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Key Facts
- Drug Class
- Beta-1 selective adrenergic blocker
- Prescription
- Required
- NAFDAC Status
- NAFDAC Registered
- Forms
- Tablet
- Price Range
- ₦200 - ₦4,000
- WHO Essential
- Yes
What is Atenolol?
Atenolol is a beta-blocker, one of the oldest and most widely used classes of blood pressure medications available in Nigeria. It belongs to the beta-1 selective subgroup, meaning it primarily targets the beta-1 receptors found in the heart. By blocking these receptors, atenolol slows down the heart rate, reduces the force of heart contractions, and lowers blood pressure. It has been a staple in Nigerian pharmacies for decades, and its affordability makes it accessible to a wide range of patients. Hypertension is estimated to affect 30-45% of Nigerian adults, and many of these individuals remain undiagnosed because the condition rarely produces noticeable symptoms until complications such as stroke, heart failure, or kidney disease occur.
While current international treatment guidelines no longer recommend beta-blockers as first-line therapy for uncomplicated hypertension — with calcium channel blockers like amlodipine and thiazide diuretics being preferred, especially in Black and African patients — atenolol remains very widely prescribed in Nigeria. This is partly due to its long track record, its low cost, and its usefulness in patients who have both hypertension and a fast heart rate (tachycardia). Atenolol is also valuable for patients with angina (chest pain caused by reduced blood flow to the heart), anxiety-related palpitations, and for the prevention of migraine headaches. It effectively controls the heart rate, which makes patients feel calmer and reduces the sensation of a racing or pounding heart.
Atenolol is available in Nigeria under several brand names including Tenormin (AstraZeneca, the original brand), Emzor Atenolol (locally manufactured), Blokium (Medochemie), and Aten (Cadila). It is taken once or twice daily depending on the condition being treated and the prescribed dose. All legitimate brands carry NAFDAC registration numbers. While atenolol is generally well tolerated, it has important side effects and precautions — particularly the warning that it should NEVER be stopped suddenly, as this can cause a dangerous rebound increase in heart rate and blood pressure.
What is Atenolol used for?
In Nigeria, Atenolol is commonly used for:
- Treatment of hypertension (high blood pressure) — although no longer first-line in current guidelines, it remains widely used in Nigeria, especially when patients also have a fast heart rate
- Management of angina pectoris (chest pain caused by reduced blood supply to the heart) — atenolol reduces the heart's oxygen demand
- Heart rate control — used to slow down a fast heart rate in various conditions including atrial fibrillation and supraventricular tachycardia
- Relief of anxiety-related palpitations and performance anxiety — atenolol blocks the physical symptoms of anxiety such as rapid heartbeat, trembling, and sweating
- Prevention of migraine headaches — used as a preventive (prophylactic) treatment to reduce the frequency and severity of migraines
- Post-heart attack treatment — to reduce the risk of further cardiac events
Dosage
IMPORTANT
Always follow your doctor's or pharmacist's instructions. The information below is for general reference only.
Adults
For hypertension: the usual starting dose is 25mg to 50mg taken once daily. The dose may be increased to 100mg once daily if blood pressure is not adequately controlled. The maximum recommended dose for hypertension is 100mg per day. For angina: 50mg to 100mg once daily. For heart rate control: dosing depends on the specific condition and is determined by the doctor. Take atenolol at the same time each day, preferably in the morning, with or without food. Swallow the tablet whole with water.
Children
Atenolol may be used in children for certain heart conditions at a dose of 0.5mg to 1mg per kg body weight per day, given as a single daily dose. Paediatric dosing should always be determined by a specialist doctor. It is not commonly prescribed for children with uncomplicated hypertension.
Elderly
Elderly patients may require a lower starting dose of 25mg once daily due to reduced kidney function and increased sensitivity to the drug's heart rate-lowering effects. Dose adjustments should be made gradually with careful monitoring.
CRITICAL WARNING: Do NOT stop taking atenolol suddenly. Abrupt discontinuation of beta-blockers can cause a dangerous rebound effect — your heart rate may surge and blood pressure can spike dramatically, potentially triggering a heart attack or severe hypertensive crisis. If your doctor decides to stop atenolol, the dose will be reduced gradually over 1-2 weeks. Always take atenolol as prescribed, even when you feel well. If you miss a dose, take it as soon as you remember unless it is almost time for your next dose — never take a double dose.
