Key Facts
- Drug Class
- First-generation antihistamine
- Prescription
- Over the counter
- NAFDAC Status
- NAFDAC Registered
- Forms
- Tablet, Syrup, Injection
- Price Range
- ₦50 - ₦1,500
- WHO Essential
- Yes
What is Chlorpheniramine?
Chlorpheniramine, universally known in Nigeria as Piriton, is the single most recognisable antihistamine brand in the country. It has been a staple in Nigerian medicine cabinets, hospital pharmacies, and patent medicine stores for decades. Chlorpheniramine is a first-generation antihistamine that works by blocking histamine H1 receptors throughout the body. Histamine is a chemical released by the body during allergic reactions, and it is responsible for symptoms like sneezing, itching, runny nose, watery eyes, and skin rashes. By blocking histamine's effects, chlorpheniramine relieves these symptoms effectively. However, unlike newer antihistamines like cetirizine, first-generation antihistamines like chlorpheniramine freely cross the blood-brain barrier, which is why they cause significant drowsiness — a property that many Nigerians actually exploit, using Piriton as a sleep aid.
The cultural significance of Piriton in Nigeria cannot be overstated. 'Piriton' has essentially become a generic word for antihistamine in Nigerian parlance, much like 'Septrin' represents antibiotics. Nigerians reach for Piriton for virtually any form of itching — from mosquito bites to heat rash (prickly heat), from food allergies to drug reactions, and from urticaria to the itching of skin conditions like eczema. It is also commonly used alongside cold and flu remedies, as it helps dry up a runny nose and reduces sneezing. The sedating effect is well known and sometimes deliberately sought — some Nigerians take Piriton at night to help with sleep, though this is not a recommended use.
Chlorpheniramine is manufactured by numerous companies in Nigeria and is one of the cheapest medications available — a strip of 10 Piriton tablets can cost as little as ₦50 to ₦200 from local manufacturers. The original GSK Piriton brand commands a premium but remains affordable by international standards. The drug is available as 4mg tablets for adults and 2mg/5ml syrup for children. While chlorpheniramine is generally safe and effective for short-term allergy relief, its sedating properties mean it is not the best choice for daytime use when alertness is required. For people who need to drive, operate machinery, or stay focused at work or school, newer non-sedating antihistamines like cetirizine offer a better alternative. All legitimate chlorpheniramine products must carry a valid NAFDAC registration number.
What is Chlorpheniramine used for?
In Nigeria, Chlorpheniramine is commonly used for:
- Allergic rhinitis — sneezing, runny nose, and nasal congestion caused by allergens including dust, pollen, and the dry Harmattan air that affects most of Nigeria from November to March
- Urticaria (hives) — itchy, raised welts on the skin from allergic reactions to foods, medications, or other triggers
- Itching (pruritus) of various causes — insect bites (particularly mosquito bites, which are ubiquitous in Nigeria), heat rash, drug reactions, and other allergic skin conditions
- Common cold — helps reduce sneezing and runny nose, often combined with paracetamol and pseudoephedrine in cold combination products
- Allergic conjunctivitis — itchy, watery eyes from allergens
- Drug allergy reactions — first-line treatment for mild allergic reactions to medications
- As an adjunct in anaphylaxis treatment — the injectable form is used in hospital emergency departments alongside adrenaline
- Adjunct to sleep — while not officially indicated as a sleep aid, the sedating effect is sometimes used short-term for insomnia; this should be under medical guidance
Dosage
IMPORTANT
Always follow your doctor's or pharmacist's instructions. The information below is for general reference only.
Adults
4mg (one tablet) taken every 4 to 6 hours as needed. Maximum daily dose is 24mg (six tablets) in 24 hours. For night-time allergy relief or when the sedating effect is desired, a single 4mg dose at bedtime may be sufficient. Take with or without food. The injectable form (hospital use only) is 10mg to 20mg by subcutaneous, intramuscular, or slow intravenous injection for acute allergic reactions.
Children
Children aged 6 to 12 years: 2mg (one 5ml spoonful of syrup or half a 4mg tablet) every 4 to 6 hours as needed. Maximum 12mg (3 tablets) in 24 hours. Children aged 2 to 5 years: 1mg (2.5ml of syrup) every 4 to 6 hours as needed. Maximum 6mg in 24 hours. Children aged 1 to 2 years: 1mg twice daily. Chlorpheniramine is NOT recommended for children under 1 year of age without medical supervision. Always use the measuring spoon or syringe provided with the syrup — do not estimate doses using household teaspoons, as this leads to inaccurate dosing.
Elderly
Elderly patients are more susceptible to the sedating and anticholinergic effects of chlorpheniramine, including drowsiness, confusion, dizziness, urinary retention, and constipation. A lower dose of 2mg (half a tablet) every 4 to 6 hours may be more appropriate. Elderly patients should avoid driving or operating machinery while taking chlorpheniramine.
Chlorpheniramine causes drowsiness in most people. Do NOT drive, operate heavy machinery, or perform tasks requiring full alertness after taking Piriton. Avoid alcohol while taking chlorpheniramine as it significantly increases drowsiness. The sedating effect is usually strongest with the first few doses and may lessen slightly with continued use, but caution should always be exercised. If you need allergy relief during the day without drowsiness, consider switching to cetirizine (a non-sedating antihistamine). Chlorpheniramine needs to be taken every 4 to 6 hours for continuous relief, unlike cetirizine which provides 24-hour coverage with a single daily dose.
