Cetirizine Powerful Action, Best Uses, Side effects and Brands in Pakistan

Introduction

Cetirizine is a second-generation antihistamine that treats allergic symptoms such as itching, runny nose, watery eyes, and sneezing. It is available over-the-counter and prescription in various forms including tablets, chewable tablets, and liquid solutions. It starts working within thirty minutes and its effects last for about a day. It provides similar benefits to other antihistamines like diphenhydramine, which is the first generation of antihistamines.

Mechanism of Action

Cetirizine works by blocking histamine, a substance in the body that causes allergic symptoms. Histamines are released by mast cells during allergic reactions and bind to receptors on certain cells, causing symptoms like swelling, redness, and itching. By inhibiting the H1 histamine receptors, cetirizine prevents these symptoms from occurring.

Uses of Cetirizine

Cetrizine is prescribed by doctors all over the world for the following health conditions:

Allergy Relief

Cetirizine is primarily used for the relief of symptoms associated with seasonal allergic rhinitis (hay fever) and perennial allergic rhinitis. These symptoms include:

• Sneezing
• Runny nose
• Itchy or watery eyes
• Itchy throat or nose

Skin Conditions

Cetirizine is also effective in treating chronic urticaria, a condition characterized by persistent hives and itching. It helps reduce the severity of itching and the number of hives (Hives are red, raised bumps or patches on the skin).

Cetirizine Uses  in Urdu

یہ دوا پوری دنیا کے ڈاکٹروں نے درج ذیل صحت کی حالتوں کے لیے تجویز کی ہے۔

الرجی سے نجات

یہ بنیادی طور پر موسمی الرجک ناک کی سوزش (گھاس بخار) اور بارہماسی الرجک ناک کی سوزش سے وابستہ علامات کو دور کرنے کے لیے استعمال کیا   جاتا ہے۔ ان علامات میں شامل ہیں

چھینکنا
ناک بہنا
کھجلی یا پانی والی آنکھیں
گلے یا ناک میں خارش

جلد کے حالات

یہ دوا دائمی چھپاکی کے علاج میں بھی موثر ہے، ایک ایسی حالت جس کی خصوصیت مسلسل چھتے اور خارش ہوتی ہے۔ یہ خارش کی شدت اور چھتے کی تعداد کو کم کرنے میں مدد کرتا ہے (چھتے سرخ ہوتے ہیں، جلد پر دھبے یا دھبے ہوتے ہیں۔)

Dosage and Administration

Dosage for Adults

The recommended dosage for adults and children over 12 years is typically 10 mg once daily. However, some individuals may find that 5 mg once daily is sufficient for symptom relief.

Dosage for Children

For children aged 6 to 11 years, the recommended dose is 5 to 10 mg once daily. For children aged 2 to 5 years, the dose is usually 2.5 to 5 mg once daily. It is crucial to follow a pediatrician’s advice regarding the correct dosage for children.

Special Populations

For individuals with liver or kidney impairments, a lower dose may be recommended. It’s important to consult with a healthcare provider for appropriate dosage adjustments.

History of Cetirizine

Patented and Medical Use

Cetirizine was patented in 1983 and came into medical use in 1987. Its development marked a significant advancement in the treatment of allergies, offering a non-sedative option compared to older antihistamines.

Essential Medicine Status

Cetirizine is on the World Health Organization’s List of Essential Medicines, which includes the most important medications needed in a basic health system. This underscores its importance and effectiveness in treating allergic conditions.

Generic Availability

Cetirizine is available as a generic medication, making it accessible and affordable for a broad range of patients. The availability of generic versions has contributed to its widespread use and affordability.

Prescription Status

In 2021, cetirizine was the 49th most commonly prescribed medication in the United States, with more than 13 million prescriptions. Its popularity reflects its effectiveness and the high prevalence of allergic conditions that it treats.

Side Effects

While cetirizine is generally well-tolerated, some individuals may experience side effects, including:

Common Side effects:

• Drowsiness
• Dry mouth
• Fatigue
• Headache
• Stomach pain

Serious Side Effects

Serious side effects are rare but may include:

• Severe allergic reactions (anaphylaxis)
• Difficulty breathing or swallowing
• Swelling of the face, lips, tongue, or throat
• Severe dizziness or fainting

If any serious side effects occur, it is important to seek immediate medical attention.

Precautions and Warnings

Before taking cetirizine, consider the following precautions:

• Medical History: Inform your doctor about any past medical conditions, especially kidney or liver disease.
• Allergies: Disclose any allergies to antihistamines or other substances.
• Alcohol Consumption: Avoid alcohol as it can increase the sedative effects of cetirizine.
• Operating Machinery: Be cautious when driving or operating heavy machinery until you know how cetirizine affects you.

