Alergan

Alergan Uses, Dosage, Side Effects, Food Interaction and all others data.

Alergan is a non-sedating antihistamine. It works by selectively binding to peripheral histamine H1-receptors on effector cells.

Like other 2nd generation antihistamines, loratadine is selective for peripheral H1 receptors. Alergan does not penetrate effectively into the central nervous system and has poor affinity for CNS H1-receptors. These qualities result in a lack of CNS depressant effects such as drowsiness, sedation, and impaired psychomotor function.

Trade Name Alergan
Availability Rx and/or OTC
Generic Loratadine
Loratadine Other Names Loratadina, Loratadine, Loratadinum
Related Drugs prednisone, hydroxyzine, cetirizine, fluticasone nasal, montelukast, promethazine, diphenhydramine, triamcinolone, Benadryl, Zyrtec
Type
Formula C22H23ClN2O2
Weight Average: 382.883
Monoisotopic: 382.144805697
Protein binding

97 - 99% of the loratadine is bound to plasma proteins.

Groups Approved, Investigational
Therapeutic Class Non-sedating antihistamines
Manufacturer
Available Country Chile
Last Updated: September 19, 2023 at 7:00 am
Alergan
Alergan

Uses

Alergan provides faster relief from the symptoms of hay fever, allergic rhinitis such as sneezing, nasal discharge, itching, ocular itching and burning, nasal and ocular sign and symptoms are relieved rapidly after oral administration.

Alergan is also effective in idiopathic chronic urticaria. In children over 2 years, Alergan is used for the symptomatic relief of seasonal allergic rhinitis and allergic skin conditions such as urticaria nettle rash.

Alergan is also used to associated treatment for these conditions: Allergic Dermatologic Disorders, Allergic Rhinitis (AR), Allergies, Chronic Urticaria, Common Cold, Eye pruritus, Fever, Nasal Congestion, Nasal Itching, Pain, Perennial Allergic Rhinitis (PAR), Perennial Rhinitis, Pollen Allergy, Pruritus, Rhinorrhoea, Seasonal Allergic Rhinitis, Sneezing, Sensation of burning in the eyes, Watery eyes, Watery itchy eyes

How Alergan works

Histamine release is a key mediator in allergic rhinitis and urticaria. As a result, loratadine exerts it's effect by targeting H1 histamine receptors.

Alergan binds to H1 histamine receptors found on the surface of epithelial cells, endothelial cells, eosinophils, neutrophils, airway cells, and vascular smooth muscle cells among others. H1 histamine receptors fall under the wider umbrella of G-protein coupled receptors, and exist in a state of equilibrium between the active and inactive forms. Histamine binding to the H1-receptor facilitates cross linking between transmembrane domains III and V, stabilizing the active form of the receptor. On the other hand, antihistamines bind to a different site on the H1 receptor favouring the inactive form.

Hence, loratadine can more accurately be classified as an "inverse agonist" as opposed to a "histamine antagonist", and can prevent or reduce the severity of histamine mediated symptoms.

Dosage

Alergan dosage

Adult & children over 12 years of age: One Alergan 10 mg tablet once daily (usually in the morning).

Children:

  • 2-12 years (body weight more than 30 Kg): 10 mg Alergan once daily.
  • 2-12 years (body weight less than 30 Kg): 5 mg Alergan once daily.
  • Below 2 years of age: Safety and efficacy of Alergan have not been established.

Liver & renal impairment: Patients with liver impairment and renal insufficiency (GFR <30 ml/min) should be given a lower initial dose (10 mg every other day).

Side Effects

Fatigue, nausea and headache were reported rarely. Scientific studies showed that Alergan does not cause drowsiness. It does not affect performance and ability to drive or tasks requiring concentration.

Toxicity

Second generation antihistamines such as loratadine have very few adverse effects; however, insomnia, headache, fatigue, drowsiness and rash have been reported. Symptoms of loratadine overdose include gastrointestinal side effects, agitation, drowsiness, tachycardia, and headache. It is advised to obtain an ECG in the event of loratadine overdose.

