Doxylamine Succinate

Class: First Generation Antihistamines
ATC Class: R06AA09
VA Class: AH102
CAS Number: 562-10-7
Brands: Aldex AN, Nighttime Sleep Aid, Unisom

Introduction

First generation antihistamine; an ethanolamine derivative.^{103 a b}

Uses for Doxylamine Succinate

Insomnia

Self-medication for short-term management of insomnia,^a particularly in individuals who have difficulty falling asleep.¹⁰²

Safety and efficacy not fully established; however, FDA states that, pending further accumulation of data, doxylamine-containing nighttime sleep aids that have been approved for this use may continue to be marketed in the US.

Allergic Rhinitis

Temporary relief of rhinorrhea, sneezing, lacrimation, itching eyes, or oronasopharyngeal itching associated with allergic rhinitis (e.g., hay fever) or other upper respiratory allergies.¹⁰¹

Doxylamine Succinate Dosage and Administration

Administration

Oral Administration

Administer orally as tablets or oral suspension.^{101 102 a}

Dosage

Available as doxylamine succinate; dosage expressed in terms of the salt.^{101 102}

Individualize dosage according to patient’s response and tolerance.^b

Pediatric Patients

Insomnia

Oral

Self-medication in children ≥12 years of age: 25 mg 30 minutes before retiring or as directed by a clinician.¹⁰²

Allergic Rhinitis

Children 2 to <6 years of age: 1.9–3.125 mg every 4–6 hours, not to exceed 18.75 mg in 24 hours.

Children 6 to <12 years of age: For self-medication, 3.75–6.25 mg every 4–6 hours, not to exceed 37.5 mg in 24 hours. Alternatively, under the direction of a clinician, up to 12.5 mg every 4–6 hours, or 2 mg/kg or 60 mg/m² daily in divided doses, not to exceed 75 mg daily.

Children ≥12 years of age: For self-medication, 7.5–12.5 mg every 4–6 hours, not to exceed 75 mg in 24 hours. Alternatively, under the direction of a clinician, up to 25 mg every 4–6 hours, or 2 mg/kg or 60 mg/m² daily in divided doses, not to exceed 150 mg daily.

Adults

Insomnia

Oral

Self-medication: 25 mg 30 minutes before retiring or as directed by a clinician.¹⁰²

Allergic Rhinitis

Oral

Self-medication: 7.5–12.5 mg every 4–6 hours, not to exceed 75 mg in 24 hours. Alternatively, under the direction of a clinician, up to 25 mg every 4–6 hours, or 2 mg/kg or 60 mg/m² daily in divided doses, not to exceed 150 mg daily.

Prescribing Limits

Pediatric Patients

Insomnia

Oral

Self-medication in children ≥12 years of age: Maximum 2 weeks.¹⁰²

Allergic Rhinitis

Oral

Children 2 to <6 years of age: Maximum 18.75 mg in 24 hours.

Children 6 to <12 years of age: For self-medication, maximum 37.5 mg in 24 hours. Under the direction of a clinician, maximum 75 mg daily.

Children ≥12 years of age: For self-medication, maximum 75 mg in 24 hours. Under the direction of a clinician, maximum 150 mg daily.

Adults

Insomnia

Oral

Self-medication: Maximum 2 weeks.¹⁰²

Allergic Rhinitis

Oral

For self-medication, maximum 75 mg in 24 hours. Under the direction of a clinician, maximum 150 mg daily.

Cautions for Doxylamine Succinate

Warnings/Precautions

Warnings

Concomitant Diseases

Because of possible anticholinergic effects (e.g., dryness of mouth, nose, and throat; dysuria; urinary retention),^b patients with glaucoma, respiratory conditions (e.g., emphysema, chronic bronchitis), or difficulty urinating due to prostatic hypertrophy should consult a clinician before initiating therapy with doxylamine.^{101 102}

Use with caution, if at all, in patients with angle-closure glaucoma, prostatic hypertrophy, stenosing peptic ulcer, pyloroduodenal obstruction, or bladder neck obstruction.^b

Use not recommended, unless under the direction of a clinician, in patients who have a breathing problem (e.g., emphysema, chronic bronchitis). Use generally not recommended in asthmatics who previously experienced a serious antihistamine-induced adverse bronchopulmonary effect.

CNS Effects

Risk of marked drowsiness.¹⁰¹ Caution when driving a motor vehicle or operating machinery.¹⁰¹ (See CNS Depressants under Interactions and also see Advice to Patients.)

