Bepotastine besilate

Bepotastine besilate is a Second generation antihistamine, selective H1-receptor antagonist belonging to Antihistamines.

Bepotastine besilate is used in treating Allergic rhinitis and Urticaria, chronic spontaneous. It is also used to treat Angioedema, acute allergic or recurrent idiopathic; Urticaria, new onset; Urticaria, nonsteroidal anti-inflammatory drug associated (prophylaxis)

Bepotastine besilate is well absorbed orally, with a bioavailability of about 80%. The peak plasma concentration is reached within 1-2 hours after oral administration. The drug is widely distributed throughout the body, with a volume of distribution of approximately 10 L/kg. Bepotastine besilate is highly protein-bound (about 95%), primarily to albumin. Bepotastine besilate undergoes extensive metabolism in the liver, primarily by CYP3A4 and CYP2D6 enzymes. The major metabolite is desmethyl bepotastine, which is pharmacologically active. Bepotastine besilate and its metabolites are primarily excreted in the urine, with about 80% of the drug being eliminated within 24 hours after administration. The elimination half-life is approximately 6-8 hours.

The onset of action of Bepotastine besilate was Within 6 minutes

The Duration of time for Bepotastine besilate was within 16 hours.

The Tmax of Bepotastine besilate is approximately 1-2 hours after oral administration.

The average Cmax of Bepotastine besilate reported being about 26-27 ng/mL after a single 20 mg oral dose.

Bepotastine besilate shows common side effects like Drowsiness or sedation, Dry mouth , Headache, Fatigue, Dizziness, Nausea, Abdominal pain, Dysgeusia (distortion or alteration of the sense of taste)

Bepotastine besilate is available in the form of opthalmic solution

Bepotastine besilate is available in India, Germany, Canada, Italy, USA

Bepotastine besilate competes with free histamine for binding at H₁-receptors in the GI tract, uterus, large blood vessels, and bronchial smooth muscle. This blocks the action of endogenous histamine, which subsequently leads to temporary relief of the negative symptoms (eg. nasal congestion, watery eyes) brought on by histamine.

Bepotastine besilate is available in the form of ophthalmic solution.

Bepotastine besilate is used in the treatment of Allergic conjunctivitis.

Bepotastine besilate binds to the histamine H1 receptor, blocking the action of histamine and thereby reducing or preventing the symptoms of allergic reactions. Additionally, bepotastine besilate has been shown to have some anti-inflammatory effects that may also contribute to its therapeutic effects in allergic rhinitis and other allergic conditions.

Bepotastine besilate is approved for use in the following clinical indications

Allergic conjunctivitis: Treatment of itching associated with allergic conjunctivitis.

Ophthalmic

Allergic conjunctivitis

Instill one drop of Bepotastine Besilate into the affected eye(s) twice a day. Remove contact lenses prior to instillation of Bepotastine Besilate.

Bepotastine besilate is available in various strengths as 1.5 mg/mL.

Bepotastine besilate is available in the form of ophthalmic solution.

• Dosage Adjustment for Pediatric Patients

Allergic conjunctivitis: Ophthalmic: Children ≥2 years: Refer to adult dosing.

Hypersensitivity to Bepotastine besilate, loratadine, or any component of the formulation.

Special populations:

• Contact lens wearers: Contains benzalkonium chloride which may be absorbed by soft contact lenses; remove lens prior to administration and wait 10 minutes before reinserting.

Pregnancy Category C: Teratogenicity studies have been performed in animals.

