Alerest

Alerest is an antihistamine containing Cetirizine Dihydrochloride 10 mg, classified as a second-generation H1-antihistamine. It works by selectively binding to peripheral H1 receptors, blocking histamine from triggering allergy symptoms such as itching, sneezing, runny nose, and hives.

Because Cetirizine minimally crosses the blood-brain barrier, it causes significantly less drowsiness than first-generation antihistamines like Chlorpheniramine (CPM). The drug is rapidly absorbed from the GI tract, takes effect within 20-60 minutes, reaches peak plasma levels at 1-2 hours, and has a half-life of approximately 8-9 hours. It is primarily excreted unchanged via urine with minimal hepatic metabolism, resulting in few drug interactions.

Alerest (Cetirizine) relieves symptoms from various allergic conditions:

• Allergic Rhinitis — both seasonal (pollen, seasonal dust) and perennial (dust mites, pet dander, year-round allergens). Reduces sneezing, itchy nose, runny nose, nasal congestion
• Chronic Idiopathic Urticaria — recurring hives with itchy, raised welts of unknown cause. Reduces the number, size, and itching of wheals
• Other allergic skin reactions — itchy rashes, contact dermatitis, insect bite reactions. Helps reduce swelling and redness
• Allergic Conjunctivitis — red, itchy, watery eyes caused by allergens

Some doctors may also prescribe Cetirizine for pollen-induced asthma symptoms alongside bronchodilators.

Adults and children 6 years and over: Take 1 tablet (10 mg) once daily. For mild symptoms, may split into half tablet (5 mg) twice daily, morning and evening.

Children 2-5 years: Half tablet (5 mg) once daily, or 2.5 mg twice daily as directed by a pharmacist.

Kidney impairment: Dose adjustment needed based on Creatinine Clearance. For CrCl 31-49 mL/min, take half tablet (5 mg) once daily.

Can be taken with or without food — food does not significantly affect absorption. Best taken before bedtime in case of mild drowsiness. Swallow whole with water. If you miss a dose, take it as soon as you remember. If close to the next dose, skip the missed one. Never double up.

Common:

• Drowsiness (about 14%, much less than 1st-gen like CPM at ~50%, but more than Fexofenadine which causes almost none)
• Headache, fatigue, mild dizziness
• Dry mouth, nausea, stomach discomfort

Uncommon: Dizziness, abdominal pain, diarrhea, slight weight gain (very rare)

Very rare: Hepatitis, tachycardia, seizures

Stop and seek medical help if: Signs of severe allergic reaction (Anaphylaxis) such as swelling of face, lips, tongue, difficulty breathing, or widespread severe rash

Do not use if:

• Allergic to Cetirizine, Hydroxyzine, or any other ingredients
• End-stage renal disease
• Children under 2 years (tablet form)

Precautions:

• Kidney disease — dose adjustment may be needed
• Avoid alcohol as it may increase drowsiness
• Pregnant or breastfeeding — consult a pharmacist before use
• Be cautious driving after first dose until you know how your body responds

Alerest (Cetirizine) compared to other antihistamines available at Intimo Life:

• vs Telfast (Fexofenadine 60/120/180 mg): Telfast is also a 2nd-gen antihistamine but causes virtually no drowsiness, making it ideal for those sensitive to sedation or who drive frequently. However, Alerest (Cetirizine) tends to provide slightly stronger symptom relief, especially for hives
• vs Fenafex (Fexofenadine 60 mg): Fenafex contains the same active ingredient as Telfast but at a more affordable price. The key difference is that Cetirizine (Alerest) works faster — within 20 minutes vs 1-2 hours for Fexofenadine

All three are safe and effective 2nd-generation antihistamines. Choose based on your needs — least drowsy: Telfast/Fenafex, most potent: Alerest

Cetirizine has fewer drug interactions compared to older antihistamines because it undergoes minimal hepatic CYP450 metabolism. However, be aware of:

• CNS depressants — Sedatives (Benzodiazepines like Diazepam, Alprazolam), Opioid painkillers (Tramadol, Codeine), certain antidepressants (Amitriptyline) may noticeably increase drowsiness if taken together
• Alcohol — Enhances sedative effects, potentially dangerously so. Avoid while using
• Theophylline — May slightly reduce renal clearance of Cetirizine, though generally not clinically significant
• Other common medications — No significant interactions. Safe to take with Paracetamol, Ibuprofen, antacids, or antibiotics

Alerest (Cetirizine) acts quickly — symptom relief begins within 20-60 minutes after taking. Peak effect occurs at around 1-2 hours, then maintains its action for a full 24 hours, making once-daily dosing convenient. For acute allergy flare-ups, Cetirizine works faster than Loratadine, which may take 1-3 hours to reach full effect.

Alerest is available at pharmacies nationwide or conveniently online through Intimo Life. Comes in a strip of 10 tablets, ideal for travel or regular use. Alerest contains the same active ingredient (Cetirizine) as Zyrtec but at a more affordable price point.