Precaution

Patients with liver impairment and renal insufficiency (GFR <30 ml/min) should be given a lower initial dose (10 mg every other day).

Interaction

When administered concurrently with alcohol, Alergan has no potentiating effect as measured by psychomotor performance studies. Interactions with other drugs have not been reported.

Food Interaction

No interactions found.

[Minor] Theoretically, grapefruit juice may increase the plasma concentrations of loratadine as it does other drugs that are substrates of the CYP450 3A4 enzymatic pathway.

The proposed mechanism is inhibition of CYP450 3A4-mediated first-pass metabolism in the gut wall by certain compounds present in grapefruits.

The clinical significance of this potential interaction is unknown.

Reported interactions with potent CYP450 3A4 inhibitors like clarithromycin, erythromycin and ketoconazole have produced substantial increases in the area under the plasma concentration-time curve (AUC) of loratadine and its active metabolite, descarboethoxyloratadine, without associated changes in the overall safety profile of the drug.

Alergan Disease Interaction

Moderate: renal/liver disease

Volume of Distribution

The volume of distribution of loratadine is 120 L/Kg.

Elimination Route

Alergan is rapidly absorbed and achieves peak plasma concentration in 1-2 hours, while it's main metabolite achieves peak plasma concentration in 3-4 hours.

In the rapid dissolve formulation, the pharmacokinetic parameters of loratadine are as follows: Cmax = 2.56 ng/ml, Tmax = 1.14 hrs, AUC = 6.14 ng x hr/ml.

In the rapid dissolve formulation, the pharmacokinetic parameters of descarboethoxyloratadine are as follows: Cmax = 3.72 ng/ml, Tmax = 1.97 hr, AUC = 49.1 ng x hr/ml.

In the conventional formulation, the pharmacokinetic parameters of loratadine are as follows: Cmax = 2.11 ng/ml, Tmax = 1.00 hr, AUC = 4.64 ng x hr/ml

In the conventional formulation, the pharmacokinetic parameters of descarboethoxyloratadine are as follows: Cmax = 3.66 ng/ml, Tmax = 1.97 hr, AUC = 48.4 ng x hr/ml

Half Life

The elimination half life is approximately 10 hours for loratadine and 20 hours for descarboethoxyloratadine.

Clearance

The clearance of loratadine after single oral doses of 20 mg and 40 mg are 12 L/h/kg and 9 L/h/kg respectively. P-glycoprotein is involved in the clearance of many 2nd generation antihistamines, including loratadine, from the central nervous system. 1st generation antihistamines are not cleared by P-glycoprotein, which may help explain why they have a different central nervous system adverse effect profile compared to their 2nd generation counterparts. It appears that an antihistamine with higher affinity for p-glycoprotein will have a lower incidence of CNS adverse effects.

Elimination Route

Over a 10 day period, 40% of loratadine is excreted in the urine, and 42% is eliminated in the faeces.

Pregnancy & Breastfeeding use

Use in pregnancy: There is no experience of the use of Alergan in human pregnancy, hence it should not be used during pregnancy.

Use in lactation: Alergan is excreted in breast milk, so it should not be administered to lactating mother.

Contraindication

Alergan is contraindicated in patients who have shown hypersensitivity or idiosyncracy to their components.

Acute Overdose

Symptoms: Somnolence, tachycardia headache, drowsiness, extrapyramidal manifestations and palpitations.

Management: Symptomatic and supportive treatment. Immediately empty stomach by inducing emesis with ipecac syrup. Admin of activated charcoal after emesis may be useful. If induction of vomiting is unsuccessful or contraindicated (e.g. patient is comatose, having seizures or lacks gag reflex), gastric lavage with NaCl 0.9% soln may be performed to prevent aspiration of gastric contents. Saline cathartics may be useful to rapidly dilute bowel contents.

Storage Condition

Store between 20-25° C.

Innovators Monograph

You find simplified version here Alergan

Alergan contains Loratadine see full prescribing information from innovator Alergan Monograph, Alergan MSDS, Alergan FDA label

FAQ

What is Alergan used for?