• Common Adverse effects:

Drowsiness, Dry mouth, Fatigue, Headache, Nausea, Dysgeusia (distorted sense of taste) Dizziness Pharyngitis (sore throat), Nasopharyngitis (inflammation of the nose and throat), Upper respiratory tract infection

• Less Common Adverse effects:

Allergic reactions such as rash, hives, itching, swelling, and difficulty breathing , Blurred vision or other changes in vision, Eye pain or discomfort (when used as ophthalmic solution) , Conjunctival hyperemia (redness of the eye) ,Asthenia (weakness or loss of strength) ,Abdominal pain Diarrhea Vomiting

• Rare Common Adverse effects:

Anaphylaxis (a severe and potentially life-threatening allergic reaction), Stevens-Johnson syndrome (a rare and serious skin disorder characterized by painful blisters and peeling of the skin) ,Toxic epidermal necrolysis (a rare and potentially fatal skin disorder characterized by extensive skin detachment) , Angioedema (swelling of the face, lips, tongue, or throat) , Seizures ,Psychomotor hyperactivity (restlessness or agitation) , Confusion or disorientation , Hallucinations, Tremors Tachycardia (rapid heartbeat).

Central nervous system (CNS) depressants: Bepotastine besilate can enhance the sedative effects of other CNS depressants, such as alcohol, benzodiazepines, and opioids, increasing the risk of drowsiness, dizziness, and impaired coordination.

CYP3A4 inhibitors and inducers: Bepotastine besilate is metabolized by the liver enzyme CYP3A4, and drugs that inhibit or induce this enzyme may affect its metabolism, leading to potential drug interactions. Examples of CYP3A4 inhibitors include ketoconazole, clarithromycin, and grapefruit juice, while inducers include rifampin, carbamazepine, and St. John's Wort.

Anticholinergic drugs: Bepotastine besilate may enhance the anticholinergic effects of other drugs, such as tricyclic antidepressants and antimuscarinic drugs, increasing the risk of side effects such as dry mouth, constipation, and blurred vision.

The common side effects of Bepotastine besilate include the following Headache Dry mouth Fatigue Somnolence (drowsiness) Nausea Pharyngitis (sore throat) Myalgia (muscle pain) Dysmenorrhea (menstrual cramps) Insomnia (difficulty sleeping) Diarrhea.

Pharmacodynamic

Bepotastine besilate is a non-sedating, selective antagonist of the histamine 1 (H1) receptor. It belongs to the second-generation piperidine chemical class. It is a mast cell stabilizer and suppresses the migration of eosinophils into inflamed tissues. Furthermore, bepotastine does not interact with serotonin, muscarinic, benzodiazepine, and beta-adrenergic receptor that would otherwise result in adverse reactions such as dry mouth or sonmolence.

Pharmacokinetics

• Absorption:

The extent of systemic exposure to bepotastine following topical ophthalmic administration of bepotastine besilate 1% and 1.5% ophthalmic solutions was evaluated in 12 healthy adults. Following one drop of 1% or 1.5% bepotastine besilate ophthalmic solution to both eyes four time daily (QID) for seven days, bepotastine plasma concentrations peaked at approximately one to two hours post-instillation. Maximum plasma concentration for the 1% and 1.5% strengths were 5.1 ± 2.5 ng/mL and 7.3 ± 1.9 ng/mL, respectively. Plasma concentration at 24 hours post-instillation were the below quantifiable limit (2ng/mL) in 11/12 subjects in the two dose groups.

• Distribution:

The extent of protein binding of bepotastine is approximately 55% and independent of bepotastine concentration.

• Metabolism:

In vitro metabolism studies with human liver microsomes demonstrated that bepotastine is minimally metabolized by CYP450 isozymes. In vitro studies demonstrated that bepotastine besilate does not inhibit the metabolism of various cytochrome P450 substrate via inhibition of CYP3A4, CYP2C9, and CYP2C19. The effect of bepotastine besilate on the metabolism of substrates of CYP1A2, CYP2C8, CYP2D6 was not studied. Bepotastine besilate has a low potential for drug interaction via inhibition of CYP3A4, CYP2C9, and CYP2C19.

• Excretion:

The main route of elimination of bepotastine besilate is urinary excretion (with approximately 75-90% excreted unchanged in urine).

• https://www.rxlist.com/dopram-drug.htm
• https://www.mims.com/india/drug/info/Bepotastine besilate?type=full&mtype=generic
• https://go.drugbank.com/drugs/DB00561
• https://www.ncbi.nlm.nih.gov/pmc/articles/PMC7003846/