# Hydrochlorothiazide in Nigeria

Hydrochlorothiazide has 56 active NAFDAC registrations in our October 2026 copy of the register, from 31 registration holders; 69 further listings have lapsed.

- Source: https://ogbogwu.com/drugs/hydrochlorothiazide/
- Drug class: Thiazide diuretic (Hypertension)
- Also known as: HCTZ, HCT, Hydrex, Esidrex, Thiazide water pill, Moduretic (with amiloride)
- Prescription required: yes
- On the WHO Model List of Essential Medicines
- Last updated: October 2026

## Price in Nigeria

Our sampled online pharmacies held no plain hydrochlorothiazide listing this cycle, so we quote no price. On its own it is one of the cheapest blood-pressure tablets a chemist sells, in strips of ten; most Nigerians take it inside a combination tablet with losartan, telmisartan, valsartan or amiloride, whose prices belong to those products. Ask a licensed pharmacy and check the NAFDAC number on the strip.

## What is Hydrochlorothiazide?

Hydrochlorothiazide is the thiazide 'water pill' — a mild diuretic that makes the kidney pass a little more salt and water, and over weeks relaxes the blood vessels, which is what lowers blood pressure. It has been treating hypertension for sixty years, costs almost nothing, and is still one of the medicines international guidelines put first. In Nigeria it is taken by hundreds of thousands of people, most of them without knowing it: it is the second ingredient in the losartan-H, telmisartan-H, valsartan-H and amlodipine-valsartan-H combination tablets that fill pharmacy shelves.

On its own the register is thin. In our October 2026 copy the current plain 25 mg tablets are Emzor Hydrochlorothiazide (A11-0946, made in Nigeria) and Esinil-25 (B4-5347); Donyhydro-25 (A4-8215) and an IDA Foundation generic (C4-1864) lapsed in 2026, and Hydrex (A4-1209, Juhel), the name many older patients still ask for, expired in October 2023. The combinations are another matter — dozens are current, led by telmisartan and amlodipine-valsartan pairings and the amiloride tablets that spare potassium. If your prescription says 'losartan-H' or 'Co-Diovan', this is the H.

It is a gentle drug with a few sharp edges. It lowers potassium and sodium, raises uric acid (gout) and blood sugar a little, and makes skin burn faster in the sun; years of use carry a small added risk of skin cancer, which matters more for fair skin than for most Nigerians but is still a reason to cover up. A blood test a few weeks after starting, and once a year after, catches the salt problems before they are felt.

## What is Hydrochlorothiazide used for?

- High blood pressure, alone or in a combination tablet
- Mild oedema from heart failure, liver cirrhosis or kidney disease
- Preventing recurrent calcium kidney stones
- Nephrogenic diabetes insipidus (specialist use)

## Dosage

Always follow a doctor's or pharmacist's instructions; this is general reference information.

- Adults: Hypertension: 12.5 to 25 mg once a day, in the morning. Doses above 25 mg add little blood-pressure benefit and more potassium loss, so the modern practice is to add a second drug rather than raise the thiazide. Oedema: 25 to 50 mg once a day, or on alternate days once fluid is controlled. In combination tablets the hydrochlorothiazide dose is fixed at 12.5 or 25 mg. Take it with or without food, early in the day so the extra urine does not disturb sleep.
- Children: Used for hypertension and oedema in children at 1 to 2 mg per kg a day, prescribed and monitored by a paediatrician. Not for infants under six months outside specialist care.
- Elderly: Start at 12.5 mg. Older people are more prone to low sodium and to dizziness on standing, and both come on quietly.

Blood pressure takes two to four weeks to settle; do not stop because the first week shows nothing. Eat potassium-rich food (bananas, beans, ugu, oranges) rather than taking supplements unless prescribed. In hot weather or during vomiting and diarrhoea the salt losses add up — drink, and seek advice if you feel weak, cramp or faint. Protect skin from the sun.

## Side effects

Common: Passing more urine in the first days; Low potassium: tiredness, muscle cramps, palpitations; Dizziness on standing, especially at first and in hot weather; Raised uric acid, which can bring on gout in people prone to it; Slightly raised blood sugar and cholesterol; Skin that burns more easily in the sun; occasional rash; Erectile difficulty in some men.

Serious (seek medical help immediately): Low sodium: confusion, severe weakness, seizures, especially in the elderly; Severe low potassium with an irregular heartbeat; Acute gout attack; Acute angle-closure glaucoma — sudden eye pain and blurred vision in the first days or weeks (rare); Severe allergic reactions, including in people allergic to sulfonamide antibiotics; A small increase in non-melanoma skin cancer with many years of use.

When to see a doctor: Go to a clinic the same day for confusion, fainting, a racing or irregular heartbeat, or sudden eye pain with blurred vision. See a doctor within days for a swollen, hot, painful joint (gout), persistent cramps and weakness, or a rash. Have potassium and sodium checked a few weeks after starting and yearly after that.