Drug Interactions

Cetirizine may interact with other medications, including:

• Sedatives and Tranquilizers: Increased risk of drowsiness.
• Alcohol: Enhanced sedative effect.
• Theophylline: May decrease the clearance of cetirizine from the body.

Always inform your healthcare provider about all medications and supplements you are taking to avoid potential interactions.

Cetirizine in Special Populations

Pregnancy and Breastfeeding

Cetirizine is classified as a Category B drug during pregnancy, indicating that there are no proven risks in humans. However, it should only be used if needed and prescribed by a healthcare provider.

Breastfeeding Considerations

Occasional and small doses of cetirizine are acceptable during breastfeeding. However, prolonged use of larger doses may lead to drowsiness and other adverse effects in the infant, especially when combined with pseudoephedrine. The use of an ophthalmic formulation of cetirizine by the mother is believed to pose minimal risk to the breastfed infant. It’s recommended that clinicians advise mothers to apply pressure over the tear duct by the corner of the eye and remove any leftover solution to minimize the drug reaching the breast milk.

Hepatic Impairment

The dose for patients with hepatic impairment should be reduced, as per the manufacturer’s prescribing information.

Renal Impairment

The dose should be reduced for patients with decreased renal function and those on hemodialysis, according to the manufacturer’s prescribing information.

Pediatric Patients

Cetirizine may improve clinical outcomes and quality of life in children with allergic rhinitis. It demonstrates comparable efficacy with other antihistamines and is generally well tolerated, although there is an increased risk of drowsiness in the pediatric population. The intravenous formulation is FDA-approved for urticaria in children 6 months and older.

Older Patients

Efficacy evaluations did not include an adequate number of patients aged 65 years and older to determine potential divergent response patterns compared to younger patients. Safety assessments of cetirizine in older patients compared to younger adults revealed no significant differences.

Ophthalmic Formulation

Clinical studies have proven Cetirizine safe and effective for pediatric patients 2 years and older. Patients need to remove contact lenses and wait before reinserting them to minimize absorption by the lenses.

Overdose and Missed Dose

Overdose

Symptoms of cetirizine overdose may include severe drowsiness, restlessness, and confusion. In case of overdose, seek immediate medical attention or contact a poison control center.

Missed Dose

If you miss a dose, take it as soon as you remember. If it is close to the time for your next dose, skip the missed dose. Do not take two doses simultaneously to make up for a missed one.

Pharmacokinetics of Cetirizine

Absorption: When taken orally in tablet or syrup form, cetirizine is rapidly and extensively absorbed, with at least 70% bioavailability. Its peak concentration (Tmax) occurs around 1.0 hours after administration and its pharmacokinetics increase linearly with doses ranging from 5 to 60 mg. Food does not affect its bioavailability but can delay Tmax and decrease Cmax. Levocetirizine, a related drug, shows similar effects when administered with a high-fat meal.

Distribution: Cetirizine is highly bound to plasma proteins (93 to 96%), primarily to albumin. Its volume of distribution is estimated to be 0.3 to 0.45 L/kg. It crosses the blood-brain barrier poorly due to its chemical properties and activity as a P-glycoprotein substrate.

Metabolism: Cetirizine undergoes minimal metabolism and is not metabolized by the cytochrome P450 system. It does undergo some oxidation and conjugation, but the responsible enzymes have not been identified.

Elimination: Approximately 70 to 85% of cetirizine is eliminated in the urine and 10 to 13% in the feces. Around 50 or 60% of the eliminated drug in the urine is unchanged. It has an elimination half-life of 6.5 to 10 hours in healthy adults, with a duration of action of at least 24 hours. The elimination half-life is increased in the elderly, in hepatic impairment, and renal impairment.

Brands in Pakistan

Cetirizine is available under various brands in Pakistan some popular brands include:

1. Axis Pharma manufactures Ceridal.
2. G.S.K Pharma manufactures Zyrtec.
3. AGP Pharmaceuticals manufactures Rigix.
4. Bayer Pharmaceutical Company manufactures Baydal.
5. Barrett Pharma manufactures Gixer.
6. PDH Pharma manufactures Cezine.
7. Sedil is manufactured by Sami Pharmaceuticals.
8. ZANLAN is manufactured by Novartis Pharma.
9. Tabros Pharma manufactures ARIX.
10. AKSON PHARMACEUTICALS (PVT) LTD manufactures AKSOZINE.

Conclusion

Cetirizine is an effective and widely used antihistamine for managing allergy symptoms and chronic urticaria. While it is generally safe and well-tolerated, it is important to follow dosage instructions and consider potential interactions and side effects. Always consult with a healthcare provider for personalized advice and recommendations. By understanding how cetirizine works and its proper usage, you can effectively manage your allergy symptoms and improve your quality of life.