Generic Name/API: doxylamine succinate and pyridoxine hydrochloride delayed release tablets

Manufacturer: Duchesnay

Dosage Forms & Strength & Pack Size:
Tablet, 10 mg, 100’s

Store at room temperature (15-30°C).
Protect from light.
Keep out of sight and reach of children.


(doxylamine succinate and pyridoxine hydrochloride) is indicated for the management
of nausea and vomiting of pregnancy.

is contraindicated in patients who:
 are hypersensitive to doxylamine succinate, other ethanolamine derivative antihistamines,
pyridoxine hydrochloride or any nonmedicinal ingredient in the formulation;
 are at risk for asthmatic attack;
 have narrow angle glaucoma;
 have stenosing peptic ulcer;
 have pyloroduodenal obstruction;
 have bladder-neck obstruction; or
Diclectin® Product Monograph Page 4 of 25
 receive monoamine oxidase inhibitors (MAOIs) [including linezolid, an antibiotic which
is a reversible non-selective MAO inhibitor and methylthioninium chloride (methylene
Due to the anticholinergic properties of antihistamines, caution should be used when Diclectin®
is taken concurrently with other medications or alcohol.

Carcinogenesis and Mutagenesis
for animal data.
Like other antihistamines, doxylamine is prone to abuse. Knowledge of the clinical presentation
of toxicity and the management of acute overdose is critical (see OVERDOSAGE).
Special Populations
Pregnant Women:
is intended for use in pregnant women. There has been a vast clinical experience
(> 33 million pregnancies worldwide) regarding the use of a combination of doxylamine
succinate, pyridoxine hydrochloride with or without dicyclomine hydrochloride in this
population. Dicyclomine hydrochloride was a component of earlier formulations intended for
nausea and vomiting of pregnancy (NVP) that has since been removed due to a lack of evidence
of its contribution to efficacy.
has been the subject of many epidemiological studies (cohort, case control and metaanalyses) designed to detect possible teratogenicity. Two separate meta-analyses have been
conducted to assess pregnancy outcome following the use of a combination of doxylamine
succinate, pyridoxine hydrochloride with or without dicyclomine hydrochloride during the first
trimester. McKeigue et al. conducted a meta-analysis of 16 cohort and 11 case-control studies
published between 1963 and 1991. No increased risk for malformations was found in first
trimester exposures to doxylamine succinate and pyridoxine hydrochloride, with or without
dicyclomine hydrochloride. A second meta-analysis, conducted by Einarson et al. incorporated
12 cohort and 5 case-control studies. No statistically significant relationships were found
between first trimester use of the combination doxylamine succinate, pyridoxine hydrochloride
with or without dicyclomine hydrochloride and fetal abnormalities.
In 1989, a report on the safety of Bendectin/Diclectin®
for use in the management of NVP was
prepared by a panel of experts for the Special Advisory Committee on Reproductive Physiology
to the Health Protection Branch of Health Canada (currently called the Health Products and Food Branch). Bendectin is no longer available in Canada. Diclectin®
contains two active ingredients:
doxylamine succinate and pyridoxine hydrochloride. The panel report stated the following main
conclusion: “Numerous studies in animals and in humans that have been reported in the scientific
and medical literature demonstrate that Bendectin is not a teratogen. A compound that has no
teratogenic effect can be expected, solely on the basis of chance, to be associated with congenital
malformations if it is used widely by pregnant women. The types of congenital malformations
reported will vary considerably, not following a consistent pattern of birth defects. The safety of
Bendectin/Diclectin in the management of nausea and vomiting of pregnancy has been
established by its use in many thousands of pregnant women. The types and numbers of
abnormal offspring born to these women were in no way different from those that would be
expected, to occur in a similar group of women who did not take these drugs during pregnancy.”
Baseline Risk: The background baseline risk of major malformations for all pregnancies is
approximately 1-3%. This is the risk of having a child with a birth defect when no teratogenic
exposure occurs in pregnancy. This underlying risk may be increased due to maternal age,
medical or family history, or exposures to certain drugs, chemicals or levels of radiation known
to cause birth defects. Published data show that Diclectin®
use in pregnancy does not increase a
woman’s baseline risk of having a child with a major malformation. No other prescription drug
has been more extensively studied for safety in pregnancy.
Nursing Women:
The molecular weight of doxylamine succinate is low enough that passage into breast milk
should be expected. Paradoxical effects on a nursing infant can be expected, such as unusual
excitement, irritability or sedation. Caution is recommended particularly in infants with apnea or
other respiratory syndrome. Pyridoxine hydrochloride is excreted into breast milk, but in the
doses provided in Diclectin®
, presents no risk to a nursing infant. Nursing mothers treated with
should not breastfeed or the use of Diclectin®
during lactation should be avoided.
Occupational Hazards
Diclectin® may cause somnolence. Caution must be exercised in activities requiring mental
alertness such as driving a car or operating heavy machinery.

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