Olmesartan (Olmetec) Tablet Side Effects in Pakistan

Olmesartan (Olmetec / Benicar) side effects are generally mild — the dry cough seen with ACE inhibitors does NOT occur. However, there is a unique serious risk: olmesartan-associated enteropathy — severe chronic diarrhoea with long-term use. This page covers everything from common to life-threatening side effects.

Compiled by the PakVita Editorial Team · AI-assisted drafting with editorial review · Sourced from DRAP, WHO, BNF · Last updated: 2026-06-17

Side Effects

Quick Answer

Olmesartan (Olmetec / Benicar) common side effects include dizziness, headache, fatigue, and upper respiratory infection. Unlike ACE inhibitors, olmesartan does NOT cause dry cough. A unique and serious rare side effect is olmesartan-associated enteropathy — severe chronic diarrhoea resembling coeliac disease in long-term users; it resolves when the drug is stopped (FDA warning). Rare but serious: angioedema (face/throat swelling — emergency, stop drug immediately), hyperkalaemia, renal impairment. Pregnancy is absolutely contraindicated.

Side Effects at a Glance

Common

Dizziness — especially with first dose or in volume-depleted patients
Headache
Fatigue
Upper respiratory tract infection
Back pain
Diarrhoea (acute — short term; long-term chronic diarrhoea see enteropathy below)
Sinusitis
NOTE: Dry cough does NOT occur — the ACEi-type cough is absent with ARBs

Serious — See a Doctor

Olmesartan-associated enteropathy — UNIQUE TO OLMESARTAN: severe chronic watery diarrhoea resembling coeliac/sprue in long-term users (months-years of use); significant weight loss; villous atrophy on biopsy; FDA black box warning; resolves on stopping olmesartan — other ARBs do NOT cause this
Angioedema — face, lips, tongue, throat swelling (rare — less common than ACEi; but EMERGENCY — STOP drug, call 115)
Hyperkalaemia — cardiac arrhythmia (with NSAIDs/K-sparing diuretics)
Renal impairment — especially bilateral renal artery stenosis
Severe hypotension — volume-depleted patients
Teratogenicity — foetal renal failure, oligohydramnios (pregnancy Category D)

When to See a Doctor Immediately

Chronic unexplained diarrhoea (weeks-months of watery diarrhoea + weight loss) — olmesartan enteropathy — STOP drug, see a gastroenterologist immediately — coeliac-like presentation
EMERGENCY: Swelling of face, lips, tongue, or throat (angioedema) — STOP drug immediately, call 115
Decreased urination (oliguria) + fatigue — renal failure + potassium check
Severe dizziness or fainting — hypotension
Irregular heartbeat — hyperkalaemia

Olmesartan (Olmetec) Tablet Side Effects (Nuksanat)

Olmesartan (Olmetec / Benicar) is generally well-tolerated. The dry cough seen with ACEi does NOT occur — this is the biggest advantage of ARBs for South Asian patients. However, there is a unique serious risk: olmesartan-associated enteropathy — chronic diarrhoea in long-term users.

Common Side Effects (Aam Nuksanat)

Dizziness — especially with the first dose; stand up slowly
Headache — usually mild; settles over time
Fatigue
Upper respiratory tract infection — nose/throat infection
Back pain
Diarrhoea (short-term acute — chronic diarrhoea see enteropathy)
Sinusitis
DRY COUGH DOES NOT OCCUR — the ACEi-type cough is absent with ARBs

Serious Side Effects — OLMESARTAN-SPECIFIC

Olmesartan-Associated Enteropathy — UNIQUE WARNING

Severe chronic watery diarrhoea in long-term users (months-years of use)
Coeliac disease / sprue jaisi presentation — villous atrophy on biopsy
Significant weight loss
FDA warning issued — not seen with other ARBs
RESOLUTION: Symptoms resolve when the drug is stopped
Action: Chronic unexplained diarrhoea → STOP olmesartan, see a doctor immediately

Angioedema (Rare)

Face, lips, tongue, throat swelling
Less common than ACEi but still possible
EMERGENCY: Stop the drug immediately, call 115

Other Serious Effects

Hyperkalaemia — cardiac arrhythmia
Renal impairment — contraindicated in bilateral renal artery stenosis
Severe hypotension — in volume-depleted patients
Teratogenicity — pregnancy Category D — foetal renal failure

When to See a Doctor (Kab Doctor Se Milna Zaroori Hai)

Chronic diarrhoea (weeks/months) + weight loss — olmesartan enteropathy — STOP drug, see a doctor
EMERGENCY: Swelling of face / lips / tongue / throat — angioedema — call 115 immediately
Decreased urination — renal failure
Irregular heartbeat — hyperkalaemia
Severe dizziness or fainting

Side Effects Comparison — ARB vs ACEi

Side Effect	Olmesartan (ARB)	ACE Inhibitor
Dry cough	Does NOT occur	Occurs — 30% South Asians
Olmesartan enteropathy	Yes (unique)	No
Angioedema	Rare (less)	Rare (slightly more)
Hyperkalaemia	Yes	Yes
Renal impairment	Yes	Yes
Pregnancy risk	Category D	Category D

Reporting Side Effects

If you notice any unexpected side effect, report it on the DRAP pharmacovigilance portal: https://www.dra.gov.pk/pharmacovigilance

The information in this guide is for educational purposes only. If you notice any side effect, contact your doctor or pharmacist.

Frequently Asked Questions

Olmesartan se kaunse side effects hote hain?

Common: dizziness, headache, fatigue, URTI. Important: the dry cough seen with ACEi does NOT occur. Rare but serious: olmesartan-associated enteropathy (chronic diarrhoea — coeliac-like), angioedema (face/throat swelling — emergency), hyperkalemia, renal impairment.

Olmesartan enteropathy kya hai?

Olmesartan-associated enteropathy is a rare but serious condition — long-term olmesartan use causes severe chronic watery diarrhoea, weight loss, and small bowel changes resembling coeliac disease. An FDA warning has been issued. It resolves when the drug is stopped. This does not occur with other ARBs.

Olmesartan se khansi hoti hai?

No — olmesartan is an ARB, not an ACEi. ARBs do not accumulate bradykinin — dry cough does NOT occur. ACEi (enalapril, lisinopril, perindopril) cause cough — olmesartan does not. This is a major advantage of ARBs.

Olmesartan se angioedema ho sakta hai?

Yes — angioedema can occur with ARBs too but is much less common than with ACEi. Swelling of the face, lips, tongue, or throat — this is an EMERGENCY. Stop the drug immediately and call 115. Use olmesartan with caution in patients with a prior history of angioedema.

Olmesartan se potassium kyun barhta hai?

Olmesartan blocks the RAAS — aldosterone is reduced, which promotes potassium excretion. This creates a risk of elevated potassium (hyperkalemia) — especially with NSAIDs, K-sparing diuretics (spironolactone), or K supplements. Regular blood tests are required.

Brand alternatives, same-class options, and other medicines used for the same conditions as Olmesartan Tablet.

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Used for the same conditions

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Sources

DRAP Registered Products Database — Drug Regulatory Authority of Pakistan
WHO Model List of Essential Medicines, 23rd ed. (2023) — World Health Organization
British National Formulary (BNF) — BMJ Group & Pharmaceutical Press

Medical disclaimer

This page is for educational use only and does not replace professional medical advice. Always confirm diagnosis, dose, and interactions with a qualified doctor or pharmacist before starting or changing any medicine.