This page contains additional content for the article Olmesartan medoxomil (Olmetec) monotherapy or in combination with hydrochlorothiazide (Olmetec Plus) for hypertension, from NPS Radar August 2007.

Questions to ask about fixed-dose combination preparations

Questions to ask Answer for olmesartan/hydrochlorothiazide
Is it a sensible combination?
  • Will the drug combination have an additive or synergistic effect, or does one drug counteract the adverse effects of the other?
  • Olmesartan/hydrochlorothiazide as a combination reduces systolic and diastolic blood pressure more effectively than either component as monotherapy16
  • Some of the potential adverse effects of hydrochlorothiazide may be counteracted by olmesartan27
  • Is the combination bioequivalent to the individual components?
  • Accepted as bioequivalent to similar doses of the individual components28
Is the dosing compatible?
  • Are the pharmacokinetics similar (e.g. absorption, duration of action)?
  • Both components are administered once daily
  • How likely are dose changes?
  • Doses need to be tailored to attain each patient’s blood pressure targets, so dose adjustments are likely
  • Will increasing the dose of one component result in an unnecessary dose increase in the other component?
  • Olmesartan doses may be titrated using the 3 dose combinations available. It is not possible to titrate the hydrochlorothiazide component without increasing the olmesartan dose
What will be the impact on adverse effects?
  • Will there be more adverse effects?
  • Adverse effects appear similar to those of the individual components16,18
  • Will it be possible to identify which drug is causing adverse effects?
  • Some adverse effects (e.g. dizziness) are common to both drugs and it may be hard to identify which medicine is responsible . Therefore, initiating treatment with combination therapy is not recommended
What is the place in therapy of the combination preparation?
  • Should this combination therapy be used for initiating treatment?
  • No. Consider the combination for patients who have been stabilised on regular doses of the individual medicines
  • Would the components be the drugs of choice as separate medicines?
  • Does the patient need both medicines?
  • Whether the patient needs both medicines will depend on how well their blood pressure is controlled. Both medicines may be needed if monotherapy provides inadequate control
  • Does evidence show advantages for the combination compared with monotherapy?
  • The combination reduces systolic and diastolic blood pressure further than either component as monotherapy.16
What is the potential for confusion and medication error?
  • What will be the consequences for the patient?
  • There is potential for confusion for patients on combination therapy whose olmesartan dose is increased from 20 mg to 40 mg. Both olmesartan combinations with hydrochlorothiazide 12.5 mg are the same colour and only differ in shape (See Information for patients)


References for this article are found on the page Olmesartan medoxomil (Olmetec) monotherapy or in combination with hydrochlorothiazide (Olmetec Plus) for hypertension, from NPS Radar August 2007.