Alergan is used to treat sneezing, runny nose, watery eyes, hives, skin rash, hay fever, itching, and other cold or allergy symptoms. It's also used to treat hay fever.

How safe is Alergan?

Generally, it's considered safe to use Alergan for a long time, but you should only take it if you need it.Depending on your condition, you may only need to use Alergan for a short period of time, or you might need to take it longer to treat stubborn allergies.

How does Alergan work?

Alergan works by blocking the action of histamine, a substance in the body that causes allergic symptoms.

What are the common side effects of Alergan?

Common side effects of Alergan are include:

  • headache
  • dry mouth
  • nosebleed
  • sore throat
  • mouth sores
  • difficulty falling asleep or staying asleep
  • nervousness
  • weakness
  • stomach pain
  • diarrhea
  • red or itchy eyes

Is Alergan safe during pregnancy?

Alergan can be taken in pregnancy. There is no good evidence that it can harm your baby.

Is Alergan safe during breastfeeding?

Considering the minimal exposure of a nursing infant to the drugs through breast milk, maternal use of Alergan in a standard therapeutic dose is unlikely to result in adverse effects in nursing infants and is considered to be compatible with breastfeeding.

Can I drink alcohol with Alergan?

If you take an allergy medication like Alergan, you may be at risk of drowsiness and confusion if you drink alcohol.

Can I drive after taking Alergan?

Alergan is classed as a non-drowsy antihistamine but it's still possible to feel sleepy after taking it. If this happens to you, do not drive a car or ride a bike until you feel better.

When is the best time to take Alergan?

Take Alergan once a day at the same time each day, either in the morning or in the evening. You can take Alergan with or without food.

Is it safe to take Alergan every day?

Alergan is safe to take daily.

Can I take Alergan on an empty stomach?

You may take Alergan with food or on an empty stomach.

How long does Alergan take to work?

Usually, Alergan tablets start to work within 30 minutes after being taken and tend to be most effective within 1-2 hours after being taken.

How long does Alergan stay in my system?

The elimination half-life of Alergan is 8–14 hours and that of its metabolite is 17–24 hours, which accounts for the 24-hour duration of action of the drug. Wheal inhibition is detected at 1.5 hours after administration, reaches a peak at 4–6 hours, and may last 36–48 hours.

Can I take Alergan for a long time?

Yes, you can take Alergan daily and long term. Alergan is an antihistamine used to treat for allergy symptoms. If your symptoms are year round then it is able to be taken long term. If your symptoms are seasonal or you have allergy symptoms occasionally, then it is taken daily when required.

Who should not take Alergan?

You should not take Alergan if you have any symptom of bellow:

  • liver failure.
  • liver problems.
  • moderate to severe kidney impairment.

What happens if I miss a dose?

Alergan is used when needed. Do not use Alergan more than once in a 24-hour period. Do not use two doses at one time.

What happens if I overdose on Alergan?

Overdose symptoms may include headache, drowsiness, and fast or pounding heartbeat.Seek emergency medical attention.

How quickly does Alergan work?

Alergan reaches peak plasma concentration in 1-2 hours; the metabolite does so in 3-4 hours. Their respective elimination half-lives are about 10 and 20 hours. Onset of action is within 1 hour and duration is at least 24 hour.

Can Alergan affect fertility?

They found Alergan could have negative long-term side effects for male fertility.

Is Alergan safe for heart patients?

Newer Alergan like Alergan are all fairly safe for the heart, with fexofenadine seeming to be the absolute safest if you are at risk of arrythmia.

Does Alergan affect blood pressure?

Alergan increase your blood pressure and heart rate.

Can Alergan affects my liver?

Patients with liver disease may be at greater risk for adverse effects from Alergan due to drug and metabolite accumulation. The manufacturer recommends one-half the regular dosage initially in patients with liver failure or decreased renal function.

Can I just stop taking Alergan?

Exposure to substances such as pollen, pet fur, house dust or insect bites can cause your body to produce allergic symptoms. Cells in the lining of your nose and eyes release histamine when they come into contact with these substances.

*** Taking medicines without doctor's advice can cause long-term problems.
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