This site is intended for UK healthcare professionals
Medscape UK Univadis Logo
Medscape UK Univadis Logo

Olmesartan oral

Updated 2 Feb 2023 | Angiotensin-II antagonists


Oral formulations containing olmesartan medoxomil

Drugs List

  • olmesartan medoxomil 10mg tablets
  • olmesartan medoxomil 20mg tablets
  • olmesartan medoxomil 40mg tablets
  • OLMETEC 10mg tablets
  • OLMETEC 20mg tablets
  • OLMETEC 40mg tablets
  • Therapeutic Indications


    Treatment of essential hypertension



    Initially 10 mg once daily
    Dose may be increased to 20 mg once daily if this dose does not adequately control blood pressure.
    A maximum dosage of 40 mg once daily may be used.

    It should be borne in mind when considering altering dose that the antihypertensive effect of olmesartan is substantially present after two weeks of initiating therapy and reaches a maximum after 8 weeks.


    (See Dosage; Adult)
    Blood pressure must be closely monitored, especially if the dose is titrated up to the maximum dose of 40 mg daily.

    Patients with Renal Impairment

    Mild to moderate renal impairment (creatinine clearance of 20 to 60 ml/minute)
    Maximum dose is 20 mg olmesartan daily, due to limited experience in the use of higher doses.

    The Renal Drug Handbook:
    Doses are suggested according to Glomerular Filtration Rate (GFR).
    For GFR of 20 to 50 ml/minute - dose as in normal renal function.
    For GFR of 10 to 20 ml/minute - dose as in normal renal function; start with low dose.
    For GFR of below 10 ml/minute - dose as in normal renal function; initial dose 10 mg daily then gradually increase.

    Patients with Hepatic Impairment

    In moderate hepatic impairment an initial dose of 10 mg olmesartan daily is recommended. The maximum dose should not exceed 20 mg daily.

    It is advisable to monitor blood pressure and renal function in patients who are already receiving diuretics and/or other antihypertensive agents.


    Children under 18 years
    Biliary obstruction
    Severe hepatic impairment

    Precautions and Warnings

    Vascular tone dependent on renin-angiotensin system
    Aortic stenosis
    Cerebrovascular disorder
    Diabetes mellitus
    Electrolyte depletion
    Glucose-galactose malabsorption syndrome
    History of angioedema
    Hypertrophic obstructive cardiomyopathy
    Ischaemic heart disease
    Lactose intolerance
    Metabolic acidosis
    Mitral stenosis
    Moderate hepatic impairment
    Peripheral vascular disease
    Renal artery stenosis
    Renal impairment
    Renovascular disorder
    Severe cardiac failure
    Severe generalised atherosclerosis

    Patients with primary aldosteronism may not benefit from this treatment
    Switch to more suitable alternative before planned pregnancy
    Advise ability to drive/operate machinery may be affected by side effects
    Advise patient that first dose hypotension may occur
    Afro-Caribbean or black patients may show reduced response
    Correct volume and/or salt depletion before initiating therapy
    Contains lactose
    Evaluate renal function before and during treatment
    Monitor serum electrolytes before and during treatment
    Monitor serum potassium regularly
    Increased risk of hyperkalaemia with K+ suppl. and K+ sparing diuretic
    Advise patient to seek advice at first indications of pregnancy
    Discontinue & do not restart if sprue-like enteropathy confirmed by biopsy
    Advise patient not to take NSAIDs unless advised by clinician
    Advise on problems of salt substitutes/high intake of potassium-rich food
    Female: Ensure adequate contraception during treatment

    Intravascular volume depletion
    Patients who have previously undergone diuretic therapy, dietary salt restrictions or suffered from diarrhoea or vomiting may be volume and/or sodium depleted. In order to reduce symptomatic hypotension (especially following the first dose), this volume depletion should be corrected before starting treatment with olmesartan.