Possible excitability (especially in children).^{101 b} (See Pediatric Use under Cautions.)

Sensitivity Reactions

Tartrazine Sensitivity

Some commercially available preparations (e.g., Aldex AN oral suspension) may contain the dye tartrazine (FD&C yellow No. 5); possible allergic reactions in susceptible individuals (e.g., those sensitive to aspirin).¹⁰¹

General Precautions

Duration of Therapy

When used for insomnia, discontinue therapy and consult a clinician if insomnia persists for >2 weeks.¹⁰²

Specific Populations

Pregnancy

Category A.¹⁰³

Women considering self-medication with doxylamine during pregnancy should consult a health professional for advice regarding the relative risks and benefits of such therapy.¹⁰¹

Lactation

Expected to be distributed into milk.¹⁰³ Discontinue nursing or the drug.

Pediatric Use

Use not recommended in premature or full-term neonates.

Possible paradoxical excitement (e.g., restlessness, insomnia, tremors, euphoria, nervousness, delirium, palpitation, seizures).^{101 b}

Safety and efficacy of doxylamine as a nighttime sleep aid in children <12 years of age not established.¹⁰² Consider risk of possible CNS stimulation when used as nighttime sleep aids.

Use as an antihistamine only under the direction of a clinician in children 2 to <6 years of age; use in children <2 years of age not recommended.

Risk of overdosage and toxicity (including death) in children <2 years of age receiving OTC preparations containing antihistamines, cough suppressants, expectorants, and nasal decongestants alone or in combination for relief of symptoms of upper respiratory tract infection. Limited evidence of efficacy for these preparations in this age group; appropriate dosages not established. Therefore, FDA recommended not to use such preparations in children <2 years of age; safety and efficacy in older children currently under evaluation. Because children 2–3 years of age also are at increased risk of overdosage and toxicity, some manufacturers of oral nonprescription cough and cold preparations recently agreed to voluntarily revise the product labeling to state that such preparations should not be used in children <4 years of age. During the transition period, some preparations on pharmacy shelves will have the new recommendation (“do not use in children <4 years of age”), while others will have the previous recommendation (“do not use in children <2 years of age”). FDA recommends that parents and caregivers adhere to dosage instructions and warnings on the product labeling that accompanies the preparation and consult a clinician about any concerns. Clinicians should ask caregivers about use of OTC cough/cold preparations to avoid overdosage.

Geriatric Use

Possible increased risk of dizziness, sedation, and hypotension.^b

Common Adverse Effects

Drowsiness.¹⁰¹

Interactions for Doxylamine Succinate

Specific Drugs and Laboratory Tests

Drug or Laboratory Test	Interaction	Comments
CNS depressants (e.g., alcohol, hypnotics, sedatives, tranquilizers)	Possible additive CNS depression101 b	Avoid alcohol101 102 104
MAO inhibitors	MAO inhibitors prolong and intensify anticholinergic effects of antihistaminesb
Test, antigen or histamine	Inhalation-challenge testing with histamine or antigen: Possible suppression of test response Antigen skin testing: Possible suppression of wheal and flare reactions

Doxylamine Succinate Pharmacokinetics

Absorption

Bioavailability

Peak plasma concentrations occur within 2–3 hours after oral administration.

Onset

Sedative effects occur approximately 30 minutes after oral administration.¹⁰⁴

Elimination

Half-life

Approximately 10 hours.

Stability

Storage

Oral

Tablets

Well-closed, light-resistant containers at <40°C, preferably at 15–30°C.^{102 a}

Suspension

20–25°C.¹⁰¹

ActionsActions

• 
  

  Blocks H₁-receptor sites and prevents the action of histamine on the cell.^b

  
  


• 
  

  Suppresses flare and pruritus that accompany the endogenous release of histamine.^b

  
  


• 
  

  Exhibits some activities common to anticholinergics, ganglionic and adrenergic blocking agents, local anesthetics, and antispasmodics.^b

  
  


• 
  

  Antihistamines do not block the stimulating effect of histamine on gastric acid secretion, which is mediated by the H₂-receptors of the parietal cells.^b

  
  

Advice to Patients

• 
  

  Risk of marked drowsiness; avoid alcohol and use caution when driving or operating machinery.^{101 102 104}

  
  


• 
  

  When used for insomnia, consult a clinician if sleeplessness persists continuously for >2 weeks.¹⁰²