Side Effects
Common side effects
- •Drowsiness and sedation — the most prominent side effect; affects the majority of users
- •Dry mouth, nose, and throat
- •Dizziness
- •Blurred vision
- •Difficulty concentrating and impaired coordination
- •Constipation
- •Thickening of mucus in the airways
Serious side effects — seek medical help immediately
- Paradoxical excitation — particularly in children, who may become hyperactive, irritable, or agitated instead of drowsy
- Severe allergic reaction to chlorpheniramine itself — rare but possible; manifests as worsening rash, swelling, or difficulty breathing
- Urinary retention — difficulty passing urine, particularly in elderly men with prostate enlargement
- Seizures — at very high doses or in overdose
- Cardiac arrhythmias — in significant overdose, chlorpheniramine can affect heart rhythm
- Severe drowsiness and respiratory depression — particularly dangerous if combined with alcohol, sedatives, or opioids
When to see a doctor
See a doctor if your allergy symptoms do not improve after several days of chlorpheniramine use, or if they worsen. Seek emergency care if you experience difficulty breathing, severe swelling of the face or throat, rapid or irregular heartbeat, seizures, or extreme drowsiness that you cannot be woken from. If a child becomes unusually agitated or hyperactive after taking chlorpheniramine (paradoxical reaction), stop the medication and consult a doctor. In cases of accidental overdose (particularly in children), seek emergency care immediately — overdose can cause seizures, hallucinations, and respiratory depression.
Warnings & Precautions
Do not take Chlorpheniramine if you have:
- Known allergy to chlorpheniramine or any ingredient in the formulation
- Narrow-angle glaucoma — chlorpheniramine can increase eye pressure and trigger a glaucoma crisis
- Urinary retention or severe prostate enlargement — chlorpheniramine can worsen urinary obstruction
- Use within 14 days of taking a monoamine oxidase inhibitor (MAOI) antidepressant
- Neonates and premature infants — do not use in babies under 1 year without medical supervision
Drug interactions
- •Alcohol — dramatically increases the sedating effect of chlorpheniramine; this combination is dangerous for driving and operating machinery
- •Other sedating drugs (benzodiazepines like diazepam, opioids like tramadol, sleeping pills, other sedating antihistamines like promethazine) — combined sedation can be profound and dangerous
- •MAO inhibitors — can cause a dangerous increase in anticholinergic effects; avoid combination
- •Other anticholinergic drugs (hyoscine butylbromide/Buscopan, tricyclic antidepressants like amitriptyline) — increased risk of dry mouth, constipation, urinary retention, and confusion
- •Phenytoin — chlorpheniramine may alter phenytoin metabolism
Pregnancy & Breastfeeding
Chlorpheniramine is generally considered one of the safer antihistamines during pregnancy and is often the antihistamine of choice when one is needed during pregnancy, as it has a long track record of use without evidence of increased birth defect risk. However, it should be used only when clearly necessary and at the lowest effective dose. Avoid using it near the time of delivery as it may cause irritability or drowsiness in the newborn. Chlorpheniramine passes into breast milk in small amounts and may cause drowsiness or irritability in the nursing infant. If you are breastfeeding and need an antihistamine, discuss options with your doctor — cetirizine or loratadine may be preferred as they cause less infant sedation.
Brands of Chlorpheniramine in Nigeria
4 brands available in Nigeria.
| Brand Name | Manufacturer | Strength | Form | NAFDAC Reg. No. |
|---|---|---|---|---|
| Piriton | GlaxoSmithKline (GSK) | 4mg, 2mg/5ml | Tablet | 04-0149 |
| Chlorpheniramine | Emzor | 4mg, 2mg/5ml | Tablet | 04-4054 |
| Alermine | Tuyil Pharmaceutical | 4mg | Tablet | |
| Telfast-CPM | Fidson Healthcare | 4mg, 2mg/5ml | Tablet |
How to Verify Your Chlorpheniramine is Genuine
- 1Check for a valid NAFDAC registration number on the packaging — chlorpheniramine/Piriton is so cheap and widely available that counterfeit risk exists, particularly for very low-priced products
- 2For GSK Piriton, check for the distinctive yellow packaging (tablets) or pink syrup bottle, the GSK logo, and consistent print quality
- 3Verify the NAFDAC number using the NAFDAC Green Book portal (greenbook.nafdac.gov.ng) or the NAFDAC mobile verification app
- 4Purchase from licensed pharmacies and registered patent medicine stores — while Piriton is available widely, buying from registered outlets ensures product quality
- 5Check the expiry date, batch number, and manufacturing date — these should be clearly printed on the packaging
- 6Genuine chlorpheniramine 4mg tablets should be small, round, and uniformly coloured. Reject any tablets that look different from your usual brand or appear damaged, discoloured, or powdery
Chlorpheniramine Price in Nigeria
Chlorpheniramine prices in Nigeria typically range from ₦50 to ₦1,500 per pack, depending on the brand, strength, and where you buy it.
₦50 – ₦1,500
per pack
Prices vary by location and vendor. Last updated: 2026-02-01
Where to Buy
Purchase Chlorpheniramine only from licensed pharmacies and verified distributors. Avoid buying medicines from unverified sources, roadside vendors, or unregistered market stalls.
Frequently Asked Questions
Sources
- •NAFDAC Greenbook — National Agency for Food and Drug Administration and Control registered products database
- •WHO Model List of Essential Medicines (23rd List, 2023)
- •British National Formulary (BNF)
- •Nigerian Standard Treatment Guidelines