    Conditions with stimulation of the renin-angiotensin-aldosterone system
    In patients whose vascular tone and renal function depend predominantly on the activity of the renin-angiotensin-aldosterone system, using drugs that act upon this system may lead to acute hypotension, azotaemia, oliguria or, rarely, acute renal failure. These adverse effects may occur with angiotensin II receptor antagonists. Such patients include those with severe congestive heart failure or underlying renal disease, including renal artery stenosis.

    Renovascular hypotension
    Patients with bilateral renal artery stenosis or stenosis of the artery to a single functioning kidney are at an increased risk of severe hypotension and renal impairment when treated with drugs that affect the renin-angiotensin-aldosterone system.

    Drugs which affect the renin-angiotensin-aldosterone system may cause hyperkalaemia, which could be fatal. The risk is increased in elderly patients, in patients with renal impairment, in patients with diabetes mellitus and in patients receiving concomitant treatment with other medicinal products that affect potassium levels.

    Additional risk factors for hyperkalaemia include dehydration, acute cardiac decompensation, metabolic acidosis, worsening renal function, sudden worsening renal condition (e.g. infection) and cellular lysis (e.g. acute limb ischaemia, rhabdomyolysis, extended trauma).

    It is advisable to assess the benefit risk ratio when administering more than one medical product that acts upon the renin-angiotensin-aldosterone system concomitantly as this may increase the risk of hyperkalaemia. If dual blockade of the renin-angiotensin-aldosterone system is considered necessary it should be done under close medical supervision, with regular monitoring of renal function, electrolytes and blood pressure.

    Sprue-like enteropathy
    In very rare cases severe chronic diarrhoea with substantial weight loss has been reported in patients taking olmesartan few months to years after drug initiation, possibly caused by a localized delayed hypersensitivity reaction. Intestinal biopsies of patients often demonstrated villous atrophy. If a patient develops these symptoms during treatment with olmesartan, exclude other etiologies. Consider discontinuation of olmesartan in cases where no other etiology is identified. In cases where symptoms disappear and sprue-like enteropathy is confirmed by biopsy, treatment with olmesartan should not be restarted.

    Pregnancy and Lactation


    Olmesartan is contraindicated during pregnancy.

    Epidemiological studies assessing the risk of teratogenicity following exposure to ACE inhibitors during the first trimester of pregnancy have not been conclusive; therefore a small increase in risk cannot be excluded for angiotensin II antagonists. Patients planning pregnancy should be changed to an alternative anti-hypertensive treatment (which has an established safety profile for use in pregnancy) unless continued angiotensin receptor blocker therapy is considered essential. Treatment with angiotensin II antagonists should be stopped when pregnancy is diagnosed and, if possible, alternative therapy should be considered. Exposure during the second and third trimesters to angiotensin II antagonists is known to cause human foetotoxicity, including decreased renal function, oligohydramnios and skull ossification retardation. Neonatal toxicity including renal failure, hypotension and hyperkalaemia has also occurred.

    An ultrasound check of renal function and skull to exclude oligohydramnios is recommended should exposure to angiotensin II antagonists have occurred past 20 weeks. It is also advisable to closely observe infants whose mothers have taken angiotensin II antagonists for renal impairment and hypotension (Schaefer, 2015).

    The antihypertensive mechanism of olmesartan and ACE inhibitors are closely related. Consequently, olmesartan may cause foetal and neonatal toxicity similar to that seen with ACE inhibitors. Such foetal toxic effects may include patent ductus arteriosus, prematurity, intrauterine growth restriction, foetal hypocalvaria, and anuria. Anuria-associated oligohydramnios may cause limb contractures, craniofacial deformations and pulmonary hypoplasia. A newborn exposed to olmesartan in utero may experience severe anuria and hypotension that is resistant to both volume expansion and pressor agents (Briggs, 2015).
    The use of all medication in pregnancy should be avoided whenever possible; particularly in the first trimester. Non-drug treatments should also be considered. When essential, a medication with the best safety record over time should be chosen, employing the lowest effective dose for the shortest possible time. Polypharmacy should be avoided. Teratogens taken in the pre-embryonic period, often quoted as lasting until 14 to 17 days post-conception, are believed to have an all-or-nothing effect. Where drugs have a short half-life, and when the date of conception is certain, this may allow women to be reassured where drug exposure has occurred within this time frame. Further advice may be available from the UK National Teratology Information Service (NTIS) and through ToxBase, available via password on the internet ( ) or if this is unavailable at the backup site ( ).


