retention
Warnings
Contraindications
Hypersensitivity
Asthma attacks
Use of MAO inhibitors within 14 days
< 2 years of age
Narrow-angle glaucoma
Breastfeeding
Symptomatic prostate hypertrophy
Bladder-neck obstruction
Stenosing peptic ulcer
Cautions
Caution in patients < 6 years of age
Doxylamine: Caution in used concomitantly with another CNS deppressatn; may exacerbate angle closure glaucoma, hyperthyroidism, peptic ulcer, or urinary tract obstruction; xerostomia may occur; caution in COPD, cardiovascular disease, asthma, increased intraocular pressure, elderly patients or GI obstruction
Dextromethorphan: Do not take for persistent or chronic cough associated with smoking, asthma, or emphysema, or if it is accompanied by excessive phlegm unless directed by a healthcare provider; may decrease respiration rate
Pregnancy & Lactation
Pregnancy category: C
Lactation: excreted in breast milk, use caution
Pregnant or breastfeeding patients should seek advice of health professional before using OTC drugs
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
Doxylamine: Competitively blocks histamine from binding to H1 receptors; significant antimuscarinic activity & penetrates CNS, which causes pronounced tendency to induce sedation
Dextromethorphan: Cough suppressant that acts centrally on the cough center in medulla