DOXYLAMINE SUCCINATE AND PYRIDOXINE HYDROCHLORIDE

Doxylamine succinate and pyridoxine hydrochloride delayed-release tablets are round, white, film‑coated, delayed-release tablets containing 10 mg of doxylamine succinate, USP and 10 mg of pyridoxine hydrochloride, USP. Tablets are imprinted on one side with “ DP 1 ” in black ink and plain on other side. Inactive ingredients are as follows: ammonium hydroxide, black iron oxide, dibasic calcium phosphate dihydrate, hypromellose, magnesium stearate, mannitol, methacrylic acid copolymer, propylene glycol, shellac glaze, silica, sodium bicarbonate, sodium lauryl sulfate, talc, titanium dioxide, and triethyl citrate. Doxylamine Succinate, USP Doxylamine succinate is classified as an antihistamine. The chemical name for doxylamine succinate is ethanamine, N,N-dimethyl-2-[1-phenyl-1-(2-pyridinyl)ethoxy]-, butanedioate (1:1). The molecular formula is C 17 H 22 N 2 O • C 4 H 6 O 4 and the molecular weight is 388.46 g/mol. The structural formula is: Doxylamine succinate, USP is a white or creamy white powder that is very soluble in water and alcohol, freely soluble in chloroform, and very slightly soluble in ether. Pyridoxine Hydrochloride, USP Pyridoxine hydrochloride, USP is a vitamin B 6 analog. The chemical name for pyridoxine hydrochloride is 3,4-pyridinedimethanol, 5-hydroxy-6-methyl-, hydrochloride. The molecular formula is C 8 H 11 NO 3 • HCl and the molecular weight is 205.6 g/mol. The structural formula is: Pyridoxine hydrochloride, USP is a white or practically white crystalline powder that is freely soluble in water, slightly soluble in alcohol, soluble in chloroform, and insoluble in ether. structure-1 structure-2

Doxylamine succinate and pyridoxine hydrochloride delayed-release tablets are indicated for the treatment of nausea and vomiting of pregnancy in women who do not respond to conservative management. Limitations of Use Doxylamine succinate and pyridoxine hydrochloride delayed-release tablets havenot been studied in women with hyperemesis gravidarum. Doxylamine succinate and pyridoxine hydrochloride delayed-release tablets are a fixed dose combination drug product of doxylamine succinate, an antihistamine, and pyridoxine hydrochloride, a Vitamin B 6 analog, indicated for the treatment of nausea and vomiting of pregnancy in women who do not respond to conservative management. ( 1 )

Take two tablets daily at bedtime. If symptoms are not adequately controlled, the dose can be increased to a maximum recommended dose of four tablets daily (one in the morning, one mid-afternoon and two at bedtime) as described in the full prescribing information. ( 2 ) 2.1 Dosage Information Initially, take two doxylamine succinate and pyridoxine hydrochloride delayed-release tablets orally at bedtime (Day 1). If this dose adequately controls symptoms the next day, continue taking two tablets daily at bedtime. However, if symptoms persist into the afternoon of Day 2, take the usual dose of two tablets at bedtime that night then take three tablets starting on Day 3 (one tablet in the morning and two tablets at bedtime). If these three tablets adequately control symptoms on Day 4, continue taking three tablets daily. Otherwise take four tablets starting on Day 4 (one tablet in the morning, one tablet mid-afternoon and two tablets at bedtime). The maximum recommended dose is four tablets (one in the morning, one in the mid-afternoon and two at bedtime) daily. Take on an empty stomach with a glass of water [see Clinical Pharmacology (12.3) ]. Swallow tablets whole. Do not crush, chew, or split doxylamine succinate and pyridoxine hydrochloride delayed-release tablets. Take as a daily prescription and not on an as needed basis. Reassess the woman for continued need for doxylamine succinate and pyridoxine hydrochloride delayed-release tablets as her pregnancy progresses.

Doxylamine succinate and pyridoxine hydrochloride delayed-release tablets are contraindicated in women with any of the following conditions: Known hypersensitivity to doxylamine succinate, other ethanolamine derivative antihistamines, pyridoxine hydrochloride or any inactive ingredient in the formulation. Monoamine oxidase (MAO) inhibitors intensify and prolong the adverse central nervous system effects of doxylamine succinate and pyridoxine hydrochloride [see Drug Interactions (7.1) ] . Known hypersensitivity to doxylamine succinate, other ethanolamine derivative antihistamines, pyridoxine hydrochloride or any inactive ingredient in the formulation. ( 4 ) Monoamine oxidase (MAO) inhibitors. ( 4 , 7 )