Side Effects
Common side effects
- •Fatigue and tiredness — this is one of the most frequently reported side effects and may affect your energy levels for daily activities
- •Cold hands and feet — caused by reduced blood flow to the extremities
- •Slow heart rate (bradycardia) — the heart rate may drop below 60 beats per minute, which is usually not dangerous but should be monitored
- •Dizziness or lightheadedness, especially when standing up
- •Nausea or stomach upset
- •Sleep disturbances, including vivid dreams or difficulty sleeping
- •Mild depression or low mood in some patients
Serious side effects — seek medical help immediately
- Severely slow heart rate (below 50 beats per minute) — may cause fainting, extreme dizziness, or shortness of breath and requires immediate medical attention
- Worsening of asthma or chronic obstructive pulmonary disease (COPD) — atenolol can trigger bronchospasm (tightening of the airways) in susceptible patients
- Heart failure symptoms — including increasing shortness of breath, ankle swelling, and inability to lie flat
- Severe hypotension (very low blood pressure) — causing fainting or shock
- Masking of hypoglycaemia symptoms in diabetic patients — atenolol can hide the warning signs (such as rapid heartbeat and trembling) of low blood sugar, making it dangerous for patients on insulin or sulfonylureas
- Rebound hypertension and tachycardia if stopped suddenly — potentially life-threatening
When to see a doctor
See your doctor promptly if you experience extreme tiredness that interferes with daily activities, a very slow pulse (below 50 beats per minute), cold or numb fingers and toes, worsening shortness of breath, or symptoms of depression. Seek EMERGENCY medical attention if you develop severe breathing difficulty (especially if you have asthma or COPD), fainting, chest pain, or if you have accidentally stopped the medication suddenly and are experiencing a racing heart or very high blood pressure. Diabetic patients should be especially vigilant about monitoring blood sugar levels while on atenolol.
Warnings & Precautions
Do not take Atenolol if you have:
- Do not use in patients with uncontrolled heart failure — atenolol can worsen the condition; it should only be used in heart failure under specialist supervision after the patient has been stabilised
- Do not use in patients with severe bradycardia (very slow heart rate below 50 beats per minute) or heart block (second or third degree)
- CAUTION in patients with asthma or COPD — atenolol can trigger bronchospasm; although it is beta-1 selective, this selectivity is not absolute, and respiratory problems can still occur. If a beta-blocker is absolutely necessary, use under close medical supervision
- Do not use in patients with untreated phaeochromocytoma (a rare adrenal gland tumour)
- Use with caution in patients with peripheral vascular disease (poor circulation to the limbs) — atenolol can worsen symptoms
- Use with caution in patients with diabetes — atenolol can mask the symptoms of hypoglycaemia (low blood sugar)
Drug interactions
- •Verapamil and diltiazem (non-dihydropyridine calcium channel blockers) — combining with atenolol can cause severely slow heart rate and dangerously low blood pressure; this combination should generally be avoided
- •Digoxin — both drugs slow the heart rate, and combining them can cause excessive bradycardia
- •Clonidine — if both drugs are being used and need to be stopped, atenolol should be discontinued first, several days before stopping clonidine, to avoid rebound hypertension
- •NSAIDs (such as ibuprofen and diclofenac) — can reduce the blood pressure-lowering effect of atenolol
- •Insulin and oral diabetes medications — atenolol can enhance the blood sugar-lowering effect and mask hypoglycaemia symptoms; more frequent blood sugar monitoring is needed
- •Other blood pressure-lowering medications — combining may cause blood pressure to drop too low; dose adjustments may be necessary
Pregnancy & Breastfeeding
Atenolol is generally NOT recommended during pregnancy. It has been associated with intrauterine growth restriction (small babies), low birth weight, and low blood sugar in newborns. If you are pregnant or planning to become pregnant, your doctor should switch you to a safer antihypertensive such as methyldopa or labetalol (a different beta-blocker with a better safety profile in pregnancy). Atenolol passes into breast milk in significant amounts and may cause slow heart rate and low blood sugar in the breastfeeding infant. It is generally not recommended during breastfeeding. Consult your doctor for safer alternatives.
NAFDAC-Registered Brands of Atenolol in Nigeria
4 brands registered with NAFDAC as of 2026-02-01.
| Brand Name | Manufacturer | Strength | Form | NAFDAC Reg. No. |
|---|---|---|---|---|
| Tenormin | AstraZeneca | 50mg, 100mg | Tablet | A4-0234 |
| Atenolol | Emzor | 50mg, 100mg | Tablet | A4-7890 |
| Blokium | Medochemie | 50mg | Tablet | B4-5678 |
| Aten | Cadila | 50mg, 100mg | Tablet | B4-6789 |
How to Verify Your Atenolol is Genuine
- 1Check the NAFDAC registration number on the packaging — all genuine atenolol brands sold in Nigeria must display a valid NAFDAC number (e.g., A4-XXXX or B4-XXXX format)
- 2Verify the NAFDAC number using the NAFDAC Green Book or the NAFDAC mobile verification app available on Android and iOS
- 3Purchase only from licensed pharmacies and registered patent medicine stores — avoid buying from unregistered vendors, open markets, or bus stops
- 4Check the expiry date and ensure the packaging is properly sealed with no evidence of tampering or moisture damage
- 5Genuine tablets should have a consistent size, shape, colour, and markings. If tablets appear uneven, crumbly, discoloured, or have an unusual smell, do not use them
- 6For imported brands like Tenormin, verify the distinctive tablet markings (usually embossed with the strength). For Emzor products, check for holographic security features and proper batch numbering
Atenolol Price in Nigeria
Atenolol prices in Nigeria typically range from ₦200 to ₦4,000 per pack (30 tablets), depending on the brand, strength, and where you buy it.
₦200 – ₦4,000
per pack (30 tablets)
Prices vary by location and vendor. Last updated: 2026-02-01
Where to Buy
Purchase Atenolol 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