## Warnings

Do not take if: No urine output (anuria) or severe kidney failure; Allergy to hydrochlorothiazide or to sulfonamide medicines; Low potassium or low sodium that has not been corrected; Addison's disease; Gout or a history of it — use only with care and advice.

Interactions: Lithium — thiazides raise lithium levels to toxic range; avoid; NSAIDs (ibuprofen, diclofenac) — blunt the blood-pressure effect and strain the kidneys; Digoxin — low potassium from the thiazide makes digoxin toxic; Corticosteroids and some laxatives — add to potassium loss; Other blood-pressure medicines — the intended additive effect; watch for dizziness; Diabetes medicines — blood sugar may need a small adjustment; Calcium and vitamin D supplements — thiazides retain calcium.

Pregnancy & breastfeeding: Not used for blood pressure in pregnancy: thiazides can reduce blood flow to the placenta and are not among the medicines chosen for pregnancy hypertension (methyldopa, nifedipine and labetalol are). A woman already taking it who becomes pregnant should see her doctor to switch. Small amounts pass into breast milk; low doses are generally considered compatible, though high doses can reduce milk supply.

## Brands in Nigeria

Well-known NAFDAC-registered brands: Emzor Hydrochlorothiazide (Emzor Pharmaceutical Industries Limited, made in Nigeria); Donyhydro-25 (Dony-Triumph and Company Nigeria Limited, made in India); Esinil-25 (Transglobe Pharmaceutical Company Limited, made in India); Hydrex (Juhel Nigeria Limited, made in Nigeria).
Full searchable brand list: https://ogbogwu.com/drugs/hydrochlorothiazide/brands/

## How to verify it is genuine

1. Check the strip for its NAFDAC number and look it up. In our October 2026 copy of the register the current plain 25 mg tablets are Emzor Hydrochlorothiazide (A11-0946) and Esinil-25 (B4-5347); Donyhydro-25 (A4-8215) and IDA Foundation's Hydrochlorothiazide Tablets BP 25 mg (C4-1864) are recorded Inactive
2. Hydrex Tablet 25 mg (A4-1209, Juhel) is recorded Expired since October 2023. A strip still on sale under that name should be checked by its printed number and expiry date, and a renewal confirmed on the official Greenbook
3. A combination tablet (losartan-H, telmisartan-H, amlodipine-valsartan-H, amiloride-hydrochlorothiazide) carries its own registration under the combination's name — check that number, not a plain hydrochlorothiazide one
4. Enter the number in our free NAFDAC checker and confirm the product name, strength and manufacturer match the pack

Verify any NAFDAC number free (no login): https://ogbogwu.com/nafdac-checker/

## FAQs

### Is Hydrex still registered in Nigeria?

Not in our October 2026 copy of the NAFDAC register: Hydrex Tablet 25 mg (A4-1209, Juhel Nigeria) is recorded Expired since 30 October 2023. Plain hydrochlorothiazide is still available under current registrations — Emzor Hydrochlorothiazide (A11-0946, made in Nigeria) and Esinil-25 (B4-5347) — and inside dozens of current combination tablets. Listings can lag renewals, so confirm a recent Hydrex pack's status on the official Greenbook.

### What is the H in losartan-H or telmisartan-H?

Hydrochlorothiazide, usually 12.5 or 25 mg, combined with the blood-pressure drug named first. The thiazide adds a second mechanism and lets both doses stay low. In our register copy the current hydrochlorothiazide combinations are led by telmisartan, amlodipine-valsartan, valsartan, losartan, candesartan and amiloride pairings. Each combination has its own NAFDAC number; verify that one.

### Does hydrochlorothiazide cause gout?

It can. Thiazides raise uric acid, and in people who are prone to gout — or who already have it — that can bring on an attack, usually in the big toe or ankle. Tell the prescriber about any history of gout; a different class of blood-pressure medicine may suit better, or the gout can be treated alongside.

### What is the difference between hydrochlorothiazide and furosemide?

Both are diuretics, but furosemide (Lasix) is far stronger and shorter-acting — it is the one for heart failure with real fluid overload. Hydrochlorothiazide is mild and long-acting and lowers blood pressure, which furosemide does poorly. For plain hypertension the thiazide is the right one; for a swollen, breathless heart-failure patient, furosemide is.

### Can I take hydrochlorothiazide in pregnancy?

It is not one of the medicines chosen for blood pressure in pregnancy, because thiazides can reduce blood flow to the placenta and shrink the mother's blood volume. Pregnancy hypertension is treated with methyldopa, nifedipine or labetalol. If you take hydrochlorothiazide and become pregnant, see your doctor promptly to switch — do not simply stop a blood-pressure medicine.

## Sources

- NAFDAC Greenbook (official register of approved products in Nigeria)
- WHO Model List of Essential Medicines
- British National Formulary (BNF)
- Nigerian Standard Treatment Guidelines (Federal Ministry of Health)