The following adverse reactions are discussed elsewhere in the labeling: Somnolence [see Warnings and Precautions (5.1) ] Falls or other accidents resulting from the effect of the combined use of doxylamine succinate and pyridoxine hydrochloride with CNS depressants including alcohol [see Warnings and Precautions (5.1) ] The most common adverse reaction with doxylamine succinate and pyridoxine hydrochloride (≥ 5 percent and exceeding the rate in placebo) is somnolence. ( 6 ) To report SUSPECTED ADVERSE REACTIONS, contact Bionpharma Inc. at 1-888-235-BION or 1-888-235-2466 or FDA at 1-800-FDA-1088 or www.fda.gov/medwatch . 6.1 Clinical Trial Experience Because clinical trials are conducted under widely varying conditions, adverse reaction rates observed in the clinical trials of a drug cannot be directly compared to rates in the clinical trials of another drug and may not reflect the rates observed in clinical practice. The safety and efficacy of doxylamine succinate and pyridoxine hydrochloride were compared to placebo in a double-blind, randomized, multi-center trial in 261 women with nausea and vomiting of pregnancy. The mean gestational age at enrollment was 9.3 weeks, range 7 weeks to 14 weeks gestation [see Clinical Studies (14) ] . Adverse reactions for doxylamine succinate and pyridoxine hydrochloride that occurred at an incidence ≥ 5 percent and exceeded the incidence for placebo are summarized in Table 1. Table 1: Number (Percent) of Subjects with ≥ 5 Percent Adverse Reactions in a 15‑Day Placebo-Controlled Study of Doxylamine Succinate and Pyridoxine Hydrochloride (Only Those Adverse Reactions Occurring at an Incidence ≥ 5 Percent and at a Higher Incidence with Doxylamine Succinate and Pyridoxine Hydrochloride than Placebo are Shown) Doxylamine Succinate and Pyridoxine Hydrochloride (N = 133) Placebo (n = 128) Somnolence 19 (14.3%) 15 (11.7%) 6.2 Postmarketing Experience The following adverse events, listed alphabetically, have been identified during post-approval use of the combination of 10 mg doxylamine succinate and 10 mg pyridoxine hydrochloride. Because these reactions are reported voluntarily from a population of uncertain size, it is not always possible to reliably estimate their frequency or establish a causal relationship to drug exposure . Cardiac disorders : dyspnea, palpitation, tachycardia Ear and labyrinth disorders : vertigo Eye disorders : vision blurred, visual disturbances Gastrointestinal disorders : abdominal distension, abdominal pain, constipation, diarrhea General disorders and administration site conditions : chest discomfort, fatigue, irritability, malaise Immune system disorders : hypersensitivity Nervous system disorders : dizziness, headache, migraines, paresthesia, psychomotor hyperactivity Psychiatric disorders : anxiety, disorientation, insomnia, nightmares Renal and urinary disorders : dysuria, urinary retention Skin and subcutaneous tissue disorders : hyperhidrosis, pruritus, rash, rash maculo-papular

Severe drowsiness can occur when used in combination with alcohol or other sedating medications. ( 7 ) 7.1 Drug Interactions Use of doxylamine succinate and pyridoxine hydrochloride is contraindicated in women who are taking monoamine oxidase inhibitors (MAOIs), which prolong and intensify the anticholinergic (drying) effects of antihistamines. Concurrent use of alcohol and other CNS depressants (such as hypnotic sedatives and tranquilizers) with doxylamine succinate and pyridoxine hydrochloride is not recommended. 7.2 Drug-Food Interactions A food-effect study demonstrated that the delay in the onset of action of doxylamine succinate and pyridoxine hydrochloride may be further delayed, and a reduction in absorption may occur when tablets are taken with food [see Dosage and Administration (2) , Clinical Pharmacology (12.3) ] . Therefore, doxylamine succinate and pyridoxine hydrochloride should be taken on an empty stomach with a glass of water [ see Dosage and Administration (2) ]. 7.3 False Positive Urine Tests for Methadone, Opiates and PCP False positive drug screens for methadone, opiates, and PCP can occur with doxylamine succinate/pyridoxine hydrochloride use. Confirmatory tests, such as Gas Chromatography Mass Spectrometry (GC-MS), should be used to confirm the identity of the substance in the event of a positive immunoassay result. 7.1 Drug Interactions Use of doxylamine succinate and pyridoxine hydrochloride is contraindicated in women who are taking monoamine oxidase inhibitors (MAOIs), which prolong and intensify the anticholinergic (drying) effects of antihistamines. Concurrent use of alcohol and other CNS depressants (such as hypnotic sedatives and tranquilizers) with doxylamine succinate and pyridoxine hydrochloride is not recommended.