Description and composition of Doxibion tablets
Doxibion tablet is a combination drug that its individual components belong to a group of drugs called antihistamines and vitamin Bs.
It contains Doxylamine Succinate and pyridoxine hydrochloride as its active ingredient. Pyridoxine hydrochloride is also known as vitamin B6.
It also contains inactive ingredients called excipients in sufficient quantities.
Therapeutic class of Doxibion tablets: Anti-emetic
Pharmacology:
The combination, doxylamine plus pyridoxine, is indicated for the treatment of pregnancy-induced nausea and vomiting in women who do not respond to diet and lifestyle modifications.
The mechanism of action is unknown. Doxylamine is a first-generation antihistamine of the ethanolamine class; it binds non-selectively to H1-receptors both centrally and peripherally.
Ethanolamines derivatives have greater anticholinergic activity than other antihistamines and are commonly associated with dry mouth, blurred vision, constipation and urinary retention; they are also more likely to cause sedation.
Vitamin B6 is composed of three forms namely pyridoxine, pyridoxal, and pyridoxamine.
Pyridoxine is converted in erythrocytes to the active moiety, pyridoxal phosphate (requiring riboflavin for the conversion), while pyridoxamine is converted into pyridoxamine phosphate.
Pyridoxine has modest antiemetic effects
How Doxibion tablets work
One of the compositions of Doxibion tablets -Doxylamine Succinate is an antihistamine drug, it therefore blocks Histamine (H1) receptor.
It can cross the blood brain barrier and has a high affinity for H1 receptors in the brain that blocks H1 receptors.
It also decreases the action of histamine at the H1 receptor by inhibiting both vestibular system & Muscarinic receptor.
It affects the vestibular system & decreases the stimulation of the vomiting center.
Its muscarinic receptor inhibition may also play a role in antihistamine antiemetic activity.
Another component of Doxibion tablets called Pyridoxine Hydrochloride is a vitamin B6 analog. It is used to prevent nausea and vomiting due to its antiemetic properties.
Uses of Doxibion tablet
This is used for the treatment of nausea and vomiting during pregnancy.
Dosage of Doxibion tablet
Based on delayed-release formulation containing Doxylamine 10 mg and Pyridoxine 10 mg
Oral: Nausea and vomiting of pregnancy, 2 tablets (a total of doxylamine 20 mg and pyridoxine 20 mg) at bedtime to control nausea and vomiting occurring in the morning. You may take 1 additional tablet in the morning and 1 tablet mid-afternoon to control symptoms throughout the day; adjust dose based on individual response, up to a maximum of 4 tablets daily
Note:
- The delayed-released tablets are taken on a daily basis for optimal effect and not on an “as needed” basis; reassess continued need for therapy as pregnancy progresses.
- To be taken on an empty stomach with a glass of water.
- Delayed-release tablets should be swallowed whole without chewing or breaking
Side Effects
The following are the side effects of Doxibion tablets:
- Drowsiness
- Dizziness
- Nervousness
- Epigastric pain
- Fatigue
- Headache
- Asthenia
- Constipation
- Dry mouth
- Anorexia
- Dry mucous membranes
- Disorientation
- Irritability
- Confusion
- Urinary retention
- Dysuria
- Insomnia
- Blurred vision
- Tachycardia
- Palpitations
- Hypersensitivity
- Pruritus
- Rash.
Precaution
Doxylamine Succinate & Pyridoxine Hydrochloride may cause somnolence due to the anticholinergic properties of Doxylamine Succinate, an antihistamine.
Women should avoid engaging in activities, such as driving or operating heavy machinery while using Doxylamine Succinate & Pyridoxine Hydrochloride.
Doxylamine Succinate & Pyridoxine Hydrochloride use is not recommended if a woman is concurrently using central nervous system (CNS) depressants including alcohol.
Doxylamine Succinate & Pyridoxine Hydrochloride has anticholinergic properties and therefore, should be used with caution in women with asthma, increased intraocular pressure, narrow angle glaucoma, stenosing peptic ulcer, pyloroduodenal obstruction or urinary bladder-neck obstruction.
Interaction
Use of Doxylamine Succinate & Pyridoxine Hydrochloride is contraindicated in women who are taking monoamine oxidase inhibitors (MAOIs), which prolong and intensify the adverse central nervous system effects (the anticholinergic effects) of antihistamines.
It is also contraindicated in women taking other drugs with anticholinergic effects such as phenothiazines, tricyclic antidepressants, some antipsychotics etc.
Concurrent use of alcohol and other CNS depressants (such as hypnotic sedatives and tranquilizers) with Doxylamine Succinate & Pyridoxine Hydrochloride is not recommended.
Pregnancy & Breastfeeding use
Doxibion tablet is a Pregnancy category A drug. This means that it’s safe in all stages (trimesters) of pregnancy.
It is intended for the treatment of nausea and vomiting during pregnancy. Both Doxylamine Succinate & Pyridoxine Hydrochloride are excreted into breast milk. Therefore, caution should be exercised while breastfeeding.
Contraindication
Doxylamine Succinate & Pyridoxine Hydrochloride is 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 therapy. MAOI therapy intensify and prolong the adverse central nervous system effects of Doxylamine Succinate & Pyridoxine Hydrochloride
Precautions
- Doxibion tablet may cause drowsiness (caution about activities that require mental alertness)
- Observe caution while using Doxibion tablet in any pregnant woman with any of these conditions.
- Asthma
- Glaucoma
- Peptic ulcer
- Epilepsy
- Other CNS depressants e.g. alcohol. Pregnancy (clinical experience limited to within 14 weeks);
- Breastfeeding
Acute Overdose
Doxylamine Succinate & Pyridoxine Hydrochloride is an extended-release or Delayed Release formulation; therefore, signs and symptoms of intoxication may not be apparent immediately. Signs and symptoms of overdose may include restlessness, dryness of mouth, dilated pupils, sleepiness, vertigo, mental confusion and tachycardia. At toxic doses, Doxylamine Succinate exhibits anticholinergic effects, including seizures, rhabdomyolysis, acute renal failure and death. If treatment is needed, it consists of gastric lavage or activated charcoal, whole bowel irrigation and symptomatic treatment.
Storage Condition
Store at below 30°C in a dry place protected from light. Keep out of reach of children.