    Olmesartan is contraindicated during breastfeeding.

    Olmesartan is excreted in the milk of lactating rats, it is unknown if it is excreted in human milk.

    The molecular weight of olmesartan is low enough that excretion in breast milk should be expected (Briggs, 2015).

    Schaefer (2015) suggests that accidental administration of a single dose does not require weaning, however, therapy should be changed to an antihypertensive which has been better studied in breastfeeding. LactMed agrees that due to the lack of available information, an alternate drug may be preferred, especially while nursing a newborn or preterm infant.

    Neonates, infants born prematurely, those with low birth weight, those with an unstable gastrointestinal function or who have serious illnesses may require special consideration. For any infant, if a drug is prescribed to the nursing mother, it should be at the lowest practical dose and for the shortest time. When drug administration is unavoidable and breastfeeding is to continue, minimisation of exposure of the infant to the drug may sometimes be achieved by timing the maternal doses to just after a feeding episode. Infants exposed to drugs via breast milk should be monitored for unusual signs or symptoms. Interactions between the drug received by the infant from the mother's milk and medication prescribed for the infant should also be considered, for example, when the drug given to the infant may prevent metabolism of the drug received via breast milk.
    Specialist advice is available from the UK Drugs in Lactation Advisory Service at

    Side Effects

    Abdominal pain
    Acute renal failure
    Allergic dermatitis
    Anaphylactic reaction
    Angina pectoris
    Back pain
    Blood urea increased
    Chest pain
    Creatine phosphokinase increased
    Facial oedema
    Increase in creatinine
    Increases in hepatic enzymes
    Influenza-like symptoms
    Muscle spasm
    Musculoskeletal pain
    Peripheral oedema
    Renal impairment
    Skeletal pain
    Sprue-like enteropathy
    Urinary tract infections


    It is strongly recommended that the UK National Poisons Information Service be consulted on cases of suspected or actual overdose where there is doubt over the degree of risk or about appropriate management.

    The following number will direct the caller to the relevant local centre (0844) 892 0111

    Information may be obtained if you have access to ToxBase the primary clinical toxicology database of the National Poisons Information Service. This is available via password on the internet ( ) or if this is unavailable at the backup site ( ).

    Further Information

    Last Full Review Date: January 2017

    Reference Sources

    Drugs During Pregnancy and Lactation: Treatment Options and Risk Assessment, 3rd edition (2015) ed. Schaefer, C., Peters, P. and Miller, R. Elsevier, London.

    Drugs in Pregnancy and Lactation: A Reference Guide to Fetal and Neonatal Risk, 10th edition (2015) ed. Briggs, G., Freeman, R. Wolters Kluwer Health, Philadelphia.

    Joint Formulary Committee. British National Formulary. 72nd ed. London: BMJ Group and Pharmaceutical Press; 2016.

    Summary of Product Characteristics: OLMETEC film-coated tablets. Daiichi-Sankyo UK Ltd. Revised February 2016.

    The Renal Drug Handbook. Fourth Edition (2014) ed. Ashley, C and Dunleavy, A, Radcliffe Publishing Ltd, London.

    US National Library of Medicine. Toxicology Data Network. Drugs and Lactation Database (LactMed).
    Available at:
    Olmesartan. Last revised: March 10, 2015
    Last accessed: January 18, 2017

    Access the full UK drug database with a FREE Medscape UK Account
    It takes just a few minutes, and you’ll get unlimited access to information on over 11,000 UK drugs.
    Register for Free

    Already a member? Log in

    Medscape UK | Univadis prescription drug monographs & interactions are based on FDB Multilex Content

    FDB Logo

    FDB Disclaimer : FDB Multilex is intended for the use of healthcare professionals and is provided on the basis that the healthcare professionals will retain FULL and SOLE responsibility for deciding what treatment to prescribe or dispense for any particular patient or circumstance.