Tag: h1-receptor

Posted on by

Loratadine – Anti Histamine – H1 Receptor

Introduction

Loratadine is an antiallergic drug, that is sold under the brand names Lorin NSA,  Xylor, Antial and others. Loratadine is an antihistamine that works by reducing the effects of the body’s natural chemical histamine. Sneezing, itching, watery eyes, and a runny nose are all symptoms of histamine. Sneezing, runny nose, watery eyes, hives, skin rash, itching, and other cold or allergy symptoms are treated with loratadine.

Class of Medicine
Loratadine belongs to the antihistamine class of drugs. Loratadine inhibits the activation of cells with H1 receptors by blocking one type of histamine receptor (the H1 receptor). It works by preventing histamine, a chemical in the body that produces allergy symptoms, from acting.

Mode of Action
In allergic rhinitis and urticaria, histamine release is a major mediator. As a result, loratadine works via binding to the H1 histamine receptors.

H1 histamine receptors can be found on the surface of epithelial cells, endothelial cells, eosinophils, neutrophils, airway cells, and vascular smooth muscle cells, among other things. H1 histamine receptors are part of the G-protein coupled receptor family, and they exist in a state of balance between active and inactive forms. Cross connecting between transmembrane domains III and V is facilitated by histamine binding to the H1-receptor, stabilising the active state of the receptor.

Antihistamines, on the other hand, bind to a different location on the H1 receptor, which favors the inactive form. As a result, loratadine is better characterised as a “inverse agonist” rather than a “histamine antagonist,” and it can help avoid or lessen the intensity of histamine-mediated symptoms.

How should this medicine be used?
Loratadine tablets should be swallowed with a glass of water, milk, or juice. If the pill has a score line, you can cut it in half if swallowing it whole is difficult. It is not to be chewed. Without the need for a drink, melt-in-the-mouth tablets dissolve instantaneously on your tongue.

Common Side Effects

Headache
Dry mouth
Nose-bleed
Sore throat
Mouth sores
Difficulty falling asleep or staying asleep
Nervousness
Weakness
sSomach pain
Diarrhea
Red or itchy eyes

Important Warning

If you are using loratadine for hives and experience any of the following symptoms, get immediate medical attention: Wheezing, drooling, dizziness, or loss of consciousness are all symptoms of difficulties swallowing, speaking, or breathing; swelling in and around the mouth or swelling of the tongue; wheezing; drooling; dizziness; or loss of consciousness.

Available Brands (list can be updated in future)
Lorin NSA
Xylor
Antial

Posted on by

Cetirizine – H1 Receptor – An Anti-Histamine

Introduction

Cetirizine sold under the bran dames of Zyrtec, Rigix, Baydal, is a second-generation antihistamine that is used to treat allergic rhinitis (hay fever), dermatitis, and urticaria, among other things (hives). It is taken orally. The effects usually start within an hour and last approximately a day.

Class of Medicine
Cetirizine belongs to the antihistamine class of drugs. It works by preventing histamine, a chemical in the body that produces allergy symptoms, from acting.

Mode of Action
Cetirizine is an antihistamine medication that is a metabolite of hydroxyzine. Its major effects are obtained by inhibiting peripheral H1 receptors selectively. Cetirizine’s antihistamine activity has been demonstrated in a range of animal and human models. Anticholinergic and antiserotonergic effects were shown to be minimal in both in vivo and ex vivo animal models. However, dry mouth was found to be more common with cetirizine than with a placebo in clinical tests. Cetirizine has no measurable affinity for histamine receptors other than H1 receptors, according to in vitro receptor binding experiments.

How should this medicine be used?
Cetirizine tablets or capsules should always be taken with a glass of water, milk, or juice. Consume them in their whole. They should not be chewed. Cetirizine liquid, rather than pills or capsules, may be easier for youngsters to swallow.

Common Side Effects

Headaches
Dry mouth
Drowsiness
Fatigue
Feeling sick
Dizziness
Stomach pain
Diarrhoea
as well as more serious but uncommon adverse effects such as heart failure, tachycardia, and edoema.

Important Warning

In conclusion, cetirizine given daily for a long time (i.e. 3 years) may reduce the development of new sensitizations in monosensitized youngsters, indicating the possibility of tertiary allergy prevention.
When you stop taking cetirizine over a long period of time (usually more than six months), you may have generalized itching.


Available Brands (list can be updated in future)
Zyrtec
Rigix
Baydal

Posted on by

Ebastine – Anti-Histamine – H1 Receptor

Introduction

Ebastine is a second-generation antihistamine, available in brand names Kestine, Ebaget, Atmos has been demonstrated to be helpful in the treatment of allergic rhinitis, both seasonal and perennial.
Ebastine is an H1 antihistamine with a modest drowsiness risk.
It does not permeate the blood–brain barrier very well, combining an effective inhibition of the H1 receptor in peripheral tissue with a low prevalence of central side effects, such as sedation and tiredness.

Class of Medicine
Ebastine is an H1 receptor antagonist of the second generation that is used to treat allergic rhinitis and chronic idiopathic urticaria. It comes in 10 and 20 mg tablets, as well as fast-dissolving tablets and paediatric syrup.

Mode of Action
Ebastine is a piperidine H1 antihistamine of the second generation. H1-antihistamines block histamine’s agonist effect at the H1 receptor and are used to reduce inflammation in allergic rhinitis, allergic conjunctivitis, and urticaria. Antigen presentation and the expression of pro-inflammatory cytokines, cell adhesion molecules, and chemotactic factors are all reduced when the activity of the NF-B immune response transcription factor is reduced via the phospholipase C and phosphatidylinositol (PIP2) signalling pathways. Furthermore, lowering the calcium ion concentration increases mast cell stability, which reduces the further release of histamine .

How should this medicine be used?
Ebastine can be taken with or without food once a day. Patients who are old or have mild–moderate hepatic impairment do not require dose adjustments. In patients with severe hepatic impairment, the maximum dose is 10 mg once day.

Common Side Effects

Nausea
Drowsiness
Dry mouth
Nose bleed
Weakness
Indigestion
Sleeplessness
Headache
Drowsiness
Abdominal pain
Pharyngitis
Dyspepsia
Asthenia
Sinusitis

Important Warning

Must talk to your doctor:
If the patient has the history of heart disease (e.g. long QT syndrome, hypokalaemia, treatment with agents known to increase QT interval). Use with CYP3A4 inhibitors at the same time.
Hepatic impairment is severe.
Children. Lactation and pregnancy.
If you are already taking certain antibiotics or drugs used to treat fungal infections

Available Brands (list can be updated in future)
Kestine
Ebaget
Atmos