  
  


• 
  

  Importance of informing clinicians of existing or contemplated concomitant therapy, including prescription and OTC drugs, as well as any concomitant illnesses.^{101 102} Importance of patients already receiving another CNS depressant (e.g., sedatives, tranquilizers) not undertaking self-medication without first consulting a clinician.^{101 102}

  
  


• 
  

  Importance of women informing clinicians if they are or plan to become pregnant or plan to breast-feed;^{101 102} women considering self-medication with doxylamine during pregnancy should consult a clinician regarding the relative risks and benefits of such therapy.^{102 104}

  
  


• 
  

  Importance of informing patients of other important precautionary information.^{101 102} (See Cautions.)

  
  

Preparations

Excipients in commercially available drug preparations may have clinically important effects in some individuals; consult specific product labeling for details.

* available from one or more manufacturer, distributor, and/or repackager by generic (nonproprietary) name

Doxylamine Succinate

Routes	Dosage Forms	Strengths	Brand Names	Manufacturer
Oral	Suspension	5 mg/5 mL*	Aldex AN	Zyber
			Doxylamine Succinate Suspension
	Tablets	25 mg*	Doxylamine Succinate Tablets
			Nighttime Sleep Aid	Perrigo, Teva
			Unisom SleepTabs (scored)	Chattem

Doxylamine succinate is also commercially available in combination with antitussives and decongestants.

Disclaimer

This report on medications is for your information only, and is not considered individual patient advice. Because of the changing nature of drug information, please consult your physician or pharmacist about specific clinical use.

The American Society of Health-System Pharmacists, Inc. and Drugs.com represent that the information provided hereunder was formulated with a reasonable standard of care, and in conformity with professional standards in the field. The American Society of Health-System Pharmacists, Inc. and Drugs.com make no representations or warranties, express or implied, including, but not limited to, any implied warranty of merchantability and/or fitness for a particular purpose, with respect to such information and specifically disclaims all such warranties. Users are advised that decisions regarding drug therapy are complex medical decisions requiring the independent, informed decision of an appropriate health care professional, and the information is provided for informational purposes only. The entire monograph for a drug should be reviewed for a thorough understanding of the drug's actions, uses and side effects. The American Society of Health-System Pharmacists, Inc. and Drugs.com do not endorse or recommend the use of any drug. The information is not a substitute for medical care.

AHFS Drug Information. © Copyright, 1959-2011, Selected Revisions November 2008. American Society of Health-System Pharmacists, Inc., 7272 Wisconsin Avenue, Bethesda, Maryland 20814.

References

101. Zyber Pharmaceuticals, Inc. Aldex AN (doxylamine succinate) oral suspension prescribing information. Gonzales, LA; undated.

102. Chattem. Unisom SleepTabs (doxylamine succinate) tablets product information. Chattanooga, TN. From Chattem website. Accessed 2008 Jan 22.

103. Doxylamine. In: Briggs GG, Freeman RK, Yaffe SJ. Drugs in pregnancy and lactation. 7th ed. Philadelphia, PA: Lippincott Williams & Wilkins; 2005:519-24.

104. Chattem. Unisom SleepTabs (doxylamine succinate) frequently asked questions. Chattanooga, TN. From Chattem website. Accessed 2008 Jan 22.

a. AHFS Drug Information 2008. McEvoy GK, ed. Doxylamine Succinate. Bethesda, MD: American Society of Health-System Pharmacists; 2008:20-1.

b. AHFS Drug Information 2008. McEvoy GK, ed. Antihistamines General Statement. Bethesda, MD: American Society of Health-System Pharmacists; 2008:1-8.

More Doxylamine Succinate resources

• Doxylamine Succinate Side Effects (in more detail)
• Doxylamine Succinate Use in Pregnancy & Breastfeeding
• Drug Images
• Doxylamine Succinate Drug Interactions
• Doxylamine Succinate Support Group
• 8 Reviews for Doxylamine Succinate - Add your own review/rating

• Doxylamine MedFacts Consumer Leaflet (Wolters Kluwer)


• Aldex AN Concise Consumer Information (Cerner Multum)


• Aldex AN Suspension MedFacts Consumer Leaflet (Wolters Kluwer)

Compare Doxylamine Succinate with other medications

• Allergies
• Conjunctivitis, Allergic
• Hay Fever
• Insomnia
• Nasal Congestion
• Rhinorrhea
• Upper Respiratory Tract Infection